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5127 lines
159 KiB
C
5127 lines
159 KiB
C
#define USE_MALLOC_LOCK
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#define DEFAULT_TRIM_THRESHOLD (256 * 1024)
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/* ---------- To make a malloc.h, start cutting here ------------ */
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/*
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****************************************************************
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* THIS IS A PRERELEASE. It has not yet been tested adequately. *
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* If you use it, please send back comments, suggestions, *
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* performance reports, etc. *
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****************************************************************
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*/
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/*
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A version (aka dlmalloc) of malloc/free/realloc written by Doug
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Lea and released to the public domain. Use this code without
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permission or acknowledgement in any way you wish. Send questions,
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comments, complaints, performance data, etc to dl@cs.oswego.edu
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* VERSION 2.7.0pre7 Wed Jan 10 13:33:01 2001 Doug Lea (dl at gee)
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Note: There may be an updated version of this malloc obtainable at
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ftp://gee.cs.oswego.edu/pub/misc/malloc.c
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Check before installing!
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* Quickstart
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This library is all in one file to simplify the most common usage:
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ftp it, compile it (-O), and link it into another program. All
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of the compile-time options default to reasonable values for use on
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most unix platforms. Compile -DWIN32 for reasonable defaults on windows.
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You might later want to step through various compile options.
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* Why use this malloc?
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This is not the fastest, most space-conserving, most portable, or
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most tunable malloc ever written. However it is among the fastest
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while also being among the most space-conserving, portable and tunable.
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Consistent balance across these factors results in a good general-purpose
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allocator for malloc-intensive programs.
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The main properties of the algorithms are:
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* For large (>= 512 bytes) requests, it is a pure best-fit allocator,
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with ties normally decided via FIFO (i.e. least recently used).
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* For small (<= 64 bytes by default) requests, it is a caching
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allocator, that maintains pools of quickly recycled chunks.
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* In between, and for combinations of large and small requests, it does
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the best it can trying to meet both goals at once.
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Compared to 2.6.X versions, this version is generally faster,
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especially for programs that allocate and free many small chunks.
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For a longer but slightly out of date high-level description, see
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http://gee.cs.oswego.edu/dl/html/malloc.html
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You may already by default be using a c library containing a malloc
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that is somehow based on some version of this malloc (for example in
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linux). You might still want to use the one in this file in order to
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customize settings or to avoid overheads associated with library
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versions.
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* Synopsis of public routines
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(Much fuller descriptions are contained in the program documentation below.)
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malloc(size_t n);
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Return a pointer to a newly allocated chunk of at least n bytes, or null
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if no space is available.
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free(Void_t* p);
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Release the chunk of memory pointed to by p, or no effect if p is null.
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realloc(Void_t* p, size_t n);
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Return a pointer to a chunk of size n that contains the same data
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as does chunk p up to the minimum of (n, p's size) bytes, or null
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if no space is available. The returned pointer may or may not be
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the same as p. If p is null, equivalent to malloc. Unless the
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#define REALLOC_ZERO_BYTES_FREES below is set, realloc with a
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size argument of zero (re)allocates a minimum-sized chunk.
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memalign(size_t alignment, size_t n);
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Return a pointer to a newly allocated chunk of n bytes, aligned
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in accord with the alignment argument, which must be a power of
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two.
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valloc(size_t n);
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Equivalent to memalign(pagesize, n), where pagesize is the page
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size of the system (or as near to this as can be figured out from
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all the includes/defines below.)
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pvalloc(size_t n);
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Equivalent to valloc(minimum-page-that-holds(n)), that is,
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round up n to nearest pagesize.
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calloc(size_t unit, size_t quantity);
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Returns a pointer to quantity * unit bytes, with all locations
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set to zero.
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cfree(Void_t* p);
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Equivalent to free(p).
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malloc_trim(size_t pad);
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Release all but pad bytes of freed top-most memory back
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to the system. Return 1 if successful, else 0.
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malloc_usable_size(Void_t* p);
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Report the number usable allocated bytes associated with allocated
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chunk p. This may or may not report more bytes than were requested,
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due to alignment and minimum size constraints.
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malloc_stats();
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Prints brief summary statistics on stderr.
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mallinfo()
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Returns (by copy) a struct containing various summary statistics.
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mallopt(int parameter_number, int parameter_value)
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Changes one of the tunable parameters described below. Returns
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1 if successful in changing the parameter, else 0.
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* Vital statistics:
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Assumed pointer representation: 4 or 8 bytes
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(Thanks to Wolfram Gloger for contributing most of the
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changes supporting dual 4/8.)
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Assumed size_t representation: 4 or 8 bytes
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Note that size_t is allowed to be 4 bytes even if pointers are 8.
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You can adjust this by defining INTERNAL_SIZE_T
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Alignment: 2 * sizeof(size_t)
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(i.e., 8 byte alignment with 4byte size_t). This suffices for
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nearly all current machines and C compilers. However, you can
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define MALLOC_ALIGNMENT to be wider than this if necessary.
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Minimum overhead per allocated chunk: 4 or 8 bytes
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Each malloced chunk has a hidden word of overhead holding size
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and status information.
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Minimum allocated size: 4-byte ptrs: 16 bytes (including 4 overhead)
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8-byte ptrs: 24/32 bytes (including, 4/8 overhead)
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When a chunk is freed, 12 (for 4byte ptrs) or 20 (for 8 byte
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ptrs but 4 byte size) or 24 (for 8/8) additional bytes are
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needed; 4 (8) for a trailing size field and 8 (16) bytes for
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free list pointers. Thus, the minimum allocatable size is
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16/24/32 bytes.
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Even a request for zero bytes (i.e., malloc(0)) returns a
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pointer to something of the minimum allocatable size.
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The maximum overhead wastage (i.e., number of extra bytes
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allocated than were requested in malloc) is less than or equal
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to the minimum size, except for requests >= mmap_threshold that
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are serviced via mmap(), where the worst case wastage is 2 *
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sizeof(size_t) bytes plus the remainder from a system page (the
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minimal mmap unit); typically 4096 bytes.
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Maximum allocated size: 4-byte size_t: 2^31 minus about two pages
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8-byte size_t: 2^63 minus about two pages
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It is assumed that (possibly signed) size_t values suffice
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to represent chunk sizes. `Possibly signed' is due to the fact
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that `size_t' may be defined on a system as either a signed or
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an unsigned type. The ISO C standard says that it must be
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unsigned, but a few systems are known not to adhere to this.
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Additionally, even when size_t is unsigned, sbrk (which is by
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default used to obtain memory from system) accepts signed
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arguments, and may not be able to handle size_t-wide arguments
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with negative sign bit. To be conservative, values that would
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appear as negative after accounting for overhead and alignment
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are rejected.
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Requests for sizes outside this range will perform an optional
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failure action and then return null. (Requests may also
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also fail because a system is out of memory.)
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Thread-safety: NOT thread-safe unless USE_MALLOC_LOCK defined
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When USE_MALLOC_LOCK is defined, wrappers are created to
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surround every public call with either a pthread mutex or
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a win32 critical section (depending on WIN32). This is not
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especially fast, and can be a major bottleneck in programs with
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many threads. It is designed only to provide minimal protection
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in concurrent environments, and to provide a basis for
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extensions. If you are using malloc in a concurrent program,
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you would be far better off obtaining ptmalloc, which is
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derived from a version of this malloc, and is well-tuned for
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concurrent programs. (See http://www.malloc.de)
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Compliance: I believe it is compliant with the 1997 Single Unix Specification
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(See http://www.opennc.org). Probably other standards as well.
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* Limitations
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Here are some features that are NOT currently supported
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* No automated mechanism for fully checking that all accesses
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to malloced memory stay within their bounds. However, there
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are several add-ons and adaptations of this or other mallocs
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available that do this.
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* No support for compaction.
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* Synopsis of compile-time options:
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People have reported using previous versions of this malloc on all
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versions of Unix, sometimes by tweaking some of the defines
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below. It has been tested most extensively on Solaris and
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Linux. It is also reported to work on WIN32 platforms.
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People also report using it in stand-alone embedded systems.
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The implementation is in straight, hand-tuned ANSI C. It is not
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at all modular. (Sorry!) It uses a lot of macros. To be at all
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usable, this code should be compiled using an optimizing compiler
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(for example gcc -O3) that can simplify expressions and control
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paths. (FAQ: some macros import variables as arguments rather than
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declare locals because people reported that some debuggers
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otherwise get confused.)
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OPTION DEFAULT VALUE
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Compilation Environment options:
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__STD_C derived from C compiler defines
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WIN32 NOT defined
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HAVE_MEMCPY defined
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USE_MEMCPY 1 if HAVE_MEMCPY is defined
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HAVE_MMAP defined as 1
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MMAP_AS_MORECORE_SIZE (1024 * 1024)
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HAVE_MREMAP defined as 0 unless linux defined
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malloc_getpagesize derived from system #includes, or 4096 if not
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HAVE_USR_INCLUDE_MALLOC_H NOT defined
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LACKS_UNISTD_H NOT defined unless WIN32
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LACKS_SYS_PARAM_H NOT defined unless WIN32
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LACKS_SYS_MMAN_H NOT defined unless WIN32
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Changing default word sizes:
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INTERNAL_SIZE_T size_t
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MALLOC_ALIGNMENT 2 * sizeof(INTERNAL_SIZE_T)
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Configuration and functionality options:
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USE_DL_PREFIX NOT defined
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USE_PUBLIC_MALLOC_WRAPPERS NOT defined
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USE_MALLOC_LOCK NOT defined
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DEBUG NOT defined
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REALLOC_ZERO_BYTES_FREES NOT defined
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MALLOC_FAILURE_ACTION errno = ENOMEM, if __STD_C defined, else no-op
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TRIM_FASTBINS 0
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Options for customizing MORECORE:
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MORECORE sbrk
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MORECORE_CONTIGUOUS 1
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Tuning options that are also dynamically changeable via mallopt:
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DEFAULT_MXFAST 64
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DEFAULT_TRIM_THRESHOLD 128 * 1024
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DEFAULT_TOP_PAD 0
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DEFAULT_MMAP_THRESHOLD 128 * 1024
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DEFAULT_MMAP_MAX 256
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There are several other #defined constants and macros that you
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probably don't want to touch unless you are extending or adapting malloc.
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*/
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#include "xpcom-private.h"
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/*
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WIN32 sets up defaults for MS environment and compilers.
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Otherwise defaults are for unix.
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*/
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/* #define WIN32 */
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#ifdef WIN32
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#include <windows.h>
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/* Win32 doesn't supply or need the following headers */
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#define LACKS_UNISTD_H
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#define LACKS_SYS_PARAM_H
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#define LACKS_SYS_MMAN_H
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/* Use the supplied emulation of sbrk */
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#define MORECORE sbrk
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#define MORECORE_CONTIGUOUS 1
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#define MORECORE_FAILURE ((void*)(-1))
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/* Use the supplied emulation mmap, munmap */
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#define HAVE_MMAP 1
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#define MUNMAP_FAILURE (-1)
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/* These values don't really matter in windows mmap emulation */
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#define MAP_PRIVATE 1
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#define MAP_ANONYMOUS 2
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#define PROT_READ 1
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#define PROT_WRITE 2
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/* Emulation functions defined at the end of this file */
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/* If USE_MALLOC_LOCK, use supplied critical-section-based lock functions */
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#ifdef USE_MALLOC_LOCK
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static int slwait(int *sl);
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static int slrelease(int *sl);
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#endif
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static long getpagesize(void);
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static long getregionsize(void);
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static void *sbrk(long size);
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static void *mmap(void *ptr, long size, long prot, long type, long handle, long arg);
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static long munmap(void *ptr, long size);
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static void vminfo (unsigned long *free, unsigned long *reserved, unsigned long *committed);
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static int cpuinfo (int whole, unsigned long *kernel, unsigned long *user);
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#endif
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/*
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__STD_C should be nonzero if using ANSI-standard C compiler, a C++
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compiler, or a C compiler sufficiently close to ANSI to get away
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with it.
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*/
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#ifndef __STD_C
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#ifdef __STDC__
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#define __STD_C 1
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#else
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#if __cplusplus
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#define __STD_C 1
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#else
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#define __STD_C 0
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#endif /*__cplusplus*/
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#endif /*__STDC__*/
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#endif /*__STD_C*/
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|
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/*
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Void_t* is the pointer type that malloc should say it returns
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||
*/
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#ifndef Void_t
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#if (__STD_C || defined(WIN32))
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#define Void_t void
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#else
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#define Void_t char
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#endif
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#endif /*Void_t*/
|
||
|
||
#if __STD_C
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#include <stddef.h> /* for size_t */
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||
#else
|
||
#include <sys/types.h>
|
||
#endif
|
||
|
||
#ifdef __cplusplus
|
||
extern "C" {
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||
#endif
|
||
|
||
/* define LACKS_UNISTD_H if your system does not have a <unistd.h>. */
|
||
|
||
/* #define LACKS_UNISTD_H */
|
||
|
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#ifndef LACKS_UNISTD_H
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#include <unistd.h>
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#endif
|
||
|
||
/* define LACKS_SYS_PARAM_H if your system does not have a <sys/param.h>. */
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||
|
||
/* #define LACKS_SYS_PARAM_H */
|
||
|
||
|
||
#include <stdio.h> /* needed for malloc_stats */
|
||
#include <errno.h> /* needed for optional MALLOC_FAILURE_ACTION */
|
||
|
||
|
||
/*
|
||
Debugging:
|
||
|
||
Because freed chunks may be overwritten with bookkeeping fields, this
|
||
malloc will often die when freed memory is overwritten by user
|
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programs. This can be very effective (albeit in an annoying way)
|
||
in helping track down dangling pointers.
|
||
|
||
If you compile with -DDEBUG, a number of assertion checks are
|
||
enabled that will catch more memory errors. You probably won't be
|
||
able to make much sense of the actual assertion errors, but they
|
||
should help you locate incorrectly overwritten memory. The
|
||
checking is fairly extensive, and will slow down execution
|
||
noticeably. Calling malloc_stats or mallinfo with DEBUG set will
|
||
attempt to check every non-mmapped allocated and free chunk in the
|
||
course of computing the summmaries. (By nature, mmapped regions
|
||
cannot be checked very much automatically.)
|
||
|
||
Setting DEBUG may also be helpful if you are trying to modify
|
||
this code. The assertions in the check routines spell out in more
|
||
detail the assumptions and invariants underlying the algorithms.
|
||
|
||
*/
|
||
|
||
#if DEBUG
|
||
#include <assert.h>
|
||
#else
|
||
#define assert(x) ((void)0)
|
||
#endif
|
||
|
||
|
||
/*
|
||
INTERNAL_SIZE_T is the word-size used for internal bookkeeping
|
||
of chunk sizes.
|
||
|
||
The default version is the same as size_t.
|
||
|
||
While not strictly necessary, it is best to define this as an
|
||
unsigned type, even if size_t is a signed type. This may avoid some
|
||
artificial size limitations on some systems.
|
||
|
||
On a 64-bit machine, you may be able to reduce malloc overhead by
|
||
defining INTERNAL_SIZE_T to be a 32 bit `unsigned int' at the
|
||
expense of not being able to handle more than 2^32 of malloced
|
||
space. If this limitation is acceptable, you are encouraged to set
|
||
this unless you are on a platform requiring 16byte alignments. In
|
||
this case the alignment requirements turn out to negate any
|
||
potential advantages of decreasing size_t word size.
|
||
|
||
Note to implementors: To deal with all this, comparisons and
|
||
difference computations among INTERNAL_SIZE_Ts should normally cast
|
||
INTERNAL_SIZE_T's to long or unsigned long, as appropriate, being
|
||
aware of the fact that casting an unsigned int to a wider long does not
|
||
sign-extend. (This also makes checking for negative numbers awkward.)
|
||
|
||
*/
|
||
|
||
#ifndef INTERNAL_SIZE_T
|
||
#define INTERNAL_SIZE_T size_t
|
||
#endif
|
||
|
||
/* The corresponding word size */
|
||
#define SIZE_SZ (sizeof(INTERNAL_SIZE_T))
|
||
|
||
|
||
/*
|
||
MALLOC_ALIGNMENT is the minimum alignment for malloc'ed chunks.
|
||
It must be a power of two at least 2 * SIZE_SZ, even on machines
|
||
for which smaller alignments would suffice. It may be defined as
|
||
larger than this though. (Note however that code and data structures
|
||
are optimized for the case of 8-byte alignment.)
|
||
|
||
*/
|
||
|
||
/* #define MALLOC_ALIGNMENT 16 */
|
||
|
||
#ifndef MALLOC_ALIGNMENT
|
||
#define MALLOC_ALIGNMENT (2 * SIZE_SZ)
|
||
#endif
|
||
|
||
/* The corresponding bit mask value */
|
||
#define MALLOC_ALIGN_MASK (MALLOC_ALIGNMENT - 1)
|
||
|
||
|
||
/*
|
||
REALLOC_ZERO_BYTES_FREES should be set if a call to
|
||
realloc with zero bytes should be the same as a call to free.
|
||
Some people think it should. Otherwise, since this malloc
|
||
returns a unique pointer for malloc(0), so does realloc(p, 0).
|
||
*/
|
||
|
||
/* #define REALLOC_ZERO_BYTES_FREES */
|
||
|
||
|
||
/*
|
||
USE_DL_PREFIX will prefix all public routines with the string 'dl'.
|
||
This is necessary when you only want to use this malloc in one part
|
||
of a program, using your regular system malloc elsewhere.
|
||
*/
|
||
|
||
/* #define USE_DL_PREFIX */
|
||
|
||
|
||
/*
|
||
USE_MALLOC_LOCK causes wrapper functions to surround each
|
||
callable routine with pthread mutex lock/unlock.
|
||
|
||
USE_MALLOC_LOCK forces USE_PUBLIC_MALLOC_WRAPPERS to be defined
|
||
*/
|
||
|
||
/* #define USE_MALLOC_LOCK */
|
||
|
||
|
||
/*
|
||
If USE_PUBLIC_MALLOC_WRAPPERS is defined, every public routine is
|
||
actually a wrapper function that first calls MALLOC_PREACTION, then
|
||
calls the internal routine, and follows it with
|
||
MALLOC_POSTACTION. This is needed for locking, but you can also use
|
||
this, without USE_MALLOC_LOCK, for purposes of interception,
|
||
instrumentation, etc. It is a sad fact that using wrappers often
|
||
noticeably degrades performance of malloc-intensive programs.
|
||
*/
|
||
|
||
#ifdef USE_MALLOC_LOCK
|
||
#define USE_PUBLIC_MALLOC_WRAPPERS
|
||
#else
|
||
/* #define USE_PUBLIC_MALLOC_WRAPPERS */
|
||
#endif
|
||
|
||
|
||
|
||
|
||
/*
|
||
HAVE_MEMCPY should be defined if you are not otherwise using
|
||
ANSI STD C, but still have memcpy and memset in your C library
|
||
and want to use them in calloc and realloc. Otherwise simple
|
||
macro versions are defined below.
|
||
|
||
USE_MEMCPY should be defined as 1 if you actually want to
|
||
have memset and memcpy called. People report that the macro
|
||
versions are faster than libc versions on some systems.
|
||
|
||
Even if USE_MEMCPY is set to 1, loops to copy/clear small chunks
|
||
(of <= 36 bytes) are manually unrolled in realloc and calloc.
|
||
*/
|
||
|
||
#define HAVE_MEMCPY
|
||
|
||
#ifndef USE_MEMCPY
|
||
#ifdef HAVE_MEMCPY
|
||
#define USE_MEMCPY 1
|
||
#else
|
||
#define USE_MEMCPY 0
|
||
#endif
|
||
#endif
|
||
|
||
|
||
#if (__STD_C || defined(HAVE_MEMCPY))
|
||
|
||
#ifdef WIN32
|
||
/*
|
||
On Win32 platforms, 'memset()' and 'memcpy()' are already declared in
|
||
'windows.h'
|
||
*/
|
||
#else
|
||
#if __STD_C
|
||
void* memset(void*, int, size_t);
|
||
void* memcpy(void*, const void*, size_t);
|
||
void* memmove(void*, const void*, size_t);
|
||
#else
|
||
Void_t* memset();
|
||
Void_t* memcpy();
|
||
Void_t* memmove();
|
||
#endif
|
||
#endif
|
||
#endif
|
||
|
||
|
||
/*
|
||
MALLOC_FAILURE_ACTION is the action to take before "return 0" when
|
||
malloc fails to be able to return memory, either because memory is
|
||
exhausted or because of illegal arguments.
|
||
|
||
By default, sets errno if running on STD_C platform, else does nothing.
|
||
*/
|
||
|
||
#ifndef MALLOC_FAILURE_ACTION
|
||
#if __STD_C
|
||
#define MALLOC_FAILURE_ACTION \
|
||
errno = ENOMEM;
|
||
|
||
#else
|
||
|
||
#define MALLOC_FAILURE_ACTION
|
||
#endif
|
||
#endif
|
||
|
||
/*
|
||
Define HAVE_MMAP as true to optionally make malloc() use mmap() to
|
||
allocate very large blocks. These will be returned to the
|
||
operating system immediately after a free(). Also, if mmap
|
||
is available, it is used as a backup strategy in cases where
|
||
MORECORE fails to provide space from system.
|
||
|
||
This malloc is best tuned to work with mmap for large requests.
|
||
If you do not have mmap, allocation of very large chunks (1MB
|
||
or so) may be slower than you'd like.
|
||
*/
|
||
|
||
#ifndef HAVE_MMAP
|
||
#define HAVE_MMAP 1
|
||
#endif
|
||
|
||
/*
|
||
MMAP_AS_MORECORE_SIZE is the minimum mmap size argument to use if
|
||
sbrk fails, and mmap is used as a backup (which is done only if
|
||
HAVE_MMAP). The value must be a multiple of page size. This
|
||
backup strategy generally applies only when systems have "holes" in
|
||
address space, so sbrk cannot perform contiguous expansion, but
|
||
there is still space available on system. On systems for which
|
||
this is known to be useful (i.e. most linux kernels), this occurs
|
||
only when programs allocate huge amounts of memory. Between this,
|
||
and the fact that mmap regions tend to be limited, the size should
|
||
be large, to avoid too many mmap calls and thus avoid running out
|
||
of kernel resources.
|
||
*/
|
||
|
||
#ifndef MMAP_AS_MORECORE_SIZE
|
||
#define MMAP_AS_MORECORE_SIZE (1024 * 1024)
|
||
#endif
|
||
|
||
|
||
|
||
/*
|
||
Define HAVE_MREMAP to make realloc() use mremap() to re-allocate
|
||
large blocks. This is currently only possible on Linux with
|
||
kernel versions newer than 1.3.77.
|
||
*/
|
||
|
||
#ifndef HAVE_MREMAP
|
||
#ifdef linux
|
||
#define HAVE_MREMAP 1
|
||
#else
|
||
#define HAVE_MREMAP 0
|
||
#endif
|
||
|
||
#endif /* HAVE_MMAP */
|
||
|
||
|
||
/*
|
||
|
||
This version of malloc supports the standard SVID/XPG mallinfo
|
||
routine that returns a struct containing usage properties and
|
||
statistics. It should work on any SVID/XPG compliant system that has
|
||
a /usr/include/malloc.h defining struct mallinfo. (If you'd like to
|
||
install such a thing yourself, cut out the preliminary declarations
|
||
as described above and below and save them in a malloc.h file. But
|
||
there's no compelling reason to bother to do this.)
|
||
|
||
The main declaration needed is the mallinfo struct that is returned
|
||
(by-copy) by mallinfo(). The SVID/XPG malloinfo struct contains a
|
||
bunch of field that are not even meaningful in this version of
|
||
malloc. These fields are are instead filled by mallinfo() with
|
||
other numbers that might be of interest.
|
||
|
||
HAVE_USR_INCLUDE_MALLOC_H should be set if you have a
|
||
/usr/include/malloc.h file that includes a declaration of struct
|
||
mallinfo. If so, it is included; else an SVID2/XPG2 compliant
|
||
version is declared below. These must be precisely the same for
|
||
mallinfo() to work.
|
||
|
||
*/
|
||
|
||
/* #define HAVE_USR_INCLUDE_MALLOC_H */
|
||
|
||
#ifdef HAVE_USR_INCLUDE_MALLOC_H
|
||
#include "/usr/include/malloc.h"
|
||
#else
|
||
|
||
/* SVID2/XPG mallinfo structure */
|
||
|
||
struct mallinfo {
|
||
int arena; /* non-mmapped space allocated from system */
|
||
int ordblks; /* number of free chunks */
|
||
int smblks; /* number of fastbin blocks */
|
||
int hblks; /* number of mmapped regions */
|
||
int hblkhd; /* space in mmapped regions */
|
||
int usmblks; /* maximum total allocated space */
|
||
int fsmblks; /* space available in freed fastbin blocks */
|
||
int uordblks; /* total allocated space */
|
||
int fordblks; /* total free space */
|
||
int keepcost; /* top-most, releasable (via malloc_trim) space */
|
||
};
|
||
|
||
/* SVID2/XPG mallopt options */
|
||
|
||
#define M_MXFAST 1 /* Set maximum fastbin size */
|
||
#define M_NLBLKS 2 /* UNUSED in this malloc */
|
||
#define M_GRAIN 3 /* UNUSED in this malloc */
|
||
#define M_KEEP 4 /* UNUSED in this malloc */
|
||
|
||
|
||
#endif
|
||
|
||
|
||
/* Additional mallopt options supported in this malloc */
|
||
|
||
#ifndef M_TRIM_THRESHOLD
|
||
#define M_TRIM_THRESHOLD -1
|
||
#endif
|
||
|
||
#ifndef M_TOP_PAD
|
||
#define M_TOP_PAD -2
|
||
#endif
|
||
|
||
#ifndef M_MMAP_THRESHOLD
|
||
#define M_MMAP_THRESHOLD -3
|
||
#endif
|
||
|
||
#ifndef M_MMAP_MAX
|
||
#define M_MMAP_MAX -4
|
||
#endif
|
||
|
||
|
||
/*
|
||
MXFAST is the maximum request size used for "fastbins", special bins
|
||
that hold returned chunks without consolidating their spaces. This
|
||
enables future requests for chunks of the same size to be handled
|
||
very quickly, but can increase fragmentation, and thus increase the
|
||
overall memory footprint of a program.
|
||
|
||
This malloc manages fastbins very conservatively yet still
|
||
efficiently, so fragmentation is rarely a problem for values less
|
||
than or equal to the default. The maximum supported value of MXFAST
|
||
is 80. You wouldn't want it any higher than this anyway. Fastbins
|
||
are designed especially for use with many small structs, objects or
|
||
strings -- the default handles structs/objects/arrays with sizes up
|
||
to 8 4byte fields, or small strings representing words, tokens,
|
||
etc. Using fastbins for larger objects normally worsens
|
||
fragmentation without improving speed.
|
||
|
||
MXFAST is set in REQUEST size units. It is internally used in
|
||
chunksize units, which adds padding and alignment. You can reduce
|
||
MXFAST to 0 to disable all use of fastbins. This causes the malloc
|
||
algorithm to be a close approximation of fifo-best-fit in all cases,
|
||
not just for larger requests, but will generally cause it to be
|
||
slower.
|
||
|
||
*/
|
||
|
||
#ifndef DEFAULT_MXFAST
|
||
#define DEFAULT_MXFAST 64
|
||
#endif
|
||
|
||
|
||
/*
|
||
M_TRIM_THRESHOLD is the maximum amount of unused top-most memory
|
||
to keep before releasing via malloc_trim in free().
|
||
|
||
Automatic trimming is mainly useful in long-lived programs.
|
||
Because trimming via sbrk can be slow on some systems, and can
|
||
sometimes be wasteful (in cases where programs immediately
|
||
afterward allocate more large chunks) the value should be high
|
||
enough so that your overall system performance would improve by
|
||
releasing.
|
||
|
||
The trim threshold and the mmap control parameters (see below)
|
||
can be traded off with one another. Trimming and mmapping are
|
||
two different ways of releasing unused memory back to the
|
||
system. Between these two, it is often possible to keep
|
||
system-level demands of a long-lived program down to a bare
|
||
minimum. For example, in one test suite of sessions measuring
|
||
the XF86 X server on Linux, using a trim threshold of 128K and a
|
||
mmap threshold of 192K led to near-minimal long term resource
|
||
consumption.
|
||
|
||
If you are using this malloc in a long-lived program, it should
|
||
pay to experiment with these values. As a rough guide, you
|
||
might set to a value close to the average size of a process
|
||
(program) running on your system. Releasing this much memory
|
||
would allow such a process to run in memory. Generally, it's
|
||
worth it to tune for trimming rather tham memory mapping when a
|
||
program undergoes phases where several large chunks are
|
||
allocated and released in ways that can reuse each other's
|
||
storage, perhaps mixed with phases where there are no such
|
||
chunks at all. And in well-behaved long-lived programs,
|
||
controlling release of large blocks via trimming versus mapping
|
||
is usually faster.
|
||
|
||
However, in most programs, these parameters serve mainly as
|
||
protection against the system-level effects of carrying around
|
||
massive amounts of unneeded memory. Since frequent calls to
|
||
sbrk, mmap, and munmap otherwise degrade performance, the default
|
||
parameters are set to relatively high values that serve only as
|
||
safeguards.
|
||
|
||
The default trim value is high enough to cause trimming only in
|
||
fairly extreme (by current memory consumption standards) cases.
|
||
It must be greater than page size to have any useful effect. To
|
||
disable trimming completely, you can set to (unsigned long)(-1);
|
||
|
||
Trim settings interact with fastbin (MXFAST) settings: Unless
|
||
TRIM_FASTBINS is defined, automatic trimming never takes place upon
|
||
freeing a chunk with size less than or equal to MXFAST. Trimming is
|
||
instead delayed until subsequent freeing of larger chunks. However,
|
||
you can still force an attempted trim by calling malloc_trim.
|
||
|
||
Also, trimming is not generally possible in cases where
|
||
the main arena is obtained via mmap.
|
||
|
||
*/
|
||
|
||
|
||
#ifndef DEFAULT_TRIM_THRESHOLD
|
||
#define DEFAULT_TRIM_THRESHOLD (128 * 1024)
|
||
#endif
|
||
|
||
|
||
|
||
/*
|
||
M_TOP_PAD is the amount of extra `padding' space to allocate or
|
||
retain whenever sbrk is called. It is used in two ways internally:
|
||
|
||
* When sbrk is called to extend the top of the arena to satisfy
|
||
a new malloc request, this much padding is added to the sbrk
|
||
request.
|
||
|
||
* When malloc_trim is called automatically from free(),
|
||
it is used as the `pad' argument.
|
||
|
||
In both cases, the actual amount of padding is rounded
|
||
so that the end of the arena is always a system page boundary.
|
||
|
||
The main reason for using padding is to avoid calling sbrk so
|
||
often. Having even a small pad greatly reduces the likelihood
|
||
that nearly every malloc request during program start-up (or
|
||
after trimming) will invoke sbrk, which needlessly wastes
|
||
time.
|
||
|
||
Automatic rounding-up to page-size units is normally sufficient
|
||
to avoid measurable overhead, so the default is 0. However, in
|
||
systems where sbrk is relatively slow, it can pay to increase
|
||
this value, at the expense of carrying around more memory than
|
||
the program needs.
|
||
|
||
*/
|
||
|
||
#ifndef DEFAULT_TOP_PAD
|
||
#define DEFAULT_TOP_PAD (0)
|
||
#endif
|
||
|
||
/*
|
||
|
||
M_MMAP_THRESHOLD is the request size threshold for using mmap()
|
||
to service a request. Requests of at least this size that cannot
|
||
be allocated using already-existing space will be serviced via mmap.
|
||
(If enough normal freed space already exists it is used instead.)
|
||
|
||
Using mmap segregates relatively large chunks of memory so that
|
||
they can be individually obtained and released from the host
|
||
system. A request serviced through mmap is never reused by any
|
||
other request (at least not directly; the system may just so
|
||
happen to remap successive requests to the same locations).
|
||
|
||
Segregating space in this way has the benefit that mmapped space
|
||
can ALWAYS be individually released back to the system, which
|
||
helps keep the system level memory demands of a long-lived
|
||
program low. Mapped memory can never become `locked' between
|
||
other chunks, as can happen with normally allocated chunks, which
|
||
means that even trimming via malloc_trim would not release them.
|
||
|
||
However, it has the disadvantages that:
|
||
|
||
1. The space cannot be reclaimed, consolidated, and then
|
||
used to service later requests, as happens with normal chunks.
|
||
2. It can lead to more wastage because of mmap page alignment
|
||
requirements
|
||
3. It causes malloc performance to be more dependent on host
|
||
system memory management support routines which may vary in
|
||
implementation quality and may impose arbitrary
|
||
limitations. Generally, servicing a request via normal
|
||
malloc steps is faster than going through a system's mmap.
|
||
|
||
All together, these considerations should lead you to use mmap
|
||
only for relatively large requests.
|
||
|
||
*/
|
||
|
||
|
||
#ifndef DEFAULT_MMAP_THRESHOLD
|
||
#define DEFAULT_MMAP_THRESHOLD (128 * 1024)
|
||
#endif
|
||
|
||
/*
|
||
M_MMAP_MAX is the maximum number of requests to simultaneously
|
||
service using mmap. This parameter exists because:
|
||
|
||
1. Some systems have a limited number of internal tables for
|
||
use by mmap.
|
||
2. In most systems, overreliance on mmap can degrade overall
|
||
performance.
|
||
3. If a program allocates many large regions, it is probably
|
||
better off using normal sbrk-based allocation routines that
|
||
can reclaim and reallocate normal heap memory.
|
||
|
||
Setting to 0 disables use of mmap for servicing large requests. If
|
||
HAVE_MMAP is not set, the default value is 0, and attempts to set it
|
||
to non-zero values in mallopt will fail.
|
||
*/
|
||
|
||
|
||
|
||
#ifndef DEFAULT_MMAP_MAX
|
||
#if HAVE_MMAP
|
||
#define DEFAULT_MMAP_MAX (256)
|
||
#else
|
||
#define DEFAULT_MMAP_MAX (0)
|
||
#endif
|
||
#endif
|
||
|
||
|
||
/*
|
||
TRIM_FASTBINS controls whether free() of a very small chunk can
|
||
immediately lead to trimming. Setting to true (1) can reduce memory
|
||
footprint, but will almost always slow down (by a few percent)
|
||
programs that use a lot of small chunks.
|
||
|
||
Define this only if you are willing to give up some speed to more
|
||
aggressively reduce system-level memory footprint when releasing
|
||
memory in programs that use many small chunks. You can get
|
||
essentially the same effect by setting MXFAST to 0, but this can
|
||
lead to even greater slowdowns in programs using many small chunks.
|
||
TRIM_FASTBINS is an in-between compile-time option, that disables
|
||
only those chunks bordering topmost memory from being placed in
|
||
fastbins.
|
||
|
||
*/
|
||
|
||
|
||
#ifndef TRIM_FASTBINS
|
||
#define TRIM_FASTBINS 0
|
||
#endif
|
||
|
||
|
||
/*
|
||
MORECORE-related declarations. By default, rely on sbrk
|
||
*/
|
||
|
||
|
||
#ifdef LACKS_UNISTD_H
|
||
#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__)
|
||
#if __STD_C
|
||
extern Void_t* sbrk(ptrdiff_t);
|
||
#else
|
||
extern Void_t* sbrk();
|
||
#endif
|
||
#endif
|
||
#endif
|
||
|
||
/*
|
||
MORECORE is the name of the routine to call to obtain more memory
|
||
from the system. See below for general guidance on writing
|
||
alternative MORECORE functions, as well as a version for WIN32 and a
|
||
sample version for pre-OSX macos.
|
||
*/
|
||
|
||
#ifndef MORECORE
|
||
#define MORECORE sbrk
|
||
#endif
|
||
|
||
|
||
/*
|
||
MORECORE_FAILURE is the value returned upon failure of MORECORE
|
||
as well as mmap. Since it cannot be an otherwise valid memory address,
|
||
and must reflect values of standard sys calls, you probably ought not
|
||
try to redefine it.
|
||
*/
|
||
|
||
#ifndef MORECORE_FAILURE
|
||
#define MORECORE_FAILURE (-1)
|
||
#endif
|
||
|
||
/*
|
||
If MORECORE_CONTIGUOUS is true, take advantage of fact that
|
||
consecutive calls to MORECORE with positive arguments always return
|
||
contiguous increasing addresses. This is true of unix sbrk. Even
|
||
if not defined, when regions happen to be contiguous, malloc will
|
||
permit allocations spanning regions obtained from different
|
||
calls. But defining this when applicable enables some stronger
|
||
consistency checks and space efficiencies.
|
||
*/
|
||
|
||
|
||
#ifndef MORECORE_CONTIGUOUS
|
||
#define MORECORE_CONTIGUOUS 1
|
||
#endif
|
||
|
||
|
||
/*
|
||
The system page size. To the extent possible, this malloc manages
|
||
memory from the system in page-size units. Note that this value is
|
||
cached during initialization into a field of malloc_state. So even
|
||
if malloc_getpagesize is a function, it is only called once.
|
||
|
||
The following mechanics for getpagesize were adapted from bsd/gnu
|
||
getpagesize.h. If none of the system-probes here apply, a value of
|
||
4096 is used, which should be OK: If they don't apply, then using
|
||
the actual value probably doesn't impact performance.
|
||
*/
|
||
|
||
#ifndef malloc_getpagesize
|
||
|
||
#ifndef LACKS_UNISTD_H
|
||
# include <unistd.h>
|
||
#endif
|
||
|
||
# ifdef _SC_PAGESIZE /* some SVR4 systems omit an underscore */
|
||
# ifndef _SC_PAGE_SIZE
|
||
# define _SC_PAGE_SIZE _SC_PAGESIZE
|
||
# endif
|
||
# endif
|
||
|
||
# ifdef _SC_PAGE_SIZE
|
||
# define malloc_getpagesize sysconf(_SC_PAGE_SIZE)
|
||
# else
|
||
# if defined(BSD) || defined(DGUX) || defined(HAVE_GETPAGESIZE)
|
||
extern size_t getpagesize();
|
||
# define malloc_getpagesize getpagesize()
|
||
# else
|
||
# ifdef WIN32 /* use supplied emulation of getpagesize */
|
||
# define malloc_getpagesize getpagesize()
|
||
# else
|
||
# ifndef LACKS_SYS_PARAM_H
|
||
# include <sys/param.h>
|
||
# endif
|
||
# ifdef EXEC_PAGESIZE
|
||
# define malloc_getpagesize EXEC_PAGESIZE
|
||
# else
|
||
# ifdef NBPG
|
||
# ifndef CLSIZE
|
||
# define malloc_getpagesize NBPG
|
||
# else
|
||
# define malloc_getpagesize (NBPG * CLSIZE)
|
||
# endif
|
||
# else
|
||
# ifdef NBPC
|
||
# define malloc_getpagesize NBPC
|
||
# else
|
||
# ifdef PAGESIZE
|
||
# define malloc_getpagesize PAGESIZE
|
||
# else /* just guess */
|
||
# define malloc_getpagesize (4096)
|
||
# endif
|
||
# endif
|
||
# endif
|
||
# endif
|
||
# endif
|
||
# endif
|
||
# endif
|
||
#endif
|
||
|
||
|
||
/* Two-phase Name mangling */
|
||
|
||
#ifndef USE_PUBLIC_MALLOC_WRAPPERS
|
||
#define cALLOc public_cALLOc
|
||
#define fREe public_fREe
|
||
#define cFREe public_cFREe
|
||
#define mALLOc public_mALLOc
|
||
#define mEMALIGn public_mEMALIGn
|
||
#define rEALLOc public_rEALLOc
|
||
#define vALLOc public_vALLOc
|
||
#define pVALLOc public_pVALLOc
|
||
#define mALLINFo public_mALLINFo
|
||
#define mALLOPt public_mALLOPt
|
||
#define mTRIm public_mTRIm
|
||
#define mSTATs public_mSTATs
|
||
#define mUSABLe public_mUSABLe
|
||
#endif
|
||
|
||
#ifdef USE_DL_PREFIX
|
||
#define public_cALLOc dlcalloc
|
||
#define public_fREe dlfree
|
||
#define public_cFREe dlcfree
|
||
#define public_mALLOc dlmalloc
|
||
#define public_mEMALIGn dlmemalign
|
||
#define public_rEALLOc dlrealloc
|
||
#define public_vALLOc dlvalloc
|
||
#define public_pVALLOc dlpvalloc
|
||
#define public_mALLINFo dlmallinfo
|
||
#define public_mALLOPt dlmallopt
|
||
#define public_mTRIm dlmalloc_trim
|
||
#define public_mSTATs dlmalloc_stats
|
||
#define public_mUSABLe dlmalloc_usable_size
|
||
#else /* USE_DL_PREFIX */
|
||
#define public_cALLOc calloc
|
||
#define public_fREe free
|
||
#define public_cFREe cfree
|
||
#define public_mALLOc malloc
|
||
#define public_mEMALIGn memalign
|
||
#define public_rEALLOc realloc
|
||
#define public_vALLOc valloc
|
||
#define public_pVALLOc pvalloc
|
||
#define public_mALLINFo mallinfo
|
||
#define public_mALLOPt mallopt
|
||
#define public_mTRIm malloc_trim
|
||
#define public_mSTATs malloc_stats
|
||
#define public_mUSABLe malloc_usable_size
|
||
#endif /* USE_DL_PREFIX */
|
||
|
||
#if __STD_C
|
||
|
||
Void_t* public_mALLOc(size_t);
|
||
void public_fREe(Void_t*);
|
||
Void_t* public_rEALLOc(Void_t*, size_t);
|
||
Void_t* public_mEMALIGn(size_t, size_t);
|
||
Void_t* public_vALLOc(size_t);
|
||
Void_t* public_pVALLOc(size_t);
|
||
Void_t* public_cALLOc(size_t, size_t);
|
||
void public_cFREe(Void_t*);
|
||
int public_mTRIm(size_t);
|
||
size_t public_mUSABLe(Void_t*);
|
||
void public_mSTATs();
|
||
int public_mALLOPt(int, int);
|
||
struct mallinfo public_mALLINFo(void);
|
||
#else
|
||
Void_t* public_mALLOc();
|
||
void public_fREe();
|
||
Void_t* public_rEALLOc();
|
||
Void_t* public_mEMALIGn();
|
||
Void_t* public_vALLOc();
|
||
Void_t* public_pVALLOc();
|
||
Void_t* public_cALLOc();
|
||
void public_cFREe();
|
||
int public_mTRIm();
|
||
size_t public_mUSABLe();
|
||
void public_mSTATs();
|
||
int public_mALLOPt();
|
||
struct mallinfo public_mALLINFo();
|
||
#endif
|
||
|
||
|
||
#ifdef __cplusplus
|
||
}; /* end of extern "C" */
|
||
#endif
|
||
|
||
|
||
|
||
/* ---------- To make a malloc.h, end cutting here ------------ */
|
||
|
||
|
||
/* Declarations of internal utilities defined below */
|
||
|
||
|
||
|
||
|
||
#ifdef USE_PUBLIC_MALLOC_WRAPPERS
|
||
#if __STD_C
|
||
|
||
static Void_t* mALLOc(size_t);
|
||
static void fREe(Void_t*);
|
||
static Void_t* rEALLOc(Void_t*, size_t);
|
||
static Void_t* mEMALIGn(size_t, size_t);
|
||
static Void_t* vALLOc(size_t);
|
||
static Void_t* pVALLOc(size_t);
|
||
static Void_t* cALLOc(size_t, size_t);
|
||
static void cFREe(Void_t*);
|
||
static int mTRIm(size_t);
|
||
static size_t mUSABLe(Void_t*);
|
||
static void mSTATs();
|
||
static int mALLOPt(int, int);
|
||
static struct mallinfo mALLINFo(void);
|
||
#else
|
||
static Void_t* mALLOc();
|
||
static void fREe();
|
||
static Void_t* rEALLOc();
|
||
static Void_t* mEMALIGn();
|
||
static Void_t* vALLOc();
|
||
static Void_t* pVALLOc();
|
||
static Void_t* cALLOc();
|
||
static void cFREe();
|
||
static int mTRIm();
|
||
static size_t mUSABLe();
|
||
static void mSTATs();
|
||
static int mALLOPt();
|
||
static struct mallinfo mALLINFo();
|
||
#endif
|
||
#endif
|
||
|
||
|
||
|
||
/* ---------- public wrappers --------------- */
|
||
|
||
#ifdef USE_PUBLIC_MALLOC_WRAPPERS
|
||
|
||
/*
|
||
MALLOC_PREACTION and MALLOC_POSTACTION should be
|
||
defined to return 0 on success, and nonzero on failure.
|
||
The return value of MALLOC_POSTACTION is currently ignored
|
||
in wrapper functions since there is no reasonable default
|
||
action to take on failure.
|
||
*/
|
||
|
||
|
||
#ifdef USE_MALLOC_LOCK
|
||
|
||
#ifdef WIN32
|
||
|
||
static int mALLOC_MUTEx;
|
||
|
||
#define MALLOC_PREACTION slwait(&mALLOC_MUTEx)
|
||
#define MALLOC_POSTACTION slrelease(&mALLOC_MUTEx)
|
||
|
||
#else
|
||
|
||
#include <pthread.h>
|
||
|
||
static pthread_mutex_t mALLOC_MUTEx = PTHREAD_MUTEX_INITIALIZER;
|
||
|
||
#define MALLOC_PREACTION pthread_mutex_lock(&mALLOC_MUTEx)
|
||
#define MALLOC_POSTACTION pthread_mutex_unlock(&mALLOC_MUTEx)
|
||
|
||
#endif /* USE_MALLOC_LOCK */
|
||
|
||
#else
|
||
|
||
/* Substitute anything you like for these */
|
||
|
||
#define MALLOC_PREACTION (0)
|
||
#define MALLOC_POSTACTION (0)
|
||
|
||
#endif
|
||
|
||
Void_t* public_mALLOc(size_t bytes) {
|
||
Void_t* m;
|
||
if (MALLOC_PREACTION != 0) {
|
||
return 0;
|
||
}
|
||
m = mALLOc(bytes);
|
||
if (MALLOC_POSTACTION != 0) {
|
||
}
|
||
return m;
|
||
}
|
||
|
||
void public_fREe(Void_t* m) {
|
||
if (MALLOC_PREACTION != 0) {
|
||
return;
|
||
}
|
||
fREe(m);
|
||
if (MALLOC_POSTACTION != 0) {
|
||
}
|
||
}
|
||
|
||
Void_t* public_rEALLOc(Void_t* m, size_t bytes) {
|
||
if (MALLOC_PREACTION != 0) {
|
||
return 0;
|
||
}
|
||
m = rEALLOc(m, bytes);
|
||
if (MALLOC_POSTACTION != 0) {
|
||
}
|
||
return m;
|
||
}
|
||
|
||
Void_t* public_mEMALIGn(size_t alignment, size_t bytes) {
|
||
Void_t* m;
|
||
if (MALLOC_PREACTION != 0) {
|
||
return 0;
|
||
}
|
||
m = mEMALIGn(alignment, bytes);
|
||
if (MALLOC_POSTACTION != 0) {
|
||
}
|
||
return m;
|
||
}
|
||
|
||
Void_t* public_vALLOc(size_t bytes) {
|
||
Void_t* m;
|
||
if (MALLOC_PREACTION != 0) {
|
||
return 0;
|
||
}
|
||
m = vALLOc(bytes);
|
||
if (MALLOC_POSTACTION != 0) {
|
||
}
|
||
return m;
|
||
}
|
||
|
||
Void_t* public_pVALLOc(size_t bytes) {
|
||
Void_t* m;
|
||
if (MALLOC_PREACTION != 0) {
|
||
return 0;
|
||
}
|
||
m = pVALLOc(bytes);
|
||
if (MALLOC_POSTACTION != 0) {
|
||
}
|
||
return m;
|
||
}
|
||
|
||
Void_t* public_cALLOc(size_t n, size_t elem_size) {
|
||
Void_t* m;
|
||
if (MALLOC_PREACTION != 0) {
|
||
return 0;
|
||
}
|
||
m = cALLOc(n, elem_size);
|
||
if (MALLOC_POSTACTION != 0) {
|
||
}
|
||
return m;
|
||
}
|
||
|
||
void public_cFREe(Void_t* m) {
|
||
if (MALLOC_PREACTION != 0) {
|
||
return;
|
||
}
|
||
cFREe(m);
|
||
if (MALLOC_POSTACTION != 0) {
|
||
}
|
||
}
|
||
|
||
int public_mTRIm(size_t s) {
|
||
int result;
|
||
if (MALLOC_PREACTION != 0) {
|
||
return 0;
|
||
}
|
||
result = mTRIm(s);
|
||
if (MALLOC_POSTACTION != 0) {
|
||
}
|
||
return result;
|
||
}
|
||
|
||
|
||
size_t public_mUSABLe(Void_t* m) {
|
||
size_t result;
|
||
if (MALLOC_PREACTION != 0) {
|
||
return 0;
|
||
}
|
||
result = mUSABLe(m);
|
||
if (MALLOC_POSTACTION != 0) {
|
||
}
|
||
return result;
|
||
}
|
||
|
||
|
||
void public_mSTATs() {
|
||
if (MALLOC_PREACTION != 0) {
|
||
return;
|
||
}
|
||
mSTATs();
|
||
if (MALLOC_POSTACTION != 0) {
|
||
}
|
||
}
|
||
|
||
struct mallinfo public_mALLINFo() {
|
||
struct mallinfo m;
|
||
if (MALLOC_PREACTION != 0) {
|
||
return m;
|
||
}
|
||
m = mALLINFo();
|
||
if (MALLOC_POSTACTION != 0) {
|
||
}
|
||
return m;
|
||
}
|
||
|
||
int public_mALLOPt(int p, int v) {
|
||
int result;
|
||
if (MALLOC_PREACTION != 0) {
|
||
return 0;
|
||
}
|
||
result = mALLOPt(p, v);
|
||
if (MALLOC_POSTACTION != 0) {
|
||
}
|
||
return result;
|
||
}
|
||
|
||
#endif
|
||
|
||
|
||
|
||
/* ------------- Optional versions of memcopy ---------------- */
|
||
|
||
|
||
#if USE_MEMCPY
|
||
|
||
#define MALLOC_COPY(dest, src, nbytes, overlap) \
|
||
((overlap) ? memmove(dest, src, nbytes) : memcpy(dest, src, nbytes))
|
||
#define MALLOC_ZERO(dest, nbytes) memset(dest, 0, nbytes)
|
||
|
||
#else /* !USE_MEMCPY */
|
||
|
||
/* Use Duff's device for good zeroing/copying performance. */
|
||
|
||
#define MALLOC_ZERO(charp, nbytes) \
|
||
do { \
|
||
INTERNAL_SIZE_T* mzp = (INTERNAL_SIZE_T*)(charp); \
|
||
long mctmp = (nbytes)/sizeof(INTERNAL_SIZE_T), mcn; \
|
||
if (mctmp < 8) mcn = 0; else { mcn = (mctmp-1)/8; mctmp %= 8; } \
|
||
switch (mctmp) { \
|
||
case 0: for(;;) { *mzp++ = 0; \
|
||
case 7: *mzp++ = 0; \
|
||
case 6: *mzp++ = 0; \
|
||
case 5: *mzp++ = 0; \
|
||
case 4: *mzp++ = 0; \
|
||
case 3: *mzp++ = 0; \
|
||
case 2: *mzp++ = 0; \
|
||
case 1: *mzp++ = 0; if(mcn <= 0) break; mcn--; } \
|
||
} \
|
||
} while(0)
|
||
|
||
/* For overlapping case, dest is always _below_ src. */
|
||
|
||
#define MALLOC_COPY(dest,src,nbytes,overlap) \
|
||
do { \
|
||
INTERNAL_SIZE_T* mcsrc = (INTERNAL_SIZE_T*) src; \
|
||
INTERNAL_SIZE_T* mcdst = (INTERNAL_SIZE_T*) dest; \
|
||
long mctmp = (nbytes)/sizeof(INTERNAL_SIZE_T), mcn; \
|
||
if (mctmp < 8) mcn = 0; else { mcn = (mctmp-1)/8; mctmp %= 8; } \
|
||
switch (mctmp) { \
|
||
case 0: for(;;) { *mcdst++ = *mcsrc++; \
|
||
case 7: *mcdst++ = *mcsrc++; \
|
||
case 6: *mcdst++ = *mcsrc++; \
|
||
case 5: *mcdst++ = *mcsrc++; \
|
||
case 4: *mcdst++ = *mcsrc++; \
|
||
case 3: *mcdst++ = *mcsrc++; \
|
||
case 2: *mcdst++ = *mcsrc++; \
|
||
case 1: *mcdst++ = *mcsrc++; if(mcn <= 0) break; mcn--; } \
|
||
} \
|
||
} while(0)
|
||
|
||
#endif
|
||
|
||
/* ------------------ MMAP support ------------------ */
|
||
|
||
|
||
#if HAVE_MMAP
|
||
|
||
#include <fcntl.h>
|
||
#ifndef LACKS_SYS_MMAN_H
|
||
#include <sys/mman.h>
|
||
#endif
|
||
|
||
#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
|
||
#define MAP_ANONYMOUS MAP_ANON
|
||
#endif
|
||
|
||
|
||
/*
|
||
Nearly all versions of mmap support MAP_ANONYMOUS,
|
||
so the following is unlikely to be needed, but is
|
||
supplied just in case.
|
||
*/
|
||
|
||
#ifndef MAP_ANONYMOUS
|
||
|
||
static int dev_zero_fd = -1; /* Cached file descriptor for /dev/zero. */
|
||
|
||
#define MMAP(addr, size, prot, flags) ((dev_zero_fd < 0) ? \
|
||
(dev_zero_fd = open("/dev/zero", O_RDWR), \
|
||
mmap((addr), (size), (prot), (flags), dev_zero_fd, 0)) : \
|
||
mmap((addr), (size), (prot), (flags), dev_zero_fd, 0))
|
||
|
||
#else
|
||
|
||
#define MMAP(addr, size, prot, flags) \
|
||
(mmap((addr), (size), (prot), (flags)|MAP_ANONYMOUS, -1, 0))
|
||
|
||
#endif
|
||
|
||
#endif /* HAVE_MMAP */
|
||
|
||
|
||
/* ---------- Alternative MORECORE functions ------------ */
|
||
|
||
|
||
/*
|
||
General Requirements for MORECORE.
|
||
|
||
The MORECORE function must have the following properties:
|
||
|
||
If MORECORE_CONTIGUOUS is false:
|
||
|
||
* MORECORE must allocate in multiples of pagesize. It will
|
||
only be called with arguments that are multiples of pagesize.
|
||
|
||
* MORECORE must page-align. That is, MORECORE(0) must
|
||
return an address at a page boundary.
|
||
|
||
else (i.e. If MORECORE_CONTIGUOUS is true):
|
||
|
||
* Consecutive calls to MORECORE with positive arguments
|
||
return increasing addresses, indicating that space has been
|
||
contiguously extended.
|
||
|
||
* MORECORE need not allocate in multiples of pagesize.
|
||
Calls to MORECORE need not have args of multiples of pagesize.
|
||
|
||
* MORECORE need not page-align.
|
||
|
||
In either case:
|
||
|
||
* MORECORE may allocate more memory than requested. (Or even less,
|
||
but this will generally result in a malloc failure.)
|
||
|
||
* MORECORE must not allocate memory when given argument zero, but
|
||
instead return one past the end address of memory from previous
|
||
nonzero call. This malloc does NOT call MORECORE(0)
|
||
until at least one call with positive arguments is made, so
|
||
the initial value returned is not important.
|
||
|
||
* Even though consecutive calls to MORECORE need not return contiguous
|
||
addresses, it must be OK for malloc'ed chunks to span multiple
|
||
regions in those cases where they do happen to be contiguous.
|
||
|
||
* MORECORE need not handle negative arguments -- it may instead
|
||
just return MORECORE_FAILURE when given negative arguments.
|
||
Negative arguments are always multiples of pagesize. MORECORE
|
||
must not misinterpret negative args as large positive unsigned
|
||
args.
|
||
|
||
There is some variation across systems about the type of the
|
||
argument to sbrk/MORECORE. If size_t is unsigned, then it cannot
|
||
actually be size_t, because sbrk supports negative args, so it is
|
||
normally the signed type of the same width as size_t (sometimes
|
||
declared as "intptr_t", and sometimes "ptrdiff_t"). It doesn't much
|
||
matter though. Internally, we use "long" as arguments, which should
|
||
work across all reasonable possibilities.
|
||
|
||
Additionally, if MORECORE ever returns failure for a positive
|
||
request, and HAVE_MMAP is true, then mmap is used as a noncontiguous
|
||
system allocator. This is a useful backup strategy for systems with
|
||
holes in address spaces -- in this case sbrk cannot contiguously
|
||
expand the heap, but mmap may be able to map noncontiguous space.
|
||
If you'd like mmap to ALWAYS be used, you can define MORECORE to be
|
||
a function that always returns MORECORE_FAILURE.
|
||
|
||
If you are using this malloc with something other than unix sbrk to
|
||
supply memory regions, you probably want to set MORECORE_CONTIGUOUS
|
||
as false. As an example, here is a custom allocator kindly
|
||
contributed for pre-OSX macOS. It uses virtually but not
|
||
necessarily physically contiguous non-paged memory (locked in,
|
||
present and won't get swapped out). You can use it by uncommenting
|
||
this section, adding some #includes, and setting up the appropriate
|
||
defines above:
|
||
|
||
#define MORECORE osMoreCore
|
||
#define MORECORE_CONTIGUOUS 0
|
||
|
||
There is also a shutdown routine that should somehow be called for
|
||
cleanup upon program exit.
|
||
|
||
#define MAX_POOL_ENTRIES 100
|
||
#define MINIMUM_MORECORE_SIZE (64 * 1024)
|
||
static int next_os_pool;
|
||
void *our_os_pools[MAX_POOL_ENTRIES];
|
||
|
||
void *osMoreCore(int size)
|
||
{
|
||
void *ptr = 0;
|
||
static void *sbrk_top = 0;
|
||
|
||
if (size > 0)
|
||
{
|
||
if (size < MINIMUM_MORECORE_SIZE)
|
||
size = MINIMUM_MORECORE_SIZE;
|
||
if (CurrentExecutionLevel() == kTaskLevel)
|
||
ptr = PoolAllocateResident(size + RM_PAGE_SIZE, 0);
|
||
if (ptr == 0)
|
||
{
|
||
return (void *) MORECORE_FAILURE;
|
||
}
|
||
// save ptrs so they can be freed during cleanup
|
||
our_os_pools[next_os_pool] = ptr;
|
||
next_os_pool++;
|
||
ptr = (void *) ((((unsigned long) ptr) + RM_PAGE_MASK) & ~RM_PAGE_MASK);
|
||
sbrk_top = (char *) ptr + size;
|
||
return ptr;
|
||
}
|
||
else if (size < 0)
|
||
{
|
||
// we don't currently support shrink behavior
|
||
return (void *) MORECORE_FAILURE;
|
||
}
|
||
else
|
||
{
|
||
return sbrk_top;
|
||
}
|
||
}
|
||
|
||
// cleanup any allocated memory pools
|
||
// called as last thing before shutting down driver
|
||
|
||
void osCleanupMem(void)
|
||
{
|
||
void **ptr;
|
||
|
||
for (ptr = our_os_pools; ptr < &our_os_pools[MAX_POOL_ENTRIES]; ptr++)
|
||
if (*ptr)
|
||
{
|
||
PoolDeallocate(*ptr);
|
||
*ptr = 0;
|
||
}
|
||
}
|
||
|
||
*/
|
||
|
||
|
||
|
||
|
||
|
||
/*
|
||
----------------------- Chunk representations -----------------------
|
||
*/
|
||
|
||
|
||
/*
|
||
This struct declaration is misleading (but accurate and necessary).
|
||
It declares a "view" into memory allowing access to necessary
|
||
fields at known offsets from a given base. See explanation below.
|
||
*/
|
||
|
||
struct malloc_chunk {
|
||
|
||
INTERNAL_SIZE_T prev_size; /* Size of previous chunk (if free). */
|
||
INTERNAL_SIZE_T size; /* Size in bytes, including overhead. */
|
||
|
||
struct malloc_chunk* fd; /* double links -- used only if free. */
|
||
struct malloc_chunk* bk;
|
||
};
|
||
|
||
|
||
typedef struct malloc_chunk* mchunkptr;
|
||
|
||
/*
|
||
|
||
malloc_chunk details:
|
||
|
||
(The following includes lightly edited explanations by Colin Plumb.)
|
||
|
||
Chunks of memory are maintained using a `boundary tag' method as
|
||
described in e.g., Knuth or Standish. (See the paper by Paul
|
||
Wilson ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a
|
||
survey of such techniques.) Sizes of free chunks are stored both
|
||
in the front of each chunk and at the end. This makes
|
||
consolidating fragmented chunks into bigger chunks very fast. The
|
||
size fields also hold bits representing whether chunks are free or
|
||
in use.
|
||
|
||
An allocated chunk looks like this:
|
||
|
||
|
||
chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| Size of previous chunk, if allocated | |
|
||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| Size of chunk, in bytes |P|
|
||
mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| User data starts here... .
|
||
. .
|
||
. (malloc_usable_space() bytes) .
|
||
. |
|
||
nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| Size of chunk |
|
||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
|
||
|
||
Where "chunk" is the front of the chunk for the purpose of most of
|
||
the malloc code, but "mem" is the pointer that is returned to the
|
||
user. "Nextchunk" is the beginning of the next contiguous chunk.
|
||
|
||
Chunks always begin on even word boundries, so the mem portion
|
||
(which is returned to the user) is also on an even word boundary, and
|
||
thus double-word aligned.
|
||
|
||
Free chunks are stored in circular doubly-linked lists, and look like this:
|
||
|
||
chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| Size of previous chunk |
|
||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
`head:' | Size of chunk, in bytes |P|
|
||
mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| Forward pointer to next chunk in list |
|
||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| Back pointer to previous chunk in list |
|
||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
| Unused space (may be 0 bytes long) .
|
||
. .
|
||
. |
|
||
nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
`foot:' | Size of chunk, in bytes |
|
||
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
||
|
||
The P (PREV_INUSE) bit, stored in the unused low-order bit of the
|
||
chunk size (which is always a multiple of two words), is an in-use
|
||
bit for the *previous* chunk. If that bit is *clear*, then the
|
||
word before the current chunk size contains the previous chunk
|
||
size, and can be used to find the front of the previous chunk.
|
||
The very first chunk allocated always has this bit set,
|
||
preventing access to non-existent (or non-owned) memory. If
|
||
prev_inuse is set for any given chunk, then you CANNOT determine
|
||
the size of the previous chunk, and might even get a memory
|
||
addressing fault when trying to do so.
|
||
|
||
Note that the `foot' of the current chunk is actually represented
|
||
as the prev_size of the NEXT chunk. (This makes it easier to
|
||
deal with alignments etc).
|
||
|
||
The two exceptions to all this are
|
||
|
||
1. The special chunk `top' doesn't bother using the
|
||
trailing size field since there is no next contiguous chunk
|
||
that would have to index off it. After initialization, `top'
|
||
is forced to always exist. If it would become less than
|
||
MINSIZE bytes long, it is replenished.
|
||
|
||
2. Chunks allocated via mmap, which have the second-lowest-order
|
||
bit (IS_MMAPPED) set in their size fields. Because they are
|
||
allocated one-by-one, each must contain its own trailing size field.
|
||
|
||
*/
|
||
|
||
|
||
|
||
/*
|
||
Size and alignment checks and conversions
|
||
*/
|
||
|
||
/* conversion from malloc headers to user pointers, and back */
|
||
|
||
#define chunk2mem(p) ((Void_t*)((char*)(p) + 2*SIZE_SZ))
|
||
#define mem2chunk(mem) ((mchunkptr)((char*)(mem) - 2*SIZE_SZ))
|
||
|
||
/* The smallest possible chunk */
|
||
#define MIN_CHUNK_SIZE (sizeof(struct malloc_chunk))
|
||
|
||
/* The smallest size we can malloc is an aligned minimal chunk */
|
||
|
||
#define MINSIZE ((MIN_CHUNK_SIZE+MALLOC_ALIGN_MASK) & ~MALLOC_ALIGN_MASK)
|
||
|
||
/* Check if m has acceptable alignment */
|
||
|
||
#define aligned_OK(m) (((unsigned long)((m)) & (MALLOC_ALIGN_MASK)) == 0)
|
||
|
||
/*
|
||
Check for negative/huge sizes.
|
||
This cannot just test for < 0 because argument might
|
||
be an unsigned type of uncertain width.
|
||
*/
|
||
|
||
#define IS_NEGATIVE(x) \
|
||
((unsigned long)x >= \
|
||
(unsigned long)((((INTERNAL_SIZE_T)(1)) << ((SIZE_SZ)*8 - 1))))
|
||
|
||
|
||
/* pad request bytes into a usable size -- internal version */
|
||
|
||
#define request2size(req) \
|
||
(((req) + SIZE_SZ + MALLOC_ALIGN_MASK < MINSIZE) ? \
|
||
MINSIZE : \
|
||
((req) + SIZE_SZ + MALLOC_ALIGN_MASK) & ~MALLOC_ALIGN_MASK)
|
||
|
||
|
||
/*
|
||
Same, except check for negative/huge arguments.
|
||
This lets through args that are positive but wrap into
|
||
negatives when padded. However, these are trapped
|
||
elsewhere.
|
||
*/
|
||
|
||
#define checked_request2size(req, sz) \
|
||
if (IS_NEGATIVE(req)) { \
|
||
MALLOC_FAILURE_ACTION; \
|
||
return 0; \
|
||
} \
|
||
(sz) = request2size(req);
|
||
|
||
|
||
|
||
|
||
/*
|
||
Physical chunk operations
|
||
*/
|
||
|
||
|
||
/* size field is or'ed with PREV_INUSE when previous adjacent chunk in use */
|
||
|
||
#define PREV_INUSE 0x1
|
||
|
||
|
||
/* size field is or'ed with IS_MMAPPED if the chunk was obtained with mmap() */
|
||
|
||
#define IS_MMAPPED 0x2
|
||
|
||
|
||
/* Bits to mask off when extracting size */
|
||
|
||
#define SIZE_BITS (PREV_INUSE|IS_MMAPPED)
|
||
|
||
|
||
/* Ptr to next physical malloc_chunk. */
|
||
|
||
#define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->size & ~PREV_INUSE) ))
|
||
|
||
|
||
/* Ptr to previous physical malloc_chunk */
|
||
|
||
#define prev_chunk(p) ((mchunkptr)( ((char*)(p)) - ((p)->prev_size) ))
|
||
|
||
|
||
/* Treat space at ptr + offset as a chunk */
|
||
|
||
#define chunk_at_offset(p, s) ((mchunkptr)(((char*)(p)) + (s)))
|
||
|
||
|
||
|
||
|
||
/*
|
||
Dealing with use bits
|
||
|
||
Note: IS_MMAPPED is intentionally not masked off from size field in
|
||
macros for which mmapped chunks should never be seen. This should
|
||
cause helpful core dumps to occur if it is tried by accident by
|
||
people extending or adapting this malloc.
|
||
|
||
*/
|
||
|
||
|
||
/* extract p's inuse bit */
|
||
|
||
#define inuse(p)\
|
||
((((mchunkptr)(((char*)(p))+((p)->size & ~PREV_INUSE)))->size) & PREV_INUSE)
|
||
|
||
|
||
/* extract inuse bit of previous chunk */
|
||
|
||
#define prev_inuse(p) ((p)->size & PREV_INUSE)
|
||
|
||
|
||
/* check for mmap()'ed chunk */
|
||
|
||
#define chunk_is_mmapped(p) ((p)->size & IS_MMAPPED)
|
||
|
||
|
||
/* set/clear chunk as being inuse without otherwise disturbing */
|
||
|
||
#define set_inuse(p)\
|
||
((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size |= PREV_INUSE
|
||
|
||
#define clear_inuse(p)\
|
||
((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size &= ~(PREV_INUSE)
|
||
|
||
|
||
/* check/set/clear inuse bits in known places */
|
||
|
||
#define inuse_bit_at_offset(p, s)\
|
||
(((mchunkptr)(((char*)(p)) + (s)))->size & PREV_INUSE)
|
||
|
||
#define set_inuse_bit_at_offset(p, s)\
|
||
(((mchunkptr)(((char*)(p)) + (s)))->size |= PREV_INUSE)
|
||
|
||
#define clear_inuse_bit_at_offset(p, s)\
|
||
(((mchunkptr)(((char*)(p)) + (s)))->size &= ~(PREV_INUSE))
|
||
|
||
|
||
|
||
|
||
/*
|
||
Dealing with size fields
|
||
*/
|
||
|
||
/* Get size, ignoring use bits */
|
||
|
||
#define chunksize(p) ((p)->size & ~(SIZE_BITS))
|
||
|
||
/* Set size at head, without disturbing its use bit */
|
||
|
||
#define set_head_size(p, s) ((p)->size = (((p)->size & PREV_INUSE) | (s)))
|
||
|
||
/* Set size/use field */
|
||
|
||
#define set_head(p, s) ((p)->size = (s))
|
||
|
||
/* Set size at footer (only when chunk is not in use) */
|
||
|
||
#define set_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_size = (s))
|
||
|
||
|
||
|
||
|
||
|
||
/*
|
||
------------------ Internal data structures --------------------
|
||
|
||
All internal state is held in an instance of malloc_state defined
|
||
below. There are no other static variables, except in two optional
|
||
cases:
|
||
* If USE_MALLOC_LOCK is defined, the mALLOC_MUTEx declared
|
||
above.
|
||
* If HAVE_MMAP is true, but mmap doesn't support
|
||
MAP_ANONYMOUS, a dummy file descriptor for mmap.
|
||
|
||
Beware of lots of tricks that minimize the total space
|
||
requirements. The result is a little over 1K bytes (for 4byte
|
||
pointers and size_t.)
|
||
|
||
*/
|
||
|
||
/*
|
||
|
||
Bins
|
||
|
||
An array of bin headers for free chunks. Each bin is doubly
|
||
linked. The bins are approximately proportionally (log) spaced.
|
||
There are a lot of these bins (128). This may look excessive, but
|
||
works very well in practice. Most bins hold sizes that are
|
||
unusual as malloc request sizes, but are more usual for fragments
|
||
and consolidated sets of chunks, which is what these bins hold, so
|
||
they can be found quickly. All procedures maintain the invariant
|
||
that no consolidated chunk physically borders another one, so each
|
||
chunk in a list is known to be preceeded and followed by either
|
||
inuse chunks or the ends of memory.
|
||
|
||
Chunks in bins are kept in size order, with ties going to the
|
||
approximately least recently used chunk. Ordering is irrelevant
|
||
for the small bins, which all contain the same-sized chunks, but
|
||
facilitates best-fit allocation for larger chunks. (These lists
|
||
are just sequential. Keeping them in order almost never requires
|
||
enough traversal to warrant using fancier ordered data
|
||
structures.) Chunks of the same size are linked with the most
|
||
recently freed at the front, and allocations are taken from the
|
||
back. This results in LRU (FIFO) allocation order, which tends
|
||
to give each chunk an equal opportunity to be consolidated with
|
||
adjacent freed chunks, resulting in larger free chunks and less
|
||
fragmentation.
|
||
|
||
To simplify use in double-linked lists, each bin header acts
|
||
as a malloc_chunk. This avoids special-casing for headers.
|
||
But to conserve space and (mainly) improve locality, we allocate
|
||
only the fd/bk pointers of bins, and then use repositioning tricks
|
||
to treat these as the fields of a malloc_chunk*.
|
||
*/
|
||
|
||
typedef struct malloc_chunk* mbinptr;
|
||
|
||
#define NBINS 128
|
||
|
||
|
||
/* addressing -- note that bin_at(0) does not exist */
|
||
|
||
#define bin_at(m, i) ((mbinptr)((char*)&((m)->bins[(i)<<1]) - (SIZE_SZ<<1)))
|
||
|
||
|
||
/* analog of ++bin */
|
||
|
||
#define next_bin(b) ((mbinptr)((char*)(b) + (sizeof(mchunkptr)<<1)))
|
||
|
||
|
||
/* Reminders about list directionality within bins */
|
||
|
||
#define first(b) ((b)->fd)
|
||
#define last(b) ((b)->bk)
|
||
|
||
/*
|
||
Take a chunk off a bin list
|
||
*/
|
||
|
||
#define unlink(P, BK, FD) { \
|
||
FD = P->fd; \
|
||
BK = P->bk; \
|
||
FD->bk = BK; \
|
||
BK->fd = FD; \
|
||
}
|
||
|
||
/*
|
||
Indexing bins
|
||
|
||
Bins for sizes < 512 bytes contain chunks of all the same size, spaced
|
||
8 bytes apart. Larger bins are approximately logarithmically spaced:
|
||
|
||
64 bins of size 8
|
||
32 bins of size 64
|
||
16 bins of size 512
|
||
8 bins of size 4096
|
||
4 bins of size 32768
|
||
2 bins of size 262144
|
||
1 bin of size what's left
|
||
|
||
There is actually a little bit of slop in the numbers in bin_index
|
||
for the sake of speed. This makes no difference elsewhere.
|
||
|
||
The bins top out at around 1mb because we expect to service large
|
||
chunks via mmap.
|
||
|
||
*/
|
||
|
||
/* The first NSMALLBIN bins (and fastbins) hold only one size */
|
||
#define NSMALLBINS 64
|
||
#define SMALLBIN_WIDTH 8
|
||
#define MIN_LARGE_SIZE 512
|
||
|
||
#define in_smallbin_range(sz) ((sz) < MIN_LARGE_SIZE)
|
||
|
||
#define smallbin_index(sz) (((unsigned)(sz)) >> 3)
|
||
|
||
#define largebin_index(sz) \
|
||
(((((unsigned long)(sz)) >> 6) <= 32)? 56 + (((unsigned long)(sz)) >> 6): \
|
||
((((unsigned long)(sz)) >> 9) <= 20)? 91 + (((unsigned long)(sz)) >> 9): \
|
||
((((unsigned long)(sz)) >> 12) <= 10)? 110 + (((unsigned long)(sz)) >> 12): \
|
||
((((unsigned long)(sz)) >> 15) <= 4)? 119 + (((unsigned long)(sz)) >> 15): \
|
||
((((unsigned long)(sz)) >> 18) <= 2)? 124 + (((unsigned long)(sz)) >> 18): \
|
||
126)
|
||
|
||
#define bin_index(sz) \
|
||
((in_smallbin_range(sz)) ? smallbin_index(sz) : largebin_index(sz))
|
||
|
||
|
||
/*
|
||
Unsorted chunks
|
||
|
||
All remainders from chunk splits, as well as all returned chunks,
|
||
are first placed in the "unsorted" bin. They are then placed
|
||
in regular bins after malloc gives them ONE chance to be used before
|
||
binning. So, basically, the unsorted_chunks list acts as a queue,
|
||
with chunks being placed on it in free (and malloc_consolidate),
|
||
and taken off (to be either used or placed in bins) in malloc.
|
||
|
||
*/
|
||
|
||
|
||
/* The otherwise unindexable 1-bin is used to hold unsorted chunks. */
|
||
|
||
#define unsorted_chunks(M) (bin_at(M, 1))
|
||
|
||
|
||
/*
|
||
Top
|
||
|
||
The top-most available chunk (i.e., the one bordering the end of
|
||
available memory) is treated specially. It is never included in
|
||
any bin, is used only if no other chunk is available, and is
|
||
released back to the system if it is very large (see
|
||
M_TRIM_THRESHOLD). `top' is never properly linked to its bin
|
||
since it is always handled specially. Because top initially
|
||
points to its own bin with initial zero size, thus forcing
|
||
extension on the first malloc request, we avoid having any special
|
||
code in malloc to check whether it even exists yet. But we still
|
||
need to do so when getting memory from system, so we make
|
||
initial_top treat the bin as a legal but unusable chunk during the
|
||
interval between initialization and the first call to
|
||
sYSMALLOc. (This is somewhat delicate, since it relies on
|
||
the 2 preceding words to be zero during this interval as well.)
|
||
*/
|
||
|
||
|
||
/* Conveniently, the unsorted bin can be used as dummy top on first call */
|
||
#define initial_top(M) (unsorted_chunks(M))
|
||
|
||
/*
|
||
Binmap
|
||
|
||
To help compensate for the large number of bins, a one-level index
|
||
structure is used for bin-by-bin searching. `binmap' is a
|
||
bitvector recording whether bins are definitely empty so they can
|
||
be skipped over during during traversals. The bits are NOT always
|
||
cleared as soon as bins are empty, but instead only
|
||
when they are noticed to be empty during traversal in malloc.
|
||
|
||
*/
|
||
|
||
/* Conservatively use 32 bits per map word, even if on 64bit system */
|
||
#define BINMAPSHIFT 5
|
||
#define BITSPERMAP (1U << BINMAPSHIFT)
|
||
#define BINMAPSIZE (NBINS / BITSPERMAP)
|
||
|
||
#define idx2block(i) ((i) >> BINMAPSHIFT)
|
||
#define idx2bit(i) ((1U << ((i) & ((1U << BINMAPSHIFT)-1))))
|
||
|
||
#define mark_bin(m,i) ((m)->binmap[idx2block(i)] |= idx2bit(i))
|
||
#define unmark_bin(m,i) ((m)->binmap[idx2block(i)] &= ~(idx2bit(i)))
|
||
#define get_binmap(m,i) ((m)->binmap[idx2block(i)] & idx2bit(i))
|
||
|
||
|
||
/*
|
||
Fastbins
|
||
|
||
An array of lists holding recently freed small chunks. Fastbins
|
||
are not doubly linked. It is faster to single-link them, and
|
||
since chunks are never removed from the middles of these lists,
|
||
double linking is not necessary.
|
||
|
||
Chunks in fastbins keep their inuse bit set, so they cannot
|
||
be consolidated with other free chunks. malloc_consolidate
|
||
releases all chunks in fastbins and consolidates them with
|
||
other free chunks.
|
||
*/
|
||
|
||
typedef struct malloc_chunk* mfastbinptr;
|
||
|
||
/* offset 2 to use otherwise unindexable first 2 bins */
|
||
#define fastbin_index(sz) ((((unsigned int)(sz)) >> 3) - 2)
|
||
|
||
/* The maximum fastbin request size we support */
|
||
#define MAX_FAST_SIZE 80
|
||
|
||
#define NFASTBINS (fastbin_index(request2size(MAX_FAST_SIZE))+1)
|
||
|
||
|
||
|
||
/*
|
||
Flag bit held in max_fast indicating that there probably are some
|
||
fastbin chunks . It is set true on entering a chunk into any fastbin,
|
||
and cleared only in malloc_consolidate.
|
||
|
||
The truth value is inverted so that have_fastchunks will be true
|
||
upon startup (since statics are zero-filled).
|
||
*/
|
||
|
||
|
||
#define have_fastchunks(M) (((M)->max_fast & 1U) == 0)
|
||
#define clear_fastchunks(M) ((M)->max_fast |= 1U)
|
||
#define set_fastchunks(M) ((M)->max_fast &= ~1U)
|
||
|
||
/*
|
||
Initialization value of max_fast.
|
||
Use impossibly small value if 0.
|
||
Value also has flag bit clear.
|
||
*/
|
||
#define req2max_fast(s) (((((s) == 0)? SMALLBIN_WIDTH: request2size(s))) | 1U)
|
||
|
||
|
||
/*
|
||
NONCONTIGUOUS_REGIONS is a special value for sbrk_base indicating that
|
||
MORECORE does not return contiguous regions. In this case, we do not check
|
||
or assume that the address of each chunk is at least sbrk_base. Otherwise,
|
||
contiguity is exploited in merging together, when possible, results
|
||
from consecutive MORECORE calls.
|
||
|
||
The possible values for sbrk_base are:
|
||
MORECORE_FAILURE:
|
||
MORECORE has not yet been called, but we expect contiguous space
|
||
NONCONTIGUOUS_REGIONS:
|
||
we don't expect or rely on contiguous space
|
||
any other legal address:
|
||
the first address returned by MORECORE when contiguous
|
||
*/
|
||
|
||
#define NONCONTIGUOUS_REGIONS ((char*)(-3))
|
||
|
||
|
||
/*
|
||
----------- Internal state representation and initialization -----------
|
||
*/
|
||
|
||
|
||
struct malloc_state {
|
||
|
||
/* The maximum chunk size to be eligible for fastbin */
|
||
INTERNAL_SIZE_T max_fast; /* low bit used as fastbin flag */
|
||
|
||
/* Base of the topmost chunk -- not otherwise kept in a bin */
|
||
mchunkptr top;
|
||
|
||
/* The remainder from the most recent split of a small request */
|
||
mchunkptr last_remainder;
|
||
|
||
/* Fastbins */
|
||
mfastbinptr fastbins[NFASTBINS];
|
||
|
||
/* Normal bins packed as described above */
|
||
mchunkptr bins[NBINS * 2];
|
||
|
||
/* Bitmap of bins */
|
||
unsigned int binmap[BINMAPSIZE];
|
||
|
||
/* Tunable parameters */
|
||
unsigned long trim_threshold;
|
||
INTERNAL_SIZE_T top_pad;
|
||
INTERNAL_SIZE_T mmap_threshold;
|
||
|
||
/* Memory map support */
|
||
int n_mmaps;
|
||
int n_mmaps_max;
|
||
int max_n_mmaps;
|
||
|
||
/* Bookkeeping for sbrk */
|
||
unsigned int pagesize; /* Cache malloc_getpagesize */
|
||
char* sbrk_base; /* first address returned by sbrk,
|
||
or NONCONTIGUOUS_REGIONS */
|
||
/* Statistics */
|
||
|
||
INTERNAL_SIZE_T mmapped_mem;
|
||
INTERNAL_SIZE_T sbrked_mem;
|
||
|
||
INTERNAL_SIZE_T max_sbrked_mem;
|
||
INTERNAL_SIZE_T max_mmapped_mem;
|
||
INTERNAL_SIZE_T max_total_mem;
|
||
};
|
||
|
||
typedef struct malloc_state *mstate;
|
||
|
||
/*
|
||
There is exactly one instance of this struct in this malloc.
|
||
|
||
If you are adapting this malloc in a way that does NOT use a static
|
||
malloc_state, you MUST explicitly zero-fill it before using. This
|
||
malloc relies on the property that malloc_state is initialized to
|
||
all zeroes (as is true of C statics).
|
||
|
||
*/
|
||
|
||
static struct malloc_state av_; /* never directly referenced */
|
||
|
||
/*
|
||
All uses of av_ are via get_malloc_state().
|
||
This simplifies construction of multithreaded, etc extensions.
|
||
|
||
At most one call to get_malloc_state is made per invocation of
|
||
the public versions of malloc, free, and all other routines
|
||
except realloc, valloc, and vpalloc. Also, it is called
|
||
in check* routines if DEBUG is set.
|
||
*/
|
||
|
||
#define get_malloc_state() (&(av_))
|
||
|
||
/*
|
||
Initialize a malloc_state struct.
|
||
|
||
This is called only from within malloc_consolidate, which needs
|
||
be called in the same contexts anyway. It is never called directly
|
||
outside of malloc_consolidate because some optimizing compilers try
|
||
to inline it at all call points, which turns out not to be an
|
||
optimization at all. (Inlining it only in malloc_consolidate is fine though.)
|
||
*/
|
||
|
||
#if __STD_C
|
||
static void malloc_init_state(mstate av)
|
||
#else
|
||
static void malloc_init_state(av) mstate av;
|
||
#endif
|
||
{
|
||
int i;
|
||
mbinptr bin;
|
||
|
||
|
||
/* Uncomment this if you are not using a static av */
|
||
/* MALLOC_ZERO(av, sizeof(struct malloc_state); */
|
||
|
||
/* Establish circular links for normal bins */
|
||
for (i = 1; i < NBINS; ++i) {
|
||
bin = bin_at(av,i);
|
||
bin->fd = bin->bk = bin;
|
||
}
|
||
|
||
av->max_fast = req2max_fast(DEFAULT_MXFAST);
|
||
|
||
av->top_pad = DEFAULT_TOP_PAD;
|
||
av->n_mmaps_max = DEFAULT_MMAP_MAX;
|
||
av->mmap_threshold = DEFAULT_MMAP_THRESHOLD;
|
||
|
||
#if MORECORE_CONTIGUOUS
|
||
av->trim_threshold = DEFAULT_TRIM_THRESHOLD;
|
||
av->sbrk_base = (char*)MORECORE_FAILURE;
|
||
#else
|
||
av->trim_threshold = (unsigned long)(-1);
|
||
av->sbrk_base = NONCONTIGUOUS_REGIONS;
|
||
#endif
|
||
|
||
av->top = initial_top(av);
|
||
av->pagesize = malloc_getpagesize;
|
||
}
|
||
|
||
/*
|
||
Other internal utilities operating on mstates
|
||
*/
|
||
|
||
#if __STD_C
|
||
static Void_t* sYSMALLOc(INTERNAL_SIZE_T, mstate);
|
||
static int sYSTRIm(size_t, mstate);
|
||
static void malloc_consolidate(mstate);
|
||
#else
|
||
static Void_t* sYSMALLOc();
|
||
static int sYSTRIm();
|
||
static void malloc_consolidate();
|
||
#endif
|
||
|
||
|
||
/*
|
||
Debugging support
|
||
|
||
These routines make a number of assertions about the states
|
||
of data structures that should be true at all times. If any
|
||
are not true, it's very likely that a user program has somehow
|
||
trashed memory. (It's also possible that there is a coding error
|
||
in malloc. In which case, please report it!)
|
||
|
||
*/
|
||
|
||
#if ! DEBUG
|
||
|
||
#define check_chunk(P)
|
||
#define check_free_chunk(P)
|
||
#define check_inuse_chunk(P)
|
||
#define check_remalloced_chunk(P,N)
|
||
#define check_malloced_chunk(P,N)
|
||
#define check_malloc_state()
|
||
|
||
#else
|
||
#define check_chunk(P) do_check_chunk(P)
|
||
#define check_free_chunk(P) do_check_free_chunk(P)
|
||
#define check_inuse_chunk(P) do_check_inuse_chunk(P)
|
||
#define check_remalloced_chunk(P,N) do_check_remalloced_chunk(P,N)
|
||
#define check_malloced_chunk(P,N) do_check_malloced_chunk(P,N)
|
||
#define check_malloc_state() do_check_malloc_state()
|
||
|
||
|
||
/*
|
||
Properties of all chunks
|
||
*/
|
||
|
||
#if __STD_C
|
||
static void do_check_chunk(mchunkptr p)
|
||
#else
|
||
static void do_check_chunk(p) mchunkptr p;
|
||
#endif
|
||
{
|
||
|
||
mstate av = get_malloc_state();
|
||
unsigned long sz = chunksize(p);
|
||
|
||
if (!chunk_is_mmapped(p)) {
|
||
|
||
/* Has legal address ... */
|
||
if (av->sbrk_base != NONCONTIGUOUS_REGIONS) {
|
||
assert(((char*)p) >= ((char*)(av->sbrk_base)));
|
||
}
|
||
|
||
if (p != av->top) {
|
||
if (av->sbrk_base != NONCONTIGUOUS_REGIONS) {
|
||
assert(((char*)p + sz) <= ((char*)(av->top)));
|
||
}
|
||
}
|
||
else {
|
||
if (av->sbrk_base != NONCONTIGUOUS_REGIONS) {
|
||
assert(((char*)p + sz) <= ((char*)(av->sbrk_base) + av->sbrked_mem));
|
||
}
|
||
/* top size is always at least MINSIZE */
|
||
assert((long)(sz) >= (long)(MINSIZE));
|
||
/* top predecessor always marked inuse */
|
||
assert(prev_inuse(p));
|
||
}
|
||
|
||
}
|
||
else {
|
||
#if HAVE_MMAP
|
||
/* address is outside main heap */
|
||
/* unless mmap has been used as sbrk backup */
|
||
if (av->sbrk_base != NONCONTIGUOUS_REGIONS) {
|
||
assert(! (((char*)p) >= ((char*)av->sbrk_base) &&
|
||
((char*)p) < ((char*)(av->sbrk_base) + av->sbrked_mem)));
|
||
}
|
||
/* chunk is page-aligned */
|
||
assert(((p->prev_size + sz) & (av->pagesize-1)) == 0);
|
||
/* mem is aligned */
|
||
assert(aligned_OK(chunk2mem(p)));
|
||
#else
|
||
/* force an appropriate assert violation if debug set */
|
||
assert(!chunk_is_mmapped(p));
|
||
#endif
|
||
}
|
||
|
||
}
|
||
|
||
/*
|
||
Properties of free chunks
|
||
*/
|
||
|
||
|
||
#if __STD_C
|
||
static void do_check_free_chunk(mchunkptr p)
|
||
#else
|
||
static void do_check_free_chunk(p) mchunkptr p;
|
||
#endif
|
||
{
|
||
mstate av = get_malloc_state();
|
||
|
||
INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE;
|
||
mchunkptr next = chunk_at_offset(p, sz);
|
||
|
||
do_check_chunk(p);
|
||
|
||
/* Chunk must claim to be free ... */
|
||
assert(!inuse(p));
|
||
assert (!chunk_is_mmapped(p));
|
||
|
||
/* Unless a special marker, must have OK fields */
|
||
if ((unsigned long)sz >= (unsigned long)MINSIZE)
|
||
{
|
||
assert((sz & MALLOC_ALIGN_MASK) == 0);
|
||
assert(aligned_OK(chunk2mem(p)));
|
||
/* ... matching footer field */
|
||
assert(next->prev_size == sz);
|
||
/* ... and is fully consolidated */
|
||
assert(prev_inuse(p));
|
||
assert (next == av->top || inuse(next));
|
||
|
||
/* ... and has minimally sane links */
|
||
assert(p->fd->bk == p);
|
||
assert(p->bk->fd == p);
|
||
}
|
||
else /* markers are always of size SIZE_SZ */
|
||
assert(sz == SIZE_SZ);
|
||
}
|
||
|
||
/*
|
||
Properties of inuse chunks
|
||
*/
|
||
|
||
|
||
#if __STD_C
|
||
static void do_check_inuse_chunk(mchunkptr p)
|
||
#else
|
||
static void do_check_inuse_chunk(p) mchunkptr p;
|
||
#endif
|
||
{
|
||
mstate av = get_malloc_state();
|
||
mchunkptr next;
|
||
do_check_chunk(p);
|
||
|
||
if (chunk_is_mmapped(p))
|
||
return; /* mmapped chunks have no next/prev */
|
||
|
||
/* Check whether it claims to be in use ... */
|
||
assert(inuse(p));
|
||
|
||
next = next_chunk(p);
|
||
|
||
/* ... and is surrounded by OK chunks.
|
||
Since more things can be checked with free chunks than inuse ones,
|
||
if an inuse chunk borders them and debug is on, it's worth doing them.
|
||
*/
|
||
if (!prev_inuse(p)) {
|
||
/* Note that we cannot even look at prev unless it is not inuse */
|
||
mchunkptr prv = prev_chunk(p);
|
||
assert(next_chunk(prv) == p);
|
||
do_check_free_chunk(prv);
|
||
}
|
||
|
||
if (next == av->top) {
|
||
assert(prev_inuse(next));
|
||
assert(chunksize(next) >= MINSIZE);
|
||
}
|
||
else if (!inuse(next))
|
||
do_check_free_chunk(next);
|
||
|
||
}
|
||
|
||
/*
|
||
Properties of chunks recycled from fastbins
|
||
*/
|
||
|
||
#if __STD_C
|
||
static void do_check_remalloced_chunk(mchunkptr p, INTERNAL_SIZE_T s)
|
||
#else
|
||
static void do_check_remalloced_chunk(p, s) mchunkptr p; INTERNAL_SIZE_T s;
|
||
#endif
|
||
{
|
||
|
||
INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE;
|
||
|
||
do_check_inuse_chunk(p);
|
||
|
||
/* Legal size ... */
|
||
assert((sz & MALLOC_ALIGN_MASK) == 0);
|
||
assert((long)sz - (long)MINSIZE >= 0);
|
||
assert((long)sz - (long)s >= 0);
|
||
assert((long)sz - (long)(s + MINSIZE) < 0);
|
||
|
||
/* ... and alignment */
|
||
assert(aligned_OK(chunk2mem(p)));
|
||
|
||
}
|
||
|
||
/*
|
||
Properties of nonrecycled chunks at the point they are malloced
|
||
*/
|
||
|
||
#if __STD_C
|
||
static void do_check_malloced_chunk(mchunkptr p, INTERNAL_SIZE_T s)
|
||
#else
|
||
static void do_check_malloced_chunk(p, s) mchunkptr p; INTERNAL_SIZE_T s;
|
||
#endif
|
||
{
|
||
/* same as recycled case ... */
|
||
do_check_remalloced_chunk(p, s);
|
||
|
||
/*
|
||
... plus, must obey implementation invariant that prev_inuse is
|
||
always true of any allocated chunk; i.e., that each allocated
|
||
chunk borders either a previously allocated and still in-use
|
||
chunk, or the base of its memory arena. This is ensured
|
||
by making all allocations from the the `lowest' part of any found
|
||
chunk. This does not necessarily hold however for chunks
|
||
recycled via fastbins.
|
||
*/
|
||
|
||
assert(prev_inuse(p));
|
||
}
|
||
|
||
|
||
/*
|
||
Properties of malloc_state.
|
||
|
||
This may be useful for debugging malloc, as well as detecting user
|
||
programmer errors that somehow write into malloc_state.
|
||
*/
|
||
|
||
static void do_check_malloc_state()
|
||
{
|
||
mstate av = get_malloc_state();
|
||
int i;
|
||
mchunkptr p;
|
||
mchunkptr q;
|
||
mbinptr b;
|
||
unsigned int biton;
|
||
int empty;
|
||
unsigned int idx;
|
||
INTERNAL_SIZE_T size;
|
||
unsigned long total = 0;
|
||
int max_fast_bin;
|
||
|
||
|
||
/* internal size_t must be no wider than pointer type */
|
||
assert(sizeof(INTERNAL_SIZE_T) <= sizeof(char*));
|
||
|
||
/* alignment is a power of 2 */
|
||
assert((MALLOC_ALIGNMENT & (MALLOC_ALIGNMENT-1)) == 0);
|
||
|
||
/* cannot run remaining checks until fully initialized */
|
||
if (av->top == 0 || av->top == initial_top(av))
|
||
return;
|
||
|
||
/* pagesize is a power of 2 */
|
||
assert((av->pagesize & (av->pagesize-1)) == 0);
|
||
|
||
/* properties of fastbins */
|
||
|
||
/* max_fast is in allowed range */
|
||
|
||
assert((av->max_fast & ~1) <= request2size(MAX_FAST_SIZE));
|
||
|
||
max_fast_bin = fastbin_index(av->max_fast);
|
||
|
||
for (i = 0; i < NFASTBINS; ++i) {
|
||
p = av->fastbins[i];
|
||
|
||
/* all bins past max_fast are empty */
|
||
if (i > max_fast_bin)
|
||
assert(p == 0);
|
||
|
||
while (p != 0) {
|
||
/* each chunk claims to be inuse */
|
||
do_check_inuse_chunk(p);
|
||
total += chunksize(p);
|
||
/* chunk belongs in this bin */
|
||
assert(fastbin_index(chunksize(p)) == i);
|
||
p = p->fd;
|
||
}
|
||
}
|
||
|
||
if (total != 0)
|
||
assert(have_fastchunks(av));
|
||
|
||
/* check normal bins */
|
||
for (i = 1; i < NBINS; ++i) {
|
||
b = bin_at(av,i);
|
||
|
||
/* binmap is accurate (except for bin 1 == unsorted_chunks) */
|
||
if (i >= 2) {
|
||
biton = get_binmap(av,i);
|
||
empty = last(b) == b;
|
||
if (!biton)
|
||
assert(empty);
|
||
else if (!empty)
|
||
assert(biton);
|
||
}
|
||
|
||
for (p = last(b); p != b; p = p->bk) {
|
||
/* each chunk claims to be free */
|
||
do_check_free_chunk(p);
|
||
size = chunksize(p);
|
||
total += size;
|
||
if (i >= 2) {
|
||
/* chunk belongs in bin */
|
||
idx = bin_index(size);
|
||
assert(idx == i);
|
||
/* lists are sorted */
|
||
assert(p->bk == b || chunksize(p->bk) >= chunksize(p));
|
||
}
|
||
/* chunk is followed by a legal chain of inuse chunks */
|
||
for (q = next_chunk(p);
|
||
q != av->top && inuse(q) && (long)(chunksize(q)) >= (long)MINSIZE;
|
||
q = next_chunk(q))
|
||
do_check_inuse_chunk(q);
|
||
|
||
}
|
||
}
|
||
|
||
/* top chunk is OK */
|
||
check_chunk(av->top);
|
||
|
||
/* sanity checks for statistics */
|
||
|
||
assert(total <= (unsigned long)(av->max_total_mem));
|
||
assert(av->n_mmaps >= 0);
|
||
assert(av->n_mmaps <= av->n_mmaps_max);
|
||
assert(av->n_mmaps <= av->max_n_mmaps);
|
||
assert(av->max_n_mmaps <= av->n_mmaps_max);
|
||
|
||
assert((unsigned long)(av->sbrked_mem) <=
|
||
(unsigned long)(av->max_sbrked_mem));
|
||
|
||
assert((unsigned long)(av->mmapped_mem) <=
|
||
(unsigned long)(av->max_mmapped_mem));
|
||
|
||
assert((unsigned long)(av->max_total_mem) >=
|
||
(unsigned long)(av->mmapped_mem) + (unsigned long)(av->sbrked_mem));
|
||
|
||
}
|
||
|
||
|
||
#endif
|
||
|
||
|
||
|
||
|
||
|
||
/* ----------- Routines dealing with system allocation -------------- */
|
||
|
||
/*
|
||
Handle malloc cases requiring more memory from system.
|
||
malloc relays to sYSMALLOc if it cannot allocate out of
|
||
existing memory.
|
||
|
||
On entry, it is assumed that av->top does not have enough
|
||
space to service request for nb bytes, thus requiring more meory
|
||
from system.
|
||
*/
|
||
|
||
#if __STD_C
|
||
static Void_t* sYSMALLOc(INTERNAL_SIZE_T nb, mstate av)
|
||
#else
|
||
static Void_t* sYSMALLOc(nb, av) INTERNAL_SIZE_T nb; mstate av;
|
||
#endif
|
||
{
|
||
mchunkptr old_top; /* incoming value of av->top */
|
||
INTERNAL_SIZE_T old_size; /* its size */
|
||
char* old_end; /* its end address */
|
||
|
||
long size; /* arg to first MORECORE or mmap call */
|
||
char* brk; /* return value from MORECORE */
|
||
char* mm; /* return value from mmap call*/
|
||
|
||
long correction; /* arg to 2nd MORECORE call */
|
||
char* snd_brk; /* 2nd return val */
|
||
|
||
INTERNAL_SIZE_T front_misalign; /* unusable bytes at front of new space */
|
||
INTERNAL_SIZE_T end_misalign; /* partial page left at end of new space */
|
||
char* aligned_brk; /* aligned offset into brk */
|
||
|
||
mchunkptr p; /* the allocated/returned chunk */
|
||
mchunkptr remainder; /* remainder from allocation */
|
||
long remainder_size; /* its size */
|
||
|
||
unsigned long sum; /* for updating stats */
|
||
|
||
size_t pagemask = av->pagesize - 1;
|
||
|
||
/*
|
||
If have mmap, and the request size meets the mmap threshold, and
|
||
the system supports mmap, and there are few enough currently
|
||
allocated mmapped regions, and a call to mmap succeeds, try to
|
||
directly map this request rather than expanding top.
|
||
*/
|
||
|
||
#if HAVE_MMAP
|
||
if ((unsigned long)nb >= (unsigned long)(av->mmap_threshold) &&
|
||
(av->n_mmaps < av->n_mmaps_max)) {
|
||
|
||
/*
|
||
Round up size to nearest page. For mmapped chunks, the overhead
|
||
is one SIZE_SZ unit larger than for normal chunks, because there
|
||
is no following chunk whose prev_size field could be used.
|
||
*/
|
||
size = (nb + SIZE_SZ + MALLOC_ALIGN_MASK + pagemask) & ~pagemask;
|
||
|
||
mm = (char*)(MMAP(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE));
|
||
|
||
if (mm != (char*)(MORECORE_FAILURE)) {
|
||
|
||
/*
|
||
The offset to the start of the mmapped region is stored
|
||
in the prev_size field of the chunk. This allows us to adjust
|
||
returned start address to meet alignment requirements here
|
||
and in memalign(), and still be able to compute proper
|
||
address argument for later munmap in free() and realloc().
|
||
*/
|
||
|
||
front_misalign = (INTERNAL_SIZE_T)chunk2mem(mm) & MALLOC_ALIGN_MASK;
|
||
if (front_misalign > 0) {
|
||
correction = MALLOC_ALIGNMENT - front_misalign;
|
||
p = (mchunkptr)(mm + correction);
|
||
p->prev_size = correction;
|
||
set_head(p, (size - correction) |IS_MMAPPED);
|
||
}
|
||
else {
|
||
p = (mchunkptr)mm;
|
||
set_head(p, size|IS_MMAPPED);
|
||
}
|
||
|
||
check_chunk(p);
|
||
|
||
/* update statistics */
|
||
|
||
if (++av->n_mmaps > av->max_n_mmaps)
|
||
av->max_n_mmaps = av->n_mmaps;
|
||
|
||
sum = av->mmapped_mem += size;
|
||
if (sum > (unsigned long)(av->max_mmapped_mem))
|
||
av->max_mmapped_mem = sum;
|
||
sum += av->sbrked_mem;
|
||
if (sum > (unsigned long)(av->max_total_mem))
|
||
av->max_total_mem = sum;
|
||
|
||
return chunk2mem(p);
|
||
}
|
||
}
|
||
#endif
|
||
|
||
/* record incoming configuration of top */
|
||
|
||
old_top = av->top;
|
||
old_size = chunksize(old_top);
|
||
old_end = (char*)(chunk_at_offset(old_top, old_size));
|
||
|
||
brk = snd_brk = (char*)(MORECORE_FAILURE);
|
||
|
||
/*
|
||
If not the first time through, we require old_size to be
|
||
at least MINSIZE and to have prev_inuse set.
|
||
*/
|
||
|
||
assert(old_top == initial_top(av) ||
|
||
((unsigned long) (old_size) >= (unsigned long)(MINSIZE) &&
|
||
prev_inuse(old_top)));
|
||
|
||
|
||
/* Request enough space for nb + pad + overhead */
|
||
|
||
size = nb + av->top_pad + MINSIZE;
|
||
|
||
/*
|
||
If contiguous, we can subtract out existing space that we hope to
|
||
combine with new space. We add it back later only if
|
||
we don't actually get contiguous space.
|
||
*/
|
||
|
||
if (av->sbrk_base != NONCONTIGUOUS_REGIONS)
|
||
size -= old_size;
|
||
|
||
/*
|
||
Round to a multiple of page size.
|
||
If MORECORE is not contiguous, this ensures that we only call it
|
||
with whole-page arguments. And if MORECORE is contiguous and
|
||
this is not first time through, this preserves page-alignment of
|
||
previous calls. Otherwise, we re-correct anyway to page-align below.
|
||
*/
|
||
|
||
size = (size + pagemask) & ~pagemask;
|
||
|
||
/*
|
||
Don't try to call MORECORE if argument is so big as to appear
|
||
negative. Note that since mmap takes size_t arg, it may succeed
|
||
below even if we cannot call MORECORE.
|
||
*/
|
||
|
||
if (size > 0)
|
||
brk = (char*)(MORECORE(size));
|
||
|
||
/*
|
||
If have mmap, try using it as a backup when MORECORE fails. This
|
||
is worth doing on systems that have "holes" in address space, so
|
||
sbrk cannot extend to give contiguous space, but space is available
|
||
elsewhere. Note that we ignore mmap max count and threshold limits,
|
||
since there is no reason to artificially limit use here.
|
||
*/
|
||
|
||
#if HAVE_MMAP
|
||
if (brk == (char*)(MORECORE_FAILURE)) {
|
||
|
||
/* Cannot merge with old top, so add its size back in */
|
||
|
||
if (av->sbrk_base != NONCONTIGUOUS_REGIONS)
|
||
size = (size + old_size + pagemask) & ~pagemask;
|
||
|
||
/* If we are relying on mmap as backup, then use larger units */
|
||
|
||
if ((unsigned long)size < (unsigned long)MMAP_AS_MORECORE_SIZE)
|
||
size = MMAP_AS_MORECORE_SIZE;
|
||
|
||
brk = (char*)(MMAP(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE));
|
||
|
||
if (brk != (char*)(MORECORE_FAILURE)) {
|
||
|
||
/* We do not need, and cannot use, another sbrk call to find end */
|
||
snd_brk = brk + size;
|
||
|
||
/*
|
||
Record that we no longer have a contiguous sbrk region.
|
||
After the first time mmap is used as backup, we cannot
|
||
ever rely on contiguous space.
|
||
*/
|
||
av->sbrk_base = NONCONTIGUOUS_REGIONS;
|
||
}
|
||
}
|
||
#endif
|
||
|
||
if (brk != (char*)(MORECORE_FAILURE)) {
|
||
|
||
av->sbrked_mem += size;
|
||
|
||
/*
|
||
If MORECORE extends previous space, we can likewise extend top size.
|
||
*/
|
||
|
||
if (brk == old_end && snd_brk == (char*)(MORECORE_FAILURE)) {
|
||
set_head(old_top, (size + old_size) | PREV_INUSE);
|
||
}
|
||
|
||
/*
|
||
Otherwise, make adjustments guided by the special values of
|
||
av->sbrk_base (MORECORE_FAILURE or NONCONTIGUOUS_REGIONS):
|
||
|
||
* If the first time through or noncontiguous, we need to call sbrk
|
||
just to find out where the end of memory lies.
|
||
|
||
* We need to ensure that all returned chunks from malloc will meet
|
||
MALLOC_ALIGNMENT
|
||
|
||
* If there was an intervening foreign sbrk, we need to adjust sbrk
|
||
request size to account for fact that we will not be able to
|
||
combine new space with existing space in old_top.
|
||
|
||
* Almost all systems internally allocate whole pages at a time, in
|
||
which case we might as well use the whole last page of request.
|
||
So we allocate enough more memory to hit a page boundary now,
|
||
which in turn causes future contiguous calls to page-align.
|
||
|
||
*/
|
||
|
||
else {
|
||
front_misalign = 0;
|
||
end_misalign = 0;
|
||
correction = 0;
|
||
aligned_brk = brk;
|
||
|
||
/* handle contiguous cases */
|
||
if (av->sbrk_base != NONCONTIGUOUS_REGIONS) {
|
||
|
||
/* Guarantee alignment of first new chunk made from this space */
|
||
|
||
front_misalign = (INTERNAL_SIZE_T)chunk2mem(brk) & MALLOC_ALIGN_MASK;
|
||
if (front_misalign > 0) {
|
||
|
||
/*
|
||
Skip over some bytes to arrive at an aligned position.
|
||
We don't need to specially mark these wasted front bytes.
|
||
They will never be accessed anyway because
|
||
prev_inuse of av->top (and any chunk created from its start)
|
||
is always true after initialization.
|
||
*/
|
||
|
||
correction = MALLOC_ALIGNMENT - front_misalign;
|
||
aligned_brk += correction;
|
||
}
|
||
|
||
/*
|
||
If this isn't adjacent to a previous sbrk, then we will not
|
||
be able to merge with old_top space, so must add to 2nd request.
|
||
*/
|
||
|
||
correction += old_size;
|
||
|
||
/* Pad out to hit a page boundary */
|
||
|
||
end_misalign = (INTERNAL_SIZE_T)(brk + size + correction);
|
||
correction += ((end_misalign + pagemask) & ~pagemask) - end_misalign;
|
||
|
||
assert(correction >= 0);
|
||
|
||
snd_brk = (char*)(MORECORE(correction));
|
||
|
||
/*
|
||
If can't allocate correction, try to at least find out current
|
||
brk. It might be enough to proceed without failing.
|
||
|
||
Note that if second sbrk did NOT fail, we assume that space
|
||
is contiguous with first sbrk. This is a safe assumption unless
|
||
program is multithreaded but doesn't use locks and a foreign sbrk
|
||
occurred between our first and second calls.
|
||
*/
|
||
|
||
if (snd_brk == (char*)(MORECORE_FAILURE)) {
|
||
correction = 0;
|
||
snd_brk = (char*)(MORECORE(0));
|
||
}
|
||
}
|
||
|
||
/* handle non-contiguous cases */
|
||
else {
|
||
|
||
/* MORECORE/mmap must correctly align etc */
|
||
assert(((unsigned long)chunk2mem(brk) & MALLOC_ALIGN_MASK) == 0);
|
||
|
||
/* Find out current end of memory */
|
||
if (snd_brk == (char*)(MORECORE_FAILURE)) {
|
||
snd_brk = (char*)(MORECORE(0));
|
||
}
|
||
|
||
/* This must lie on a page boundary */
|
||
if (snd_brk != (char*)(MORECORE_FAILURE)) {
|
||
assert(((INTERNAL_SIZE_T)(snd_brk) & pagemask) == 0);
|
||
}
|
||
}
|
||
|
||
/* Adjust top based on results of second sbrk */
|
||
if (snd_brk != (char*)(MORECORE_FAILURE)) {
|
||
|
||
av->top = (mchunkptr)aligned_brk;
|
||
set_head(av->top, (snd_brk - aligned_brk + correction) | PREV_INUSE);
|
||
|
||
av->sbrked_mem += correction;
|
||
|
||
/* If first time through and contiguous, record base */
|
||
if (old_top == initial_top(av)) {
|
||
if (av->sbrk_base == (char*)(MORECORE_FAILURE))
|
||
av->sbrk_base = brk;
|
||
}
|
||
|
||
/*
|
||
Otherwise, we either have a gap due to foreign sbrk or a
|
||
non-contiguous region. Insert a double fencepost at old_top
|
||
to prevent consolidation with space we don't own. These
|
||
fenceposts are artificial chunks that are marked as inuse
|
||
and are in any case too small to use. We need two to make
|
||
sizes and alignments work out.
|
||
*/
|
||
|
||
else {
|
||
|
||
/*
|
||
Shrink old_top to insert fenceposts, keeping size a
|
||
multiple of MALLOC_ALIGNMENT.
|
||
*/
|
||
old_size = (old_size - 3*SIZE_SZ) & ~MALLOC_ALIGN_MASK;
|
||
set_head(old_top, old_size | PREV_INUSE);
|
||
|
||
/*
|
||
Note that the following assignments overwrite old_top when
|
||
old_size was previously MINSIZE. This is intentional. We
|
||
need the fencepost, even if old_top otherwise gets lost.
|
||
*/
|
||
chunk_at_offset(old_top, old_size )->size =
|
||
SIZE_SZ|PREV_INUSE;
|
||
|
||
chunk_at_offset(old_top, old_size + SIZE_SZ)->size =
|
||
SIZE_SZ|PREV_INUSE;
|
||
|
||
/* If possible, release the rest. */
|
||
if (old_size >= MINSIZE)
|
||
fREe(chunk2mem(old_top));
|
||
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Update statistics */
|
||
|
||
sum = av->sbrked_mem;
|
||
if (sum > (unsigned long)(av->max_sbrked_mem))
|
||
av->max_sbrked_mem = sum;
|
||
|
||
sum += av->mmapped_mem;
|
||
if (sum > (unsigned long)(av->max_total_mem))
|
||
av->max_total_mem = sum;
|
||
|
||
check_malloc_state();
|
||
|
||
/* finally, do the allocation */
|
||
|
||
p = av->top;
|
||
size = chunksize(p);
|
||
remainder_size = (long)size - (long)nb;
|
||
|
||
/* check that one of the above allocation paths succeeded */
|
||
if (remainder_size >= (long)MINSIZE) {
|
||
remainder = chunk_at_offset(p, nb);
|
||
av->top = remainder;
|
||
set_head(p, nb | PREV_INUSE);
|
||
set_head(remainder, remainder_size | PREV_INUSE);
|
||
|
||
check_malloced_chunk(p, nb);
|
||
return chunk2mem(p);
|
||
}
|
||
}
|
||
|
||
/* catch all failure paths */
|
||
MALLOC_FAILURE_ACTION;
|
||
return 0;
|
||
}
|
||
|
||
|
||
/*
|
||
sYSTRIm is an inverse of sorts to sYSMALLOc.
|
||
It gives memory back to the system (via negative
|
||
arguments to sbrk) if there is unused memory at the `high' end of
|
||
the malloc pool. It is called automatically by free()
|
||
when top space exceeds the trim threshold.
|
||
returns 1 if it actually released any memory, else 0.
|
||
*/
|
||
|
||
#if __STD_C
|
||
static int sYSTRIm(size_t pad, mstate av)
|
||
#else
|
||
static int sYSTRIm(pad, av) size_t pad; mstate av;
|
||
#endif
|
||
{
|
||
long top_size; /* Amount of top-most memory */
|
||
long extra; /* Amount to release */
|
||
long released; /* Amount actually released */
|
||
char* current_brk; /* address returned by pre-check sbrk call */
|
||
char* new_brk; /* address returned by post-check sbrk call */
|
||
size_t pagesz;
|
||
|
||
/* Don't bother trying if sbrk doesn't provide contiguous regions */
|
||
if (av->sbrk_base != NONCONTIGUOUS_REGIONS) {
|
||
|
||
pagesz = av->pagesize;
|
||
top_size = chunksize(av->top);
|
||
|
||
/* Release in pagesize units, keeping at least one page */
|
||
extra = ((top_size - pad - MINSIZE + (pagesz-1)) / pagesz - 1) * pagesz;
|
||
|
||
if (extra > 0) {
|
||
|
||
/*
|
||
Only proceed if end of memory is where we last set it.
|
||
This avoids problems if there were foreign sbrk calls.
|
||
*/
|
||
current_brk = (char*)(MORECORE(0));
|
||
if (current_brk == (char*)(av->top) + top_size) {
|
||
|
||
/*
|
||
Attempt to release memory. We ignore return value,
|
||
and instead call again to find out where new end of memory is.
|
||
This avoids problems if first call releases less than we asked,
|
||
of if failure somehow altered brk value. (We could still
|
||
encounter problems if it altered brk in some very bad way,
|
||
but the only thing we can do is adjust anyway, which will cause
|
||
some downstream failure.)
|
||
*/
|
||
|
||
MORECORE(-extra);
|
||
new_brk = (char*)(MORECORE(0));
|
||
|
||
if (new_brk != (char*)MORECORE_FAILURE) {
|
||
released = (long)(current_brk - new_brk);
|
||
|
||
if (released != 0) {
|
||
/* Success. Adjust top. */
|
||
av->sbrked_mem -= released;
|
||
set_head(av->top, (top_size - released) | PREV_INUSE);
|
||
check_malloc_state();
|
||
return 1;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* ----------------------- Main public routines ----------------------- */
|
||
|
||
|
||
/*
|
||
Malloc routine. See running comments for algorithm description.
|
||
*/
|
||
|
||
#if __STD_C
|
||
Void_t* mALLOc(size_t bytes)
|
||
#else
|
||
Void_t* mALLOc(bytes) size_t bytes;
|
||
#endif
|
||
{
|
||
mstate av = get_malloc_state();
|
||
|
||
INTERNAL_SIZE_T nb; /* normalized request size */
|
||
unsigned int idx; /* associated bin index */
|
||
mbinptr bin; /* associated bin */
|
||
mfastbinptr* fb; /* associated fastbin */
|
||
|
||
mchunkptr victim; /* inspected/selected chunk */
|
||
INTERNAL_SIZE_T size; /* its size */
|
||
int victim_index; /* its bin index */
|
||
|
||
mchunkptr remainder; /* remainder from a split */
|
||
long remainder_size; /* its size */
|
||
|
||
unsigned int block; /* bit map traverser */
|
||
unsigned int bit; /* bit map traverser */
|
||
unsigned int map; /* current word of binmap */
|
||
|
||
mchunkptr fwd; /* misc temp for linking */
|
||
mchunkptr bck; /* misc temp for linking */
|
||
|
||
|
||
/*
|
||
Check request for legality and convert to internal form, nb.
|
||
This rejects negative arguments when size_t is treated as
|
||
signed. It also rejects arguments that are so large that the size
|
||
appears negative when aligned and padded. The converted form
|
||
adds SIZE_T bytes overhead plus possibly more to obtain necessary
|
||
alignment and/or to obtain a size of at least MINSIZE, the
|
||
smallest allocatable size.
|
||
*/
|
||
|
||
checked_request2size(bytes, nb);
|
||
|
||
/*
|
||
If the size qualifies as a fastbin, first check corresponding bin.
|
||
This code is safe to execute even if av not yet initialized, so we
|
||
can try it first, which saves some time on this fast path.
|
||
*/
|
||
|
||
if (nb <= av->max_fast) {
|
||
fb = &(av->fastbins[(fastbin_index(nb))]);
|
||
if ( (victim = *fb) != 0) {
|
||
*fb = victim->fd;
|
||
check_remalloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
}
|
||
}
|
||
|
||
/*
|
||
If a small request, check regular bin. Since these "smallbins"
|
||
hold one size each, no searching within bins is necessary.
|
||
|
||
(If a large request, we need to wait until unsorted chunks are
|
||
processed to find best fit. But for small ones, fits are exact
|
||
anyway, so we can check now, which is faster.)
|
||
*/
|
||
|
||
if (in_smallbin_range(nb)) {
|
||
idx = smallbin_index(nb);
|
||
bin = bin_at(av,idx);
|
||
|
||
if ( (victim = last(bin)) != bin) {
|
||
if (victim == 0) /* initialization check */
|
||
malloc_consolidate(av);
|
||
else {
|
||
bck = victim->bk;
|
||
set_inuse_bit_at_offset(victim, nb);
|
||
bin->bk = bck;
|
||
bck->fd = bin;
|
||
|
||
check_malloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
}
|
||
}
|
||
}
|
||
|
||
/*
|
||
If a large request, consolidate fastbins before continuing.
|
||
While it might look excessive to kill all fastbins before
|
||
even seeing if there is space available, this avoids
|
||
fragmentation problems normally associated with fastbins.
|
||
Also, in practice, programs tend to have runs of either small or
|
||
large requests, but less often mixtures, so consolidation is not
|
||
usually invoked all that often.
|
||
*/
|
||
|
||
else {
|
||
idx = largebin_index(nb);
|
||
if (have_fastchunks(av)) /* consolidation/initialization check */
|
||
malloc_consolidate(av);
|
||
}
|
||
|
||
|
||
/*
|
||
Process recently freed or remaindered chunks, taking one only if
|
||
it is exact fit, or, if a small request, it is the remainder from
|
||
the most recent non-exact fit. Place other traversed chunks in
|
||
bins. Note that this step is the only place in any routine where
|
||
chunks are placed in bins.
|
||
|
||
The outer loop here is needed because we might not realize until
|
||
near the end of malloc that we should have consolidated, so must
|
||
do so and retry. This happens at most once, and only when we would
|
||
otherwise need to expand memory to service a "small" request.
|
||
*/
|
||
|
||
|
||
for(;;) {
|
||
|
||
while ( (victim = unsorted_chunks(av)->bk) != unsorted_chunks(av)) {
|
||
bck = victim->bk;
|
||
size = chunksize(victim);
|
||
|
||
/*
|
||
If a small request, try to use last remainder if it is the
|
||
only chunk in unsorted bin. This helps promote locality for
|
||
runs of consecutive small requests. This is the only
|
||
exception to best-fit.
|
||
*/
|
||
|
||
if (in_smallbin_range(nb) &&
|
||
victim == av->last_remainder &&
|
||
bck == unsorted_chunks(av) &&
|
||
(remainder_size = (long)size - (long)nb) >= (long)MINSIZE) {
|
||
|
||
/* split and reattach remainder */
|
||
remainder = chunk_at_offset(victim, nb);
|
||
unsorted_chunks(av)->bk = unsorted_chunks(av)->fd = remainder;
|
||
av->last_remainder = remainder;
|
||
remainder->bk = remainder->fd = unsorted_chunks(av);
|
||
|
||
set_head(victim, nb | PREV_INUSE);
|
||
set_head(remainder, remainder_size | PREV_INUSE);
|
||
set_foot(remainder, remainder_size);
|
||
|
||
check_malloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
}
|
||
|
||
/* remove from unsorted list */
|
||
unsorted_chunks(av)->bk = bck;
|
||
bck->fd = unsorted_chunks(av);
|
||
|
||
/* Take now instead of binning if exact fit */
|
||
|
||
if (size == nb) {
|
||
set_inuse_bit_at_offset(victim, size);
|
||
check_malloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
}
|
||
|
||
/* place chunk in bin */
|
||
|
||
if (in_smallbin_range(size)) {
|
||
victim_index = smallbin_index(size);
|
||
bck = bin_at(av, victim_index);
|
||
fwd = bck->fd;
|
||
}
|
||
else {
|
||
victim_index = largebin_index(size);
|
||
bck = bin_at(av, victim_index);
|
||
fwd = bck->fd;
|
||
|
||
/* maintain large bins in sorted order */
|
||
if (fwd != bck) {
|
||
/* if smaller than smallest, bypass loop below */
|
||
if ((unsigned long)size <=
|
||
(unsigned long)(chunksize(bck->bk))) {
|
||
fwd = bck;
|
||
bck = bck->bk;
|
||
}
|
||
else {
|
||
while (fwd != bck &&
|
||
(unsigned long)size < (unsigned long)(chunksize(fwd))) {
|
||
fwd = fwd->fd;
|
||
}
|
||
bck = fwd->bk;
|
||
}
|
||
}
|
||
}
|
||
|
||
mark_bin(av, victim_index);
|
||
victim->bk = bck;
|
||
victim->fd = fwd;
|
||
fwd->bk = victim;
|
||
bck->fd = victim;
|
||
}
|
||
|
||
/*
|
||
If a large request, scan through the chunks of current bin in
|
||
sorted order to find smallest that fits. This is the only step
|
||
where an unbounded number of chunks might be scanned without doing
|
||
anything useful with them. However the lists tend to be very
|
||
short.
|
||
*/
|
||
|
||
if (!in_smallbin_range(nb)) {
|
||
bin = bin_at(av, idx);
|
||
|
||
/* skip scan if largest chunk is too small */
|
||
if ((victim = last(bin)) != bin &&
|
||
(long)(chunksize(first(bin))) - (long)(nb) >= 0) {
|
||
do {
|
||
size = chunksize(victim);
|
||
remainder_size = (long)size - (long)nb;
|
||
|
||
if (remainder_size >= 0) {
|
||
unlink(victim, bck, fwd);
|
||
|
||
/* Exhaust */
|
||
if (remainder_size < (long)MINSIZE) {
|
||
set_inuse_bit_at_offset(victim, size);
|
||
check_malloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
}
|
||
/* Split */
|
||
else {
|
||
remainder = chunk_at_offset(victim, nb);
|
||
unsorted_chunks(av)->bk = unsorted_chunks(av)->fd = remainder;
|
||
remainder->bk = remainder->fd = unsorted_chunks(av);
|
||
set_head(victim, nb | PREV_INUSE);
|
||
set_head(remainder, remainder_size | PREV_INUSE);
|
||
set_foot(remainder, remainder_size);
|
||
check_malloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
}
|
||
}
|
||
} while ( (victim = victim->bk) != bin);
|
||
}
|
||
}
|
||
|
||
/*
|
||
Search for a chunk by scanning bins, starting with next largest
|
||
bin. This search is strictly by best-fit; i.e., the smallest
|
||
(with ties going to approximately the least recently used) chunk
|
||
that fits is selected.
|
||
|
||
The bitmap avoids needing to check that most blocks are nonempty.
|
||
The particular case of skipping all bins during warm-up phases
|
||
when no chunks have been returned yet is faster than it might look.
|
||
*/
|
||
|
||
++idx;
|
||
bin = bin_at(av,idx);
|
||
block = idx2block(idx);
|
||
map = av->binmap[block];
|
||
bit = idx2bit(idx);
|
||
|
||
for (;;) {
|
||
/*
|
||
Skip rest of block if there are no more set bits in this block.
|
||
*/
|
||
|
||
if (bit > map || bit == 0) {
|
||
for (;;) {
|
||
if (++block >= BINMAPSIZE) /* out of bins */
|
||
break;
|
||
|
||
else if ( (map = av->binmap[block]) != 0) {
|
||
bin = bin_at(av, (block << BINMAPSHIFT));
|
||
bit = 1;
|
||
break;
|
||
}
|
||
}
|
||
/* Optimizers seem to like this double-break better than goto */
|
||
if (block >= BINMAPSIZE)
|
||
break;
|
||
}
|
||
|
||
/* Advance to bin with set bit. There must be one. */
|
||
while ((bit & map) == 0) {
|
||
bin = next_bin(bin);
|
||
bit <<= 1;
|
||
}
|
||
|
||
victim = last(bin);
|
||
|
||
/* False alarm -- the bin is empty. Clear the bit. */
|
||
if (victim == bin) {
|
||
av->binmap[block] = map &= ~bit; /* Write through */
|
||
bin = next_bin(bin);
|
||
bit <<= 1;
|
||
}
|
||
|
||
/* We know the first chunk in this bin is big enough to use. */
|
||
else {
|
||
size = chunksize(victim);
|
||
remainder_size = (long)size - (long)nb;
|
||
|
||
assert(remainder_size >= 0);
|
||
|
||
/* unlink */
|
||
bck = victim->bk;
|
||
bin->bk = bck;
|
||
bck->fd = bin;
|
||
|
||
|
||
/* Exhaust */
|
||
if (remainder_size < (long)MINSIZE) {
|
||
set_inuse_bit_at_offset(victim, size);
|
||
check_malloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
}
|
||
|
||
/* Split */
|
||
else {
|
||
remainder = chunk_at_offset(victim, nb);
|
||
|
||
unsorted_chunks(av)->bk = unsorted_chunks(av)->fd = remainder;
|
||
remainder->bk = remainder->fd = unsorted_chunks(av);
|
||
/* advertise as last remainder */
|
||
if (in_smallbin_range(nb))
|
||
av->last_remainder = remainder;
|
||
|
||
set_head(victim, nb | PREV_INUSE);
|
||
set_head(remainder, remainder_size | PREV_INUSE);
|
||
set_foot(remainder, remainder_size);
|
||
check_malloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
}
|
||
}
|
||
}
|
||
|
||
/*
|
||
If large enough, split off the chunk bordering the end of memory
|
||
("top"). Note that this use of top is in accord with the best-fit search
|
||
rule. In effect, top is treated as larger (and thus less well
|
||
fitting) than any other available chunk since it can be extended
|
||
to be as large as necessary (up to system limitations).
|
||
|
||
We require that "top" always exists (i.e., has size >= MINSIZE)
|
||
after initialization, so if it would otherwise be exhuasted by
|
||
current request, it is replenished. (Among the reasons for
|
||
ensuring it exists is that we may need MINSIZE space to put in
|
||
fenceposts in sysmalloc.)
|
||
*/
|
||
|
||
victim = av->top;
|
||
size = chunksize(victim);
|
||
remainder_size = (long)size - (long)nb;
|
||
|
||
if (remainder_size >= (long)MINSIZE) {
|
||
remainder = chunk_at_offset(victim, nb);
|
||
av->top = remainder;
|
||
set_head(victim, nb | PREV_INUSE);
|
||
set_head(remainder, remainder_size | PREV_INUSE);
|
||
|
||
check_malloced_chunk(victim, nb);
|
||
return chunk2mem(victim);
|
||
}
|
||
|
||
/*
|
||
If there is space available in fastbins, consolidate and retry,
|
||
to possibly avoid expanding memory. This can occur only if nb is
|
||
in smallbin range so we didn't consolidate upon entry.
|
||
*/
|
||
|
||
else if (have_fastchunks(av)) {
|
||
assert(in_smallbin_range(nb));
|
||
idx = smallbin_index(nb); /* restore original bin index */
|
||
malloc_consolidate(av);
|
||
}
|
||
|
||
/*
|
||
Otherwise, relay to handle system-dependent cases
|
||
*/
|
||
else
|
||
return sYSMALLOc(nb, av);
|
||
}
|
||
}
|
||
|
||
|
||
|
||
/*
|
||
Free routine. See running comments for algorithm description.
|
||
*/
|
||
|
||
#if __STD_C
|
||
void fREe(Void_t* mem)
|
||
#else
|
||
void fREe(mem) Void_t* mem;
|
||
#endif
|
||
{
|
||
mstate av = get_malloc_state();
|
||
|
||
mchunkptr p; /* chunk corresponding to mem */
|
||
INTERNAL_SIZE_T size; /* its size */
|
||
mfastbinptr* fb; /* associated fastbin */
|
||
mchunkptr nextchunk; /* next contiguous chunk */
|
||
INTERNAL_SIZE_T nextsize; /* its size */
|
||
int nextinuse; /* true if nextchunk is used */
|
||
INTERNAL_SIZE_T prevsize; /* size of previous contiguous chunk */
|
||
mchunkptr bck; /* misc temp for linking */
|
||
mchunkptr fwd; /* misc temp for linking */
|
||
|
||
|
||
/* free(0) has no effect */
|
||
if (mem != 0) {
|
||
|
||
p = mem2chunk(mem);
|
||
check_inuse_chunk(p);
|
||
|
||
size = chunksize(p);
|
||
|
||
/*
|
||
If eligible, place chunk on a fastbin so it can be found
|
||
and used quickly in malloc.
|
||
*/
|
||
|
||
if ((unsigned long)size <= (unsigned long)av->max_fast
|
||
|
||
#if TRIM_FASTBINS
|
||
/*
|
||
If TRIM_FASTBINS set, don't place chunks
|
||
bordering top into fastbins
|
||
*/
|
||
&& (chunk_at_offset(p, size) != av->top)
|
||
#endif
|
||
) {
|
||
|
||
set_fastchunks(av);
|
||
fb = &(av->fastbins[fastbin_index(size)]);
|
||
p->fd = *fb;
|
||
*fb = p;
|
||
}
|
||
|
||
/*
|
||
Consolidate non-mmapped chunks as they arrive.
|
||
*/
|
||
|
||
else if (!chunk_is_mmapped(p)) {
|
||
|
||
nextchunk = chunk_at_offset(p, size);
|
||
|
||
/* consolidate backward */
|
||
if (!prev_inuse(p)) {
|
||
prevsize = p->prev_size;
|
||
size += prevsize;
|
||
p = chunk_at_offset(p, -((long) prevsize));
|
||
unlink(p, bck, fwd);
|
||
}
|
||
|
||
nextsize = chunksize(nextchunk);
|
||
|
||
if (nextchunk != av->top) {
|
||
|
||
/* get and clear inuse bit */
|
||
nextinuse = inuse_bit_at_offset(nextchunk, nextsize);
|
||
set_head(nextchunk, nextsize);
|
||
|
||
/* consolidate forward */
|
||
if (!nextinuse) {
|
||
unlink(nextchunk, bck, fwd);
|
||
size += nextsize;
|
||
}
|
||
|
||
/*
|
||
Place chunk in unsorted chunk list. Chunks are
|
||
not placed into regular bins until after they have
|
||
been given one chance to be used in malloc.
|
||
*/
|
||
|
||
bck = unsorted_chunks(av);
|
||
fwd = bck->fd;
|
||
p->bk = bck;
|
||
p->fd = fwd;
|
||
bck->fd = p;
|
||
fwd->bk = p;
|
||
|
||
set_head(p, size | PREV_INUSE);
|
||
set_foot(p, size);
|
||
}
|
||
|
||
/*
|
||
If the chunk borders the current high end of memory,
|
||
consolidate into top
|
||
*/
|
||
|
||
else {
|
||
size += nextsize;
|
||
set_head(p, size | PREV_INUSE);
|
||
av->top = p;
|
||
|
||
/*
|
||
If the total unused topmost memory exceeds trim
|
||
threshold, ask malloc_trim to reduce top.
|
||
|
||
Unless max_fast is 0, we don't know if there are fastbins
|
||
bordering top, so we cannot tell for sure whether threshold has
|
||
been reached unless fastbins are consolidated. But we don't
|
||
want to consolidate on each free. As a compromise,
|
||
consolidation is performed if half the threshold is
|
||
reached.
|
||
|
||
*/
|
||
|
||
if ((unsigned long)(size) > (unsigned long)(av->trim_threshold / 2)) {
|
||
if (have_fastchunks(av)) {
|
||
malloc_consolidate(av);
|
||
size = chunksize(av->top);
|
||
}
|
||
|
||
if ((unsigned long)(size) > (unsigned long)(av->trim_threshold))
|
||
sYSTRIm(av->top_pad, av);
|
||
}
|
||
}
|
||
}
|
||
|
||
/*
|
||
If the chunk was allocated via mmap, release via munmap()
|
||
Note that if HAVE_MMAP is false but chunk_is_mmapped is
|
||
true, then user must have overwritten memory. There's nothing
|
||
we can do to catch this error unless DEBUG is set, in which case
|
||
check_inuse_chunk (above) will have triggered error.
|
||
*/
|
||
|
||
else {
|
||
#if HAVE_MMAP
|
||
int ret;
|
||
INTERNAL_SIZE_T offset = p->prev_size;
|
||
av->n_mmaps--;
|
||
av->mmapped_mem -= (size + offset);
|
||
ret = munmap((char*)p - offset, size + offset);
|
||
/* munmap returns non-zero on failure */
|
||
assert(ret == 0);
|
||
#endif
|
||
}
|
||
}
|
||
}
|
||
|
||
|
||
|
||
/*
|
||
malloc_consolidate is a specialized version of free() that tears
|
||
down chunks held in fastbins. Free itself cannot be used for this
|
||
purpose since, among other things, it might place chunks back onto
|
||
fastbins. So, instead, we need to use a minor variant of the same
|
||
code.
|
||
|
||
Also, because this routine needs to be called the first time through
|
||
malloc anyway, it turns out to be the perfect place to bury
|
||
initialization code.
|
||
*/
|
||
|
||
#if __STD_C
|
||
static void malloc_consolidate(mstate av)
|
||
#else
|
||
static void malloc_consolidate(av) mstate av;
|
||
#endif
|
||
{
|
||
mfastbinptr* fb;
|
||
mfastbinptr* maxfb;
|
||
mchunkptr p;
|
||
mchunkptr nextp;
|
||
mchunkptr unsorted_bin;
|
||
mchunkptr first_unsorted;
|
||
|
||
/* These have same use as in free() */
|
||
mchunkptr nextchunk;
|
||
INTERNAL_SIZE_T size;
|
||
INTERNAL_SIZE_T nextsize;
|
||
INTERNAL_SIZE_T prevsize;
|
||
int nextinuse;
|
||
mchunkptr bck;
|
||
mchunkptr fwd;
|
||
|
||
/*
|
||
If max_fast is 0, we know that malloc hasn't
|
||
yet been initialized, in which case do so.
|
||
*/
|
||
|
||
if (av->max_fast == 0) {
|
||
malloc_init_state(av);
|
||
check_malloc_state();
|
||
}
|
||
else if (have_fastchunks(av)) {
|
||
clear_fastchunks(av);
|
||
|
||
unsorted_bin = unsorted_chunks(av);
|
||
|
||
/*
|
||
Remove each chunk from fast bin and consolidate it, placing it
|
||
then in unsorted bin. Among other reasons for doing this,
|
||
placing in unsorted bin avoids needing to calculate actual bins
|
||
until malloc is sure that chunks aren't immediately going to be
|
||
reused anyway.
|
||
*/
|
||
|
||
maxfb = &(av->fastbins[fastbin_index(av->max_fast)]);
|
||
fb = &(av->fastbins[0]);
|
||
do {
|
||
if ( (p = *fb) != 0) {
|
||
*fb = 0;
|
||
|
||
do {
|
||
check_inuse_chunk(p);
|
||
nextp = p->fd;
|
||
|
||
/* Slightly streamlined version of consolidation code in free() */
|
||
size = p->size & ~PREV_INUSE;
|
||
nextchunk = chunk_at_offset(p, size);
|
||
|
||
if (!prev_inuse(p)) {
|
||
prevsize = p->prev_size;
|
||
size += prevsize;
|
||
p = chunk_at_offset(p, -((long) prevsize));
|
||
unlink(p, bck, fwd);
|
||
}
|
||
|
||
nextsize = chunksize(nextchunk);
|
||
|
||
if (nextchunk != av->top) {
|
||
|
||
nextinuse = inuse_bit_at_offset(nextchunk, nextsize);
|
||
set_head(nextchunk, nextsize);
|
||
|
||
if (!nextinuse) {
|
||
size += nextsize;
|
||
unlink(nextchunk, bck, fwd);
|
||
}
|
||
|
||
first_unsorted = unsorted_bin->fd;
|
||
unsorted_bin->fd = p;
|
||
first_unsorted->bk = p;
|
||
|
||
set_head(p, size | PREV_INUSE);
|
||
p->bk = unsorted_bin;
|
||
p->fd = first_unsorted;
|
||
set_foot(p, size);
|
||
}
|
||
|
||
else {
|
||
size += nextsize;
|
||
set_head(p, size | PREV_INUSE);
|
||
av->top = p;
|
||
}
|
||
|
||
} while ( (p = nextp) != 0);
|
||
|
||
}
|
||
} while (fb++ != maxfb);
|
||
}
|
||
}
|
||
|
||
|
||
|
||
|
||
/*
|
||
Realloc algorithm cases:
|
||
|
||
* Chunks that were obtained via mmap cannot be extended or shrunk
|
||
unless HAVE_MREMAP is defined, in which case mremap is used.
|
||
Otherwise, if the reallocation is for additional space, they are
|
||
copied. If for less, they are just left alone.
|
||
|
||
* Otherwise, if the reallocation is for additional space, and the
|
||
chunk can be extended, it is, else a malloc-copy-free sequence is
|
||
taken. There are several different ways that a chunk could be
|
||
extended. All are tried:
|
||
|
||
* Extending forward into following adjacent free chunk.
|
||
* Shifting backwards, joining preceding adjacent space
|
||
* Both shifting backwards and extending forward.
|
||
* Extending into newly sbrked space
|
||
|
||
* If there is not enough memory available to realloc, realloc
|
||
returns null, but does NOT free the existing space.
|
||
|
||
* If the reallocation is for less space, the newly unused space is
|
||
lopped off and freed. Unless the #define REALLOC_ZERO_BYTES_FREES
|
||
is set, realloc with a size argument of zero (re)allocates a
|
||
minimum-sized chunk.
|
||
|
||
|
||
The old unix realloc convention of allowing the last-free'd chunk
|
||
to be used as an argument to realloc is no longer supported.
|
||
I don't know of any programs still relying on this feature,
|
||
and allowing it would also allow too many other incorrect
|
||
usages of realloc to be sensible.
|
||
*/
|
||
|
||
#if __STD_C
|
||
Void_t* rEALLOc(Void_t* oldmem, size_t bytes)
|
||
#else
|
||
Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes;
|
||
#endif
|
||
{
|
||
mstate av = get_malloc_state();
|
||
|
||
INTERNAL_SIZE_T nb; /* padded request size */
|
||
|
||
mchunkptr oldp; /* chunk corresponding to oldmem */
|
||
INTERNAL_SIZE_T oldsize; /* its size */
|
||
|
||
mchunkptr newp; /* chunk to return */
|
||
INTERNAL_SIZE_T newsize; /* its size */
|
||
Void_t* newmem; /* corresponding user mem */
|
||
|
||
mchunkptr next; /* next contiguous chunk after oldp */
|
||
mchunkptr prev; /* previous contiguous chunk before oldp */
|
||
|
||
mchunkptr remainder; /* extra space at end of newp */
|
||
long remainder_size; /* its size */
|
||
|
||
mchunkptr bck; /* misc temp for linking */
|
||
mchunkptr fwd; /* misc temp for linking */
|
||
|
||
INTERNAL_SIZE_T copysize; /* bytes to copy */
|
||
int ncopies; /* INTERNAL_SIZE_T words to copy */
|
||
INTERNAL_SIZE_T* s; /* copy source */
|
||
INTERNAL_SIZE_T* d; /* copy destination */
|
||
|
||
|
||
#ifdef REALLOC_ZERO_BYTES_FREES
|
||
if (bytes == 0) {
|
||
fREe(oldmem);
|
||
return 0;
|
||
}
|
||
#endif
|
||
|
||
/* realloc of null is supposed to be same as malloc */
|
||
if (oldmem == 0) return mALLOc(bytes);
|
||
|
||
checked_request2size(bytes, nb);
|
||
|
||
oldp = mem2chunk(oldmem);
|
||
oldsize = chunksize(oldp);
|
||
|
||
check_inuse_chunk(oldp);
|
||
|
||
if (!chunk_is_mmapped(oldp)) {
|
||
|
||
if ((unsigned long)(oldsize) >= (unsigned long)(nb)) {
|
||
/* already big enough; split below */
|
||
newp = oldp;
|
||
newsize = oldsize;
|
||
}
|
||
|
||
else {
|
||
newp = 0;
|
||
newsize = 0;
|
||
|
||
next = chunk_at_offset(oldp, oldsize);
|
||
|
||
if (next == av->top) { /* Expand forward into top */
|
||
newsize = oldsize + chunksize(next);
|
||
|
||
if ((unsigned long)(newsize) >= (unsigned long)(nb + MINSIZE)) {
|
||
set_head_size(oldp, nb);
|
||
av->top = chunk_at_offset(oldp, nb);
|
||
set_head(av->top, (newsize - nb) | PREV_INUSE);
|
||
return chunk2mem(oldp);
|
||
}
|
||
|
||
else if (!prev_inuse(oldp)) { /* Shift backwards + top */
|
||
prev = prev_chunk(oldp);
|
||
newsize += chunksize(prev);
|
||
|
||
if ((unsigned long)(newsize) >= (unsigned long)(nb + MINSIZE)) {
|
||
newp = prev;
|
||
unlink(prev, bck, fwd);
|
||
av->top = chunk_at_offset(newp, nb);
|
||
set_head(av->top, (newsize - nb) | PREV_INUSE);
|
||
newsize = nb;
|
||
}
|
||
}
|
||
}
|
||
|
||
else if (!inuse(next)) { /* Forward into next chunk */
|
||
newsize = oldsize + chunksize(next);
|
||
|
||
if (((unsigned long)(newsize) >= (unsigned long)(nb))) {
|
||
newp = oldp;
|
||
unlink(next, bck, fwd);
|
||
}
|
||
|
||
else if (!prev_inuse(oldp)) { /* Forward + backward */
|
||
prev = prev_chunk(oldp);
|
||
newsize += chunksize(prev);
|
||
|
||
if (((unsigned long)(newsize) >= (unsigned long)(nb))) {
|
||
newp = prev;
|
||
unlink(prev, bck, fwd);
|
||
unlink(next, bck, fwd);
|
||
}
|
||
}
|
||
}
|
||
|
||
else if (!prev_inuse(oldp)) { /* Backward only */
|
||
prev = prev_chunk(oldp);
|
||
newsize = oldsize + chunksize(prev);
|
||
|
||
if ((unsigned long)(newsize) >= (unsigned long)(nb)) {
|
||
newp = prev;
|
||
unlink(prev, bck, fwd);
|
||
}
|
||
}
|
||
|
||
if (newp != 0) {
|
||
if (newp != oldp) {
|
||
/* Backward copies are not worth unrolling */
|
||
MALLOC_COPY(chunk2mem(newp), oldmem, oldsize - SIZE_SZ, 1);
|
||
}
|
||
}
|
||
|
||
/* Must allocate */
|
||
else {
|
||
newmem = mALLOc(nb - MALLOC_ALIGN_MASK);
|
||
if (newmem == 0)
|
||
return 0; /* propagate failure */
|
||
|
||
newp = mem2chunk(newmem);
|
||
newsize = chunksize(newp);
|
||
|
||
/*
|
||
Avoid copy if newp is next chunk after oldp.
|
||
*/
|
||
if (newp == next) {
|
||
newsize += oldsize;
|
||
newp = oldp;
|
||
}
|
||
else {
|
||
|
||
/*
|
||
Unroll copy of <= 36 bytes (72 if 8byte sizes)
|
||
We know that contents have an odd number of
|
||
INTERNAL_SIZE_T-sized words; minimally 3.
|
||
*/
|
||
|
||
copysize = oldsize - SIZE_SZ;
|
||
s = (INTERNAL_SIZE_T*)oldmem;
|
||
d = (INTERNAL_SIZE_T*)(chunk2mem(newp));
|
||
ncopies = copysize / sizeof(INTERNAL_SIZE_T);
|
||
assert(ncopies >= 3);
|
||
|
||
if (ncopies > 9)
|
||
MALLOC_COPY(d, s, copysize, 0);
|
||
|
||
else {
|
||
*(d+0) = *(s+0);
|
||
*(d+1) = *(s+1);
|
||
*(d+2) = *(s+2);
|
||
if (ncopies > 4) {
|
||
*(d+3) = *(s+3);
|
||
*(d+4) = *(s+4);
|
||
if (ncopies > 6) {
|
||
*(d+5) = *(s+5);
|
||
*(d+6) = *(s+6);
|
||
if (ncopies > 8) {
|
||
*(d+7) = *(s+7);
|
||
*(d+8) = *(s+8);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
fREe(oldmem);
|
||
check_inuse_chunk(newp);
|
||
return chunk2mem(newp);
|
||
}
|
||
}
|
||
}
|
||
|
||
|
||
/* If possible, free extra space in old or extended chunk */
|
||
|
||
remainder_size = (long)newsize - (long)nb;
|
||
assert(remainder_size >= 0);
|
||
|
||
if (remainder_size >= (long)MINSIZE) { /* split remainder */
|
||
remainder = chunk_at_offset(newp, nb);
|
||
set_head_size(newp, nb);
|
||
set_head(remainder, remainder_size | PREV_INUSE);
|
||
/* Mark remainder as inuse so free() won't complain */
|
||
set_inuse_bit_at_offset(remainder, remainder_size);
|
||
fREe(chunk2mem(remainder));
|
||
}
|
||
|
||
else { /* not enough extra to split off */
|
||
set_head_size(newp, newsize);
|
||
set_inuse_bit_at_offset(newp, newsize);
|
||
}
|
||
|
||
check_inuse_chunk(newp);
|
||
return chunk2mem(newp);
|
||
}
|
||
|
||
/*
|
||
Handle mmap cases
|
||
*/
|
||
|
||
else {
|
||
#if HAVE_MMAP
|
||
|
||
#if HAVE_MREMAP
|
||
INTERNAL_SIZE_T offset = oldp->prev_size;
|
||
size_t pagemask = av->pagesize - 1;
|
||
char *cp;
|
||
unsigned long sum;
|
||
|
||
/* Note the extra SIZE_SZ overhead */
|
||
newsize = (nb + offset + SIZE_SZ + pagemask) & ~pagemask;
|
||
|
||
/* don't need to remap if still within same page */
|
||
if (oldsize == newsize - offset)
|
||
return oldmem;
|
||
|
||
cp = (char*)mremap((char*)oldp - offset, oldsize + offset, newsize, 1);
|
||
|
||
if (cp != (char*)MORECORE_FAILURE) {
|
||
|
||
newp = (mchunkptr)(cp + offset);
|
||
set_head(newp, (newsize - offset)|IS_MMAPPED);
|
||
|
||
assert(aligned_OK(chunk2mem(newp)));
|
||
assert((newp->prev_size == offset));
|
||
|
||
/* update statistics */
|
||
sum = av->mmapped_mem += newsize - oldsize;
|
||
if (sum > (unsigned long)(av->max_mmapped_mem))
|
||
av->max_mmapped_mem = sum;
|
||
sum += av->sbrked_mem;
|
||
if (sum > (unsigned long)(av->max_total_mem))
|
||
av->max_total_mem = sum;
|
||
|
||
return chunk2mem(newp);
|
||
}
|
||
|
||
#endif
|
||
|
||
/* Note the extra SIZE_SZ overhead. */
|
||
if ((long)oldsize - (long)SIZE_SZ >= (long)nb)
|
||
newmem = oldmem; /* do nothing */
|
||
else {
|
||
/* Must alloc, copy, free. */
|
||
newmem = mALLOc(nb - MALLOC_ALIGN_MASK);
|
||
if (newmem != 0) {
|
||
MALLOC_COPY(newmem, oldmem, oldsize - 2*SIZE_SZ, 0);
|
||
fREe(oldmem);
|
||
}
|
||
}
|
||
return newmem;
|
||
|
||
#else
|
||
/* If !HAVE_MMAP, but chunk_is_mmapped, user must have overwritten mem */
|
||
check_malloc_state();
|
||
MALLOC_FAILURE_ACTION;
|
||
return 0;
|
||
#endif
|
||
}
|
||
|
||
}
|
||
|
||
|
||
|
||
/*
|
||
memalign requests more than enough space from malloc, finds a spot
|
||
within that chunk that meets the alignment request, and then
|
||
possibly frees the leading and trailing space.
|
||
|
||
Alignments must be powers of two. If the argument is not a
|
||
power of two, the nearest greater power is used.
|
||
|
||
8-byte alignment is guaranteed by normal malloc calls, so don't
|
||
bother calling memalign with an argument of 8 or less.
|
||
|
||
Overreliance on memalign is a sure way to fragment space.
|
||
*/
|
||
|
||
|
||
#if __STD_C
|
||
Void_t* mEMALIGn(size_t alignment, size_t bytes)
|
||
#else
|
||
Void_t* mEMALIGn(alignment, bytes) size_t alignment; size_t bytes;
|
||
#endif
|
||
{
|
||
INTERNAL_SIZE_T nb; /* padded request size */
|
||
char* m; /* memory returned by malloc call */
|
||
mchunkptr p; /* corresponding chunk */
|
||
char* brk; /* alignment point within p */
|
||
mchunkptr newp; /* chunk to return */
|
||
INTERNAL_SIZE_T newsize; /* its size */
|
||
INTERNAL_SIZE_T leadsize; /* leading space befor alignment point */
|
||
mchunkptr remainder; /* spare room at end to split off */
|
||
long remainder_size; /* its size */
|
||
|
||
|
||
/* If need less alignment than we give anyway, just relay to malloc */
|
||
|
||
if (alignment <= MALLOC_ALIGNMENT) return mALLOc(bytes);
|
||
|
||
/* Otherwise, ensure that it is at least a minimum chunk size */
|
||
|
||
if (alignment < MINSIZE) alignment = MINSIZE;
|
||
|
||
/* Make sure alignment is power of 2 (in case MINSIZE is not). */
|
||
if ((alignment & (alignment - 1)) != 0) {
|
||
size_t a = MALLOC_ALIGNMENT * 2;
|
||
while ((unsigned long)a < (unsigned long)alignment) a <<= 1;
|
||
alignment = a;
|
||
}
|
||
|
||
checked_request2size(bytes, nb);
|
||
|
||
/* Call malloc with worst case padding to hit alignment. */
|
||
|
||
m = (char*)(mALLOc(nb + alignment + MINSIZE));
|
||
|
||
if (m == 0) return 0; /* propagate failure */
|
||
|
||
p = mem2chunk(m);
|
||
|
||
if ((((unsigned long)(m)) % alignment) != 0) { /* misaligned */
|
||
|
||
/*
|
||
Find an aligned spot inside chunk. Since we need to give back
|
||
leading space in a chunk of at least MINSIZE, if the first
|
||
calculation places us at a spot with less than MINSIZE leader,
|
||
we can move to the next aligned spot -- we've allocated enough
|
||
total room so that this is always possible.
|
||
*/
|
||
|
||
brk = (char*)mem2chunk(((unsigned long)(m + alignment - 1)) &
|
||
-((signed long) alignment));
|
||
if ((long)(brk - (char*)(p)) < (long)MINSIZE)
|
||
brk = brk + alignment;
|
||
|
||
newp = (mchunkptr)brk;
|
||
leadsize = brk - (char*)(p);
|
||
newsize = chunksize(p) - leadsize;
|
||
|
||
/* For mmapped chunks, just adjust offset */
|
||
if (chunk_is_mmapped(p)) {
|
||
newp->prev_size = p->prev_size + leadsize;
|
||
set_head(newp, newsize|IS_MMAPPED);
|
||
return chunk2mem(newp);
|
||
}
|
||
|
||
/* Otherwise, give back leader, use the rest */
|
||
|
||
set_head(newp, newsize | PREV_INUSE);
|
||
set_inuse_bit_at_offset(newp, newsize);
|
||
set_head_size(p, leadsize);
|
||
fREe(chunk2mem(p));
|
||
p = newp;
|
||
|
||
assert (newsize >= nb &&
|
||
(((unsigned long)(chunk2mem(p))) % alignment) == 0);
|
||
}
|
||
|
||
/* Also give back spare room at the end */
|
||
if (!chunk_is_mmapped(p)) {
|
||
|
||
remainder_size = (long)(chunksize(p)) - (long)nb;
|
||
|
||
if (remainder_size >= (long)MINSIZE) {
|
||
remainder = chunk_at_offset(p, nb);
|
||
set_head(remainder, remainder_size | PREV_INUSE);
|
||
set_head_size(p, nb);
|
||
fREe(chunk2mem(remainder));
|
||
}
|
||
}
|
||
|
||
check_inuse_chunk(p);
|
||
return chunk2mem(p);
|
||
|
||
}
|
||
|
||
|
||
|
||
|
||
/*
|
||
calloc calls malloc, then zeroes out the allocated chunk.
|
||
*/
|
||
|
||
#if __STD_C
|
||
Void_t* cALLOc(size_t n_elements, size_t elem_size)
|
||
#else
|
||
Void_t* cALLOc(n_elements, elem_size) size_t n_elements; size_t elem_size;
|
||
#endif
|
||
{
|
||
mchunkptr p;
|
||
INTERNAL_SIZE_T clearsize;
|
||
int nclears;
|
||
INTERNAL_SIZE_T* d;
|
||
|
||
Void_t* mem = mALLOc(n_elements * elem_size);
|
||
|
||
if (mem != 0) {
|
||
p = mem2chunk(mem);
|
||
if (!chunk_is_mmapped(p)) { /* don't need to clear mmapped space */
|
||
|
||
/*
|
||
Unroll clear of <= 36 bytes (72 if 8byte sizes)
|
||
We know that contents have an odd number of
|
||
INTERNAL_SIZE_T-sized words; minimally 3.
|
||
*/
|
||
|
||
d = (INTERNAL_SIZE_T*)mem;
|
||
clearsize = chunksize(p) - SIZE_SZ;
|
||
nclears = clearsize / sizeof(INTERNAL_SIZE_T);
|
||
assert(nclears >= 3);
|
||
|
||
if (nclears > 9)
|
||
MALLOC_ZERO(d, clearsize);
|
||
|
||
else {
|
||
*(d+0) = 0;
|
||
*(d+1) = 0;
|
||
*(d+2) = 0;
|
||
if (nclears > 4) {
|
||
*(d+3) = 0;
|
||
*(d+4) = 0;
|
||
if (nclears > 6) {
|
||
*(d+5) = 0;
|
||
*(d+6) = 0;
|
||
if (nclears > 8) {
|
||
*(d+7) = 0;
|
||
*(d+8) = 0;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
return mem;
|
||
}
|
||
|
||
|
||
/*
|
||
cfree just calls free. It is needed/defined on some systems
|
||
that pair it with calloc, presumably for odd historical reasons
|
||
(such as: cfree is used in example code in first edition of K&R).
|
||
*/
|
||
|
||
#if __STD_C
|
||
void cFREe(Void_t *mem)
|
||
#else
|
||
void cFREe(mem) Void_t *mem;
|
||
#endif
|
||
{
|
||
fREe(mem);
|
||
}
|
||
|
||
|
||
|
||
|
||
|
||
/*
|
||
valloc just invokes memalign with alignment argument equal
|
||
to the page size of the system (or as near to this as can
|
||
be figured out from all the includes/defines above.)
|
||
*/
|
||
|
||
#if __STD_C
|
||
Void_t* vALLOc(size_t bytes)
|
||
#else
|
||
Void_t* vALLOc(bytes) size_t bytes;
|
||
#endif
|
||
{
|
||
/* Ensure initialization/consolidation */
|
||
mstate av = get_malloc_state();
|
||
malloc_consolidate(av);
|
||
return mEMALIGn(av->pagesize, bytes);
|
||
}
|
||
|
||
/*
|
||
pvalloc just invokes valloc for the nearest pagesize
|
||
that will accommodate request
|
||
*/
|
||
|
||
|
||
#if __STD_C
|
||
Void_t* pVALLOc(size_t bytes)
|
||
#else
|
||
Void_t* pVALLOc(bytes) size_t bytes;
|
||
#endif
|
||
{
|
||
mstate av = get_malloc_state();
|
||
size_t pagesz;
|
||
|
||
/* Ensure initialization/consolidation */
|
||
malloc_consolidate(av);
|
||
|
||
pagesz = av->pagesize;
|
||
return mEMALIGn(pagesz, (bytes + pagesz - 1) & ~(pagesz - 1));
|
||
}
|
||
|
||
|
||
/*
|
||
Malloc_Trim gives memory back to the system (via negative
|
||
arguments to sbrk) if there is unused memory at the `high' end of
|
||
the malloc pool. You can call this after freeing large blocks of
|
||
memory to potentially reduce the system-level memory requirements
|
||
of a program. However, it cannot guarantee to reduce memory. Under
|
||
some allocation patterns, some large free blocks of memory will be
|
||
locked between two used chunks, so they cannot be given back to
|
||
the system.
|
||
|
||
The `pad' argument to malloc_trim represents the amount of free
|
||
trailing space to leave untrimmed. If this argument is zero,
|
||
only the minimum amount of memory to maintain internal data
|
||
structures will be left (one page or less). Non-zero arguments
|
||
can be supplied to maintain enough trailing space to service
|
||
future expected allocations without having to re-obtain memory
|
||
from the system.
|
||
|
||
Malloc_trim returns 1 if it actually released any memory, else 0.
|
||
*/
|
||
|
||
#if __STD_C
|
||
int mTRIm(size_t pad)
|
||
#else
|
||
int mTRIm(pad) size_t pad;
|
||
#endif
|
||
{
|
||
mstate av = get_malloc_state();
|
||
/* Ensure initialization/consolidation */
|
||
malloc_consolidate(av);
|
||
|
||
return sYSTRIm(pad, av);
|
||
}
|
||
|
||
/*
|
||
malloc_usable_size tells you how many bytes you can actually use in
|
||
an allocated chunk, which may be more than you requested (although
|
||
often not). You can use this many bytes without worrying about
|
||
overwriting other allocated objects. Not a particularly great
|
||
programming practice, but still sometimes useful.
|
||
*/
|
||
|
||
#if __STD_C
|
||
size_t mUSABLe(Void_t* mem)
|
||
#else
|
||
size_t mUSABLe(mem) Void_t* mem;
|
||
#endif
|
||
{
|
||
mchunkptr p;
|
||
if (mem != 0) {
|
||
p = mem2chunk(mem);
|
||
if (chunk_is_mmapped(p))
|
||
return chunksize(p) - 2*SIZE_SZ;
|
||
else if (inuse(p))
|
||
return chunksize(p) - SIZE_SZ;
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
|
||
|
||
|
||
/*
|
||
mallinfo returns a copy of updated current mallinfo.
|
||
*/
|
||
|
||
struct mallinfo mALLINFo()
|
||
{
|
||
mstate av = get_malloc_state();
|
||
struct mallinfo mi;
|
||
int i;
|
||
mbinptr b;
|
||
mchunkptr p;
|
||
INTERNAL_SIZE_T avail;
|
||
int navail;
|
||
int nfastblocks;
|
||
int fastbytes;
|
||
|
||
/* Ensure initialization */
|
||
if (av->top == 0) malloc_consolidate(av);
|
||
|
||
check_malloc_state();
|
||
|
||
/* Account for top */
|
||
avail = chunksize(av->top);
|
||
navail = 1; /* top always exists */
|
||
|
||
/* traverse fastbins */
|
||
nfastblocks = 0;
|
||
fastbytes = 0;
|
||
|
||
for (i = 0; i < NFASTBINS; ++i) {
|
||
for (p = av->fastbins[i]; p != 0; p = p->fd) {
|
||
++nfastblocks;
|
||
fastbytes += chunksize(p);
|
||
}
|
||
}
|
||
|
||
avail += fastbytes;
|
||
|
||
/* traverse regular bins */
|
||
for (i = 1; i < NBINS; ++i) {
|
||
b = bin_at(av, i);
|
||
for (p = last(b); p != b; p = p->bk) {
|
||
avail += chunksize(p);
|
||
navail++;
|
||
}
|
||
}
|
||
|
||
mi.smblks = nfastblocks;
|
||
mi.ordblks = navail;
|
||
mi.fordblks = avail;
|
||
mi.uordblks = av->sbrked_mem - avail;
|
||
mi.arena = av->sbrked_mem;
|
||
mi.hblks = av->n_mmaps;
|
||
mi.hblkhd = av->mmapped_mem;
|
||
mi.fsmblks = fastbytes;
|
||
mi.keepcost = chunksize(av->top);
|
||
mi.usmblks = av->max_total_mem;
|
||
return mi;
|
||
}
|
||
|
||
|
||
|
||
/*
|
||
malloc_stats prints on stderr the amount of space obtained from the
|
||
system (both via sbrk and mmap), the maximum amount (which may be
|
||
more than current if malloc_trim and/or munmap got called), and the
|
||
current number of bytes allocated via malloc (or realloc, etc) but
|
||
not yet freed. Note that this is the number of bytes allocated, not
|
||
the number requested. It will be larger than the number requested
|
||
because of alignment and bookkeeping overhead. Because it includes
|
||
alignment wastage as being in use, this figure may be greater than zero
|
||
even when no user-level chunks are allocated.
|
||
|
||
The reported current and maximum system memory can be inaccurate if
|
||
a program makes other calls to system memory allocation functions
|
||
(normally sbrk) outside of malloc.
|
||
|
||
malloc_stats prints only the most commonly interesting statistics.
|
||
More information can be obtained by calling mallinfo.
|
||
*/
|
||
|
||
void mSTATs()
|
||
{
|
||
struct mallinfo mi = mALLINFo();
|
||
|
||
#ifdef WIN32
|
||
{
|
||
unsigned long free, reserved, committed;
|
||
vminfo (&free, &reserved, &committed);
|
||
fprintf(stderr, "free bytes = %10lu\n",
|
||
free);
|
||
fprintf(stderr, "reserved bytes = %10lu\n",
|
||
reserved);
|
||
fprintf(stderr, "committed bytes = %10lu\n",
|
||
committed);
|
||
}
|
||
#endif
|
||
|
||
|
||
fprintf(stderr, "max system bytes = %10lu\n",
|
||
(unsigned long)(mi.usmblks));
|
||
fprintf(stderr, "system bytes = %10lu\n",
|
||
(unsigned long)(mi.arena + mi.hblkhd));
|
||
fprintf(stderr, "in use bytes = %10lu\n",
|
||
(unsigned long)(mi.uordblks + mi.hblkhd));
|
||
|
||
#ifdef WIN32
|
||
{
|
||
unsigned long kernel, user;
|
||
if (cpuinfo (TRUE, &kernel, &user)) {
|
||
fprintf(stderr, "kernel ms = %10lu\n",
|
||
kernel);
|
||
fprintf(stderr, "user ms = %10lu\n",
|
||
user);
|
||
}
|
||
}
|
||
#endif
|
||
}
|
||
|
||
|
||
|
||
/*
|
||
mallopt is the general SVID/XPG interface to tunable parameters.
|
||
The format is to provide a (parameter-number, parameter-value)
|
||
pair. mallopt then sets the corresponding parameter to the
|
||
argument value if it can (i.e., so long as the value is
|
||
meaningful), and returns 1 if successful else 0. See descriptions
|
||
of tunable parameters above for meanings.
|
||
*/
|
||
|
||
#if __STD_C
|
||
int mALLOPt(int param_number, int value)
|
||
#else
|
||
int mALLOPt(param_number, value) int param_number; int value;
|
||
#endif
|
||
{
|
||
mstate av = get_malloc_state();
|
||
/* Ensure initialization/consolidation */
|
||
malloc_consolidate(av);
|
||
|
||
switch(param_number) {
|
||
case M_MXFAST:
|
||
if (value >= 0 && value <= MAX_FAST_SIZE) {
|
||
av->max_fast = req2max_fast(value);
|
||
return 1;
|
||
}
|
||
else
|
||
return 0;
|
||
|
||
case M_TRIM_THRESHOLD:
|
||
av->trim_threshold = value;
|
||
return 1;
|
||
|
||
case M_TOP_PAD:
|
||
av->top_pad = value;
|
||
return 1;
|
||
|
||
case M_MMAP_THRESHOLD:
|
||
av->mmap_threshold = value;
|
||
return 1;
|
||
|
||
case M_MMAP_MAX:
|
||
#if HAVE_MMAP
|
||
av->n_mmaps_max = value;
|
||
return 1;
|
||
#else
|
||
if (value != 0)
|
||
return 0;
|
||
else {
|
||
av->n_mmaps_max = value;
|
||
return 1;
|
||
}
|
||
#endif
|
||
|
||
default:
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
|
||
/* -------------------------------------------------------------- */
|
||
|
||
/*
|
||
Emulation of sbrk for win32.
|
||
Donated by J. Walter <Walter@GeNeSys-e.de>.
|
||
For additional information about this code, and malloc on Win32, see
|
||
http://www.genesys-e.de/jwalter/
|
||
|
||
*/
|
||
|
||
|
||
#ifdef WIN32
|
||
|
||
#ifdef _DEBUG
|
||
/* #define TRACE */
|
||
#endif
|
||
|
||
/* Support for USE_MALLOC_LOCK */
|
||
#ifdef USE_MALLOC_LOCK
|
||
|
||
/* Wait for spin lock */
|
||
static int slwait (int *sl) {
|
||
while (InterlockedCompareExchange ((void **) sl, (void *) 1, (void *) 0) != 0)
|
||
Sleep (0);
|
||
return 0;
|
||
}
|
||
|
||
/* Release spin lock */
|
||
static int slrelease (int *sl) {
|
||
InterlockedExchange (sl, 0);
|
||
return 0;
|
||
}
|
||
|
||
#ifdef NEEDED
|
||
/* Spin lock for emulation code */
|
||
static int g_sl;
|
||
#endif
|
||
|
||
#endif /* USE_MALLOC_LOCK */
|
||
|
||
/* getpagesize for windows */
|
||
static long getpagesize (void) {
|
||
static long g_pagesize = 0;
|
||
if (! g_pagesize) {
|
||
SYSTEM_INFO system_info;
|
||
GetSystemInfo (&system_info);
|
||
g_pagesize = system_info.dwPageSize;
|
||
}
|
||
return g_pagesize;
|
||
}
|
||
static long getregionsize (void) {
|
||
static long g_regionsize = 0;
|
||
if (! g_regionsize) {
|
||
SYSTEM_INFO system_info;
|
||
GetSystemInfo (&system_info);
|
||
g_regionsize = system_info.dwAllocationGranularity;
|
||
}
|
||
return g_regionsize;
|
||
}
|
||
|
||
/* A region list entry */
|
||
typedef struct _region_list_entry {
|
||
void *top_allocated;
|
||
void *top_committed;
|
||
void *top_reserved;
|
||
long reserve_size;
|
||
struct _region_list_entry *previous;
|
||
} region_list_entry;
|
||
|
||
/* Allocate and link a region entry in the region list */
|
||
static int region_list_append (region_list_entry **last, void *base_reserved, long reserve_size) {
|
||
region_list_entry *next = HeapAlloc (GetProcessHeap (), 0, sizeof (region_list_entry));
|
||
if (! next)
|
||
return FALSE;
|
||
next->top_allocated = (char *) base_reserved;
|
||
next->top_committed = (char *) base_reserved;
|
||
next->top_reserved = (char *) base_reserved + reserve_size;
|
||
next->reserve_size = reserve_size;
|
||
next->previous = *last;
|
||
*last = next;
|
||
return TRUE;
|
||
}
|
||
/* Free and unlink the last region entry from the region list */
|
||
static int region_list_remove (region_list_entry **last) {
|
||
region_list_entry *previous = (*last)->previous;
|
||
if (! HeapFree (GetProcessHeap (), sizeof (region_list_entry), *last))
|
||
return FALSE;
|
||
*last = previous;
|
||
return TRUE;
|
||
}
|
||
|
||
#define CEIL(size,to) (((size)+(to)-1)&~((to)-1))
|
||
#define FLOOR(size,to) ((size)&~((to)-1))
|
||
|
||
#define SBRK_SCALE 0
|
||
/* #define SBRK_SCALE 1 */
|
||
/* #define SBRK_SCALE 2 */
|
||
/* #define SBRK_SCALE 4 */
|
||
|
||
/* sbrk for windows */
|
||
static void *sbrk (long size) {
|
||
static long g_pagesize, g_my_pagesize;
|
||
static long g_regionsize, g_my_regionsize;
|
||
static region_list_entry *g_last;
|
||
void *result = (void *) MORECORE_FAILURE;
|
||
#ifdef TRACE
|
||
printf ("sbrk %d\n", size);
|
||
#endif
|
||
#if defined (USE_MALLOC_LOCK) && defined (NEEDED)
|
||
/* Wait for spin lock */
|
||
slwait (&g_sl);
|
||
#endif
|
||
/* First time initialization */
|
||
if (! g_pagesize) {
|
||
g_pagesize = getpagesize ();
|
||
g_my_pagesize = g_pagesize << SBRK_SCALE;
|
||
}
|
||
if (! g_regionsize) {
|
||
g_regionsize = getregionsize ();
|
||
g_my_regionsize = g_regionsize << SBRK_SCALE;
|
||
}
|
||
if (! g_last) {
|
||
if (! region_list_append (&g_last, 0, 0))
|
||
goto sbrk_exit;
|
||
}
|
||
/* Assert invariants */
|
||
assert (g_last);
|
||
assert ((char *) g_last->top_reserved - g_last->reserve_size <= (char *) g_last->top_allocated &&
|
||
g_last->top_allocated <= g_last->top_committed);
|
||
assert ((char *) g_last->top_reserved - g_last->reserve_size <= (char *) g_last->top_committed &&
|
||
g_last->top_committed <= g_last->top_reserved &&
|
||
(unsigned) g_last->top_committed % g_pagesize == 0);
|
||
assert ((unsigned) g_last->top_reserved % g_regionsize == 0);
|
||
assert ((unsigned) g_last->reserve_size % g_regionsize == 0);
|
||
/* Allocation requested? */
|
||
if (size >= 0) {
|
||
/* Allocation size is the requested size */
|
||
long allocate_size = size;
|
||
/* Compute the size to commit */
|
||
long to_commit = (char *) g_last->top_allocated + allocate_size - (char *) g_last->top_committed;
|
||
/* Do we reach the commit limit? */
|
||
if (to_commit > 0) {
|
||
/* Round size to commit */
|
||
long commit_size = CEIL (to_commit, g_my_pagesize);
|
||
/* Compute the size to reserve */
|
||
long to_reserve = (char *) g_last->top_committed + commit_size - (char *) g_last->top_reserved;
|
||
/* Do we reach the reserve limit? */
|
||
if (to_reserve > 0) {
|
||
/* Compute the remaining size to commit in the current region */
|
||
long remaining_commit_size = (char *) g_last->top_reserved - (char *) g_last->top_committed;
|
||
if (remaining_commit_size > 0) {
|
||
/* Assert preconditions */
|
||
assert ((unsigned) g_last->top_committed % g_pagesize == 0);
|
||
assert (0 < remaining_commit_size && remaining_commit_size % g_pagesize == 0); {
|
||
/* Commit this */
|
||
void *base_committed = VirtualAlloc (g_last->top_committed, remaining_commit_size,
|
||
MEM_COMMIT, PAGE_READWRITE);
|
||
/* Check returned pointer for consistency */
|
||
if (base_committed != g_last->top_committed)
|
||
goto sbrk_exit;
|
||
/* Assert postconditions */
|
||
assert ((unsigned) base_committed % g_pagesize == 0);
|
||
#ifdef TRACE
|
||
printf ("Commit %p %d\n", base_committed, remaining_commit_size);
|
||
#endif
|
||
/* Adjust the regions commit top */
|
||
g_last->top_committed = (char *) base_committed + remaining_commit_size;
|
||
}
|
||
} {
|
||
/* Now we are going to search and reserve. */
|
||
int contiguous = -1;
|
||
int found = FALSE;
|
||
MEMORY_BASIC_INFORMATION memory_info;
|
||
void *base_reserved;
|
||
long reserve_size;
|
||
do {
|
||
/* Assume contiguous memory */
|
||
contiguous = TRUE;
|
||
/* Round size to reserve */
|
||
reserve_size = CEIL (to_reserve, g_my_regionsize);
|
||
/* Start with the current region's top */
|
||
memory_info.BaseAddress = g_last->top_reserved;
|
||
/* Assert preconditions */
|
||
assert ((unsigned) memory_info.BaseAddress % g_pagesize == 0);
|
||
assert (0 < reserve_size && reserve_size % g_regionsize == 0);
|
||
while (VirtualQuery (memory_info.BaseAddress, &memory_info, sizeof (memory_info))) {
|
||
/* Assert postconditions */
|
||
assert ((unsigned) memory_info.BaseAddress % g_pagesize == 0);
|
||
#ifdef TRACE
|
||
printf ("Query %p %d %s\n", memory_info.BaseAddress, memory_info.RegionSize,
|
||
memory_info.State == MEM_FREE ? "FREE":
|
||
(memory_info.State == MEM_RESERVE ? "RESERVED":
|
||
(memory_info.State == MEM_COMMIT ? "COMMITTED": "?")));
|
||
#endif
|
||
/* Region is free, well aligned and big enough: we are done */
|
||
if (memory_info.State == MEM_FREE &&
|
||
(unsigned) memory_info.BaseAddress % g_regionsize == 0 &&
|
||
memory_info.RegionSize >= (unsigned) reserve_size) {
|
||
found = TRUE;
|
||
break;
|
||
}
|
||
/* From now on we can't get contiguous memory! */
|
||
contiguous = FALSE;
|
||
/* Recompute size to reserve */
|
||
reserve_size = CEIL (allocate_size, g_my_regionsize);
|
||
memory_info.BaseAddress = (char *) memory_info.BaseAddress + memory_info.RegionSize;
|
||
/* Assert preconditions */
|
||
assert ((unsigned) memory_info.BaseAddress % g_pagesize == 0);
|
||
assert (0 < reserve_size && reserve_size % g_regionsize == 0);
|
||
}
|
||
/* Search failed? */
|
||
if (! found)
|
||
goto sbrk_exit;
|
||
/* Assert preconditions */
|
||
assert ((unsigned) memory_info.BaseAddress % g_regionsize == 0);
|
||
assert (0 < reserve_size && reserve_size % g_regionsize == 0);
|
||
/* Try to reserve this */
|
||
base_reserved = VirtualAlloc (memory_info.BaseAddress, reserve_size,
|
||
MEM_RESERVE, PAGE_NOACCESS);
|
||
if (! base_reserved) {
|
||
int rc = GetLastError ();
|
||
if (rc != ERROR_INVALID_ADDRESS)
|
||
goto sbrk_exit;
|
||
}
|
||
/* A null pointer signals (hopefully) a race condition with another thread. */
|
||
/* In this case, we try again. */
|
||
} while (! base_reserved);
|
||
/* Check returned pointer for consistency */
|
||
if (memory_info.BaseAddress && base_reserved != memory_info.BaseAddress)
|
||
goto sbrk_exit;
|
||
/* Assert postconditions */
|
||
assert ((unsigned) base_reserved % g_regionsize == 0);
|
||
#ifdef TRACE
|
||
printf ("Reserve %p %d\n", base_reserved, reserve_size);
|
||
#endif
|
||
/* Did we get contiguous memory? */
|
||
if (contiguous) {
|
||
long start_size = (char *) g_last->top_committed - (char *) g_last->top_allocated;
|
||
/* Adjust allocation size */
|
||
allocate_size -= start_size;
|
||
/* Adjust the regions allocation top */
|
||
g_last->top_allocated = g_last->top_committed;
|
||
/* Recompute the size to commit */
|
||
to_commit = (char *) g_last->top_allocated + allocate_size - (char *) g_last->top_committed;
|
||
/* Round size to commit */
|
||
commit_size = CEIL (to_commit, g_my_pagesize);
|
||
}
|
||
/* Append the new region to the list */
|
||
if (! region_list_append (&g_last, base_reserved, reserve_size))
|
||
goto sbrk_exit;
|
||
/* Didn't we get contiguous memory? */
|
||
if (! contiguous) {
|
||
/* Recompute the size to commit */
|
||
to_commit = (char *) g_last->top_allocated + allocate_size - (char *) g_last->top_committed;
|
||
/* Round size to commit */
|
||
commit_size = CEIL (to_commit, g_my_pagesize);
|
||
}
|
||
}
|
||
}
|
||
/* Assert preconditions */
|
||
assert ((unsigned) g_last->top_committed % g_pagesize == 0);
|
||
assert (0 < commit_size && commit_size % g_pagesize == 0); {
|
||
/* Commit this */
|
||
void *base_committed = VirtualAlloc (g_last->top_committed, commit_size,
|
||
MEM_COMMIT, PAGE_READWRITE);
|
||
/* Check returned pointer for consistency */
|
||
if (base_committed != g_last->top_committed)
|
||
goto sbrk_exit;
|
||
/* Assert postconditions */
|
||
assert ((unsigned) base_committed % g_pagesize == 0);
|
||
#ifdef TRACE
|
||
printf ("Commit %p %d\n", base_committed, commit_size);
|
||
#endif
|
||
/* Adjust the regions commit top */
|
||
g_last->top_committed = (char *) base_committed + commit_size;
|
||
}
|
||
}
|
||
/* Adjust the regions allocation top */
|
||
g_last->top_allocated = (char *) g_last->top_allocated + allocate_size;
|
||
result = (char *) g_last->top_allocated - size;
|
||
/* Deallocation requested? */
|
||
} else if (size < 0) {
|
||
long deallocate_size = - size;
|
||
/* As long as we have a region to release */
|
||
while ((char *) g_last->top_allocated - deallocate_size < (char *) g_last->top_reserved - g_last->reserve_size) {
|
||
/* Get the size to release */
|
||
long release_size = g_last->reserve_size;
|
||
/* Get the base address */
|
||
void *base_reserved = (char *) g_last->top_reserved - release_size;
|
||
/* Assert preconditions */
|
||
assert ((unsigned) base_reserved % g_regionsize == 0);
|
||
assert (0 < release_size && release_size % g_regionsize == 0); {
|
||
/* Release this */
|
||
int rc = VirtualFree (base_reserved, 0,
|
||
MEM_RELEASE);
|
||
/* Check returned code for consistency */
|
||
if (! rc)
|
||
goto sbrk_exit;
|
||
#ifdef TRACE
|
||
printf ("Release %p %d\n", base_reserved, release_size);
|
||
#endif
|
||
}
|
||
/* Adjust deallocation size */
|
||
deallocate_size -= (char *) g_last->top_allocated - (char *) base_reserved;
|
||
/* Remove the old region from the list */
|
||
if (! region_list_remove (&g_last))
|
||
goto sbrk_exit;
|
||
} {
|
||
/* Compute the size to decommit */
|
||
long to_decommit = (char *) g_last->top_committed - ((char *) g_last->top_allocated - deallocate_size);
|
||
if (to_decommit >= g_my_pagesize) {
|
||
/* Compute the size to decommit */
|
||
long decommit_size = FLOOR (to_decommit, g_my_pagesize);
|
||
/* Compute the base address */
|
||
void *base_committed = (char *) g_last->top_committed - decommit_size;
|
||
/* Assert preconditions */
|
||
assert ((unsigned) base_committed % g_pagesize == 0);
|
||
assert (0 < decommit_size && decommit_size % g_pagesize == 0); {
|
||
/* Decommit this */
|
||
int rc = VirtualFree ((char *) base_committed, decommit_size,
|
||
MEM_DECOMMIT);
|
||
/* Check returned code for consistency */
|
||
if (! rc)
|
||
goto sbrk_exit;
|
||
#ifdef TRACE
|
||
printf ("Decommit %p %d\n", base_committed, decommit_size);
|
||
#endif
|
||
}
|
||
/* Adjust deallocation size and regions commit and allocate top */
|
||
deallocate_size -= (char *) g_last->top_allocated - (char *) base_committed;
|
||
g_last->top_committed = base_committed;
|
||
g_last->top_allocated = base_committed;
|
||
}
|
||
}
|
||
/* Adjust regions allocate top */
|
||
g_last->top_allocated = (char *) g_last->top_allocated - deallocate_size;
|
||
/* Check for underflow */
|
||
if ((char *) g_last->top_reserved - g_last->reserve_size > (char *) g_last->top_allocated ||
|
||
g_last->top_allocated > g_last->top_committed) {
|
||
/* Adjust regions allocate top */
|
||
g_last->top_allocated = (char *) g_last->top_reserved - g_last->reserve_size;
|
||
goto sbrk_exit;
|
||
}
|
||
result = g_last->top_allocated;
|
||
}
|
||
/* Assert invariants */
|
||
assert (g_last);
|
||
assert ((char *) g_last->top_reserved - g_last->reserve_size <= (char *) g_last->top_allocated &&
|
||
g_last->top_allocated <= g_last->top_committed);
|
||
assert ((char *) g_last->top_reserved - g_last->reserve_size <= (char *) g_last->top_committed &&
|
||
g_last->top_committed <= g_last->top_reserved &&
|
||
(unsigned) g_last->top_committed % g_pagesize == 0);
|
||
assert ((unsigned) g_last->top_reserved % g_regionsize == 0);
|
||
assert ((unsigned) g_last->reserve_size % g_regionsize == 0);
|
||
|
||
sbrk_exit:
|
||
#if defined (USE_MALLOC_LOCK) && defined (NEEDED)
|
||
/* Release spin lock */
|
||
slrelease (&g_sl);
|
||
#endif
|
||
return result;
|
||
}
|
||
|
||
/* mmap for windows */
|
||
static void *mmap (void *ptr, long size, long prot, long type, long handle, long arg) {
|
||
static long g_pagesize;
|
||
static long g_regionsize;
|
||
#ifdef TRACE
|
||
printf ("mmap %d\n", size);
|
||
#endif
|
||
#if defined (USE_MALLOC_LOCK) && defined (NEEDED)
|
||
/* Wait for spin lock */
|
||
slwait (&g_sl);
|
||
#endif
|
||
/* First time initialization */
|
||
if (! g_pagesize)
|
||
g_pagesize = getpagesize ();
|
||
if (! g_regionsize)
|
||
g_regionsize = getregionsize ();
|
||
/* Assert preconditions */
|
||
assert ((unsigned) ptr % g_regionsize == 0);
|
||
assert (size % g_pagesize == 0);
|
||
/* Allocate this */
|
||
ptr = VirtualAlloc (ptr, size,
|
||
MEM_RESERVE | MEM_COMMIT | MEM_TOP_DOWN, PAGE_READWRITE);
|
||
if (! ptr) {
|
||
ptr = (void *) MORECORE_FAILURE;
|
||
goto mmap_exit;
|
||
}
|
||
/* Assert postconditions */
|
||
assert ((unsigned) ptr % g_regionsize == 0);
|
||
#ifdef TRACE
|
||
printf ("Commit %p %d\n", ptr, size);
|
||
#endif
|
||
mmap_exit:
|
||
#if defined (USE_MALLOC_LOCK) && defined (NEEDED)
|
||
/* Release spin lock */
|
||
slrelease (&g_sl);
|
||
#endif
|
||
return ptr;
|
||
}
|
||
|
||
/* munmap for windows */
|
||
static long munmap (void *ptr, long size) {
|
||
static long g_pagesize;
|
||
static long g_regionsize;
|
||
int rc = MUNMAP_FAILURE;
|
||
#ifdef TRACE
|
||
printf ("munmap %p %d\n", ptr, size);
|
||
#endif
|
||
#if defined (USE_MALLOC_LOCK) && defined (NEEDED)
|
||
/* Wait for spin lock */
|
||
slwait (&g_sl);
|
||
#endif
|
||
/* First time initialization */
|
||
if (! g_pagesize)
|
||
g_pagesize = getpagesize ();
|
||
if (! g_regionsize)
|
||
g_regionsize = getregionsize ();
|
||
/* Assert preconditions */
|
||
assert ((unsigned) ptr % g_regionsize == 0);
|
||
assert (size % g_pagesize == 0);
|
||
/* Free this */
|
||
if (! VirtualFree (ptr, 0,
|
||
MEM_RELEASE))
|
||
goto munmap_exit;
|
||
rc = 0;
|
||
#ifdef TRACE
|
||
printf ("Release %p %d\n", ptr, size);
|
||
#endif
|
||
munmap_exit:
|
||
#if defined (USE_MALLOC_LOCK) && defined (NEEDED)
|
||
/* Release spin lock */
|
||
slrelease (&g_sl);
|
||
#endif
|
||
return rc;
|
||
}
|
||
|
||
static void vminfo (unsigned long *free, unsigned long *reserved, unsigned long *committed) {
|
||
MEMORY_BASIC_INFORMATION memory_info;
|
||
memory_info.BaseAddress = 0;
|
||
*free = *reserved = *committed = 0;
|
||
while (VirtualQuery (memory_info.BaseAddress, &memory_info, sizeof (memory_info))) {
|
||
switch (memory_info.State) {
|
||
case MEM_FREE:
|
||
*free += memory_info.RegionSize;
|
||
break;
|
||
case MEM_RESERVE:
|
||
*reserved += memory_info.RegionSize;
|
||
break;
|
||
case MEM_COMMIT:
|
||
*committed += memory_info.RegionSize;
|
||
break;
|
||
}
|
||
memory_info.BaseAddress = (char *) memory_info.BaseAddress + memory_info.RegionSize;
|
||
}
|
||
}
|
||
|
||
static int cpuinfo (int whole, unsigned long *kernel, unsigned long *user) {
|
||
if (whole) {
|
||
__int64 creation64, exit64, kernel64, user64;
|
||
int rc = GetProcessTimes (GetCurrentProcess (),
|
||
(FILETIME *) &creation64,
|
||
(FILETIME *) &exit64,
|
||
(FILETIME *) &kernel64,
|
||
(FILETIME *) &user64);
|
||
if (! rc) {
|
||
*kernel = 0;
|
||
*user = 0;
|
||
return FALSE;
|
||
}
|
||
*kernel = (unsigned long) (kernel64 / 10000);
|
||
*user = (unsigned long) (user64 / 10000);
|
||
return TRUE;
|
||
} else {
|
||
__int64 creation64, exit64, kernel64, user64;
|
||
int rc = GetThreadTimes (GetCurrentThread (),
|
||
(FILETIME *) &creation64,
|
||
(FILETIME *) &exit64,
|
||
(FILETIME *) &kernel64,
|
||
(FILETIME *) &user64);
|
||
if (! rc) {
|
||
*kernel = 0;
|
||
*user = 0;
|
||
return FALSE;
|
||
}
|
||
*kernel = (unsigned long) (kernel64 / 10000);
|
||
*user = (unsigned long) (user64 / 10000);
|
||
return TRUE;
|
||
}
|
||
}
|
||
|
||
#endif /* WIN32 */
|
||
|
||
/*
|
||
|
||
History:
|
||
|
||
V2.7.0
|
||
* new WIN32 sbrk, mmap, munmap, lock code from <Walter@GeNeSys-e.de>.
|
||
* Allow override of MALLOC_ALIGNMENT (Thanks to Ruud Waij for
|
||
helping test this.)
|
||
* memalign: check alignment arg
|
||
* realloc: use memmove when regions may overlap.
|
||
* Collect all cases in malloc requiring system memory into sYSMALLOc
|
||
* Use mmap as backup to sbrk, if available; fold these mmap-related
|
||
operations into others.
|
||
* Place all internal state in malloc_state
|
||
* Introduce fastbins (although similar to 2.5.1)
|
||
* Many minor tunings and cosmetic improvements
|
||
* Introduce USE_PUBLIC_MALLOC_WRAPPERS, USE_MALLOC_LOCK
|
||
* Introduce MALLOC_FAILURE_ACTION, MORECORE_CONTIGUOUS
|
||
Thanks to Tony E. Bennett <tbennett@nvidia.com> and others.
|
||
* Adjust request2size to fit with MALLOC_FAILURE_ACTION.
|
||
* Include errno.h to support default failure action.
|
||
* Further improve WIN32 'sbrk()' emulation's 'findRegion()' routine
|
||
to avoid infinite loop when allocating initial memory larger
|
||
than RESERVED_SIZE and/or subsequent memory larger than
|
||
NEXT_SIZE. Thanks to Andreas Mueller <a.mueller at paradatec.de>
|
||
for finding this one.
|
||
|
||
V2.6.6 Sun Dec 5 07:42:19 1999 Doug Lea (dl at gee)
|
||
* return null for negative arguments
|
||
* Added Several WIN32 cleanups from Martin C. Fong <mcfong at yahoo.com>
|
||
* Add 'LACKS_SYS_PARAM_H' for those systems without 'sys/param.h'
|
||
(e.g. WIN32 platforms)
|
||
* Cleanup header file inclusion for WIN32 platforms
|
||
* Cleanup code to avoid Microsoft Visual C++ compiler complaints
|
||
* Add 'USE_DL_PREFIX' to quickly allow co-existence with existing
|
||
memory allocation routines
|
||
* Set 'malloc_getpagesize' for WIN32 platforms (needs more work)
|
||
* Use 'assert' rather than 'ASSERT' in WIN32 code to conform to
|
||
usage of 'assert' in non-WIN32 code
|
||
* Improve WIN32 'sbrk()' emulation's 'findRegion()' routine to
|
||
avoid infinite loop
|
||
* Always call 'fREe()' rather than 'free()'
|
||
|
||
V2.6.5 Wed Jun 17 15:57:31 1998 Doug Lea (dl at gee)
|
||
* Fixed ordering problem with boundary-stamping
|
||
|
||
V2.6.3 Sun May 19 08:17:58 1996 Doug Lea (dl at gee)
|
||
* Added pvalloc, as recommended by H.J. Liu
|
||
* Added 64bit pointer support mainly from Wolfram Gloger
|
||
* Added anonymously donated WIN32 sbrk emulation
|
||
* Malloc, calloc, getpagesize: add optimizations from Raymond Nijssen
|
||
* malloc_extend_top: fix mask error that caused wastage after
|
||
foreign sbrks
|
||
* Add linux mremap support code from HJ Liu
|
||
|
||
V2.6.2 Tue Dec 5 06:52:55 1995 Doug Lea (dl at gee)
|
||
* Integrated most documentation with the code.
|
||
* Add support for mmap, with help from
|
||
Wolfram Gloger (Gloger@lrz.uni-muenchen.de).
|
||
* Use last_remainder in more cases.
|
||
* Pack bins using idea from colin@nyx10.cs.du.edu
|
||
* Use ordered bins instead of best-fit threshhold
|
||
* Eliminate block-local decls to simplify tracing and debugging.
|
||
* Support another case of realloc via move into top
|
||
* Fix error occuring when initial sbrk_base not word-aligned.
|
||
* Rely on page size for units instead of SBRK_UNIT to
|
||
avoid surprises about sbrk alignment conventions.
|
||
* Add mallinfo, mallopt. Thanks to Raymond Nijssen
|
||
(raymond@es.ele.tue.nl) for the suggestion.
|
||
* Add `pad' argument to malloc_trim and top_pad mallopt parameter.
|
||
* More precautions for cases where other routines call sbrk,
|
||
courtesy of Wolfram Gloger (Gloger@lrz.uni-muenchen.de).
|
||
* Added macros etc., allowing use in linux libc from
|
||
H.J. Lu (hjl@gnu.ai.mit.edu)
|
||
* Inverted this history list
|
||
|
||
V2.6.1 Sat Dec 2 14:10:57 1995 Doug Lea (dl at gee)
|
||
* Re-tuned and fixed to behave more nicely with V2.6.0 changes.
|
||
* Removed all preallocation code since under current scheme
|
||
the work required to undo bad preallocations exceeds
|
||
the work saved in good cases for most test programs.
|
||
* No longer use return list or unconsolidated bins since
|
||
no scheme using them consistently outperforms those that don't
|
||
given above changes.
|
||
* Use best fit for very large chunks to prevent some worst-cases.
|
||
* Added some support for debugging
|
||
|
||
V2.6.0 Sat Nov 4 07:05:23 1995 Doug Lea (dl at gee)
|
||
* Removed footers when chunks are in use. Thanks to
|
||
Paul Wilson (wilson@cs.texas.edu) for the suggestion.
|
||
|
||
V2.5.4 Wed Nov 1 07:54:51 1995 Doug Lea (dl at gee)
|
||
* Added malloc_trim, with help from Wolfram Gloger
|
||
(wmglo@Dent.MED.Uni-Muenchen.DE).
|
||
|
||
V2.5.3 Tue Apr 26 10:16:01 1994 Doug Lea (dl at g)
|
||
|
||
V2.5.2 Tue Apr 5 16:20:40 1994 Doug Lea (dl at g)
|
||
* realloc: try to expand in both directions
|
||
* malloc: swap order of clean-bin strategy;
|
||
* realloc: only conditionally expand backwards
|
||
* Try not to scavenge used bins
|
||
* Use bin counts as a guide to preallocation
|
||
* Occasionally bin return list chunks in first scan
|
||
* Add a few optimizations from colin@nyx10.cs.du.edu
|
||
|
||
V2.5.1 Sat Aug 14 15:40:43 1993 Doug Lea (dl at g)
|
||
* faster bin computation & slightly different binning
|
||
* merged all consolidations to one part of malloc proper
|
||
(eliminating old malloc_find_space & malloc_clean_bin)
|
||
* Scan 2 returns chunks (not just 1)
|
||
* Propagate failure in realloc if malloc returns 0
|
||
* Add stuff to allow compilation on non-ANSI compilers
|
||
from kpv@research.att.com
|
||
|
||
V2.5 Sat Aug 7 07:41:59 1993 Doug Lea (dl at g.oswego.edu)
|
||
* removed potential for odd address access in prev_chunk
|
||
* removed dependency on getpagesize.h
|
||
* misc cosmetics and a bit more internal documentation
|
||
* anticosmetics: mangled names in macros to evade debugger strangeness
|
||
* tested on sparc, hp-700, dec-mips, rs6000
|
||
with gcc & native cc (hp, dec only) allowing
|
||
Detlefs & Zorn comparison study (in SIGPLAN Notices.)
|
||
|
||
Trial version Fri Aug 28 13:14:29 1992 Doug Lea (dl at g.oswego.edu)
|
||
* Based loosely on libg++-1.2X malloc. (It retains some of the overall
|
||
structure of old version, but most details differ.)
|
||
|
||
*/
|
||
|
||
|