gecko-dev/nsprpub/pr/include/prmem.h
1998-03-28 02:44:41 +00:00

244 lines
9.5 KiB
C

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
/*
** File: prmem.h
** Description: API to NSPR 2.0 memory management functions
**
*/
#ifndef prmem_h___
#define prmem_h___
#include "prtypes.h"
#include <stddef.h>
#include <stdlib.h>
PR_BEGIN_EXTERN_C
/*
** Thread safe memory allocation.
**
** NOTE: pr wraps up malloc, free, calloc, realloc so they are already
** thread safe (and are not declared here - look in stdlib.h).
*/
/*
** PR_Malloc, PR_Calloc, PR_Realloc, and PR_Free have the same signatures
** as their libc equivalent malloc, calloc, realloc, and free, and have
** the same semantics. (Note that the argument type size_t is replaced
** by PRUint32.) Memory allocated by PR_Malloc, PR_Calloc, or PR_Realloc
** must be freed by PR_Free.
*/
PR_EXTERN(void *) PR_Malloc(PRUint32 size);
PR_EXTERN(void *) PR_Calloc(PRUint32 nelem, PRUint32 elsize);
PR_EXTERN(void *) PR_Realloc(void *ptr, PRUint32 size);
PR_EXTERN(void) PR_Free(void *ptr);
/*
** The following are some convenience macros defined in terms of
** PR_Malloc, PR_Calloc, PR_Realloc, and PR_Free.
*/
/***********************************************************************
** FUNCTION: PR_MALLOC()
** DESCRIPTION:
** PR_NEW() allocates an untyped item of size _size from the heap.
** INPUTS: _size: size in bytes of item to be allocated
** OUTPUTS: untyped pointer to the node allocated
** RETURN: pointer to node or error returned from malloc().
***********************************************************************/
#define PR_MALLOC(_bytes) (PR_Malloc((_bytes)))
/***********************************************************************
** FUNCTION: PR_NEW()
** DESCRIPTION:
** PR_NEW() allocates an item of type _struct from the heap.
** INPUTS: _struct: a data type
** OUTPUTS: pointer to _struct
** RETURN: pointer to _struct or error returns from malloc().
***********************************************************************/
#define PR_NEW(_struct) ((_struct *) PR_MALLOC(sizeof(_struct)))
/***********************************************************************
** FUNCTION: PR_REALLOC()
** DESCRIPTION:
** PR_REALLOC() re-allocates _ptr bytes from the heap as a _size
** untyped item.
** INPUTS: _ptr: pointer to node to reallocate
** _size: size of node to allocate
** OUTPUTS: pointer to node allocated
** RETURN: pointer to node allocated
***********************************************************************/
#define PR_REALLOC(_ptr, _size) (PR_Realloc((_ptr), (_size)))
/***********************************************************************
** FUNCTION: PR_CALLOC()
** DESCRIPTION:
** PR_CALLOC() allocates a _size bytes untyped item from the heap
** and sets the allocated memory to all 0x00.
** INPUTS: _size: size of node to allocate
** OUTPUTS: pointer to node allocated
** RETURN: pointer to node allocated
***********************************************************************/
#define PR_CALLOC(_size) (PR_Calloc(1, (_size)))
/***********************************************************************
** FUNCTION: PR_NEWZAP()
** DESCRIPTION:
** PR_NEWZAP() allocates an item of type _struct from the heap
** and sets the allocated memory to all 0x00.
** INPUTS: _struct: a data type
** OUTPUTS: pointer to _struct
** RETURN: pointer to _struct
***********************************************************************/
#define PR_NEWZAP(_struct) ((_struct*)PR_Calloc(1, sizeof(_struct)))
/***********************************************************************
** FUNCTION: PR_DELETE()
** DESCRIPTION:
** PR_DELETE() unallocates an object previosly allocated via PR_NEW()
** or PR_NEWZAP() to the heap.
** INPUTS: pointer to previously allocated object
** OUTPUTS: the referenced object is returned to the heap
** RETURN: void
***********************************************************************/
#define PR_DELETE(_ptr) { PR_Free(_ptr); (_ptr) = NULL; }
/***********************************************************************
** FUNCTION: PR_FREEIF()
** DESCRIPTION:
** PR_FREEIF() conditionally unallocates an object previously allocated
** vial PR_NEW() or PR_NEWZAP(). If the pointer to the object is
** equal to zero (0), the object is not released.
** INPUTS: pointer to previously allocated object
** OUTPUTS: the referenced object is conditionally returned to the heap
** RETURN: void
***********************************************************************/
#define PR_FREEIF(_ptr) if (_ptr) PR_DELETE(_ptr)
/***********************************************************************
** Typedef ENUM: PRSegmentAccess
** DESCRIPTION:
** Defines a number of segment accessor types for PR_Seg* functions
**
***********************************************************************/
typedef struct PRSegment PRSegment;
typedef enum {
PR_SEGMENT_NONE,
PR_SEGMENT_RDONLY,
PR_SEGMENT_RDWR
} PRSegmentAccess;
/***********************************************************************
** FUNCTION: PR_NewSegment()
** DESCRIPTION:
** Allocate a memory segment. The "size" value is rounded up to the
** native system page size and a page aligned portion of memory is
** returned. This memory is not part of the malloc heap. If "vaddr" is
** not NULL then PR tries to allocate the segment at the desired virtual
** address. Segments are mapped PR_SEGMENT_RDWR when created.
** INPUTS: size: size of the desired memory segment
** vaddr: address at which the newly aquired segment is to be
** mapped into memory.
** OUTPUTS: a memory segment is allocated, a PRSegment is allocated
** RETURN: pointer to PRSegment
***********************************************************************/
PR_EXTERN(PRSegment*) PR_NewSegment(PRUint32 size, void *vaddr);
/***********************************************************************
** FUNCTION: PR_DestroySegment()
** DESCRIPTION:
** The memory segment and the PRSegment are freed
** INPUTS: seg: pointer to PRSegment to be freed
** OUTPUTS: the the PRSegment and its associated memory segment are freed
** RETURN: void
***********************************************************************/
PR_EXTERN(void) PR_DestroySegment(PRSegment *seg);
/***********************************************************************
** FUNCTION: PR_GrowSegment()
** DESCRIPTION:
** Attempt to grow/shrink a memory segment. If deltaBytes is positive,
** the segment is grown. If deltaBytes is negative, the segment is
** shrunk. This returns the number of bytes added to the segment if
** successful, zero otherwise.
** INPUTS: seg: pointer to a PRSegment
** OUTPUTS:
** RETURN: PRUint32: number of bytes added to the memory segment or zero
***********************************************************************/
PR_EXTERN(PRUint32) PR_GrowSegment(PRSegment *seg, PRInt32 deltaBytes);
/***********************************************************************
** FUNCTION: PR_GetSegmentVaddr()
** DESCRIPTION:
** PR_Segment member accessor function.
** Return the virtual address of the memory segment
**
** INPUTS: seg: pointer to a PRSegment
** OUTPUTS: none
** RETURN: void*: Address where the memory segment is mapped.
***********************************************************************/
PR_EXTERN(void*) PR_GetSegmentVaddr(PRSegment *seg);
/***********************************************************************
** FUNCTION: PR_GetSegmentSize()
** DESCRIPTION:
** PR_Segment member accessor function.
** Return the size of the associated memory segment
** INPUTS: seg: pointer to a PRSegment
** OUTPUTS: none
** RETURN: size_t: size of the associated memory segment
***********************************************************************/
PR_EXTERN(size_t) PR_GetSegmentSize(PRSegment *seg);
/***********************************************************************
** FUNCTION: PR_MapSegment()
** DESCRIPTION:
** Change the mapping on a segment.
** "how" == PR_SEGMENT_NONE: the segment becomes unmapped
** "how" == PR_SEGMENT_RDONLY: the segment becomes mapped and readable
** "how" == PR_SEGMENT_RDWR: the segment becomes mapped read/write
**
** Note: If a segment can be read then it is also possible to execute
** code in it.
** INPUTS: seg: pointer to a PRSegment
** how: one of PRSegmentAccess enumerated values
** OUTPUTS: the access for the associated memory segment is changed
** RETURN: void
***********************************************************************/
PR_EXTERN(void) PR_MapSegment(PRSegment *seg, PRSegmentAccess how);
/***********************************************************************
** FUNCTION: PR_GetSegmentAccess()
** DESCRIPTION:
** PR_Segment member accessor function.
** Return a memory segment's current access rights
** INPUTS: seg: pointer to a PRSegment
** OUTPUTS:
** RETURN: PRSegmentAccess: current access rights
***********************************************************************/
PR_EXTERN(PRSegmentAccess) PR_GetSegmentAccess(PRSegment *seg);
PR_END_EXTERN_C
#endif /* prmem_h___ */