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40760d12ba
darling-objc4/runtime/objc-private.h
Ariel Abreu 4d6225bbe3
objc4-781.2
2020-06-09 21:50:17 -04:00

1120 lines
32 KiB
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/*
* Copyright (c) 1999-2007 Apple Inc. All Rights Reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
/*
* objc-private.h
* Copyright 1988-1996, NeXT Software, Inc.
*/
#ifndef _OBJC_PRIVATE_H_
#define _OBJC_PRIVATE_H_
#include "objc-config.h"
/* Isolate ourselves from the definitions of id and Class in the compiler
* and public headers.
*/
#ifdef _OBJC_OBJC_H_
#error include objc-private.h before other headers
#endif
#define OBJC_TYPES_DEFINED 1
#undef OBJC_OLD_DISPATCH_PROTOTYPES
#define OBJC_OLD_DISPATCH_PROTOTYPES 0
#include <cstddef> // for nullptr_t
#include <stdint.h>
#include <assert.h>
// An assert that's disabled for release builds but still ensures the expression compiles.
#ifdef NDEBUG
#define ASSERT(x) (void)sizeof(!(x))
#else
#define ASSERT(x) assert(x)
#endif
struct objc_class;
struct objc_object;
typedef struct objc_class *Class;
typedef struct objc_object *id;
namespace {
struct SideTable;
};
#include "isa.h"
union isa_t {
isa_t() { }
isa_t(uintptr_t value) : bits(value) { }
Class cls;
uintptr_t bits;
#if defined(ISA_BITFIELD)
struct {
ISA_BITFIELD; // defined in isa.h
};
#endif
};
struct objc_object {
private:
isa_t isa;
public:
// ISA() assumes this is NOT a tagged pointer object
Class ISA();
// rawISA() assumes this is NOT a tagged pointer object or a non pointer ISA
Class rawISA();
// getIsa() allows this to be a tagged pointer object
Class getIsa();
uintptr_t isaBits() const;
// initIsa() should be used to init the isa of new objects only.
// If this object already has an isa, use changeIsa() for correctness.
// initInstanceIsa(): objects with no custom RR/AWZ
// initClassIsa(): class objects
// initProtocolIsa(): protocol objects
// initIsa(): other objects
void initIsa(Class cls /*nonpointer=false*/);
void initClassIsa(Class cls /*nonpointer=maybe*/);
void initProtocolIsa(Class cls /*nonpointer=maybe*/);
void initInstanceIsa(Class cls, bool hasCxxDtor);
// changeIsa() should be used to change the isa of existing objects.
// If this is a new object, use initIsa() for performance.
Class changeIsa(Class newCls);
bool hasNonpointerIsa();
bool isTaggedPointer();
bool isBasicTaggedPointer();
bool isExtTaggedPointer();
bool isClass();
// object may have associated objects?
bool hasAssociatedObjects();
void setHasAssociatedObjects();
// object may be weakly referenced?
bool isWeaklyReferenced();
void setWeaklyReferenced_nolock();
// object may have -.cxx_destruct implementation?
bool hasCxxDtor();
// Optimized calls to retain/release methods
id retain();
void release();
id autorelease();
// Implementations of retain/release methods
id rootRetain();
bool rootRelease();
id rootAutorelease();
bool rootTryRetain();
bool rootReleaseShouldDealloc();
uintptr_t rootRetainCount();
// Implementation of dealloc methods
bool rootIsDeallocating();
void clearDeallocating();
void rootDealloc();
private:
void initIsa(Class newCls, bool nonpointer, bool hasCxxDtor);
// Slow paths for inline control
id rootAutorelease2();
uintptr_t overrelease_error();
#if SUPPORT_NONPOINTER_ISA
// Unified retain count manipulation for nonpointer isa
id rootRetain(bool tryRetain, bool handleOverflow);
bool rootRelease(bool performDealloc, bool handleUnderflow);
id rootRetain_overflow(bool tryRetain);
uintptr_t rootRelease_underflow(bool performDealloc);
void clearDeallocating_slow();
// Side table retain count overflow for nonpointer isa
void sidetable_lock();
void sidetable_unlock();
void sidetable_moveExtraRC_nolock(size_t extra_rc, bool isDeallocating, bool weaklyReferenced);
bool sidetable_addExtraRC_nolock(size_t delta_rc);
size_t sidetable_subExtraRC_nolock(size_t delta_rc);
size_t sidetable_getExtraRC_nolock();
#endif
// Side-table-only retain count
bool sidetable_isDeallocating();
void sidetable_clearDeallocating();
bool sidetable_isWeaklyReferenced();
void sidetable_setWeaklyReferenced_nolock();
id sidetable_retain();
id sidetable_retain_slow(SideTable& table);
uintptr_t sidetable_release(bool performDealloc = true);
uintptr_t sidetable_release_slow(SideTable& table, bool performDealloc = true);
bool sidetable_tryRetain();
uintptr_t sidetable_retainCount();
#if DEBUG
bool sidetable_present();
#endif
};
#if __OBJC2__
typedef struct method_t *Method;
typedef struct ivar_t *Ivar;
typedef struct category_t *Category;
typedef struct property_t *objc_property_t;
#else
typedef struct old_method *Method;
typedef struct old_ivar *Ivar;
typedef struct old_category *Category;
typedef struct old_property *objc_property_t;
#endif
// Public headers
#include "objc.h"
#include "runtime.h"
#include "objc-os.h"
#include "objc-abi.h"
#include "objc-api.h"
#include "objc-config.h"
#include "objc-internal.h"
#include "maptable.h"
#include "hashtable2.h"
/* Do not include message.h here. */
/* #include "message.h" */
#define __APPLE_API_PRIVATE
#include "objc-gdb.h"
#undef __APPLE_API_PRIVATE
// Private headers
#include "objc-ptrauth.h"
#if __OBJC2__
#include "objc-runtime-new.h"
#else
#include "objc-runtime-old.h"
#endif
#include "objc-references.h"
#include "objc-initialize.h"
#include "objc-loadmethod.h"
#if SUPPORT_PREOPT && __cplusplus
#include <objc-shared-cache.h>
using objc_selopt_t = const objc_opt::objc_selopt_t;
#else
struct objc_selopt_t;
#endif
#define STRINGIFY(x) #x
#define STRINGIFY2(x) STRINGIFY(x)
__BEGIN_DECLS
namespace objc {
struct SafeRanges {
private:
struct Range {
uintptr_t start;
uintptr_t end;
inline bool contains(uintptr_t ptr) const {
uintptr_t m_start, m_end;
#if __arm64__
// <rdar://problem/48304934> Force the compiler to use ldp
// we really don't want 2 loads and 2 jumps.
__asm__(
# if __LP64__
"ldp %x[one], %x[two], [%x[src]]"
# else
"ldp %w[one], %w[two], [%x[src]]"
# endif
: [one] "=r" (m_start), [two] "=r" (m_end)
: [src] "r" (this)
);
#else
m_start = start;
m_end = end;
#endif
return m_start <= ptr && ptr < m_end;
}
};
struct Range *ranges;
uint32_t count;
uint32_t size : 31;
uint32_t sorted : 1;
public:
inline bool contains(uint16_t witness, uintptr_t ptr) const {
return witness < count && ranges[witness].contains(ptr);
}
bool find(uintptr_t ptr, uint32_t &pos);
void add(uintptr_t start, uintptr_t end);
void remove(uintptr_t start, uintptr_t end);
};
extern struct SafeRanges dataSegmentsRanges;
} // objc
struct header_info;
// Split out the rw data from header info. For now put it in a huge array
// that more than exceeds the space needed. In future we'll just allocate
// this in the shared cache builder.
typedef struct header_info_rw {
bool getLoaded() const {
return isLoaded;
}
void setLoaded(bool v) {
isLoaded = v ? 1: 0;
}
bool getAllClassesRealized() const {
return allClassesRealized;
}
void setAllClassesRealized(bool v) {
allClassesRealized = v ? 1: 0;
}
header_info *getNext() const {
return (header_info *)(next << 2);
}
void setNext(header_info *v) {
next = ((uintptr_t)v) >> 2;
}
private:
#ifdef __LP64__
uintptr_t isLoaded : 1;
uintptr_t allClassesRealized : 1;
uintptr_t next : 62;
#else
uintptr_t isLoaded : 1;
uintptr_t allClassesRealized : 1;
uintptr_t next : 30;
#endif
} header_info_rw;
struct header_info_rw* getPreoptimizedHeaderRW(const struct header_info *const hdr);
typedef struct header_info {
private:
// Note, this is no longer a pointer, but instead an offset to a pointer
// from this location.
intptr_t mhdr_offset;
// Note, this is no longer a pointer, but instead an offset to a pointer
// from this location.
intptr_t info_offset;
// Do not add fields without editing ObjCModernAbstraction.hpp
public:
header_info_rw *getHeaderInfoRW() {
header_info_rw *preopt =
isPreoptimized() ? getPreoptimizedHeaderRW(this) : nil;
if (preopt) return preopt;
else return &rw_data[0];
}
const headerType *mhdr() const {
return (const headerType *)(((intptr_t)&mhdr_offset) + mhdr_offset);
}
void setmhdr(const headerType *mhdr) {
mhdr_offset = (intptr_t)mhdr - (intptr_t)&mhdr_offset;
}
const objc_image_info *info() const {
return (const objc_image_info *)(((intptr_t)&info_offset) + info_offset);
}
void setinfo(const objc_image_info *info) {
info_offset = (intptr_t)info - (intptr_t)&info_offset;
}
bool isLoaded() {
return getHeaderInfoRW()->getLoaded();
}
void setLoaded(bool v) {
getHeaderInfoRW()->setLoaded(v);
}
bool areAllClassesRealized() {
return getHeaderInfoRW()->getAllClassesRealized();
}
void setAllClassesRealized(bool v) {
getHeaderInfoRW()->setAllClassesRealized(v);
}
header_info *getNext() {
return getHeaderInfoRW()->getNext();
}
void setNext(header_info *v) {
getHeaderInfoRW()->setNext(v);
}
bool isBundle() {
return mhdr()->filetype == MH_BUNDLE;
}
const char *fname() const {
return dyld_image_path_containing_address(mhdr());
}
bool isPreoptimized() const;
bool hasPreoptimizedSelectors() const;
bool hasPreoptimizedClasses() const;
bool hasPreoptimizedProtocols() const;
#if !__OBJC2__
struct old_protocol **proto_refs;
struct objc_module *mod_ptr;
size_t mod_count;
# if TARGET_OS_WIN32
struct objc_module **modules;
size_t moduleCount;
struct old_protocol **protocols;
size_t protocolCount;
void *imageinfo;
size_t imageinfoBytes;
SEL *selrefs;
size_t selrefCount;
struct objc_class **clsrefs;
size_t clsrefCount;
TCHAR *moduleName;
# endif
#endif
private:
// Images in the shared cache will have an empty array here while those
// allocated at run time will allocate a single entry.
header_info_rw rw_data[];
} header_info;
extern header_info *FirstHeader;
extern header_info *LastHeader;
extern void appendHeader(header_info *hi);
extern void removeHeader(header_info *hi);
extern objc_image_info *_getObjcImageInfo(const headerType *head, size_t *size);
extern bool _hasObjcContents(const header_info *hi);
// Mach-O segment and section names are 16 bytes and may be un-terminated.
static inline bool segnameEquals(const char *lhs, const char *rhs) {
return 0 == strncmp(lhs, rhs, 16);
}
static inline bool segnameStartsWith(const char *segname, const char *prefix) {
return 0 == strncmp(segname, prefix, strlen(prefix));
}
static inline bool sectnameEquals(const char *lhs, const char *rhs) {
return segnameEquals(lhs, rhs);
}
static inline bool sectnameStartsWith(const char *sectname, const char *prefix){
return segnameStartsWith(sectname, prefix);
}
#if __OBJC2__
extern bool didCallDyldNotifyRegister;
#endif
/* selectors */
extern void sel_init(size_t selrefCount);
extern SEL sel_registerNameNoLock(const char *str, bool copy);
extern SEL SEL_cxx_construct;
extern SEL SEL_cxx_destruct;
/* preoptimization */
extern void preopt_init(void);
extern void disableSharedCacheOptimizations(void);
extern bool isPreoptimized(void);
extern bool noMissingWeakSuperclasses(void);
extern header_info *preoptimizedHinfoForHeader(const headerType *mhdr);
extern objc_selopt_t *preoptimizedSelectors(void);
extern bool sharedCacheSupportsProtocolRoots(void);
extern Protocol *getPreoptimizedProtocol(const char *name);
extern Protocol *getSharedCachePreoptimizedProtocol(const char *name);
extern unsigned getPreoptimizedClassUnreasonableCount();
extern Class getPreoptimizedClass(const char *name);
extern Class* copyPreoptimizedClasses(const char *name, int *outCount);
extern Class _calloc_class(size_t size);
/* method lookup */
enum {
LOOKUP_INITIALIZE = 1,
LOOKUP_RESOLVER = 2,
LOOKUP_CACHE = 4,
LOOKUP_NIL = 8,
};
extern IMP lookUpImpOrForward(id obj, SEL, Class cls, int behavior);
static inline IMP
lookUpImpOrNil(id obj, SEL sel, Class cls, int behavior = 0)
{
return lookUpImpOrForward(obj, sel, cls, behavior | LOOKUP_CACHE | LOOKUP_NIL);
}
extern IMP lookupMethodInClassAndLoadCache(Class cls, SEL sel);
extern BOOL class_respondsToSelector_inst(id inst, SEL sel, Class cls);
extern Class class_initialize(Class cls, id inst);
extern bool objcMsgLogEnabled;
extern bool logMessageSend(bool isClassMethod,
const char *objectsClass,
const char *implementingClass,
SEL selector);
/* message dispatcher */
#if !OBJC_OLD_DISPATCH_PROTOTYPES
extern void _objc_msgForward_impcache(void);
#else
extern id _objc_msgForward_impcache(id, SEL, ...);
#endif
/* errors */
extern id(*badAllocHandler)(Class);
extern id _objc_callBadAllocHandler(Class cls) __attribute__((cold, noinline));
extern void __objc_error(id, const char *, ...) __attribute__((cold, format (printf, 2, 3), noreturn));
extern void _objc_inform(const char *fmt, ...) __attribute__((cold, format(printf, 1, 2)));
extern void _objc_inform_on_crash(const char *fmt, ...) __attribute__((cold, format (printf, 1, 2)));
extern void _objc_inform_now_and_on_crash(const char *fmt, ...) __attribute__((cold, format (printf, 1, 2)));
extern void _objc_inform_deprecated(const char *oldname, const char *newname) __attribute__((cold, noinline));
extern void inform_duplicate(const char *name, Class oldCls, Class cls);
/* magic */
extern Class _objc_getFreedObjectClass (void);
/* map table additions */
extern void *NXMapKeyCopyingInsert(NXMapTable *table, const void *key, const void *value);
extern void *NXMapKeyFreeingRemove(NXMapTable *table, const void *key);
/* hash table additions */
extern unsigned _NXHashCapacity(NXHashTable *table);
extern void _NXHashRehashToCapacity(NXHashTable *table, unsigned newCapacity);
/* property attribute parsing */
extern const char *copyPropertyAttributeString(const objc_property_attribute_t *attrs, unsigned int count);
extern objc_property_attribute_t *copyPropertyAttributeList(const char *attrs, unsigned int *outCount);
extern char *copyPropertyAttributeValue(const char *attrs, const char *name);
/* locking */
class monitor_locker_t : nocopy_t {
monitor_t& lock;
public:
monitor_locker_t(monitor_t& newLock) : lock(newLock) { lock.enter(); }
~monitor_locker_t() { lock.leave(); }
};
class recursive_mutex_locker_t : nocopy_t {
recursive_mutex_t& lock;
public:
recursive_mutex_locker_t(recursive_mutex_t& newLock)
: lock(newLock) { lock.lock(); }
~recursive_mutex_locker_t() { lock.unlock(); }
};
/* Exceptions */
struct alt_handler_list;
extern void exception_init(void);
extern void _destroyAltHandlerList(struct alt_handler_list *list);
/* Class change notifications (gdb only for now) */
#define OBJC_CLASS_ADDED (1<<0)
#define OBJC_CLASS_REMOVED (1<<1)
#define OBJC_CLASS_IVARS_CHANGED (1<<2)
#define OBJC_CLASS_METHODS_CHANGED (1<<3)
extern void gdb_objc_class_changed(Class cls, unsigned long changes, const char *classname)
__attribute__((noinline));
// Settings from environment variables
#define OPTION(var, env, help) extern bool var;
#include "objc-env.h"
#undef OPTION
extern void environ_init(void);
extern void runtime_init(void);
extern void logReplacedMethod(const char *className, SEL s, bool isMeta, const char *catName, IMP oldImp, IMP newImp);
// objc per-thread storage
typedef struct {
struct _objc_initializing_classes *initializingClasses; // for +initialize
struct SyncCache *syncCache; // for @synchronize
struct alt_handler_list *handlerList; // for exception alt handlers
char *printableNames[4]; // temporary demangled names for logging
const char **classNameLookups; // for objc_getClass() hooks
unsigned classNameLookupsAllocated;
unsigned classNameLookupsUsed;
// If you add new fields here, don't forget to update
// _objc_pthread_destroyspecific()
} _objc_pthread_data;
extern _objc_pthread_data *_objc_fetch_pthread_data(bool create);
extern void tls_init(void);
// encoding.h
extern unsigned int encoding_getNumberOfArguments(const char *typedesc);
extern unsigned int encoding_getSizeOfArguments(const char *typedesc);
extern unsigned int encoding_getArgumentInfo(const char *typedesc, unsigned int arg, const char **type, int *offset);
extern void encoding_getReturnType(const char *t, char *dst, size_t dst_len);
extern char * encoding_copyReturnType(const char *t);
extern void encoding_getArgumentType(const char *t, unsigned int index, char *dst, size_t dst_len);
extern char *encoding_copyArgumentType(const char *t, unsigned int index);
// sync.h
extern void _destroySyncCache(struct SyncCache *cache);
// arr
extern void arr_init(void);
extern id objc_autoreleaseReturnValue(id obj);
// block trampolines
extern void _imp_implementationWithBlock_init(void);
extern IMP _imp_implementationWithBlockNoCopy(id block);
// layout.h
typedef struct {
uint8_t *bits;
size_t bitCount;
size_t bitsAllocated;
bool weak;
} layout_bitmap;
extern layout_bitmap layout_bitmap_create(const unsigned char *layout_string, size_t layoutStringInstanceSize, size_t instanceSize, bool weak);
extern layout_bitmap layout_bitmap_create_empty(size_t instanceSize, bool weak);
extern void layout_bitmap_free(layout_bitmap bits);
extern const unsigned char *layout_string_create(layout_bitmap bits);
extern void layout_bitmap_set_ivar(layout_bitmap bits, const char *type, size_t offset);
extern void layout_bitmap_grow(layout_bitmap *bits, size_t newCount);
extern void layout_bitmap_slide(layout_bitmap *bits, size_t oldPos, size_t newPos);
extern void layout_bitmap_slide_anywhere(layout_bitmap *bits, size_t oldPos, size_t newPos);
extern bool layout_bitmap_splat(layout_bitmap dst, layout_bitmap src,
size_t oldSrcInstanceSize);
extern bool layout_bitmap_or(layout_bitmap dst, layout_bitmap src, const char *msg);
extern bool layout_bitmap_clear(layout_bitmap dst, layout_bitmap src, const char *msg);
extern void layout_bitmap_print(layout_bitmap bits);
// fixme runtime
extern bool MultithreadedForkChild;
extern id objc_noop_imp(id self, SEL _cmd);
extern Class look_up_class(const char *aClassName, bool includeUnconnected, bool includeClassHandler);
extern "C" void map_images(unsigned count, const char * const paths[],
const struct mach_header * const mhdrs[]);
extern void map_images_nolock(unsigned count, const char * const paths[],
const struct mach_header * const mhdrs[]);
extern void load_images(const char *path, const struct mach_header *mh);
extern void unmap_image(const char *path, const struct mach_header *mh);
extern void unmap_image_nolock(const struct mach_header *mh);
extern void _read_images(header_info **hList, uint32_t hCount, int totalClasses, int unoptimizedTotalClass);
extern void _unload_image(header_info *hi);
extern const header_info *_headerForClass(Class cls);
extern Class _class_remap(Class cls);
extern Ivar _class_getVariable(Class cls, const char *name);
extern unsigned _class_createInstancesFromZone(Class cls, size_t extraBytes, void *zone, id *results, unsigned num_requested);
extern const char *_category_getName(Category cat);
extern const char *_category_getClassName(Category cat);
extern Class _category_getClass(Category cat);
extern IMP _category_getLoadMethod(Category cat);
enum {
OBJECT_CONSTRUCT_NONE = 0,
OBJECT_CONSTRUCT_FREE_ONFAILURE = 1,
OBJECT_CONSTRUCT_CALL_BADALLOC = 2,
};
extern id object_cxxConstructFromClass(id obj, Class cls, int flags);
extern void object_cxxDestruct(id obj);
extern void fixupCopiedIvars(id newObject, id oldObject);
extern Class _class_getClassForIvar(Class cls, Ivar ivar);
#define OBJC_WARN_DEPRECATED \
do { \
static int warned = 0; \
if (!warned) { \
warned = 1; \
_objc_inform_deprecated(__FUNCTION__, NULL); \
} \
} while (0) \
__END_DECLS
#ifndef STATIC_ASSERT
# define STATIC_ASSERT(x) _STATIC_ASSERT2(x, __LINE__)
# define _STATIC_ASSERT2(x, line) _STATIC_ASSERT3(x, line)
# define _STATIC_ASSERT3(x, line) \
typedef struct { \
int _static_assert[(x) ? 0 : -1]; \
} _static_assert_ ## line __attribute__((unavailable))
#endif
#define countof(arr) (sizeof(arr) / sizeof((arr)[0]))
static __inline uint32_t _objc_strhash(const char *s) {
uint32_t hash = 0;
for (;;) {
int a = *s++;
if (0 == a) break;
hash += (hash << 8) + a;
}
return hash;
}
#if __cplusplus
template <typename T>
static inline T log2u(T x) {
return (x<2) ? 0 : log2u(x>>1)+1;
}
template <typename T>
static inline T exp2u(T x) {
return (1 << x);
}
template <typename T>
static T exp2m1u(T x) {
return (1 << x) - 1;
}
#endif
// Misalignment-safe integer types
__attribute__((aligned(1))) typedef uintptr_t unaligned_uintptr_t;
__attribute__((aligned(1))) typedef intptr_t unaligned_intptr_t;
__attribute__((aligned(1))) typedef uint64_t unaligned_uint64_t;
__attribute__((aligned(1))) typedef int64_t unaligned_int64_t;
__attribute__((aligned(1))) typedef uint32_t unaligned_uint32_t;
__attribute__((aligned(1))) typedef int32_t unaligned_int32_t;
__attribute__((aligned(1))) typedef uint16_t unaligned_uint16_t;
__attribute__((aligned(1))) typedef int16_t unaligned_int16_t;
// Global operator new and delete. We must not use any app overrides.
// This ALSO REQUIRES each of these be in libobjc's unexported symbol list.
#if __cplusplus
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Winline-new-delete"
#include <new>
inline void* operator new(std::size_t size) throw (std::bad_alloc) { return malloc(size); }
inline void* operator new[](std::size_t size) throw (std::bad_alloc) { return malloc(size); }
inline void* operator new(std::size_t size, const std::nothrow_t&) throw() { return malloc(size); }
inline void* operator new[](std::size_t size, const std::nothrow_t&) throw() { return malloc(size); }
inline void operator delete(void* p) throw() { free(p); }
inline void operator delete[](void* p) throw() { free(p); }
inline void operator delete(void* p, const std::nothrow_t&) throw() { free(p); }
inline void operator delete[](void* p, const std::nothrow_t&) throw() { free(p); }
#pragma clang diagnostic pop
#endif
class TimeLogger {
uint64_t mStart;
bool mRecord;
public:
TimeLogger(bool record = true)
: mStart(nanoseconds())
, mRecord(record)
{ }
void log(const char *msg) {
if (mRecord) {
uint64_t end = nanoseconds();
_objc_inform("%.2f ms: %s", (end - mStart) / 1000000.0, msg);
mStart = nanoseconds();
}
}
};
enum { CacheLineSize = 64 };
// StripedMap<T> is a map of void* -> T, sized appropriately
// for cache-friendly lock striping.
// For example, this may be used as StripedMap<spinlock_t>
// or as StripedMap<SomeStruct> where SomeStruct stores a spin lock.
template<typename T>
class StripedMap {
#if TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
enum { StripeCount = 8 };
#else
enum { StripeCount = 64 };
#endif
struct PaddedT {
T value alignas(CacheLineSize);
};
PaddedT array[StripeCount];
static unsigned int indexForPointer(const void *p) {
uintptr_t addr = reinterpret_cast<uintptr_t>(p);
return ((addr >> 4) ^ (addr >> 9)) % StripeCount;
}
public:
T& operator[] (const void *p) {
return array[indexForPointer(p)].value;
}
const T& operator[] (const void *p) const {
return const_cast<StripedMap<T>>(this)[p];
}
// Shortcuts for StripedMaps of locks.
void lockAll() {
for (unsigned int i = 0; i < StripeCount; i++) {
array[i].value.lock();
}
}
void unlockAll() {
for (unsigned int i = 0; i < StripeCount; i++) {
array[i].value.unlock();
}
}
void forceResetAll() {
for (unsigned int i = 0; i < StripeCount; i++) {
array[i].value.forceReset();
}
}
void defineLockOrder() {
for (unsigned int i = 1; i < StripeCount; i++) {
lockdebug_lock_precedes_lock(&array[i-1].value, &array[i].value);
}
}
void precedeLock(const void *newlock) {
// assumes defineLockOrder is also called
lockdebug_lock_precedes_lock(&array[StripeCount-1].value, newlock);
}
void succeedLock(const void *oldlock) {
// assumes defineLockOrder is also called
lockdebug_lock_precedes_lock(oldlock, &array[0].value);
}
const void *getLock(int i) {
if (i < StripeCount) return &array[i].value;
else return nil;
}
#if DEBUG
StripedMap() {
// Verify alignment expectations.
uintptr_t base = (uintptr_t)&array[0].value;
uintptr_t delta = (uintptr_t)&array[1].value - base;
ASSERT(delta % CacheLineSize == 0);
ASSERT(base % CacheLineSize == 0);
}
#else
constexpr StripedMap() {}
#endif
};
// DisguisedPtr<T> acts like pointer type T*, except the
// stored value is disguised to hide it from tools like `leaks`.
// nil is disguised as itself so zero-filled memory works as expected,
// which means 0x80..00 is also disguised as itself but we don't care.
// Note that weak_entry_t knows about this encoding.
template <typename T>
class DisguisedPtr {
uintptr_t value;
static uintptr_t disguise(T* ptr) {
return -(uintptr_t)ptr;
}
static T* undisguise(uintptr_t val) {
return (T*)-val;
}
public:
DisguisedPtr() { }
DisguisedPtr(T* ptr)
: value(disguise(ptr)) { }
DisguisedPtr(const DisguisedPtr<T>& ptr)
: value(ptr.value) { }
DisguisedPtr<T>& operator = (T* rhs) {
value = disguise(rhs);
return *this;
}
DisguisedPtr<T>& operator = (const DisguisedPtr<T>& rhs) {
value = rhs.value;
return *this;
}
operator T* () const {
return undisguise(value);
}
T* operator -> () const {
return undisguise(value);
}
T& operator * () const {
return *undisguise(value);
}
T& operator [] (size_t i) const {
return undisguise(value)[i];
}
// pointer arithmetic operators omitted
// because we don't currently use them anywhere
};
// fixme type id is weird and not identical to objc_object*
static inline bool operator == (DisguisedPtr<objc_object> lhs, id rhs) {
return lhs == (objc_object *)rhs;
}
static inline bool operator != (DisguisedPtr<objc_object> lhs, id rhs) {
return lhs != (objc_object *)rhs;
}
// Storage for a thread-safe chained hook function.
// get() returns the value for calling.
// set() installs a new function and returns the old one for chaining.
// More precisely, set() writes the old value to a variable supplied by
// the caller. get() and set() use appropriate barriers so that the
// old value is safely written to the variable before the new value is
// called to use it.
//
// T1: store to old variable; store-release to hook variable
// T2: load-acquire from hook variable; call it; called hook loads old variable
template <typename Fn>
class ChainedHookFunction {
std::atomic<Fn> hook{nil};
public:
ChainedHookFunction(Fn f) : hook{f} { };
Fn get() {
return hook.load(std::memory_order_acquire);
}
void set(Fn newValue, Fn *oldVariable)
{
Fn oldValue = hook.load(std::memory_order_relaxed);
do {
*oldVariable = oldValue;
} while (!hook.compare_exchange_weak(oldValue, newValue,
std::memory_order_release,
std::memory_order_relaxed));
}
};
// A small vector for use as a global variable. Only supports appending and
// iteration. Stores a single element inline, and multiple elements in a heap
// allocation. There is no attempt to amortize reallocation cost; this is
// intended to be used in situation where zero or one element is common, two
// might happen, and three or more is very rare.
//
// This does not clean up its allocation, and thus cannot be used as a local
// variable or member of something with limited lifetime.
template <typename T, unsigned InlineCount>
class GlobalSmallVector {
static_assert(std::is_pod<T>::value, "SmallVector requires POD types");
protected:
unsigned count{0};
union {
T inlineElements[InlineCount];
T *elements;
};
public:
void append(const T &val) {
if (count < InlineCount) {
// We have space. Store the new value inline.
inlineElements[count] = val;
} else if (count == InlineCount) {
// Inline storage is full. Switch to a heap allocation.
T *newElements = (T *)malloc((count + 1) * sizeof(T));
memcpy(newElements, inlineElements, count * sizeof(T));
newElements[count] = val;
elements = newElements;
} else {
// Resize the heap allocation and append.
elements = (T *)realloc(elements, (count + 1) * sizeof(T));
elements[count] = val;
}
count++;
}
const T *begin() const {
return count <= InlineCount ? inlineElements : elements;
}
const T *end() const {
return begin() + count;
}
};
// A small vector that cleans up its internal memory allocation when destroyed.
template <typename T, unsigned InlineCount>
class SmallVector: public GlobalSmallVector<T, InlineCount> {
public:
~SmallVector() {
if (this->count > InlineCount)
free(this->elements);
}
template <unsigned OtherCount>
void initFrom(const GlobalSmallVector<T, OtherCount> &other) {
ASSERT(this->count == 0);
this->count = (unsigned)(other.end() - other.begin());
if (this->count > InlineCount) {
this->elements = (T *)memdup(other.begin(), this->count * sizeof(T));
} else {
memcpy(this->inlineElements, other.begin(), this->count * sizeof(T));
}
}
};
// Pointer hash function.
// This is not a terrific hash, but it is fast
// and not outrageously flawed for our purposes.
// Based on principles from http://locklessinc.com/articles/fast_hash/
// and evaluation ideas from http://floodyberry.com/noncryptohashzoo/
#if __LP64__
static inline uint32_t ptr_hash(uint64_t key)
{
key ^= key >> 4;
key *= 0x8a970be7488fda55;
key ^= __builtin_bswap64(key);
return (uint32_t)key;
}
#else
static inline uint32_t ptr_hash(uint32_t key)
{
key ^= key >> 4;
key *= 0x5052acdb;
key ^= __builtin_bswap32(key);
return key;
}
#endif
/*
Higher-quality hash function. This is measurably slower in some workloads.
#if __LP64__
uint32_t ptr_hash(uint64_t key)
{
key -= __builtin_bswap64(key);
key *= 0x8a970be7488fda55;
key ^= __builtin_bswap64(key);
key *= 0x8a970be7488fda55;
key ^= __builtin_bswap64(key);
return (uint32_t)key;
}
#else
static uint32_t ptr_hash(uint32_t key)
{
key -= __builtin_bswap32(key);
key *= 0x5052acdb;
key ^= __builtin_bswap32(key);
key *= 0x5052acdb;
key ^= __builtin_bswap32(key);
return key;
}
#endif
*/
// Lock declarations
#include "objc-locks.h"
// Inlined parts of objc_object's implementation
#include "objc-object.h"
#endif /* _OBJC_PRIVATE_H_ */
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