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Diffstat (limited to 'nsprpub/pr/src/malloc/prmem.c')
-rw-r--r--nsprpub/pr/src/malloc/prmem.c694
1 files changed, 694 insertions, 0 deletions
diff --git a/nsprpub/pr/src/malloc/prmem.c b/nsprpub/pr/src/malloc/prmem.c
new file mode 100644
index 000000000..e4ae42a91
--- /dev/null
+++ b/nsprpub/pr/src/malloc/prmem.c
@@ -0,0 +1,694 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+** Thread safe versions of malloc, free, realloc, calloc and cfree.
+*/
+
+#include "primpl.h"
+
+#ifdef _PR_ZONE_ALLOCATOR
+
+/*
+** The zone allocator code must use native mutexes and cannot
+** use PRLocks because PR_NewLock calls PR_Calloc, resulting
+** in cyclic dependency of initialization.
+*/
+
+#include <string.h>
+
+union memBlkHdrUn;
+
+typedef struct MemoryZoneStr {
+ union memBlkHdrUn *head; /* free list */
+ pthread_mutex_t lock;
+ size_t blockSize; /* size of blocks on this free list */
+ PRUint32 locked; /* current state of lock */
+ PRUint32 contention; /* counter: had to wait for lock */
+ PRUint32 hits; /* allocated from free list */
+ PRUint32 misses; /* had to call malloc */
+ PRUint32 elements; /* on free list */
+} MemoryZone;
+
+typedef union memBlkHdrUn {
+ unsigned char filler[48]; /* fix the size of this beast */
+ struct memBlkHdrStr {
+ union memBlkHdrUn *next;
+ MemoryZone *zone;
+ size_t blockSize;
+ size_t requestedSize;
+ PRUint32 magic;
+ } s;
+} MemBlockHdr;
+
+#define MEM_ZONES 7
+#define THREAD_POOLS 11 /* prime number for modulus */
+#define ZONE_MAGIC 0x0BADC0DE
+
+static MemoryZone zones[MEM_ZONES][THREAD_POOLS];
+
+static PRBool use_zone_allocator = PR_FALSE;
+
+static void pr_ZoneFree(void *ptr);
+
+void
+_PR_DestroyZones(void)
+{
+ int i, j;
+
+ if (!use_zone_allocator)
+ return;
+
+ for (j = 0; j < THREAD_POOLS; j++) {
+ for (i = 0; i < MEM_ZONES; i++) {
+ MemoryZone *mz = &zones[i][j];
+ pthread_mutex_destroy(&mz->lock);
+ while (mz->head) {
+ MemBlockHdr *hdr = mz->head;
+ mz->head = hdr->s.next; /* unlink it */
+ free(hdr);
+ mz->elements--;
+ }
+ }
+ }
+ use_zone_allocator = PR_FALSE;
+}
+
+/*
+** pr_FindSymbolInProg
+**
+** Find the specified data symbol in the program and return
+** its address.
+*/
+
+#ifdef HAVE_DLL
+
+#if defined(USE_DLFCN) && !defined(NO_DLOPEN_NULL)
+
+#include <dlfcn.h>
+
+static void *
+pr_FindSymbolInProg(const char *name)
+{
+ void *h;
+ void *sym;
+
+ h = dlopen(0, RTLD_LAZY);
+ if (h == NULL)
+ return NULL;
+ sym = dlsym(h, name);
+ (void)dlclose(h);
+ return sym;
+}
+
+#elif defined(USE_HPSHL)
+
+#include <dl.h>
+
+static void *
+pr_FindSymbolInProg(const char *name)
+{
+ shl_t h = NULL;
+ void *sym;
+
+ if (shl_findsym(&h, name, TYPE_DATA, &sym) == -1)
+ return NULL;
+ return sym;
+}
+
+#elif defined(USE_MACH_DYLD) || defined(NO_DLOPEN_NULL)
+
+static void *
+pr_FindSymbolInProg(const char *name)
+{
+ /* FIXME: not implemented */
+ return NULL;
+}
+
+#else
+
+#error "The zone allocator is not supported on this platform"
+
+#endif
+
+#else /* !defined(HAVE_DLL) */
+
+static void *
+pr_FindSymbolInProg(const char *name)
+{
+ /* can't be implemented */
+ return NULL;
+}
+
+#endif /* HAVE_DLL */
+
+void
+_PR_InitZones(void)
+{
+ int i, j;
+ char *envp;
+ PRBool *sym;
+
+ if ((sym = (PRBool *)pr_FindSymbolInProg("nspr_use_zone_allocator")) != NULL) {
+ use_zone_allocator = *sym;
+ } else if ((envp = getenv("NSPR_USE_ZONE_ALLOCATOR")) != NULL) {
+ use_zone_allocator = (atoi(envp) == 1);
+ }
+
+ if (!use_zone_allocator)
+ return;
+
+ for (j = 0; j < THREAD_POOLS; j++) {
+ for (i = 0; i < MEM_ZONES; i++) {
+ MemoryZone *mz = &zones[i][j];
+ int rv = pthread_mutex_init(&mz->lock, NULL);
+ PR_ASSERT(0 == rv);
+ if (rv != 0) {
+ goto loser;
+ }
+ mz->blockSize = 16 << ( 2 * i);
+ }
+ }
+ return;
+
+loser:
+ _PR_DestroyZones();
+ return;
+}
+
+PR_IMPLEMENT(void)
+PR_FPrintZoneStats(PRFileDesc *debug_out)
+{
+ int i, j;
+
+ for (j = 0; j < THREAD_POOLS; j++) {
+ for (i = 0; i < MEM_ZONES; i++) {
+ MemoryZone *mz = &zones[i][j];
+ MemoryZone zone = *mz;
+ if (zone.elements || zone.misses || zone.hits) {
+ PR_fprintf(debug_out,
+"pool: %d, zone: %d, size: %d, free: %d, hit: %d, miss: %d, contend: %d\n",
+ j, i, zone.blockSize, zone.elements,
+ zone.hits, zone.misses, zone.contention);
+ }
+ }
+ }
+}
+
+static void *
+pr_ZoneMalloc(PRUint32 size)
+{
+ void *rv;
+ unsigned int zone;
+ size_t blockSize;
+ MemBlockHdr *mb, *mt;
+ MemoryZone *mz;
+
+ /* Always allocate a non-zero amount of bytes */
+ if (size < 1) {
+ size = 1;
+ }
+ for (zone = 0, blockSize = 16; zone < MEM_ZONES; ++zone, blockSize <<= 2) {
+ if (size <= blockSize) {
+ break;
+ }
+ }
+ if (zone < MEM_ZONES) {
+ pthread_t me = pthread_self();
+ unsigned int pool = (PRUptrdiff)me % THREAD_POOLS;
+ PRUint32 wasLocked;
+ mz = &zones[zone][pool];
+ wasLocked = mz->locked;
+ pthread_mutex_lock(&mz->lock);
+ mz->locked = 1;
+ if (wasLocked)
+ mz->contention++;
+ if (mz->head) {
+ mb = mz->head;
+ PR_ASSERT(mb->s.magic == ZONE_MAGIC);
+ PR_ASSERT(mb->s.zone == mz);
+ PR_ASSERT(mb->s.blockSize == blockSize);
+ PR_ASSERT(mz->blockSize == blockSize);
+
+ mt = (MemBlockHdr *)(((char *)(mb + 1)) + blockSize);
+ PR_ASSERT(mt->s.magic == ZONE_MAGIC);
+ PR_ASSERT(mt->s.zone == mz);
+ PR_ASSERT(mt->s.blockSize == blockSize);
+
+ mz->hits++;
+ mz->elements--;
+ mz->head = mb->s.next; /* take off free list */
+ mz->locked = 0;
+ pthread_mutex_unlock(&mz->lock);
+
+ mt->s.next = mb->s.next = NULL;
+ mt->s.requestedSize = mb->s.requestedSize = size;
+
+ rv = (void *)(mb + 1);
+ return rv;
+ }
+
+ mz->misses++;
+ mz->locked = 0;
+ pthread_mutex_unlock(&mz->lock);
+
+ mb = (MemBlockHdr *)malloc(blockSize + 2 * (sizeof *mb));
+ if (!mb) {
+ PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+ return NULL;
+ }
+ mb->s.next = NULL;
+ mb->s.zone = mz;
+ mb->s.magic = ZONE_MAGIC;
+ mb->s.blockSize = blockSize;
+ mb->s.requestedSize = size;
+
+ mt = (MemBlockHdr *)(((char *)(mb + 1)) + blockSize);
+ memcpy(mt, mb, sizeof *mb);
+
+ rv = (void *)(mb + 1);
+ return rv;
+ }
+
+ /* size was too big. Create a block with no zone */
+ blockSize = (size & 15) ? size + 16 - (size & 15) : size;
+ mb = (MemBlockHdr *)malloc(blockSize + 2 * (sizeof *mb));
+ if (!mb) {
+ PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+ return NULL;
+ }
+ mb->s.next = NULL;
+ mb->s.zone = NULL;
+ mb->s.magic = ZONE_MAGIC;
+ mb->s.blockSize = blockSize;
+ mb->s.requestedSize = size;
+
+ mt = (MemBlockHdr *)(((char *)(mb + 1)) + blockSize);
+ memcpy(mt, mb, sizeof *mb);
+
+ rv = (void *)(mb + 1);
+ return rv;
+}
+
+
+static void *
+pr_ZoneCalloc(PRUint32 nelem, PRUint32 elsize)
+{
+ PRUint32 size = nelem * elsize;
+ void *p = pr_ZoneMalloc(size);
+ if (p) {
+ memset(p, 0, size);
+ }
+ return p;
+}
+
+static void *
+pr_ZoneRealloc(void *oldptr, PRUint32 bytes)
+{
+ void *rv;
+ MemBlockHdr *mb;
+ int ours;
+ MemBlockHdr phony;
+
+ if (!oldptr)
+ return pr_ZoneMalloc(bytes);
+ mb = (MemBlockHdr *)((char *)oldptr - (sizeof *mb));
+ if (mb->s.magic != ZONE_MAGIC) {
+ /* Maybe this just came from ordinary malloc */
+#ifdef DEBUG
+ fprintf(stderr,
+ "Warning: reallocing memory block %p from ordinary malloc\n",
+ oldptr);
+#endif
+ /*
+ * We are going to realloc oldptr. If realloc succeeds, the
+ * original value of oldptr will point to freed memory. So this
+ * function must not fail after a successfull realloc call. We
+ * must perform any operation that may fail before the realloc
+ * call.
+ */
+ rv = pr_ZoneMalloc(bytes); /* this may fail */
+ if (!rv) {
+ return rv;
+ }
+
+ /* We don't know how big it is. But we can fix that. */
+ oldptr = realloc(oldptr, bytes);
+ /*
+ * If realloc returns NULL, this function loses the original
+ * value of oldptr. This isn't a leak because the caller of
+ * this function still has the original value of oldptr.
+ */
+ if (!oldptr) {
+ if (bytes) {
+ PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
+ pr_ZoneFree(rv);
+ return oldptr;
+ }
+ }
+ phony.s.requestedSize = bytes;
+ mb = &phony;
+ ours = 0;
+ } else {
+ size_t blockSize = mb->s.blockSize;
+ MemBlockHdr *mt = (MemBlockHdr *)(((char *)(mb + 1)) + blockSize);
+
+ PR_ASSERT(mt->s.magic == ZONE_MAGIC);
+ PR_ASSERT(mt->s.zone == mb->s.zone);
+ PR_ASSERT(mt->s.blockSize == blockSize);
+
+ if (bytes <= blockSize) {
+ /* The block is already big enough. */
+ mt->s.requestedSize = mb->s.requestedSize = bytes;
+ return oldptr;
+ }
+ ours = 1;
+ rv = pr_ZoneMalloc(bytes);
+ if (!rv) {
+ return rv;
+ }
+ }
+
+ if (oldptr && mb->s.requestedSize)
+ memcpy(rv, oldptr, mb->s.requestedSize);
+ if (ours)
+ pr_ZoneFree(oldptr);
+ else if (oldptr)
+ free(oldptr);
+ return rv;
+}
+
+static void
+pr_ZoneFree(void *ptr)
+{
+ MemBlockHdr *mb, *mt;
+ MemoryZone *mz;
+ size_t blockSize;
+ PRUint32 wasLocked;
+
+ if (!ptr)
+ return;
+
+ mb = (MemBlockHdr *)((char *)ptr - (sizeof *mb));
+
+ if (mb->s.magic != ZONE_MAGIC) {
+ /* maybe this came from ordinary malloc */
+#ifdef DEBUG
+ fprintf(stderr,
+ "Warning: freeing memory block %p from ordinary malloc\n", ptr);
+#endif
+ free(ptr);
+ return;
+ }
+
+ blockSize = mb->s.blockSize;
+ mz = mb->s.zone;
+ mt = (MemBlockHdr *)(((char *)(mb + 1)) + blockSize);
+ PR_ASSERT(mt->s.magic == ZONE_MAGIC);
+ PR_ASSERT(mt->s.zone == mz);
+ PR_ASSERT(mt->s.blockSize == blockSize);
+ if (!mz) {
+ PR_ASSERT(blockSize > 65536);
+ /* This block was not in any zone. Just free it. */
+ free(mb);
+ return;
+ }
+ PR_ASSERT(mz->blockSize == blockSize);
+ wasLocked = mz->locked;
+ pthread_mutex_lock(&mz->lock);
+ mz->locked = 1;
+ if (wasLocked)
+ mz->contention++;
+ mt->s.next = mb->s.next = mz->head; /* put on head of list */
+ mz->head = mb;
+ mz->elements++;
+ mz->locked = 0;
+ pthread_mutex_unlock(&mz->lock);
+}
+
+PR_IMPLEMENT(void *) PR_Malloc(PRUint32 size)
+{
+ if (!_pr_initialized) _PR_ImplicitInitialization();
+
+ return use_zone_allocator ? pr_ZoneMalloc(size) : malloc(size);
+}
+
+PR_IMPLEMENT(void *) PR_Calloc(PRUint32 nelem, PRUint32 elsize)
+{
+ if (!_pr_initialized) _PR_ImplicitInitialization();
+
+ return use_zone_allocator ?
+ pr_ZoneCalloc(nelem, elsize) : calloc(nelem, elsize);
+}
+
+PR_IMPLEMENT(void *) PR_Realloc(void *ptr, PRUint32 size)
+{
+ if (!_pr_initialized) _PR_ImplicitInitialization();
+
+ return use_zone_allocator ? pr_ZoneRealloc(ptr, size) : realloc(ptr, size);
+}
+
+PR_IMPLEMENT(void) PR_Free(void *ptr)
+{
+ if (use_zone_allocator)
+ pr_ZoneFree(ptr);
+ else
+ free(ptr);
+}
+
+#else /* !defined(_PR_ZONE_ALLOCATOR) */
+
+/*
+** The PR_Malloc, PR_Calloc, PR_Realloc, and PR_Free functions simply
+** call their libc equivalents now. This may seem redundant, but it
+** ensures that we are calling into the same runtime library. On
+** Win32, it is possible to have multiple runtime libraries (e.g.,
+** objects compiled with /MD and /MDd) in the same process, and
+** they maintain separate heaps, which cannot be mixed.
+*/
+PR_IMPLEMENT(void *) PR_Malloc(PRUint32 size)
+{
+#if defined (WIN16)
+ return PR_MD_malloc( (size_t) size);
+#else
+ return malloc(size);
+#endif
+}
+
+PR_IMPLEMENT(void *) PR_Calloc(PRUint32 nelem, PRUint32 elsize)
+{
+#if defined (WIN16)
+ return PR_MD_calloc( (size_t)nelem, (size_t)elsize );
+
+#else
+ return calloc(nelem, elsize);
+#endif
+}
+
+PR_IMPLEMENT(void *) PR_Realloc(void *ptr, PRUint32 size)
+{
+#if defined (WIN16)
+ return PR_MD_realloc( ptr, (size_t) size);
+#else
+ return realloc(ptr, size);
+#endif
+}
+
+PR_IMPLEMENT(void) PR_Free(void *ptr)
+{
+#if defined (WIN16)
+ PR_MD_free( ptr );
+#else
+ free(ptr);
+#endif
+}
+
+#endif /* _PR_ZONE_ALLOCATOR */
+
+/*
+** Complexity alert!
+**
+** If malloc/calloc/free (etc.) were implemented to use pr lock's then
+** the entry points could block when called if some other thread had the
+** lock.
+**
+** Most of the time this isn't a problem. However, in the case that we
+** are using the thread safe malloc code after PR_Init but before
+** PR_AttachThread has been called (on a native thread that nspr has yet
+** to be told about) we could get royally screwed if the lock was busy
+** and we tried to context switch the thread away. In this scenario
+** PR_CURRENT_THREAD() == NULL
+**
+** To avoid this unfortunate case, we use the low level locking
+** facilities for malloc protection instead of the slightly higher level
+** locking. This makes malloc somewhat faster so maybe it's a good thing
+** anyway.
+*/
+#ifdef _PR_OVERRIDE_MALLOC
+
+/* Imports */
+extern void *_PR_UnlockedMalloc(size_t size);
+extern void *_PR_UnlockedMemalign(size_t alignment, size_t size);
+extern void _PR_UnlockedFree(void *ptr);
+extern void *_PR_UnlockedRealloc(void *ptr, size_t size);
+extern void *_PR_UnlockedCalloc(size_t n, size_t elsize);
+
+static PRBool _PR_malloc_initialised = PR_FALSE;
+
+#ifdef _PR_PTHREADS
+static pthread_mutex_t _PR_MD_malloc_crustylock;
+
+#define _PR_Lock_Malloc() { \
+ if(PR_TRUE == _PR_malloc_initialised) { \
+ PRStatus rv; \
+ rv = pthread_mutex_lock(&_PR_MD_malloc_crustylock); \
+ PR_ASSERT(0 == rv); \
+ }
+
+#define _PR_Unlock_Malloc() if(PR_TRUE == _PR_malloc_initialised) { \
+ PRStatus rv; \
+ rv = pthread_mutex_unlock(&_PR_MD_malloc_crustylock); \
+ PR_ASSERT(0 == rv); \
+ } \
+ }
+#else /* _PR_PTHREADS */
+static _MDLock _PR_MD_malloc_crustylock;
+
+#ifdef IRIX
+#define _PR_Lock_Malloc() { \
+ PRIntn _is; \
+ if(PR_TRUE == _PR_malloc_initialised) { \
+ if (_PR_MD_GET_ATTACHED_THREAD() && \
+ !_PR_IS_NATIVE_THREAD( \
+ _PR_MD_GET_ATTACHED_THREAD())) \
+ _PR_INTSOFF(_is); \
+ _PR_MD_LOCK(&_PR_MD_malloc_crustylock); \
+ }
+
+#define _PR_Unlock_Malloc() if(PR_TRUE == _PR_malloc_initialised) { \
+ _PR_MD_UNLOCK(&_PR_MD_malloc_crustylock); \
+ if (_PR_MD_GET_ATTACHED_THREAD() && \
+ !_PR_IS_NATIVE_THREAD( \
+ _PR_MD_GET_ATTACHED_THREAD())) \
+ _PR_INTSON(_is); \
+ } \
+ }
+#else /* IRIX */
+#define _PR_Lock_Malloc() { \
+ PRIntn _is; \
+ if(PR_TRUE == _PR_malloc_initialised) { \
+ if (_PR_MD_CURRENT_THREAD() && \
+ !_PR_IS_NATIVE_THREAD( \
+ _PR_MD_CURRENT_THREAD())) \
+ _PR_INTSOFF(_is); \
+ _PR_MD_LOCK(&_PR_MD_malloc_crustylock); \
+ }
+
+#define _PR_Unlock_Malloc() if(PR_TRUE == _PR_malloc_initialised) { \
+ _PR_MD_UNLOCK(&_PR_MD_malloc_crustylock); \
+ if (_PR_MD_CURRENT_THREAD() && \
+ !_PR_IS_NATIVE_THREAD( \
+ _PR_MD_CURRENT_THREAD())) \
+ _PR_INTSON(_is); \
+ } \
+ }
+#endif /* IRIX */
+#endif /* _PR_PTHREADS */
+
+PR_IMPLEMENT(PRStatus) _PR_MallocInit(void)
+{
+ PRStatus rv = PR_SUCCESS;
+
+ if( PR_TRUE == _PR_malloc_initialised ) return PR_SUCCESS;
+
+#ifdef _PR_PTHREADS
+ {
+ int status;
+ pthread_mutexattr_t mattr;
+
+ status = _PT_PTHREAD_MUTEXATTR_INIT(&mattr);
+ PR_ASSERT(0 == status);
+ status = _PT_PTHREAD_MUTEX_INIT(_PR_MD_malloc_crustylock, mattr);
+ PR_ASSERT(0 == status);
+ status = _PT_PTHREAD_MUTEXATTR_DESTROY(&mattr);
+ PR_ASSERT(0 == status);
+ }
+#else /* _PR_PTHREADS */
+ _MD_NEW_LOCK(&_PR_MD_malloc_crustylock);
+#endif /* _PR_PTHREADS */
+
+ if( PR_SUCCESS == rv )
+ {
+ _PR_malloc_initialised = PR_TRUE;
+ }
+
+ return rv;
+}
+
+void *malloc(size_t size)
+{
+ void *p;
+ _PR_Lock_Malloc();
+ p = _PR_UnlockedMalloc(size);
+ _PR_Unlock_Malloc();
+ return p;
+}
+
+#if defined(IRIX)
+void *memalign(size_t alignment, size_t size)
+{
+ void *p;
+ _PR_Lock_Malloc();
+ p = _PR_UnlockedMemalign(alignment, size);
+ _PR_Unlock_Malloc();
+ return p;
+}
+
+void *valloc(size_t size)
+{
+ return(memalign(sysconf(_SC_PAGESIZE),size));
+}
+#endif /* IRIX */
+
+void free(void *ptr)
+{
+ _PR_Lock_Malloc();
+ _PR_UnlockedFree(ptr);
+ _PR_Unlock_Malloc();
+}
+
+void *realloc(void *ptr, size_t size)
+{
+ void *p;
+ _PR_Lock_Malloc();
+ p = _PR_UnlockedRealloc(ptr, size);
+ _PR_Unlock_Malloc();
+ return p;
+}
+
+void *calloc(size_t n, size_t elsize)
+{
+ void *p;
+ _PR_Lock_Malloc();
+ p = _PR_UnlockedCalloc(n, elsize);
+ _PR_Unlock_Malloc();
+ return p;
+}
+
+void cfree(void *p)
+{
+ _PR_Lock_Malloc();
+ _PR_UnlockedFree(p);
+ _PR_Unlock_Malloc();
+}
+
+void _PR_InitMem(void)
+{
+ PRStatus rv;
+ rv = _PR_MallocInit();
+ PR_ASSERT(PR_SUCCESS == rv);
+}
+
+#endif /* _PR_OVERRIDE_MALLOC */