+++ /dev/null
-// Copyright (c) 2005, 2007, Google Inc.
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-// * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-// * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-// * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// ---
-// Author: Sanjay Ghemawat
-
-#include "config.h"
-#if !(defined(USE_SYSTEM_MALLOC) && USE_SYSTEM_MALLOC)
-#include "TCSystemAlloc.h"
-
-#include <algorithm>
-#include "Assertions.h"
-#include "TCSpinLock.h"
-#include "UnusedParam.h"
-#include "VMTags.h"
-
-#if HAVE(STDINT_H)
-#include <stdint.h>
-#elif HAVE(INTTYPES_H)
-#include <inttypes.h>
-#else
-#include <sys/types.h>
-#endif
-
-#if OS(WINDOWS)
-#include "windows.h"
-#else
-#include <errno.h>
-#include <unistd.h>
-#include <sys/mman.h>
-#endif
-
-#ifndef MAP_ANONYMOUS
-#define MAP_ANONYMOUS MAP_ANON
-#endif
-
-using namespace std;
-
-// Structure for discovering alignment
-union MemoryAligner {
- void* p;
- double d;
- size_t s;
-};
-
-static SpinLock spinlock = SPINLOCK_INITIALIZER;
-
-// Page size is initialized on demand
-static size_t pagesize = 0;
-
-// Configuration parameters.
-//
-// if use_devmem is true, either use_sbrk or use_mmap must also be true.
-// For 2.2 kernels, it looks like the sbrk address space (500MBish) and
-// the mmap address space (1300MBish) are disjoint, so we need both allocators
-// to get as much virtual memory as possible.
-#ifndef WTF_CHANGES
-static bool use_devmem = false;
-#endif
-
-#if HAVE(SBRK)
-static bool use_sbrk = false;
-#endif
-
-#if HAVE(MMAP)
-static bool use_mmap = true;
-#endif
-
-#if HAVE(VIRTUALALLOC)
-static bool use_VirtualAlloc = true;
-#endif
-
-// Flags to keep us from retrying allocators that failed.
-static bool devmem_failure = false;
-static bool sbrk_failure = false;
-static bool mmap_failure = false;
-static bool VirtualAlloc_failure = false;
-
-#ifndef WTF_CHANGES
-DEFINE_int32(malloc_devmem_start, 0,
- "Physical memory starting location in MB for /dev/mem allocation."
- " Setting this to 0 disables /dev/mem allocation");
-DEFINE_int32(malloc_devmem_limit, 0,
- "Physical memory limit location in MB for /dev/mem allocation."
- " Setting this to 0 means no limit.");
-#else
-static const int32_t FLAGS_malloc_devmem_start = 0;
-static const int32_t FLAGS_malloc_devmem_limit = 0;
-#endif
-
-#if HAVE(SBRK)
-
-static void* TrySbrk(size_t size, size_t *actual_size, size_t alignment) {
- size = ((size + alignment - 1) / alignment) * alignment;
-
- // could theoretically return the "extra" bytes here, but this
- // is simple and correct.
- if (actual_size)
- *actual_size = size;
-
- void* result = sbrk(size);
- if (result == reinterpret_cast<void*>(-1)) {
- sbrk_failure = true;
- return NULL;
- }
-
- // Is it aligned?
- uintptr_t ptr = reinterpret_cast<uintptr_t>(result);
- if ((ptr & (alignment-1)) == 0) return result;
-
- // Try to get more memory for alignment
- size_t extra = alignment - (ptr & (alignment-1));
- void* r2 = sbrk(extra);
- if (reinterpret_cast<uintptr_t>(r2) == (ptr + size)) {
- // Contiguous with previous result
- return reinterpret_cast<void*>(ptr + extra);
- }
-
- // Give up and ask for "size + alignment - 1" bytes so
- // that we can find an aligned region within it.
- result = sbrk(size + alignment - 1);
- if (result == reinterpret_cast<void*>(-1)) {
- sbrk_failure = true;
- return NULL;
- }
- ptr = reinterpret_cast<uintptr_t>(result);
- if ((ptr & (alignment-1)) != 0) {
- ptr += alignment - (ptr & (alignment-1));
- }
- return reinterpret_cast<void*>(ptr);
-}
-
-#endif /* HAVE(SBRK) */
-
-#if HAVE(MMAP)
-
-static void* TryMmap(size_t size, size_t *actual_size, size_t alignment) {
- // Enforce page alignment
- if (pagesize == 0) pagesize = getpagesize();
- if (alignment < pagesize) alignment = pagesize;
- size = ((size + alignment - 1) / alignment) * alignment;
-
- // could theoretically return the "extra" bytes here, but this
- // is simple and correct.
- if (actual_size)
- *actual_size = size;
-
- // Ask for extra memory if alignment > pagesize
- size_t extra = 0;
- if (alignment > pagesize) {
- extra = alignment - pagesize;
- }
- void* result = mmap(NULL, size + extra,
- PROT_READ | PROT_WRITE,
- MAP_PRIVATE|MAP_ANONYMOUS,
- VM_TAG_FOR_TCMALLOC_MEMORY, 0);
- if (result == reinterpret_cast<void*>(MAP_FAILED)) {
- mmap_failure = true;
- return NULL;
- }
-
- // Adjust the return memory so it is aligned
- uintptr_t ptr = reinterpret_cast<uintptr_t>(result);
- size_t adjust = 0;
- if ((ptr & (alignment - 1)) != 0) {
- adjust = alignment - (ptr & (alignment - 1));
- }
-
- // Return the unused memory to the system
- if (adjust > 0) {
- munmap(reinterpret_cast<void*>(ptr), adjust);
- }
- if (adjust < extra) {
- munmap(reinterpret_cast<void*>(ptr + adjust + size), extra - adjust);
- }
-
- ptr += adjust;
- return reinterpret_cast<void*>(ptr);
-}
-
-#endif /* HAVE(MMAP) */
-
-#if HAVE(VIRTUALALLOC)
-
-static void* TryVirtualAlloc(size_t size, size_t *actual_size, size_t alignment) {
- // Enforce page alignment
- if (pagesize == 0) {
- SYSTEM_INFO system_info;
- GetSystemInfo(&system_info);
- pagesize = system_info.dwPageSize;
- }
-
- if (alignment < pagesize) alignment = pagesize;
- size = ((size + alignment - 1) / alignment) * alignment;
-
- // could theoretically return the "extra" bytes here, but this
- // is simple and correct.
- if (actual_size)
- *actual_size = size;
-
- // Ask for extra memory if alignment > pagesize
- size_t extra = 0;
- if (alignment > pagesize) {
- extra = alignment - pagesize;
- }
- void* result = VirtualAlloc(NULL, size + extra,
- MEM_RESERVE | MEM_COMMIT | MEM_TOP_DOWN,
- PAGE_READWRITE);
-
- if (result == NULL) {
- VirtualAlloc_failure = true;
- return NULL;
- }
-
- // Adjust the return memory so it is aligned
- uintptr_t ptr = reinterpret_cast<uintptr_t>(result);
- size_t adjust = 0;
- if ((ptr & (alignment - 1)) != 0) {
- adjust = alignment - (ptr & (alignment - 1));
- }
-
- // Return the unused memory to the system - we'd like to release but the best we can do
- // is decommit, since Windows only lets you free the whole allocation.
- if (adjust > 0) {
- VirtualFree(reinterpret_cast<void*>(ptr), adjust, MEM_DECOMMIT);
- }
- if (adjust < extra) {
- VirtualFree(reinterpret_cast<void*>(ptr + adjust + size), extra-adjust, MEM_DECOMMIT);
- }
-
- ptr += adjust;
- return reinterpret_cast<void*>(ptr);
-}
-
-#endif /* HAVE(MMAP) */
-
-#ifndef WTF_CHANGES
-static void* TryDevMem(size_t size, size_t *actual_size, size_t alignment) {
- static bool initialized = false;
- static off_t physmem_base; // next physical memory address to allocate
- static off_t physmem_limit; // maximum physical address allowed
- static int physmem_fd; // file descriptor for /dev/mem
-
- // Check if we should use /dev/mem allocation. Note that it may take
- // a while to get this flag initialized, so meanwhile we fall back to
- // the next allocator. (It looks like 7MB gets allocated before
- // this flag gets initialized -khr.)
- if (FLAGS_malloc_devmem_start == 0) {
- // NOTE: not a devmem_failure - we'd like TCMalloc_SystemAlloc to
- // try us again next time.
- return NULL;
- }
-
- if (!initialized) {
- physmem_fd = open("/dev/mem", O_RDWR);
- if (physmem_fd < 0) {
- devmem_failure = true;
- return NULL;
- }
- physmem_base = FLAGS_malloc_devmem_start*1024LL*1024LL;
- physmem_limit = FLAGS_malloc_devmem_limit*1024LL*1024LL;
- initialized = true;
- }
-
- // Enforce page alignment
- if (pagesize == 0) pagesize = getpagesize();
- if (alignment < pagesize) alignment = pagesize;
- size = ((size + alignment - 1) / alignment) * alignment;
-
- // could theoretically return the "extra" bytes here, but this
- // is simple and correct.
- if (actual_size)
- *actual_size = size;
-
- // Ask for extra memory if alignment > pagesize
- size_t extra = 0;
- if (alignment > pagesize) {
- extra = alignment - pagesize;
- }
-
- // check to see if we have any memory left
- if (physmem_limit != 0 && physmem_base + size + extra > physmem_limit) {
- devmem_failure = true;
- return NULL;
- }
- void *result = mmap(0, size + extra, PROT_READ | PROT_WRITE,
- MAP_SHARED, physmem_fd, physmem_base);
- if (result == reinterpret_cast<void*>(MAP_FAILED)) {
- devmem_failure = true;
- return NULL;
- }
- uintptr_t ptr = reinterpret_cast<uintptr_t>(result);
-
- // Adjust the return memory so it is aligned
- size_t adjust = 0;
- if ((ptr & (alignment - 1)) != 0) {
- adjust = alignment - (ptr & (alignment - 1));
- }
-
- // Return the unused virtual memory to the system
- if (adjust > 0) {
- munmap(reinterpret_cast<void*>(ptr), adjust);
- }
- if (adjust < extra) {
- munmap(reinterpret_cast<void*>(ptr + adjust + size), extra - adjust);
- }
-
- ptr += adjust;
- physmem_base += adjust + size;
-
- return reinterpret_cast<void*>(ptr);
-}
-#endif
-
-void* TCMalloc_SystemAlloc(size_t size, size_t *actual_size, size_t alignment) {
- // Discard requests that overflow
- if (size + alignment < size) return NULL;
-
- SpinLockHolder lock_holder(&spinlock);
-
- // Enforce minimum alignment
- if (alignment < sizeof(MemoryAligner)) alignment = sizeof(MemoryAligner);
-
- // Try twice, once avoiding allocators that failed before, and once
- // more trying all allocators even if they failed before.
- for (int i = 0; i < 2; i++) {
-
-#ifndef WTF_CHANGES
- if (use_devmem && !devmem_failure) {
- void* result = TryDevMem(size, actual_size, alignment);
- if (result != NULL) return result;
- }
-#endif
-
-#if HAVE(SBRK)
- if (use_sbrk && !sbrk_failure) {
- void* result = TrySbrk(size, actual_size, alignment);
- if (result != NULL) return result;
- }
-#endif
-
-#if HAVE(MMAP)
- if (use_mmap && !mmap_failure) {
- void* result = TryMmap(size, actual_size, alignment);
- if (result != NULL) return result;
- }
-#endif
-
-#if HAVE(VIRTUALALLOC)
- if (use_VirtualAlloc && !VirtualAlloc_failure) {
- void* result = TryVirtualAlloc(size, actual_size, alignment);
- if (result != NULL) return result;
- }
-#endif
-
- // nothing worked - reset failure flags and try again
- devmem_failure = false;
- sbrk_failure = false;
- mmap_failure = false;
- VirtualAlloc_failure = false;
- }
- return NULL;
-}
-
-#if HAVE(MADV_FREE_REUSE)
-
-void TCMalloc_SystemRelease(void* start, size_t length)
-{
- while (madvise(start, length, MADV_FREE_REUSABLE) == -1 && errno == EAGAIN) { }
-}
-
-#elif HAVE(MADV_FREE) || HAVE(MADV_DONTNEED)
-
-void TCMalloc_SystemRelease(void* start, size_t length)
-{
- // MADV_FREE clears the modified bit on pages, which allows
- // them to be discarded immediately.
-#if HAVE(MADV_FREE)
- const int advice = MADV_FREE;
-#else
- const int advice = MADV_DONTNEED;
-#endif
- if (FLAGS_malloc_devmem_start) {
- // It's not safe to use MADV_DONTNEED if we've been mapping
- // /dev/mem for heap memory
- return;
- }
- if (pagesize == 0) pagesize = getpagesize();
- const size_t pagemask = pagesize - 1;
-
- size_t new_start = reinterpret_cast<size_t>(start);
- size_t end = new_start + length;
- size_t new_end = end;
-
- // Round up the starting address and round down the ending address
- // to be page aligned:
- new_start = (new_start + pagesize - 1) & ~pagemask;
- new_end = new_end & ~pagemask;
-
- ASSERT((new_start & pagemask) == 0);
- ASSERT((new_end & pagemask) == 0);
- ASSERT(new_start >= reinterpret_cast<size_t>(start));
- ASSERT(new_end <= end);
-
- if (new_end > new_start) {
- // Note -- ignoring most return codes, because if this fails it
- // doesn't matter...
- while (madvise(reinterpret_cast<char*>(new_start), new_end - new_start,
- advice) == -1 &&
- errno == EAGAIN) {
- // NOP
- }
- }
-}
-
-#elif HAVE(MMAP)
-
-void TCMalloc_SystemRelease(void* start, size_t length)
-{
- void* newAddress = mmap(start, length, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
- // If the mmap failed then that's ok, we just won't return the memory to the system.
- ASSERT_UNUSED(newAddress, newAddress == start || newAddress == reinterpret_cast<void*>(MAP_FAILED));
-}
-
-#elif HAVE(VIRTUALALLOC)
-
-void TCMalloc_SystemRelease(void* start, size_t length)
-{
- if (VirtualFree(start, length, MEM_DECOMMIT))
- return;
-
- // The decommit may fail if the memory region consists of allocations
- // from more than one call to VirtualAlloc. In this case, fall back to
- // using VirtualQuery to retrieve the allocation boundaries and decommit
- // them each individually.
-
- char* ptr = static_cast<char*>(start);
- char* end = ptr + length;
- MEMORY_BASIC_INFORMATION info;
- while (ptr < end) {
- size_t resultSize = VirtualQuery(ptr, &info, sizeof(info));
- ASSERT_UNUSED(resultSize, resultSize == sizeof(info));
-
- size_t decommitSize = min<size_t>(info.RegionSize, end - ptr);
- BOOL success = VirtualFree(ptr, decommitSize, MEM_DECOMMIT);
- ASSERT_UNUSED(success, success);
- ptr += decommitSize;
- }
-}
-
-#else
-
-// Platforms that don't support returning memory use an empty inline version of TCMalloc_SystemRelease
-// declared in TCSystemAlloc.h
-
-#endif
-
-#if HAVE(MADV_FREE_REUSE)
-
-void TCMalloc_SystemCommit(void* start, size_t length)
-{
- while (madvise(start, length, MADV_FREE_REUSE) == -1 && errno == EAGAIN) { }
-}
-
-#elif HAVE(VIRTUALALLOC)
-
-void TCMalloc_SystemCommit(void* start, size_t length)
-{
- if (VirtualAlloc(start, length, MEM_COMMIT, PAGE_READWRITE) == start)
- return;
-
- // The commit may fail if the memory region consists of allocations
- // from more than one call to VirtualAlloc. In this case, fall back to
- // using VirtualQuery to retrieve the allocation boundaries and commit them
- // each individually.
-
- char* ptr = static_cast<char*>(start);
- char* end = ptr + length;
- MEMORY_BASIC_INFORMATION info;
- while (ptr < end) {
- size_t resultSize = VirtualQuery(ptr, &info, sizeof(info));
- ASSERT_UNUSED(resultSize, resultSize == sizeof(info));
-
- size_t commitSize = min<size_t>(info.RegionSize, end - ptr);
- void* newAddress = VirtualAlloc(ptr, commitSize, MEM_COMMIT, PAGE_READWRITE);
- ASSERT_UNUSED(newAddress, newAddress == ptr);
- ptr += commitSize;
- }
-}
-
-#else
-
-// Platforms that don't need to explicitly commit memory use an empty inline version of TCMalloc_SystemCommit
-// declared in TCSystemAlloc.h
-
-#endif
-
-#endif // #if !(defined(USE_SYSTEM_MALLOC) && USE_SYSTEM_MALLOC)
-
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