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Diffstat (limited to 'third_party/tcmalloc/system-alloc.cc')
| -rw-r--r-- | third_party/tcmalloc/system-alloc.cc | 505 |
1 files changed, 0 insertions, 505 deletions
diff --git a/third_party/tcmalloc/system-alloc.cc b/third_party/tcmalloc/system-alloc.cc deleted file mode 100644 index 21d9b43..0000000 --- a/third_party/tcmalloc/system-alloc.cc +++ /dev/null @@ -1,505 +0,0 @@ -// Copyright (c) 2005, 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 HAVE_STDINT_H -#include <stdint.h> -#elif defined HAVE_INTTYPES_H -#include <inttypes.h> -#else -#include <sys/types.h> -#endif -#ifdef HAVE_UNISTD_H -#include <unistd.h> -#endif -#include <fcntl.h> // for open() -#ifdef HAVE_MMAP -#include <sys/mman.h> -#endif -#include <errno.h> -#include "system-alloc.h" -#include "internal_logging.h" -#include "base/logging.h" -#include "base/commandlineflags.h" -#include "base/spinlock.h" - -// On systems (like freebsd) that don't define MAP_ANONYMOUS, use the old -// form of the name instead. -#ifndef MAP_ANONYMOUS -# define MAP_ANONYMOUS MAP_ANON -#endif - -// Solaris has a bug where it doesn't declare madvise() for C++. -// http://www.opensolaris.org/jive/thread.jspa?threadID=21035&tstart=0 -#if defined(__sun) && defined(__SVR4) -# include <sys/types.h> // for caddr_t - extern "C" { extern int madvise(caddr_t, size_t, int); } -#endif - -// Set kDebugMode mode so that we can have use C++ conditionals -// instead of preprocessor conditionals. -#ifdef NDEBUG -static const bool kDebugMode = false; -#else -static const bool kDebugMode = true; -#endif - -// Structure for discovering alignment -union MemoryAligner { - void* p; - double d; - size_t s; -}; - -static SpinLock spinlock(SpinLock::LINKER_INITIALIZED); - -#if defined(HAVE_MMAP) || defined(MADV_DONTNEED) -// Page size is initialized on demand (only needed for mmap-based allocators) -static size_t pagesize = 0; -#endif - -// Configuration parameters. - -DEFINE_int32(malloc_devmem_start, - EnvToInt("TCMALLOC_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, - EnvToInt("TCMALLOC_DEVMEM_LIMIT", 0), - "Physical memory limit location in MB for /dev/mem allocation." - " Setting this to 0 means no limit."); -DEFINE_bool(malloc_skip_sbrk, - EnvToBool("TCMALLOC_SKIP_SBRK", false), - "Whether sbrk can be used to obtain memory."); -DEFINE_bool(malloc_skip_mmap, - EnvToBool("TCMALLOC_SKIP_MMAP", false), - "Whether mmap can be used to obtain memory."); - -// static allocators -class SbrkSysAllocator : public SysAllocator { -public: - SbrkSysAllocator() : SysAllocator() { - } - void* Alloc(size_t size, size_t *actual_size, size_t alignment); - void DumpStats(TCMalloc_Printer* printer); -}; -static char sbrk_space[sizeof(SbrkSysAllocator)]; - -class MmapSysAllocator : public SysAllocator { -public: - MmapSysAllocator() : SysAllocator() { - } - void* Alloc(size_t size, size_t *actual_size, size_t alignment); - void DumpStats(TCMalloc_Printer* printer); -}; -static char mmap_space[sizeof(MmapSysAllocator)]; - -class DevMemSysAllocator : public SysAllocator { -public: - DevMemSysAllocator() : SysAllocator() { - } - void* Alloc(size_t size, size_t *actual_size, size_t alignment); - void DumpStats(TCMalloc_Printer* printer); -}; -static char devmem_space[sizeof(DevMemSysAllocator)]; - -static const int kStaticAllocators = 3; -// kMaxDynamicAllocators + kStaticAllocators; -static const int kMaxAllocators = 5; -static SysAllocator *allocators[kMaxAllocators]; - -bool RegisterSystemAllocator(SysAllocator *a, int priority) { - SpinLockHolder lock_holder(&spinlock); - - // No two allocators should have a priority conflict, since the order - // is determined at compile time. - CHECK_CONDITION(allocators[priority] == NULL); - allocators[priority] = a; - return true; -} - - -void* SbrkSysAllocator::Alloc(size_t size, size_t *actual_size, - size_t alignment) { - // Check if we should use sbrk allocation. - // FLAGS_malloc_skip_sbrk starts out as false (its uninitialized - // state) and eventually gets initialized to the specified value. Note - // that this code runs for a while before the flags are initialized. - // That means that even if this flag is set to true, some (initial) - // memory will be allocated with sbrk before the flag takes effect. - if (FLAGS_malloc_skip_sbrk) { - return NULL; - } - - // sbrk will release memory if passed a negative number, so we do - // a strict check here - if (static_cast<ptrdiff_t>(size + alignment) < 0) return NULL; - - // could theoretically return the "extra" bytes here, but this - // is simple and correct. - if (actual_size) { - *actual_size = size; - } - - // This doesn't overflow because TCMalloc_SystemAlloc has already - // tested for overflow at the alignment boundary. - size = ((size + alignment - 1) / alignment) * alignment; - - // Check that we we're not asking for so much more memory that we'd - // wrap around the end of the virtual address space. (This seems - // like something sbrk() should check for us, and indeed opensolaris - // does, but glibc does not: - // http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/lib/libc/port/sys/sbrk.c?a=true - // http://sourceware.org/cgi-bin/cvsweb.cgi/~checkout~/libc/misc/sbrk.c?rev=1.1.2.1&content-type=text/plain&cvsroot=glibc - // Without this check, sbrk may succeed when it ought to fail.) - if (reinterpret_cast<intptr_t>(sbrk(0)) + size < size) { - failed_ = true; - return NULL; - } - - void* result = sbrk(size); - if (result == reinterpret_cast<void*>(-1)) { - failed_ = 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)) { - failed_ = true; - return NULL; - } - ptr = reinterpret_cast<uintptr_t>(result); - if ((ptr & (alignment-1)) != 0) { - ptr += alignment - (ptr & (alignment-1)); - } - return reinterpret_cast<void*>(ptr); -} - -void SbrkSysAllocator::DumpStats(TCMalloc_Printer* printer) { - printer->printf("SbrkSysAllocator: failed_=%d\n", failed_); -} - -void* MmapSysAllocator::Alloc(size_t size, size_t *actual_size, - size_t alignment) { -#ifndef HAVE_MMAP - failed_ = true; - return NULL; -#else - // Check if we should use mmap allocation. - // FLAGS_malloc_skip_mmap starts out as false (its uninitialized - // state) and eventually gets initialized to the specified value. Note - // that this code runs for a while before the flags are initialized. - // Chances are we never get here before the flags are initialized since - // sbrk is used until the heap is exhausted (before mmap is used). - if (FLAGS_malloc_skip_mmap) { - return NULL; - } - - // could theoretically return the "extra" bytes here, but this - // is simple and correct. - if (actual_size) { - *actual_size = size; - } - - // Enforce page alignment - if (pagesize == 0) pagesize = getpagesize(); - if (alignment < pagesize) alignment = pagesize; - size_t aligned_size = ((size + alignment - 1) / alignment) * alignment; - if (aligned_size < size) { - return NULL; - } - size = aligned_size; - - // Ask for extra memory if alignment > pagesize - size_t extra = 0; - if (alignment > pagesize) { - extra = alignment - pagesize; - } - - // Note: size + extra does not overflow since: - // size + alignment < (1<<NBITS). - // and extra <= alignment - // therefore size + extra < (1<<NBITS) - void* result = mmap(NULL, size + extra, - PROT_READ|PROT_WRITE, - MAP_PRIVATE|MAP_ANONYMOUS, - -1, 0); - if (result == reinterpret_cast<void*>(MAP_FAILED)) { - failed_ = 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 -} - -void MmapSysAllocator::DumpStats(TCMalloc_Printer* printer) { - printer->printf("MmapSysAllocator: failed_=%d\n", failed_); -} - -void* DevMemSysAllocator::Alloc(size_t size, size_t *actual_size, - size_t alignment) { -#ifndef HAVE_MMAP - failed_ = true; - return NULL; -#else - 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) { - failed_ = true; - return NULL; - } - physmem_base = FLAGS_malloc_devmem_start*1024LL*1024LL; - physmem_limit = FLAGS_malloc_devmem_limit*1024LL*1024LL; - initialized = true; - } - - // could theoretically return the "extra" bytes here, but this - // is simple and correct. - if (actual_size) { - *actual_size = size; - } - - // Enforce page alignment - if (pagesize == 0) pagesize = getpagesize(); - if (alignment < pagesize) alignment = pagesize; - size_t aligned_size = ((size + alignment - 1) / alignment) * alignment; - if (aligned_size < size) { - return NULL; - } - size = aligned_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 && - ((size + extra) > (physmem_limit - physmem_base))) { - failed_ = true; - return NULL; - } - - // Note: size + extra does not overflow since: - // size + alignment < (1<<NBITS). - // and extra <= alignment - // therefore size + extra < (1<<NBITS) - void *result = mmap(0, size + extra, PROT_WRITE|PROT_READ, - MAP_SHARED, physmem_fd, physmem_base); - if (result == reinterpret_cast<void*>(MAP_FAILED)) { - failed_ = 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 // HAVE_MMAP -} - -void DevMemSysAllocator::DumpStats(TCMalloc_Printer* printer) { - printer->printf("DevMemSysAllocator: failed_=%d\n", failed_); -} - -static bool system_alloc_inited = false; -void InitSystemAllocators(void) { - // This determines the order in which system allocators are called - int i = kMaxDynamicAllocators; - allocators[i++] = new (devmem_space) DevMemSysAllocator(); - - // In 64-bit debug mode, place the mmap allocator first since it - // allocates pointers that do not fit in 32 bits and therefore gives - // us better testing of code's 64-bit correctness. It also leads to - // less false negatives in heap-checking code. (Numbers are less - // likely to look like pointers and therefore the conservative gc in - // the heap-checker is less likely to misinterpret a number as a - // pointer). - if (kDebugMode && sizeof(void*) > 4) { - allocators[i++] = new (mmap_space) MmapSysAllocator(); - allocators[i++] = new (sbrk_space) SbrkSysAllocator(); - } else { - allocators[i++] = new (sbrk_space) SbrkSysAllocator(); - allocators[i++] = new (mmap_space) MmapSysAllocator(); - } -} - -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); - - if (!system_alloc_inited) { - InitSystemAllocators(); - system_alloc_inited = true; - } - - // 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++) { - for (int j = 0; j < kMaxAllocators; j++) { - SysAllocator *a = allocators[j]; - if (a == NULL) continue; - if (a->usable_ && !a->failed_) { - void* result = a->Alloc(size, actual_size, alignment); - if (result != NULL) return result; - } - } - - // nothing worked - reset failed_ flags and try again - for (int j = 0; j < kMaxAllocators; j++) { - SysAllocator *a = allocators[j]; - if (a == NULL) continue; - a->failed_ = false; - } - } - return NULL; -} - -void TCMalloc_SystemRelease(void* start, size_t length) { -#ifdef MADV_DONTNEED - 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, - MADV_DONTNEED) == -1 && - errno == EAGAIN) { - // NOP - } - } -#endif -} - -void TCMalloc_SystemCommit(void* start, size_t length) { - // Nothing to do here. TCMalloc_SystemRelease does not alter pages - // such that they need to be re-committed before they can be used by the - // application. -} - -void DumpSystemAllocatorStats(TCMalloc_Printer* printer) { - for (int j = 0; j < kMaxAllocators; j++) { - SysAllocator *a = allocators[j]; - if (a == NULL) continue; - if (a->usable_) { - a->DumpStats(printer); - } - } -} |