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Diffstat (limited to 'trunk/src/heap-profiler.cc')
| -rw-r--r-- | trunk/src/heap-profiler.cc | 621 |
1 files changed, 621 insertions, 0 deletions
diff --git a/trunk/src/heap-profiler.cc b/trunk/src/heap-profiler.cc new file mode 100644 index 0000000..a1c643a --- /dev/null +++ b/trunk/src/heap-profiler.cc @@ -0,0 +1,621 @@ +// 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 +// +// TODO: Log large allocations + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif +#ifdef HAVE_INTTYPES_H +#include <inttypes.h> +#endif +#ifdef HAVE_FCNTL_H +#include <fcntl.h> // for open() +#endif +#ifdef HAVE_MMAP +#include <sys/mman.h> +#endif +#include <errno.h> +#include <assert.h> +#include <sys/types.h> + +#include <algorithm> +#include <string> + +#include <google/heap-profiler.h> + +#include "base/logging.h" +#include "base/basictypes.h" // for PRId64, among other things +#include "base/googleinit.h" +#include "base/commandlineflags.h" +#include "malloc_hook-inl.h" +#include "tcmalloc_guard.h" +#include <google/malloc_hook.h> +#include <google/malloc_extension.h> +#include "base/spinlock.h" +#include "base/low_level_alloc.h" +#include "base/sysinfo.h" // for GetUniquePathFromEnv() +#include "heap-profile-table.h" +#include "memory_region_map.h" + + +#ifndef PATH_MAX +#ifdef MAXPATHLEN +#define PATH_MAX MAXPATHLEN +#else +#define PATH_MAX 4096 // seems conservative for max filename len! +#endif +#endif + +using STL_NAMESPACE::string; +using STL_NAMESPACE::sort; + +//---------------------------------------------------------------------- +// Flags that control heap-profiling +// +// The thread-safety of the profiler depends on these being immutable +// after main starts, so don't change them. +//---------------------------------------------------------------------- + +DEFINE_int64(heap_profile_allocation_interval, + EnvToInt64("HEAP_PROFILE_ALLOCATION_INTERVAL", 1 << 30 /*1GB*/), + "If non-zero, dump heap profiling information once every " + "specified number of bytes allocated by the program since " + "the last dump."); +DEFINE_int64(heap_profile_deallocation_interval, + EnvToInt64("HEAP_PROFILE_DEALLOCATION_INTERVAL", 0), + "If non-zero, dump heap profiling information once every " + "specified number of bytes deallocated by the program " + "since the last dump."); +// We could also add flags that report whenever inuse_bytes changes by +// X or -X, but there hasn't been a need for that yet, so we haven't. +DEFINE_int64(heap_profile_inuse_interval, + EnvToInt64("HEAP_PROFILE_INUSE_INTERVAL", 100 << 20 /*100MB*/), + "If non-zero, dump heap profiling information whenever " + "the high-water memory usage mark increases by the specified " + "number of bytes."); +DEFINE_bool(mmap_log, + EnvToBool("HEAP_PROFILE_MMAP_LOG", false), + "Should mmap/munmap calls be logged?"); +DEFINE_bool(mmap_profile, + EnvToBool("HEAP_PROFILE_MMAP", false), + "If heap-profiling is on, also profile mmap, mremap, and sbrk)"); +DEFINE_bool(only_mmap_profile, + EnvToBool("HEAP_PROFILE_ONLY_MMAP", false), + "If heap-profiling is on, only profile mmap, mremap, and sbrk; " + "do not profile malloc/new/etc"); + + +//---------------------------------------------------------------------- +// Locking +//---------------------------------------------------------------------- + +// A pthread_mutex has way too much lock contention to be used here. +// +// I would like to use Mutex, but it can call malloc(), +// which can cause us to fall into an infinite recursion. +// +// So we use a simple spinlock. +static SpinLock heap_lock(SpinLock::LINKER_INITIALIZED); + +//---------------------------------------------------------------------- +// Simple allocator for heap profiler's internal memory +//---------------------------------------------------------------------- + +static LowLevelAlloc::Arena *heap_profiler_memory; + +static void* ProfilerMalloc(size_t bytes) { + return LowLevelAlloc::AllocWithArena(bytes, heap_profiler_memory); +} +static void ProfilerFree(void* p) { + LowLevelAlloc::Free(p); +} + +// We use buffers of this size in DoGetHeapProfile. +static const int kProfileBufferSize = 1 << 20; + +// This is a last-ditch buffer we use in DumpProfileLocked in case we +// can't allocate more memory from ProfilerMalloc. We expect this +// will be used by HeapProfileEndWriter when the application has to +// exit due to out-of-memory. This buffer is allocated in +// HeapProfilerStart. Access to this must be protected by heap_lock. +static char* global_profiler_buffer = NULL; + + +//---------------------------------------------------------------------- +// Profiling control/state data +//---------------------------------------------------------------------- + +// Access to all of these is protected by heap_lock. +static bool is_on = false; // If are on as a subsytem. +static bool dumping = false; // Dumping status to prevent recursion +static char* filename_prefix = NULL; // Prefix used for profile file names + // (NULL if no need for dumping yet) +static int dump_count = 0; // How many dumps so far +static int64 last_dump_alloc = 0; // alloc_size when did we last dump +static int64 last_dump_free = 0; // free_size when did we last dump +static int64 high_water_mark = 0; // In-use-bytes at last high-water dump + +static HeapProfileTable* heap_profile = NULL; // the heap profile table + +//---------------------------------------------------------------------- +// Profile generation +//---------------------------------------------------------------------- + +enum AddOrRemove { ADD, REMOVE }; + +// Add or remove all MMap-allocated regions to/from *heap_profile. +// Assumes heap_lock is held. +static void AddRemoveMMapDataLocked(AddOrRemove mode) { + RAW_DCHECK(heap_lock.IsHeld(), ""); + if (!FLAGS_mmap_profile || !is_on) return; + if (!FLAGS_mmap_log) MemoryRegionMap::CheckMallocHooks(); + // MemoryRegionMap maintained all the data we need for all + // mmap-like allocations, so we just use it here: + MemoryRegionMap::LockHolder l; + for (MemoryRegionMap::RegionIterator r = MemoryRegionMap::BeginRegionLocked(); + r != MemoryRegionMap::EndRegionLocked(); ++r) { + if (mode == ADD) { + heap_profile->RecordAllocWithStack( + reinterpret_cast<const void*>(r->start_addr), + r->end_addr - r->start_addr, + r->call_stack_depth, r->call_stack); + } else { + heap_profile->RecordFree(reinterpret_cast<void*>(r->start_addr)); + } + } +} + +// Input must be a buffer of size at least 1MB. +static char* DoGetHeapProfileLocked(char* buf, int buflen) { + // We used to be smarter about estimating the required memory and + // then capping it to 1MB and generating the profile into that. + if (buf == NULL || buflen < 1) + return NULL; + + RAW_DCHECK(heap_lock.IsHeld(), ""); + int bytes_written = 0; + if (is_on) { + HeapProfileTable::Stats const stats = heap_profile->total(); + AddRemoveMMapDataLocked(ADD); + bytes_written = heap_profile->FillOrderedProfile(buf, buflen - 1); + // FillOrderedProfile should not reduce the set of active mmap-ed regions, + // hence MemoryRegionMap will let us remove everything we've added above: + AddRemoveMMapDataLocked(REMOVE); + RAW_DCHECK(stats.Equivalent(heap_profile->total()), ""); + // if this fails, we somehow removed by AddRemoveMMapDataLocked + // more than we have added. + } + buf[bytes_written] = '\0'; + RAW_DCHECK(bytes_written == strlen(buf), ""); + + return buf; +} + +extern "C" char* GetHeapProfile() { + // Use normal malloc: we return the profile to the user to free it: + char* buffer = reinterpret_cast<char*>(malloc(kProfileBufferSize)); + SpinLockHolder l(&heap_lock); + return DoGetHeapProfileLocked(buffer, kProfileBufferSize); +} + +// defined below +static void NewHook(const void* ptr, size_t size); +static void DeleteHook(const void* ptr); + +// Helper for HeapProfilerDump. +static void DumpProfileLocked(const char* reason) { + RAW_DCHECK(heap_lock.IsHeld(), ""); + RAW_DCHECK(is_on, ""); + RAW_DCHECK(!dumping, ""); + + if (filename_prefix == NULL) return; // we do not yet need dumping + + if (FLAGS_only_mmap_profile == false) { + if (MallocHook::GetNewHook() != NewHook || + MallocHook::GetDeleteHook() != DeleteHook) { + RAW_LOG(FATAL, "Had our new/delete MallocHook-s replaced. " + "Are you using another MallocHook client? " + "Do not use --heap_profile=... to avoid this conflict."); + } + } + + dumping = true; + + // Make file name + char file_name[1000]; + dump_count++; + snprintf(file_name, sizeof(file_name), "%s.%04d%s", + filename_prefix, dump_count, HeapProfileTable::kFileExt); + + // Dump the profile + RAW_VLOG(0, "Dumping heap profile to %s (%s)", file_name, reason); + // We must use file routines that don't access memory, since we hold + // a memory lock now. + RawFD fd = RawOpenForWriting(file_name); + if (fd == kIllegalRawFD) { + RAW_LOG(ERROR, "Failed dumping heap profile to %s", file_name); + dumping = false; + return; + } + + // This case may be impossible, but it's best to be safe. + // It's safe to use the global buffer: we're protected by heap_lock. + if (global_profiler_buffer == NULL) { + global_profiler_buffer = + reinterpret_cast<char*>(ProfilerMalloc(kProfileBufferSize)); + } + + char* profile = DoGetHeapProfileLocked(global_profiler_buffer, + kProfileBufferSize); + RawWrite(fd, profile, strlen(profile)); + RawClose(fd); + + dumping = false; +} + +//---------------------------------------------------------------------- +// Profile collection +//---------------------------------------------------------------------- + +// Dump a profile after either an allocation or deallocation, if +// the memory use has changed enough since the last dump. +static void MaybeDumpProfileLocked() { + if (!dumping) { + const HeapProfileTable::Stats& total = heap_profile->total(); + const int64 inuse_bytes = total.alloc_size - total.free_size; + bool need_to_dump = false; + char buf[128]; + if (FLAGS_heap_profile_allocation_interval > 0 && + total.alloc_size >= + last_dump_alloc + FLAGS_heap_profile_allocation_interval) { + snprintf(buf, sizeof(buf), ("%"PRId64" MB allocated cumulatively, " + "%"PRId64" MB currently in use"), + total.alloc_size >> 20, inuse_bytes >> 20); + need_to_dump = true; + } else if (FLAGS_heap_profile_deallocation_interval > 0 && + total.free_size >= + last_dump_free + FLAGS_heap_profile_deallocation_interval) { + snprintf(buf, sizeof(buf), ("%"PRId64" MB freed cumulatively, " + "%"PRId64" MB currently in use"), + total.free_size >> 20, inuse_bytes >> 20); + need_to_dump = true; + } else if (FLAGS_heap_profile_inuse_interval > 0 && + inuse_bytes > + high_water_mark + FLAGS_heap_profile_inuse_interval) { + snprintf(buf, sizeof(buf), "%"PRId64" MB currently in use", + inuse_bytes >> 20); + need_to_dump = true; + } + if (need_to_dump) { + DumpProfileLocked(buf); + + last_dump_alloc = total.alloc_size; + last_dump_free = total.free_size; + if (inuse_bytes > high_water_mark) + high_water_mark = inuse_bytes; + } + } +} + +// Record an allocation in the profile. +static void RecordAlloc(const void* ptr, size_t bytes, int skip_count) { + SpinLockHolder l(&heap_lock); + if (is_on) { + heap_profile->RecordAlloc(ptr, bytes, skip_count + 1); + MaybeDumpProfileLocked(); + } +} + +// Record a deallocation in the profile. +static void RecordFree(const void* ptr) { + SpinLockHolder l(&heap_lock); + if (is_on) { + heap_profile->RecordFree(ptr); + MaybeDumpProfileLocked(); + } +} + +//---------------------------------------------------------------------- +// Allocation/deallocation hooks for MallocHook +//---------------------------------------------------------------------- + +// static +void NewHook(const void* ptr, size_t size) { + if (ptr != NULL) RecordAlloc(ptr, size, 0); +} + +// static +void DeleteHook(const void* ptr) { + if (ptr != NULL) RecordFree(ptr); +} + +// TODO(jandrews): Re-enable stack tracing +#ifdef TODO_REENABLE_STACK_TRACING +static void RawInfoStackDumper(const char* message, void*) { + RAW_LOG(INFO, "%.*s", static_cast<int>(strlen(message) - 1), message); + // -1 is to chop the \n which will be added by RAW_LOG +} +#endif + +// Saved MemoryRegionMap's hooks to daisy-chain calls to. +MallocHook::MmapHook saved_mmap_hook = NULL; +MallocHook::MremapHook saved_mremap_hook = NULL; +MallocHook::MunmapHook saved_munmap_hook = NULL; +MallocHook::SbrkHook saved_sbrk_hook = NULL; + +static void MmapHook(const void* result, const void* start, size_t size, + int prot, int flags, int fd, off_t offset) { + if (FLAGS_mmap_log) { // log it + // We use PRIxS not just '%p' to avoid deadlocks + // in pretty-printing of NULL as "nil". + // TODO(maxim): instead should use a safe snprintf reimplementation + RAW_LOG(INFO, + "mmap(start=0x%"PRIxPTR", len=%"PRIuS", prot=0x%x, flags=0x%x, " + "fd=%d, offset=0x%x) = 0x%"PRIxPTR"", + (uintptr_t) start, size, prot, flags, fd, (unsigned int) offset, + (uintptr_t) result); +#ifdef TODO_REENABLE_STACK_TRACING + DumpStackTrace(1, RawInfoStackDumper, NULL); +#endif + } + if (saved_mmap_hook) { + // Call MemoryRegionMap's hook: it will record needed info about the mmap + // for us w/o deadlocks: + (*saved_mmap_hook)(result, start, size, prot, flags, fd, offset); + } +} + +static void MremapHook(const void* result, const void* old_addr, + size_t old_size, size_t new_size, + int flags, const void* new_addr) { + if (FLAGS_mmap_log) { // log it + // We use PRIxS not just '%p' to avoid deadlocks + // in pretty-printing of NULL as "nil". + // TODO(maxim): instead should use a safe snprintf reimplementation + RAW_LOG(INFO, + "mremap(old_addr=0x%"PRIxPTR", old_size=%"PRIuS", " + "new_size=%"PRIuS", flags=0x%x, new_addr=0x%"PRIxPTR") = " + "0x%"PRIxPTR"", + (uintptr_t) old_addr, old_size, new_size, flags, + (uintptr_t) new_addr, (uintptr_t) result); +#ifdef TODO_REENABLE_STACK_TRACING + DumpStackTrace(1, RawInfoStackDumper, NULL); +#endif + } + if (saved_mremap_hook) { // call MemoryRegionMap's hook + (*saved_mremap_hook)(result, old_addr, old_size, new_size, flags, new_addr); + } +} + +static void MunmapHook(const void* ptr, size_t size) { + if (FLAGS_mmap_log) { // log it + // We use PRIxS not just '%p' to avoid deadlocks + // in pretty-printing of NULL as "nil". + // TODO(maxim): instead should use a safe snprintf reimplementation + RAW_LOG(INFO, "munmap(start=0x%"PRIxPTR", len=%"PRIuS")", + (uintptr_t) ptr, size); +#ifdef TODO_REENABLE_STACK_TRACING + DumpStackTrace(1, RawInfoStackDumper, NULL); +#endif + } + if (saved_munmap_hook) { // call MemoryRegionMap's hook + (*saved_munmap_hook)(ptr, size); + } +} + +static void SbrkHook(const void* result, ptrdiff_t increment) { + if (FLAGS_mmap_log) { // log it + RAW_LOG(INFO, "sbrk(inc=%"PRIdS") = 0x%"PRIxPTR"", + increment, (uintptr_t) result); +#ifdef TODO_REENABLE_STACK_TRACING + DumpStackTrace(1, RawInfoStackDumper, NULL); +#endif + } + if (saved_sbrk_hook) { // call MemoryRegionMap's hook + (*saved_sbrk_hook)(result, increment); + } +} + +//---------------------------------------------------------------------- +// Starting/stopping/dumping +//---------------------------------------------------------------------- + +extern "C" void HeapProfilerStart(const char* prefix) { + SpinLockHolder l(&heap_lock); + + if (is_on) return; + + is_on = true; + + RAW_VLOG(0, "Starting tracking the heap"); + + // This should be done before the hooks are set up, since it should + // call new, and we want that to be accounted for correctly. + MallocExtension::Initialize(); + + if (FLAGS_only_mmap_profile) { + FLAGS_mmap_profile = true; + } + + if (FLAGS_mmap_profile) { + // Ask MemoryRegionMap to record all mmap, mremap, and sbrk + // call stack traces of at least size kMaxStackDepth: + MemoryRegionMap::Init(HeapProfileTable::kMaxStackDepth); + } + + if (FLAGS_mmap_log) { + // Install our hooks to do the logging + // and maybe save MemoryRegionMap's hooks to call: + saved_mmap_hook = MallocHook::SetMmapHook(MmapHook); + saved_mremap_hook = MallocHook::SetMremapHook(MremapHook); + saved_munmap_hook = MallocHook::SetMunmapHook(MunmapHook); + saved_sbrk_hook = MallocHook::SetSbrkHook(SbrkHook); + } + + heap_profiler_memory = + LowLevelAlloc::NewArena(0, LowLevelAlloc::DefaultArena()); + + // Reserve space now for the heap profiler, so we can still write a + // heap profile even if the application runs out of memory. + global_profiler_buffer = + reinterpret_cast<char*>(ProfilerMalloc(kProfileBufferSize)); + + heap_profile = new(ProfilerMalloc(sizeof(HeapProfileTable))) + HeapProfileTable(ProfilerMalloc, ProfilerFree); + + last_dump_alloc = 0; + last_dump_free = 0; + high_water_mark = 0; + + // We do not reset dump_count so if the user does a sequence of + // HeapProfilerStart/HeapProfileStop, we will get a continuous + // sequence of profiles. + + if (FLAGS_only_mmap_profile == false) { + // Now set the hooks that capture new/delete and malloc/free + // and check that these are the only hooks: + if (MallocHook::SetNewHook(NewHook) != NULL || + MallocHook::SetDeleteHook(DeleteHook) != NULL) { + RAW_LOG(FATAL, "Had other new/delete MallocHook-s set. " + "Are you using the heap leak checker? " + "Use --heap_check=\"\" to avoid this conflict."); + } + } + + // Copy filename prefix + RAW_DCHECK(filename_prefix == NULL, ""); + const int prefix_length = strlen(prefix); + filename_prefix = reinterpret_cast<char*>(ProfilerMalloc(prefix_length + 1)); + memcpy(filename_prefix, prefix, prefix_length); + filename_prefix[prefix_length] = '\0'; +} + +extern "C" bool IsHeapProfilerRunning() { + SpinLockHolder l(&heap_lock); + return is_on; +} + +extern "C" void HeapProfilerStop() { + SpinLockHolder l(&heap_lock); + + if (!is_on) return; + + if (FLAGS_only_mmap_profile == false) { + // Unset our new/delete hooks, checking they were the ones set: + if (MallocHook::SetNewHook(NULL) != NewHook || + MallocHook::SetDeleteHook(NULL) != DeleteHook) { + RAW_LOG(FATAL, "Had our new/delete MallocHook-s replaced. " + "Are you using another MallocHook client? " + "Do not use --heap_profile=... to avoid this conflict."); + } + } + if (FLAGS_mmap_log) { + // Restore mmap/sbrk hooks, checking that our hooks were the ones set: + if (MallocHook::SetMmapHook(saved_mmap_hook) != MmapHook || + MallocHook::SetMremapHook(saved_mremap_hook) != MremapHook || + MallocHook::SetMunmapHook(saved_munmap_hook) != MunmapHook || + MallocHook::SetSbrkHook(saved_sbrk_hook) != SbrkHook) { + RAW_LOG(FATAL, "Had our mmap/mremap/munmap/sbrk MallocHook-s replaced. " + "Are you using another MallocHook client? " + "Do not use --heap_profile=... to avoid this conflict."); + } + } + + // free profile + heap_profile->~HeapProfileTable(); + ProfilerFree(heap_profile); + heap_profile = NULL; + + // free output-buffer memory + ProfilerFree(global_profiler_buffer); + + // free prefix + ProfilerFree(filename_prefix); + filename_prefix = NULL; + + if (!LowLevelAlloc::DeleteArena(heap_profiler_memory)) { + RAW_LOG(FATAL, "Memory leak in HeapProfiler:"); + } + + if (FLAGS_mmap_profile) { + MemoryRegionMap::Shutdown(); + } + + is_on = false; +} + +extern "C" void HeapProfilerDump(const char *reason) { + SpinLockHolder l(&heap_lock); + if (is_on && !dumping) { + DumpProfileLocked(reason); + } +} + +//---------------------------------------------------------------------- +// Initialization/finalization code +//---------------------------------------------------------------------- + +// Initialization code +static void HeapProfilerInit() { + // Everything after this point is for setting up the profiler based on envvar + char fname[PATH_MAX]; + if (!GetUniquePathFromEnv("HEAPPROFILE", fname)) { + return; + } + // We do a uid check so we don't write out files in a setuid executable. +#ifdef HAVE_GETEUID + if (getuid() != geteuid()) { + RAW_LOG(WARNING, ("HeapProfiler: ignoring HEAPPROFILE because " + "program seems to be setuid\n")); + return; + } +#endif + + HeapProfileTable::CleanupOldProfiles(fname); + + HeapProfilerStart(fname); +} + +// class used for finalization -- dumps the heap-profile at program exit +struct HeapProfileEndWriter { + ~HeapProfileEndWriter() { HeapProfilerDump("Exiting"); } +}; + +// We want to make sure tcmalloc is up and running before starting the profiler +static const TCMallocGuard tcmalloc_initializer; +REGISTER_MODULE_INITIALIZER(heapprofiler, HeapProfilerInit()); +static HeapProfileEndWriter heap_profile_end_writer; |