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// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
// 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 <stddef.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 <signal.h>
#include <algorithm>
#include <string>
#include <gperftools/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 <gperftools/malloc_hook.h>
#include <gperftools/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_int64(heap_profile_time_interval,
EnvToInt64("HEAP_PROFILE_TIME_INTERVAL", 0),
"If non-zero, dump heap profiling information once every "
"specified number of seconds since the last dump.");
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 int64 last_dump_time = 0; // The time of the last dump
static HeapProfileTable* heap_profile = NULL; // the heap profile table
//----------------------------------------------------------------------
// Profile generation
//----------------------------------------------------------------------
// 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();
(void)stats; // avoid an unused-variable warning in non-debug mode.
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:
RAW_DCHECK(stats.Equivalent(heap_profile->total()), "");
// if this fails, we somehow removed by FillOrderedProfile
// 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
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];
int64 current_time = time(NULL);
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;
} else if (FLAGS_heap_profile_time_interval > 0 &&
current_time - last_dump_time >=
FLAGS_heap_profile_time_interval) {
snprintf(buf, sizeof(buf), "%" PRId64 " sec since the last dump",
current_time - last_dump_time);
need_to_dump = true;
last_dump_time = current_time;
}
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) {
// Take the stack trace outside the critical section.
void* stack[HeapProfileTable::kMaxStackDepth];
int depth = HeapProfileTable::GetCallerStackTrace(skip_count + 1, stack);
SpinLockHolder l(&heap_lock);
if (is_on) {
heap_profile->RecordAlloc(ptr, bytes, depth, stack);
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
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
}
}
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
}
}
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
}
}
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
}
}
//----------------------------------------------------------------------
// 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,
/* use_buckets */ true);
}
if (FLAGS_mmap_log) {
// Install our hooks to do the logging:
RAW_CHECK(MallocHook::AddMmapHook(&MmapHook), "");
RAW_CHECK(MallocHook::AddMremapHook(&MremapHook), "");
RAW_CHECK(MallocHook::AddMunmapHook(&MunmapHook), "");
RAW_CHECK(MallocHook::AddSbrkHook(&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, FLAGS_mmap_profile);
last_dump_alloc = 0;
last_dump_free = 0;
high_water_mark = 0;
last_dump_time = 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.
RAW_CHECK(MallocHook::AddNewHook(&NewHook), "");
RAW_CHECK(MallocHook::AddDeleteHook(&DeleteHook), "");
}
// 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" int IsHeapProfilerRunning() {
SpinLockHolder l(&heap_lock);
return is_on ? 1 : 0; // return an int, because C code doesn't have bool
}
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 set:
RAW_CHECK(MallocHook::RemoveNewHook(&NewHook), "");
RAW_CHECK(MallocHook::RemoveDeleteHook(&DeleteHook), "");
}
if (FLAGS_mmap_log) {
// Restore mmap/sbrk hooks, checking that our hooks were set:
RAW_CHECK(MallocHook::RemoveMmapHook(&MmapHook), "");
RAW_CHECK(MallocHook::RemoveMremapHook(&MremapHook), "");
RAW_CHECK(MallocHook::RemoveSbrkHook(&SbrkHook), "");
RAW_CHECK(MallocHook::RemoveMunmapHook(&MunmapHook), "");
}
// 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);
}
}
// Signal handler that is registered when a user selectable signal
// number is defined in the environment variable HEAPPROFILESIGNAL.
static void HeapProfilerDumpSignal(int signal_number) {
(void)signal_number;
if (!heap_lock.TryLock()) {
return;
}
if (is_on && !dumping) {
DumpProfileLocked("signal");
}
heap_lock.Unlock();
}
//----------------------------------------------------------------------
// 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
char *signal_number_str = getenv("HEAPPROFILESIGNAL");
if (signal_number_str != NULL) {
long int signal_number = strtol(signal_number_str, NULL, 10);
intptr_t old_signal_handler = reinterpret_cast<intptr_t>(signal(signal_number, HeapProfilerDumpSignal));
if (old_signal_handler == reinterpret_cast<intptr_t>(SIG_ERR)) {
RAW_LOG(FATAL, "Failed to set signal. Perhaps signal number %s is invalid\n", signal_number_str);
} else if (old_signal_handler == 0) {
RAW_LOG(INFO,"Using signal %d as heap profiling switch", signal_number);
} else {
RAW_LOG(FATAL, "Signal %d already in use\n", signal_number);
}
}
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;