third_party/tcmalloc/chromium/src/heap-profiler.cc

   1 // Copyright (c) 2005, Google Inc.
   2 // All rights reserved.
   3 //
   4 // Redistribution and use in source and binary forms, with or without
   5 // modification, are permitted provided that the following conditions are
   6 // met:
   7 //
   8 //     * Redistributions of source code must retain the above copyright
   9 // notice, this list of conditions and the following disclaimer.
  10 //     * Redistributions in binary form must reproduce the above
  11 // copyright notice, this list of conditions and the following disclaimer
  12 // in the documentation and/or other materials provided with the
  13 // distribution.
  14 //     * Neither the name of Google Inc. nor the names of its
  15 // contributors may be used to endorse or promote products derived from
  16 // this software without specific prior written permission.
  17 //
  18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29
  30 // ---
  31 // Author: Sanjay Ghemawat
  32 //
  33 // TODO: Log large allocations
  34
  35 #include <config.h>
  36 #include <stddef.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #ifdef HAVE_UNISTD_H
  40 #include <unistd.h>
  41 #endif
  42 #ifdef HAVE_INTTYPES_H
  43 #include <inttypes.h>
  44 #endif
  45 #ifdef HAVE_FCNTL_H
  46 #include <fcntl.h>    // for open()
  47 #endif
  48 #ifdef HAVE_MMAP
  49 #include <sys/mman.h>
  50 #endif
  51 #include <errno.h>
  52 #include <assert.h>
  53 #include <sys/types.h>
  54
  55 #include <algorithm>
  56 #include <string>
  57
  58 #include <gperftools/heap-profiler.h>
  59
  60 #include "base/logging.h"
  61 #include "base/basictypes.h"   // for PRId64, among other things
  62 #include "base/googleinit.h"
  63 #include "base/commandlineflags.h"
  64 #include "malloc_hook-inl.h"
  65 #include "tcmalloc_guard.h"
  66 #include <gperftools/malloc_hook.h>
  67 #include <gperftools/malloc_extension.h>
  68 #include "base/spinlock.h"
  69 #include "base/low_level_alloc.h"
  70 #include "base/sysinfo.h"      // for GetUniquePathFromEnv()
  71 #include "heap-profile-table.h"
  72 #include "memory_region_map.h"
  73
  74
  75 #ifndef PATH_MAX
  76 #ifdef MAXPATHLEN
  77 #define PATH_MAX        MAXPATHLEN
  78 #else
  79 #define PATH_MAX        4096         // seems conservative for max filename len!
  80 #endif
  81 #endif
  82
  83 #if defined(__ANDROID__) || defined(ANDROID)
  84 // On android, there are no environment variables.
  85 // Instead, we use system properties, set via:
  86 //   adb shell setprop prop_name prop_value
  87 // From <sys/system_properties.h>,
  88 //   PROP_NAME_MAX   32
  89 //   PROP_VALUE_MAX  92
  90 #define HEAPPROFILE "heapprof"
  91 #define HEAP_PROFILE_ALLOCATION_INTERVAL "heapprof.allocation_interval"
  92 #define HEAP_PROFILE_DEALLOCATION_INTERVAL "heapprof.deallocation_interval"
  93 #define HEAP_PROFILE_INUSE_INTERVAL "heapprof.inuse_interval"
  94 #define HEAP_PROFILE_TIME_INTERVAL "heapprof.time_interval"
  95 #define HEAP_PROFILE_MMAP_LOG "heapprof.mmap_log"
  96 #define HEAP_PROFILE_MMAP "heapprof.mmap"
  97 #define HEAP_PROFILE_ONLY_MMAP "heapprof.only_mmap"
  98 #else  // defined(__ANDROID__) || defined(ANDROID)
  99 #define HEAPPROFILE "HEAPPROFILE"
 100 #define HEAP_PROFILE_ALLOCATION_INTERVAL "HEAP_PROFILE_ALLOCATION_INTERVAL"
 101 #define HEAP_PROFILE_DEALLOCATION_INTERVAL "HEAP_PROFILE_DEALLOCATION_INTERVAL"
 102 #define HEAP_PROFILE_INUSE_INTERVAL "HEAP_PROFILE_INUSE_INTERVAL"
 103 #define HEAP_PROFILE_TIME_INTERVAL "HEAP_PROFILE_TIME_INTERVAL"
 104 #define HEAP_PROFILE_MMAP_LOG "HEAP_PROFILE_MMAP_LOG"
 105 #define HEAP_PROFILE_MMAP "HEAP_PROFILE_MMAP"
 106 #define HEAP_PROFILE_ONLY_MMAP "HEAP_PROFILE_ONLY_MMAP"
 107 #endif  // defined(__ANDROID__) || defined(ANDROID)
 108
 109 using STL_NAMESPACE::string;
 110 using STL_NAMESPACE::sort;
 111
 112 //----------------------------------------------------------------------
 113 // Flags that control heap-profiling
 114 //
 115 // The thread-safety of the profiler depends on these being immutable
 116 // after main starts, so don't change them.
 117 //----------------------------------------------------------------------
 118
 119 DEFINE_int64(heap_profile_allocation_interval,
 120              EnvToInt64(HEAP_PROFILE_ALLOCATION_INTERVAL, 1 << 30 /*1GB*/),
 121              "If non-zero, dump heap profiling information once every "
 122              "specified number of bytes allocated by the program since "
 123              "the last dump.");
 124 DEFINE_int64(heap_profile_deallocation_interval,
 125              EnvToInt64(HEAP_PROFILE_DEALLOCATION_INTERVAL, 0),
 126              "If non-zero, dump heap profiling information once every "
 127              "specified number of bytes deallocated by the program "
 128              "since the last dump.");
 129 // We could also add flags that report whenever inuse_bytes changes by
 130 // X or -X, but there hasn't been a need for that yet, so we haven't.
 131 DEFINE_int64(heap_profile_inuse_interval,
 132              EnvToInt64(HEAP_PROFILE_INUSE_INTERVAL, 100 << 20 /*100MB*/),
 133              "If non-zero, dump heap profiling information whenever "
 134              "the high-water memory usage mark increases by the specified "
 135              "number of bytes.");
 136 DEFINE_int64(heap_profile_time_interval,
 137              EnvToInt64(HEAP_PROFILE_TIME_INTERVAL, 0),
 138              "If non-zero, dump heap profiling information once every "
 139              "specified number of seconds since the last dump.");
 140 DEFINE_bool(mmap_log,
 141             EnvToBool(HEAP_PROFILE_MMAP_LOG, false),
 142             "Should mmap/munmap calls be logged?");
 143 DEFINE_bool(mmap_profile,
 144             EnvToBool(HEAP_PROFILE_MMAP, false),
 145             "If heap-profiling is on, also profile mmap, mremap, and sbrk)");
 146 DEFINE_bool(only_mmap_profile,
 147             EnvToBool(HEAP_PROFILE_ONLY_MMAP, false),
 148             "If heap-profiling is on, only profile mmap, mremap, and sbrk; "
 149             "do not profile malloc/new/etc");
 150 //----------------------------------------------------------------------
 151 // Locking
 152 //----------------------------------------------------------------------
 153
 154 // A pthread_mutex has way too much lock contention to be used here.
 155 //
 156 // I would like to use Mutex, but it can call malloc(),
 157 // which can cause us to fall into an infinite recursion.
 158 //
 159 // So we use a simple spinlock.
 160 static SpinLock heap_lock(SpinLock::LINKER_INITIALIZED);
 161
 162 //----------------------------------------------------------------------
 163 // Simple allocator for heap profiler's internal memory
 164 //----------------------------------------------------------------------
 165
 166 static LowLevelAlloc::Arena *heap_profiler_memory;
 167
 168 static void* ProfilerMalloc(size_t bytes) {
 169   return LowLevelAlloc::AllocWithArena(bytes, heap_profiler_memory);
 170 }
 171 static void ProfilerFree(void* p) {
 172   LowLevelAlloc::Free(p);
 173 }
 174
 175 // We use buffers of this size in DoGetHeapProfile.
 176 static const int kProfileBufferSize = 1 << 20;
 177
 178 // This is a last-ditch buffer we use in DumpProfileLocked in case we
 179 // can't allocate more memory from ProfilerMalloc.  We expect this
 180 // will be used by HeapProfileEndWriter when the application has to
 181 // exit due to out-of-memory.  This buffer is allocated in
 182 // HeapProfilerStart.  Access to this must be protected by heap_lock.
 183 static char* global_profiler_buffer = NULL;
 184
 185
 186 //----------------------------------------------------------------------
 187 // Profiling control/state data
 188 //----------------------------------------------------------------------
 189
 190 // Access to all of these is protected by heap_lock.
 191 static bool  is_on = false;           // If are on as a subsytem.
 192 static bool  dumping = false;         // Dumping status to prevent recursion
 193 static char* filename_prefix = NULL;  // Prefix used for profile file names
 194                                       // (NULL if no need for dumping yet)
 195 static int   dump_count = 0;          // How many dumps so far
 196 static int64 last_dump_alloc = 0;     // alloc_size when did we last dump
 197 static int64 last_dump_free = 0;      // free_size when did we last dump
 198 static int64 high_water_mark = 0;     // In-use-bytes at last high-water dump
 199 static int64 last_dump_time = 0;      // The time of the last dump
 200
 201 static HeapProfileTable* heap_profile = NULL;  // the heap profile table
 202
 203 // Callback to generate a stack trace for an allocation. May be overriden
 204 // by an application to provide its own pseudo-stacks.
 205 static StackGeneratorFunction stack_generator_function =
 206     HeapProfileTable::GetCallerStackTrace;
 207
 208 //----------------------------------------------------------------------
 209 // Profile generation
 210 //----------------------------------------------------------------------
 211
 212 // Input must be a buffer of size at least 1MB.
 213 static char* DoGetHeapProfileLocked(char* buf, int buflen) {
 214   // We used to be smarter about estimating the required memory and
 215   // then capping it to 1MB and generating the profile into that.
 216   if (buf == NULL || buflen < 1)
 217     return NULL;
 218
 219   RAW_DCHECK(heap_lock.IsHeld(), "");
 220   int bytes_written = 0;
 221   if (is_on) {
 222     HeapProfileTable::Stats const stats = heap_profile->total();
 223     (void)stats;   // avoid an unused-variable warning in non-debug mode.
 224     bytes_written = heap_profile->FillOrderedProfile(buf, buflen - 1);
 225     // FillOrderedProfile should not reduce the set of active mmap-ed regions,
 226     // hence MemoryRegionMap will let us remove everything we've added above:
 227     RAW_DCHECK(stats.Equivalent(heap_profile->total()), "");
 228     // if this fails, we somehow removed by FillOrderedProfile
 229     // more than we have added.
 230   }
 231   buf[bytes_written] = '\0';
 232   RAW_DCHECK(bytes_written == strlen(buf), "");
 233
 234   return buf;
 235 }
 236
 237 extern "C" char* GetHeapProfile() {
 238   // Use normal malloc: we return the profile to the user to free it:
 239   char* buffer = reinterpret_cast<char*>(malloc(kProfileBufferSize));
 240   SpinLockHolder l(&heap_lock);
 241   return DoGetHeapProfileLocked(buffer, kProfileBufferSize);
 242 }
 243
 244 // defined below
 245 static void NewHook(const void* ptr, size_t size);
 246 static void DeleteHook(const void* ptr);
 247
 248 // Helper for HeapProfilerDump.
 249 static void DumpProfileLocked(const char* reason) {
 250   RAW_DCHECK(heap_lock.IsHeld(), "");
 251   RAW_DCHECK(is_on, "");
 252   RAW_DCHECK(!dumping, "");
 253
 254   if (filename_prefix == NULL) return;  // we do not yet need dumping
 255
 256   dumping = true;
 257
 258   // Make file name
 259   char file_name[1000];
 260   dump_count++;
 261   snprintf(file_name, sizeof(file_name), "%s.%05d.%04d%s",
 262            filename_prefix, getpid(), dump_count, HeapProfileTable::kFileExt);
 263
 264   // Dump the profile
 265   RAW_VLOG(0, "Dumping heap profile to %s (%s)", file_name, reason);
 266   // We must use file routines that don't access memory, since we hold
 267   // a memory lock now.
 268   RawFD fd = RawOpenForWriting(file_name);
 269   if (fd == kIllegalRawFD) {
 270     RAW_LOG(ERROR, "Failed dumping heap profile to %s", file_name);
 271     dumping = false;
 272     return;
 273   }
 274
 275   // This case may be impossible, but it's best to be safe.
 276   // It's safe to use the global buffer: we're protected by heap_lock.
 277   if (global_profiler_buffer == NULL) {
 278     global_profiler_buffer =
 279         reinterpret_cast<char*>(ProfilerMalloc(kProfileBufferSize));
 280   }
 281
 282   char* profile = DoGetHeapProfileLocked(global_profiler_buffer,
 283                                          kProfileBufferSize);
 284   RawWrite(fd, profile, strlen(profile));
 285   RawClose(fd);
 286
 287   dumping = false;
 288 }
 289
 290 //----------------------------------------------------------------------
 291 // Profile collection
 292 //----------------------------------------------------------------------
 293
 294 // Dump a profile after either an allocation or deallocation, if
 295 // the memory use has changed enough since the last dump.
 296 static void MaybeDumpProfileLocked() {
 297   if (!dumping) {
 298     const HeapProfileTable::Stats& total = heap_profile->total();
 299     const int64 inuse_bytes = total.alloc_size - total.free_size;
 300     bool need_to_dump = false;
 301     char buf[128];
 302     int64 current_time = time(NULL);
 303     if (FLAGS_heap_profile_allocation_interval > 0 &&
 304         total.alloc_size >=
 305         last_dump_alloc + FLAGS_heap_profile_allocation_interval) {
 306       snprintf(buf, sizeof(buf), ("%" PRId64 " MB allocated cumulatively, "
 307                                   "%" PRId64 " MB currently in use"),
 308                total.alloc_size >> 20, inuse_bytes >> 20);
 309       need_to_dump = true;
 310     } else if (FLAGS_heap_profile_deallocation_interval > 0 &&
 311                total.free_size >=
 312                last_dump_free + FLAGS_heap_profile_deallocation_interval) {
 313       snprintf(buf, sizeof(buf), ("%" PRId64 " MB freed cumulatively, "
 314                                   "%" PRId64 " MB currently in use"),
 315                total.free_size >> 20, inuse_bytes >> 20);
 316       need_to_dump = true;
 317     } else if (FLAGS_heap_profile_inuse_interval > 0 &&
 318                inuse_bytes >
 319                high_water_mark + FLAGS_heap_profile_inuse_interval) {
 320       snprintf(buf, sizeof(buf), "%" PRId64 " MB currently in use",
 321                inuse_bytes >> 20);
 322       need_to_dump = true;
 323     } else if (FLAGS_heap_profile_time_interval > 0 &&
 324                current_time - last_dump_time >=
 325                FLAGS_heap_profile_time_interval) {
 326       snprintf(buf, sizeof(buf), "%" PRId64 " sec since the last dump",
 327                current_time - last_dump_time);
 328       need_to_dump = true;
 329       last_dump_time = current_time;
 330     }
 331     if (need_to_dump) {
 332       DumpProfileLocked(buf);
 333
 334       last_dump_alloc = total.alloc_size;
 335       last_dump_free = total.free_size;
 336       if (inuse_bytes > high_water_mark)
 337         high_water_mark = inuse_bytes;
 338     }
 339   }
 340 }
 341
 342 // Record an allocation in the profile.
 343 static void RecordAlloc(const void* ptr, size_t bytes, int skip_count) {
 344   // Take the stack trace outside the critical section.
 345   void* stack[HeapProfileTable::kMaxStackDepth];
 346   int depth = stack_generator_function(skip_count + 1, stack);
 347   SpinLockHolder l(&heap_lock);
 348   if (is_on) {
 349     heap_profile->RecordAlloc(ptr, bytes, depth, stack);
 350     MaybeDumpProfileLocked();
 351   }
 352 }
 353
 354 // Record a deallocation in the profile.
 355 static void RecordFree(const void* ptr) {
 356   SpinLockHolder l(&heap_lock);
 357   if (is_on) {
 358     heap_profile->RecordFree(ptr);
 359     MaybeDumpProfileLocked();
 360   }
 361 }
 362
 363 //----------------------------------------------------------------------
 364 // Allocation/deallocation hooks for MallocHook
 365 //----------------------------------------------------------------------
 366
 367 // static
 368 void NewHook(const void* ptr, size_t size) {
 369   if (ptr != NULL) RecordAlloc(ptr, size, 0);
 370 }
 371
 372 // static
 373 void DeleteHook(const void* ptr) {
 374   if (ptr != NULL) RecordFree(ptr);
 375 }
 376
 377 // TODO(jandrews): Re-enable stack tracing
 378 #ifdef TODO_REENABLE_STACK_TRACING
 379 static void RawInfoStackDumper(const char* message, void*) {
 380   RAW_LOG(INFO, "%.*s", static_cast<int>(strlen(message) - 1), message);
 381   // -1 is to chop the \n which will be added by RAW_LOG
 382 }
 383 #endif
 384
 385 static void MmapHook(const void* result, const void* start, size_t size,
 386                      int prot, int flags, int fd, off_t offset) {
 387   if (FLAGS_mmap_log) {  // log it
 388     // We use PRIxS not just '%p' to avoid deadlocks
 389     // in pretty-printing of NULL as "nil".
 390     // TODO(maxim): instead should use a safe snprintf reimplementation
 391     RAW_LOG(INFO,
 392             "mmap(start=0x%" PRIxPTR ", len=%" PRIuS ", prot=0x%x, flags=0x%x, "
 393             "fd=%d, offset=0x%x) = 0x%" PRIxPTR,
 394             (uintptr_t) start, size, prot, flags, fd, (unsigned int) offset,
 395             (uintptr_t) result);
 396 #ifdef TODO_REENABLE_STACK_TRACING
 397     DumpStackTrace(1, RawInfoStackDumper, NULL);
 398 #endif
 399   }
 400 }
 401
 402 static void MremapHook(const void* result, const void* old_addr,
 403                        size_t old_size, size_t new_size,
 404                        int flags, const void* new_addr) {
 405   if (FLAGS_mmap_log) {  // log it
 406     // We use PRIxS not just '%p' to avoid deadlocks
 407     // in pretty-printing of NULL as "nil".
 408     // TODO(maxim): instead should use a safe snprintf reimplementation
 409     RAW_LOG(INFO,
 410             "mremap(old_addr=0x%" PRIxPTR ", old_size=%" PRIuS ", "
 411             "new_size=%" PRIuS ", flags=0x%x, new_addr=0x%" PRIxPTR ") = "
 412             "0x%" PRIxPTR,
 413             (uintptr_t) old_addr, old_size, new_size, flags,
 414             (uintptr_t) new_addr, (uintptr_t) result);
 415 #ifdef TODO_REENABLE_STACK_TRACING
 416     DumpStackTrace(1, RawInfoStackDumper, NULL);
 417 #endif
 418   }
 419 }
 420
 421 static void MunmapHook(const void* ptr, size_t size) {
 422   if (FLAGS_mmap_log) {  // log it
 423     // We use PRIxS not just '%p' to avoid deadlocks
 424     // in pretty-printing of NULL as "nil".
 425     // TODO(maxim): instead should use a safe snprintf reimplementation
 426     RAW_LOG(INFO, "munmap(start=0x%" PRIxPTR ", len=%" PRIuS ")",
 427                   (uintptr_t) ptr, size);
 428 #ifdef TODO_REENABLE_STACK_TRACING
 429     DumpStackTrace(1, RawInfoStackDumper, NULL);
 430 #endif
 431   }
 432 }
 433
 434 static void SbrkHook(const void* result, ptrdiff_t increment) {
 435   if (FLAGS_mmap_log) {  // log it
 436     RAW_LOG(INFO, "sbrk(inc=%" PRIdS ") = 0x%" PRIxPTR,
 437                   increment, (uintptr_t) result);
 438 #ifdef TODO_REENABLE_STACK_TRACING
 439     DumpStackTrace(1, RawInfoStackDumper, NULL);
 440 #endif
 441   }
 442 }
 443
 444 //----------------------------------------------------------------------
 445 // Starting/stopping/dumping
 446 //----------------------------------------------------------------------
 447
 448 extern "C" void HeapProfilerStart(const char* prefix) {
 449   SpinLockHolder l(&heap_lock);
 450
 451   if (is_on) return;
 452
 453   is_on = true;
 454
 455   RAW_VLOG(0, "Starting tracking the heap");
 456
 457   // This should be done before the hooks are set up, since it should
 458   // call new, and we want that to be accounted for correctly.
 459   MallocExtension::Initialize();
 460
 461   if (FLAGS_only_mmap_profile) {
 462     FLAGS_mmap_profile = true;
 463   }
 464
 465   if (FLAGS_mmap_profile) {
 466     // Ask MemoryRegionMap to record all mmap, mremap, and sbrk
 467     // call stack traces of at least size kMaxStackDepth:
 468     MemoryRegionMap::Init(HeapProfileTable::kMaxStackDepth,
 469                           /* use_buckets */ true);
 470   }
 471
 472   if (FLAGS_mmap_log) {
 473     // Install our hooks to do the logging:
 474     RAW_CHECK(MallocHook::AddMmapHook(&MmapHook), "");
 475     RAW_CHECK(MallocHook::AddMremapHook(&MremapHook), "");
 476     RAW_CHECK(MallocHook::AddMunmapHook(&MunmapHook), "");
 477     RAW_CHECK(MallocHook::AddSbrkHook(&SbrkHook), "");
 478   }
 479
 480   heap_profiler_memory =
 481     LowLevelAlloc::NewArena(0, LowLevelAlloc::DefaultArena());
 482
 483   // Reserve space now for the heap profiler, so we can still write a
 484   // heap profile even if the application runs out of memory.
 485   global_profiler_buffer =
 486       reinterpret_cast<char*>(ProfilerMalloc(kProfileBufferSize));
 487
 488   heap_profile = new(ProfilerMalloc(sizeof(HeapProfileTable)))
 489       HeapProfileTable(ProfilerMalloc, ProfilerFree, FLAGS_mmap_profile);
 490
 491   last_dump_alloc = 0;
 492   last_dump_free = 0;
 493   high_water_mark = 0;
 494   last_dump_time = 0;
 495
 496   // We do not reset dump_count so if the user does a sequence of
 497   // HeapProfilerStart/HeapProfileStop, we will get a continuous
 498   // sequence of profiles.
 499
 500   if (FLAGS_only_mmap_profile == false) {
 501     // Now set the hooks that capture new/delete and malloc/free.
 502     RAW_CHECK(MallocHook::AddNewHook(&NewHook), "");
 503     RAW_CHECK(MallocHook::AddDeleteHook(&DeleteHook), "");
 504   }
 505
 506   // Copy filename prefix only if provided.
 507   if (!prefix)
 508     return;
 509   RAW_DCHECK(filename_prefix == NULL, "");
 510   const int prefix_length = strlen(prefix);
 511   filename_prefix = reinterpret_cast<char*>(ProfilerMalloc(prefix_length + 1));
 512   memcpy(filename_prefix, prefix, prefix_length);
 513   filename_prefix[prefix_length] = '\0';
 514 }
 515
 516 extern "C" void HeapProfilerWithPseudoStackStart(
 517     StackGeneratorFunction callback) {
 518   {
 519     // Ensure the callback is set before allocations can be recorded.
 520     SpinLockHolder l(&heap_lock);
 521     stack_generator_function = callback;
 522   }
 523   HeapProfilerStart(NULL);
 524 }
 525
 526 extern "C" void IterateAllocatedObjects(AddressVisitor visitor, void* data) {
 527   SpinLockHolder l(&heap_lock);
 528
 529   if (!is_on) return;
 530
 531   heap_profile->IterateAllocationAddresses(visitor, data);
 532 }
 533
 534 extern "C" int IsHeapProfilerRunning() {
 535   SpinLockHolder l(&heap_lock);
 536   return is_on ? 1 : 0;   // return an int, because C code doesn't have bool
 537 }
 538
 539 extern "C" void HeapProfilerStop() {
 540   SpinLockHolder l(&heap_lock);
 541
 542   if (!is_on) return;
 543
 544   if (FLAGS_only_mmap_profile == false) {
 545     // Unset our new/delete hooks, checking they were set:
 546     RAW_CHECK(MallocHook::RemoveNewHook(&NewHook), "");
 547     RAW_CHECK(MallocHook::RemoveDeleteHook(&DeleteHook), "");
 548   }
 549   if (FLAGS_mmap_log) {
 550     // Restore mmap/sbrk hooks, checking that our hooks were set:
 551     RAW_CHECK(MallocHook::RemoveMmapHook(&MmapHook), "");
 552     RAW_CHECK(MallocHook::RemoveMremapHook(&MremapHook), "");
 553     RAW_CHECK(MallocHook::RemoveSbrkHook(&SbrkHook), "");
 554     RAW_CHECK(MallocHook::RemoveMunmapHook(&MunmapHook), "");
 555   }
 556
 557   // free profile
 558   heap_profile->~HeapProfileTable();
 559   ProfilerFree(heap_profile);
 560   heap_profile = NULL;
 561
 562   // free output-buffer memory
 563   ProfilerFree(global_profiler_buffer);
 564
 565   // free prefix
 566   ProfilerFree(filename_prefix);
 567   filename_prefix = NULL;
 568
 569   if (!LowLevelAlloc::DeleteArena(heap_profiler_memory)) {
 570     RAW_LOG(FATAL, "Memory leak in HeapProfiler:");
 571   }
 572
 573   if (FLAGS_mmap_profile) {
 574     MemoryRegionMap::Shutdown();
 575   }
 576
 577   is_on = false;
 578 }
 579
 580 extern "C" void HeapProfilerDump(const char* reason) {
 581   SpinLockHolder l(&heap_lock);
 582   if (is_on && !dumping) {
 583     DumpProfileLocked(reason);
 584   }
 585 }
 586
 587 extern "C" void HeapProfilerMarkBaseline() {
 588   SpinLockHolder l(&heap_lock);
 589
 590   if (!is_on) return;
 591
 592   heap_profile->MarkCurrentAllocations(HeapProfileTable::MARK_ONE);
 593 }
 594
 595 extern "C" void HeapProfilerMarkInteresting() {
 596   SpinLockHolder l(&heap_lock);
 597
 598   if (!is_on) return;
 599
 600   heap_profile->MarkUnmarkedAllocations(HeapProfileTable::MARK_TWO);
 601 }
 602
 603 extern "C" void HeapProfilerDumpAliveObjects(const char* filename) {
 604   SpinLockHolder l(&heap_lock);
 605
 606   if (!is_on) return;
 607
 608   heap_profile->DumpMarkedObjects(HeapProfileTable::MARK_TWO, filename);
 609 }
 610
 611 //----------------------------------------------------------------------
 612 // Initialization/finalization code
 613 //----------------------------------------------------------------------
 614 #if defined(ENABLE_PROFILING)
 615 // Initialization code
 616 static void HeapProfilerInit() {
 617   // Everything after this point is for setting up the profiler based on envvar
 618   char fname[PATH_MAX];
 619   if (!GetUniquePathFromEnv(HEAPPROFILE, fname)) {
 620     return;
 621   }
 622   // We do a uid check so we don't write out files in a setuid executable.
 623 #ifdef HAVE_GETEUID
 624   if (getuid() != geteuid()) {
 625     RAW_LOG(WARNING, ("HeapProfiler: ignoring " HEAPPROFILE " because "
 626                       "program seems to be setuid\n"));
 627     return;
 628   }
 629 #endif
 630
 631   HeapProfileTable::CleanupOldProfiles(fname);
 632
 633   HeapProfilerStart(fname);
 634 }
 635
 636 // class used for finalization -- dumps the heap-profile at program exit
 637 struct HeapProfileEndWriter {
 638   ~HeapProfileEndWriter() { HeapProfilerDump("Exiting"); }
 639 };
 640
 641 // We want to make sure tcmalloc is up and running before starting the profiler
 642 static const TCMallocGuard tcmalloc_initializer;
 643 REGISTER_MODULE_INITIALIZER(heapprofiler, HeapProfilerInit());
 644 static HeapProfileEndWriter heap_profile_end_writer;
 645 #endif   // defined(ENABLE_PROFILING)