Dump /proc/<pid>/maps with every heap profile dump.

third_party/tcmalloc/chromium/src/deep-heap-profile.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // ---
 // Author: Sainbayar Sukhbaatar
 //         Dai Mikurube
 //
 
 #include "deep-heap-profile.h"
@@ skipping 72 matching lines @@
     pagemap_fd_ = OpenProcPagemap();
 
     for (int i = 0; i < kHashTableSize; i++) {
       for (DeepBucket* deep_bucket = deep_table_[i];
            deep_bucket != NULL;
            deep_bucket = deep_bucket->next) {
         deep_bucket->is_logged = false;
       }
     }
 
-    // Write maps into a .maps file with using the global buffer.
-    WriteMapsToFile(filename_prefix_, kProfilerBufferSize, profiler_buffer_);
+    // Write maps into "|filename_prefix|.<pid>.maps" using global buffer.
+    WriteMapsToFile(filename_prefix_, 0,
+                    kProfilerBufferSize, profiler_buffer_);
   }
+  // Write maps into "|filename_prefix|.<pid>.|count|.maps" using global buffer.
+  WriteMapsToFile(filename_prefix_, dump_count_,
+                  kProfilerBufferSize, profiler_buffer_);
 
   // Reset committed sizes of buckets.
   ResetCommittedSize(deep_table_);
 
   // Allocate a list for mmap'ed regions.
   num_mmap_allocations_ = 0;
   heap_profile_->mmap_address_map_->Iterate(CountMMap, this);
   mmap_list_length_ = 0;
   mmap_list_ = reinterpret_cast<MMapListEntry*>(heap_profile_->alloc_(
       sizeof(MMapListEntry) * num_mmap_allocations_));
@@ skipping 210 matching lines @@
       break;
     }
     page_address += page_size;
   }
 
   return committed_size;
 }
 
 // static
 void DeepHeapProfile::WriteMapsToFile(const char* filename_prefix,
+                                      unsigned count,
                                       int buffer_size,
                                       char buffer[]) {
   char filename[100];
-  snprintf(filename, sizeof(filename),
-           "%s.%05d.maps", filename_prefix, static_cast<int>(getpid()));
+  if (count > 0) {
+    snprintf(filename, sizeof(filename),
+             "%s.%05d.%04d.maps", filename_prefix, static_cast<int>(getpid()),
+             count);
+  } else {
+    snprintf(filename, sizeof(filename),
+             "%s.%05d.maps", filename_prefix, static_cast<int>(getpid()));
+  }
 
   RawFD maps_fd = RawOpenForWriting(filename);
   RAW_DCHECK(maps_fd != kIllegalRawFD, "");
 
   int map_length;
   bool wrote_all;
   map_length = tcmalloc::FillProcSelfMaps(buffer, buffer_size, &wrote_all);
   RAW_DCHECK(wrote_all, "");
   RAW_DCHECK(map_length <= buffer_size, "");
   RawWrite(maps_fd, buffer, map_length);
@@ skipping 466 matching lines @@
 }
 
 DeepHeapProfile::~DeepHeapProfile() {
 }
 
 int DeepHeapProfile::FillOrderedProfile(char buffer[], int buffer_size) {
   return heap_profile_->FillOrderedProfile(buffer, buffer_size);
 }
 
 #endif  // DEEP_HEAP_PROFILE