Type profiler by intercepting 'new' and 'delete' expressions.

third_party/tcmalloc/chromium/src/allocated_type_map.cc

Index: third_party/tcmalloc/chromium/src/allocated_type_map.cc
diff --git a/third_party/tcmalloc/chromium/src/allocated_type_map.cc b/third_party/tcmalloc/chromium/src/allocated_type_map.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e826fb55915c53283b796e9a3d6948643c033f3e
--- /dev/null
+++ b/third_party/tcmalloc/chromium/src/allocated_type_map.cc
@@ -0,0 +1,88 @@
+// 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.
+
+#include <config.h>
+
+#include <new>
+#include <typeinfo>
+
+#include <gperftools/allocated_type_map.h>
+
+#include "addressmap-inl.h"
+#include "base/low_level_alloc.h"
+#include "base/spinlock.h"
+#include "tcmalloc_guard.h"
+
+
+//----------------------------------------------------------------------
+// Locking
+//----------------------------------------------------------------------
+
+static SpinLock allocated_type_lock(SpinLock::LINKER_INITIALIZED);
+
+//----------------------------------------------------------------------
+// Simple allocator for allocated type map's internal memory
+//----------------------------------------------------------------------
+
+static LowLevelAlloc::Arena* allocated_type_map_memory = NULL;
+
+static void* AllocatedTypeMalloc(size_t bytes) {
+  return LowLevelAlloc::AllocWithArena(bytes, allocated_type_map_memory);
+}
+
+static void AllocatedTypeFree(void* p) {
+  LowLevelAlloc::Free(p);
+}
+
+//----------------------------------------------------------------------
+// Profiling control/state data
+//----------------------------------------------------------------------
+
+static AddressMap<AllocatedObject>* allocated_type_map = NULL;
+
+//----------------------------------------------------------------------
+// Manage allocated type map
+//----------------------------------------------------------------------
+
+static void InitializeAllocatedTypeMemory() {
+  if (allocated_type_map_memory == NULL) {

[jar (doing other things), 2012/08/08 23:21:04]

Given that both of these should be NULL, or both should be non-NULL, why not
just test one each time we enter:
if (allocated_type_map_memory != NULL) {
  DCHECK_NE(allocated_type_map, NULL);
  return;
}

It was sad that this lazy initialization is on the path for every malloc and
free, so you may as well not go out of your way to do extra work.

Also note that IF the allocation fails for either call, you're doomed to crash
RSN anyway... so both had better succeed (with calling code as written).

[Dai Mikurube (NOT FULLTIME), 2012/08/09 10:23:54]

Agreed.  Done.

+    allocated_type_map_memory =
+        LowLevelAlloc::NewArena(0, LowLevelAlloc::DefaultArena());
+  }
+
+  if (allocated_type_map == NULL) {
+    allocated_type_map =
+        new(AllocatedTypeMalloc(sizeof(AddressMap<AllocatedObject>)))
+            AddressMap<AllocatedObject>(AllocatedTypeMalloc, AllocatedTypeFree);
+  }
+}
+
+extern "C" void InsertAllocatedType(void* address,

[jar (doing other things), 2012/08/08 23:21:04]

Why do these need to be "C"?  Who is calling them?

[Dai Mikurube (NOT FULLTIME), 2012/08/09 10:23:54]

Callers must be C++.  Ok, removed them.

+                                    unsigned int size,
+                                    const std::type_info& type) {
+  SpinLockHolder l(&allocated_type_lock);
+  InitializeAllocatedTypeMemory();
+
+  allocated_type_map->Insert(address, AllocatedObject(size, &type));
+}
+
+extern "C" void EraseAllocatedType(void* address) {
+  SpinLockHolder l(&allocated_type_lock);
+  InitializeAllocatedTypeMemory();
+
+  AllocatedObject obj;
+  allocated_type_map->FindAndRemove(address, &obj);
+}
+
+extern "C" const std::type_info* LookupAllocatedType(const void* address) {
+  SpinLockHolder l(&allocated_type_lock);
+  InitializeAllocatedTypeMemory();
+
+  const AllocatedObject* found = allocated_type_map->Find(address);
+  if (found == NULL)
+    return NULL;
+  return found->type;
+}
+
+static const TCMallocGuard tcmalloc_initializer;