Route calls to tcmalloc MallocExtension through allocator agnostic interface

base/allocator/allocator_extension.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.
+
+#include "base/allocator/allocator_extension.h"
+
+#include "base/logging.h"
+
+namespace base {
+namespace allocator {
+
+static GetStatsFunction* g_get_stats_function = 0;

[willchan no longer on Chromium, 2012/04/26 22:08:48]

nit: s/0/NULL/. I've never seen = 0 for a pointer in chromium code s'all. If you
strongly prefer this style though, I won't argue :)

+static ReleaseFreeMemoryFunction* g_release_free_memory_function = 0;
+
+void GetStats(char* buffer, int buffer_length) {

[willchan no longer on Chromium, 2012/04/26 22:08:48]

You may need BASE_EXPORT here too.

+  DCHECK_GT(buffer_length, 0);
+  if (g_get_stats_function)
+    g_get_stats_function(buffer, buffer_length);
+  else
+    buffer[0] = '\0';
+}
+
+void ReleaseFreeMemory() {
+  if (g_release_free_memory_function)
+    g_release_free_memory_function();
+}
+
+void SetGetStatsFunction(GetStatsFunction* get_stats_function) {
+  DCHECK_EQ(g_get_stats_function, reinterpret_cast<GetStatsFunction*>(NULL));
+  g_get_stats_function = get_stats_function;
+}
+
+void SetReleaseFreeMemoryFunction(
+      ReleaseFreeMemoryFunction* release_free_memory_function) {
+  DCHECK_EQ(g_release_free_memory_function,
+            reinterpret_cast<ReleaseFreeMemoryFunction*>(NULL));
+  g_release_free_memory_function = release_free_memory_function;
+}
+
+}  // namespace allocator
+}  // namespace base