Report memory retained by memory allocator internals.

webkit/glue/webkitplatformsupport_impl.cc

Index: webkit/glue/webkitplatformsupport_impl.cc
diff --git a/webkit/glue/webkitplatformsupport_impl.cc b/webkit/glue/webkitplatformsupport_impl.cc
index fe80547877be6ca318df6f55d462bcbcbba6903c..3ff674f8635d684b31f05f9d68f79a513cff70f9 100644
--- a/webkit/glue/webkitplatformsupport_impl.cc
+++ b/webkit/glue/webkitplatformsupport_impl.cc
@@ -48,6 +48,10 @@
 #include "webkit/plugins/npapi/plugin_instance.h"
 #include "webkit/plugins/webplugininfo.h"
 
+#if defined(USE_TCMALLOC)
+#include "third_party/tcmalloc/chromium/src/gperftools/malloc_extension.h"
+#endif
+
 #if defined(OS_LINUX)
 #include "v8/include/v8.h"
 #endif
@@ -758,6 +762,37 @@ bool WebKitPlatformSupportImpl::processMemorySizesInBytes(
   return CurrentProcessMetrics()->GetMemoryBytes(private_bytes, shared_bytes);
 }
 
+bool WebKitPlatformSupportImpl::memoryAllocatorWasteInBytes(size_t* psize) {

[darin (slow to review), 2012/08/07 22:06:14]

nit: avoid Hungarian notation... psize -> size

[alexeif, 2012/08/08 17:18:36]

Done.

+#if defined(USE_TCMALLOC)

[jamesr, 2012/08/07 22:15:59]

having defined(USE_TCMALLOC) set does not mean that you are definitely using
tcmalloc on all platforms. On windows, we support runtime allocator switching
(via an environment variable) so there's no way to know at compile time which
allocator you are going to be using.  Read base/allocator/README and the other
files in that directory for some more background.

Having this somewhat direct dependency on tcmalloc is also somewhat unfortunate.
 Can you look at base/allocator/allocator_extension and plumb this extension
through that mechanism instead?

[alexeif, 2012/08/08 17:18:36]

done it in a separate CL https://chromiumcodereview.appspot.com/10825250/ 

+    MallocExtension* malloc_ext = MallocExtension::instance();

[darin (slow to review), 2012/08/07 22:06:14]

nit: indentation

[alexeif, 2012/08/08 17:18:36]

Done.

+    DCHECK(malloc_ext);
+    std::vector<MallocExtension::FreeListInfo> free_list_info;
+    malloc_ext->GetFreeListSizes(&free_list_info);
+    size_t size = 0;
+    std::vector<MallocExtension::FreeListInfo>::iterator it;
+    for (it = free_list_info.begin(); it != free_list_info.end(); ++it) {
+#ifdef NDEBUG
+        if (it->total_bytes_free == 0)
+            continue;
+#endif
+        if (strcmp(it->type, "tcmalloc.central") == 0 ||
+            strcmp(it->type, "tcmalloc.transfer") == 0 ||
+            strcmp(it->type, "tcmalloc.thread") == 0 ||
+            strcmp(it->type, "tcmalloc.large") == 0 ||
+            strcmp(it->type, "tcmalloc.page") == 0) {
+            size += it->total_bytes_free;
+            continue;
+        }
+        DCHECK(strcmp(it->type, "tcmalloc.large_unmapped") == 0 ||
+               strcmp(it->type, "tcmalloc.page_unmapped") == 0);
+    }
+    *psize = size;
+    return true;
+#else
+    return false;
+#endif
+}
+
 void WebKitPlatformSupportImpl::SuspendSharedTimer() {
   ++shared_timer_suspended_;
 }