Add a benchmarking_extension API to call TCMalloc's HeapProfilerDump().

chrome/renderer/memory_benchmarking_extension.cc

Index: chrome/renderer/memory_benchmarking_extension.cc
diff --git a/chrome/renderer/memory_benchmarking_extension.cc b/chrome/renderer/memory_benchmarking_extension.cc
new file mode 100644
index 0000000000000000000000000000000000000000..99483dce674a13fc58d286fb52ea9dc41abc2d4e
--- /dev/null
+++ b/chrome/renderer/memory_benchmarking_extension.cc
@@ -0,0 +1,77 @@
+// Copyright (c) 2013 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 "chrome/renderer/memory_benchmarking_extension.h"
+
+#include "base/string_util.h"
+#include "chrome/common/benchmarking_messages.h"
+#include "content/public/renderer/render_thread.h"
+#if !defined(NO_TCMALLOC) && (defined(OS_LINUX) || defined(OS_CHROMEOS))

[jochen (gone - plz use gerrit), 2013/02/06 11:57:57]

#if clauses should come after all includes with an empty line in between

also, why not windows as well?

I think if you don't have tcmalloc, you just shouldn't compile the extension in.

[Dai Mikurube (NOT FULLTIME), 2013/02/06 12:24:45]

Done.
Since Windows dump is not tested.  (Now, I don't have an environment to test
it.)
I'd like to allow users to check it by
chrome.memoryBenchmarking.isHeapProfilerRunning.

+#include "third_party/tcmalloc/chromium/src/gperftools/heap-profiler.h"
+#endif  // !defined(NO_TCMALLOC) && (defined(OS_LINUX) || defined(OS_CHROMEOS))
+#include "v8/include/v8.h"
+
+const char kMemoryBenchmarkingExtensionName[] = "v8/MemoryBenchmarking";

[jochen (gone - plz use gerrit), 2013/02/06 11:57:57]

should also go into an anonymous namespace

[Dai Mikurube (NOT FULLTIME), 2013/02/06 12:24:45]

Done.

+
+namespace extensions_v8 {
+
+class MemoryBenchmarkingWrapper : public v8::Extension {

[jochen (gone - plz use gerrit), 2013/02/06 11:57:57]

this class and the static functions below should go into an anonymous namespace

[Dai Mikurube (NOT FULLTIME), 2013/02/06 12:24:45]

In an anonymous namespace, how can I call MemoryBenchmarkingExtension::Get() to
register the extension?  (It's now registered in render_thread_impl.)

It's the same way with content/render/gpu/gpu_benchmarking_extension.

[jochen (gone - plz use gerrit), 2013/02/06 12:31:41]

I meant that the Wrapper should go into the anon namespace. You only need the
static MemoryBenchmarkingExtension::Get() outside of the namespace. 

[Dai Mikurube (NOT FULLTIME), 2013/02/06 12:38:01]

Makes sense.  Done.

+ public:
+  MemoryBenchmarkingWrapper() :
+      v8::Extension(kMemoryBenchmarkingExtensionName,

[jochen (gone - plz use gerrit), 2013/02/06 11:57:57]

usually, we put the code in a .js file in the resources/ subdirectory and load
it via resource bundle

[Dai Mikurube (NOT FULLTIME), 2013/02/06 12:24:45]

Almost all the benchmarking_extension does this.  What do you think, Nat?

[jochen (gone - plz use gerrit), 2013/02/06 12:31:41]

I'd argue they do it wrong :)

+        "if (typeof(chrome) == 'undefined') {"
+        "  chrome = {};"

[jochen (gone - plz use gerrit), 2013/02/06 12:31:41]

this should be just 

chrome = chrome || {};
chrome.benchmarking = chrome.benchmarking || {};

[Dai Mikurube (NOT FULLTIME), 2013/02/06 12:38:01]

IIRC, they have different meaning in JS.  I'm not sure how these extensions
(including other extensions which do the same thing) should behave.

Wdyt, Nat?

+        "};"
+        "if (typeof(chrome.benchmarking) == 'undefined') {"
+        "  chrome.benchmarking = {};"
+        "};"
+        "chrome.benchmarking.isHeapProfilerRunning = function() {"
+        "  native function IsHeapProfilerRunning();"
+        "  return IsHeapProfilerRunning();"
+        "};"
+        "chrome.benchmarking.heapProfilerDump = function(reason) {"
+        "  native function HeapProfilerDump();"
+        "  HeapProfilerDump(reason);"
+        "};"
+        ) {}
+
+  virtual v8::Handle<v8::FunctionTemplate> GetNativeFunction(
+      v8::Handle<v8::String> name) {
+    if (name->Equals(v8::String::New("IsHeapProfilerRunning"))) {

[jochen (gone - plz use gerrit), 2013/02/06 12:31:41]

no { } for single-line bodies

[Dai Mikurube (NOT FULLTIME), 2013/02/06 12:38:01]

Done.

+      return v8::FunctionTemplate::New(IsHeapProfilerRunning);
+    } else if (name->Equals(v8::String::New("HeapProfilerDump"))) {
+      return v8::FunctionTemplate::New(HeapProfilerDump);
+    }
+
+    return v8::Handle<v8::FunctionTemplate>();
+  }
+
+  static v8::Handle<v8::Value>
+  IsHeapProfilerRunning(const v8::Arguments& args) {

[jochen (gone - plz use gerrit), 2013/02/06 11:57:57]

i think you should wrap after IsHeapProfilerRunning( instead of before

[Dai Mikurube (NOT FULLTIME), 2013/02/06 12:24:45]

Done.

+#if !defined(NO_TCMALLOC) && (defined(OS_LINUX) || defined(OS_CHROMEOS))
+    return v8::Boolean::New(::IsHeapProfilerRunning());
+#else
+    return v8::Boolean::New(false);
+#endif  // !defined(NO_TCMALLOC) && (defined(OS_LINUX) || defined(OS_CHROMEOS))
+  }
+
+  static v8::Handle<v8::Value> HeapProfilerDump(const v8::Arguments& args) {
+#if !defined(NO_TCMALLOC) && (defined(OS_LINUX) || defined(OS_CHROMEOS))
+    char reason[256];

[jochen (gone - plz use gerrit), 2013/02/06 11:57:57]

why not 

std::string reason("benchmarking_extension");
if (args.Length() > 0 && args[0].isString())
  reason = *v8::String::AsciiValue(args[0]);
::HeapProfilerDump(reason.c_str());

[Dai Mikurube (NOT FULLTIME), 2013/02/06 12:24:45]

Done.

I didn't know AsciiValue().  I did the same way with
chrome/renderer/benchmarking_extension.cc.

+    if (args.Length() && args[0]->IsString())
+      args[0]->ToString()->WriteAscii(reason, 0, sizeof(reason) - 1);
+    else
+      base::strlcpy(reason, "benchmarking_extension", sizeof(reason));
+
+    ::HeapProfilerDump(reason);
+#endif  // !defined(NO_TCMALLOC) && (defined(OS_LINUX) || defined(OS_CHROMEOS))
+    return v8::Undefined();
+  }
+};
+
+v8::Extension* MemoryBenchmarkingExtension::Get() {
+  return new MemoryBenchmarkingWrapper();
+}
+
+}  // namespace extensions_v8