Per-host V8 histograms.

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 93ce9fb58dc8125e3ca5c091fab3de9adb2db186..07def6467ef25028df90c8ed8c102418a246849a 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -157,22 +157,65 @@ class RenderViewZoomer : public content::RenderViewVisitor {
   DISALLOW_COPY_AND_ASSIGN(RenderViewZoomer);
 };
 
-}  // namespace
+std::string HostToCustomPage(const std::string& host) {
+  if (host == "mail.google.com")
+    return ".gmail";
+  if (host == "docs.google.com" || host == "drive.google.com")
+    return ".docs";
+  if (host == "plus.google.com")
+    return ".plus";
+  return "";
+}
 
-static void* CreateHistogram(
+std::string common_host;

[Charlie Reis, 2012/08/21 22:46:49]

These are globals and should start with g_, right?  Actually, can we avoid
having them as globals?  (There's only one render thread per process, right?)

[marja, 2012/08/22 14:59:31]

They're inside an unnamed namespace, so only visible in this file and thus not
globals.

But I changed them to be member variables in the RenderThread instead.

+std::string custom_page;
+base::LazyInstance<std::set<std::string> > custom_histograms =
+    LAZY_INSTANCE_INITIALIZER;
+
+void InitializeCustomHistograms() {
+  std::set<std::string>* histograms = custom_histograms.Pointer();
+  if (!histograms->empty())
+    return;
+  histograms->insert("V8.GCCompactor");
+  histograms->insert("V8.GCScavenger");
+  histograms->insert("V8.GCContext");
+  histograms->insert("V8.Parse");
+  histograms->insert("V8.ParseLazy");
+  histograms->insert("V8.PreParse");
+  histograms->insert("V8.Compile");
+  histograms->insert("V8.CompileEval");
+  histograms->insert("V8.CompileLazy");
+  histograms->insert("V8.MemoryExternalFragmentationTotal");
+  histograms->insert("V8.MemoryExternalFragmentationOldPointerSpace");
+  histograms->insert("V8.MemoryExternalFragmentationOldDataSpace");
+  histograms->insert("V8.MemoryExternalFragmentationCodeSpace");
+  histograms->insert("V8.MemoryExternalFragmentationMapSpace");
+  histograms->insert("V8.MemoryExternalFragmentationCellSpace");
+  histograms->insert("V8.MemoryExternalFragmentationLoSpace");
+}
+
+void* CreateHistogram(
     const char *name, int min, int max, size_t buckets) {
   if (min <= 0)
     min = 1;
+  InitializeCustomHistograms();
+  std::string histogram_name(name);
+  if (custom_histograms.Get().find(histogram_name) !=
+      custom_histograms.Get().end())
+    histogram_name += custom_page;
   base::Histogram* histogram = base::Histogram::FactoryGet(
-      name, min, max, buckets, base::Histogram::kUmaTargetedHistogramFlag);
+      histogram_name, min, max, buckets,
+      base::Histogram::kUmaTargetedHistogramFlag);
   return histogram;
 }
 
-static void AddHistogramSample(void* hist, int sample) {
+void AddHistogramSample(void* hist, int sample) {
   base::Histogram* histogram = static_cast<base::Histogram*>(hist);
   histogram->Add(sample);
 }
 
+}  // namespace
+
 RenderThreadImpl* RenderThreadImpl::current() {
   return lazy_tls.Pointer()->Get();
 }
@@ -779,6 +822,20 @@ RenderThreadImpl::GetAudioRendererMixerManager() {
   return audio_renderer_mixer_manager_.get();
 }
 
+// static
+std::string RenderThreadImpl::CommonHost() {
+  return common_host;
+}
+
+// static
+void RenderThreadImpl::SetCommonHost(const std::string& host) {
+  if (host != common_host) {

[Charlie Reis, 2012/08/21 22:46:49]

Can we move some of the logic into here rather than at the call site?  At the
moment, we're relying on every caller to carefully check if there's still a
common host.  Seems like it might be a better contract to let this class listen
for the hosts that are present and decide if there's a common one or not.

[marja, 2012/08/22 14:59:31]

Done: Moved the logic to RenderThreadImpl. RenderViewImpl just calls
RenderViewNavigatedToHost in RenderViewImpl::didCommitProvisionalLoad; is that
ok?

[Charlie Reis, 2012/08/22 23:09:59]

Yes, much better, thanks.

+    common_host = host;
+    custom_page = HostToCustomPage(host);
+    v8::V8::SetCreateHistogramFunction(CreateHistogram);
+  }
+}
+
 #if defined(OS_WIN)
 void RenderThreadImpl::PreCacheFont(const LOGFONT& log_font) {
   Send(new ChildProcessHostMsg_PreCacheFont(log_font));