trace_event support for thread names

base/debug/trace_event.cc

Index: base/debug/trace_event.cc
diff --git a/base/debug/trace_event.cc b/base/debug/trace_event.cc
index d467055be9646f6aea8216eaf80f89a0b68a48e4..d765f5195bd747eced80ad0de4578fd50698ec29 100644
--- a/base/debug/trace_event.cc
+++ b/base/debug/trace_event.cc
@@ -104,6 +104,8 @@ const char* GetPhaseStr(TraceEventPhase phase) {
       return "I";
     case TRACE_EVENT_PHASE_END:
       return "E";
+    case TRACE_EVENT_PHASE_METADATA:
+      return "M";
     default:
       NOTREACHED() << "Invalid phase argument";
       return "?";
@@ -295,8 +297,10 @@ void TraceLog::SetEnabled(bool enabled) {
       g_categories[i].enabled = enabled;
     }
   } // release lock
-  if (!enabled)
+  if (!enabled) {
+    AddCurrentMetadataEvents();
     Flush();
+  }
 }
 
 float TraceLog::GetBufferPercentFull() const {
@@ -419,6 +423,33 @@ void TraceLog::AddTraceEventEtw(TraceEventPhase phase,
   }
 }
 
+void TraceLog::SetCurrentThreadName(const char* name) {
+  AutoLock lock(lock_);
+  thread_names_[PlatformThread::CurrentId()] = name;
+}
+
+void TraceLog::AddCurrentMetadataEvents() {
+  const TraceCategory* metadata_category = GetCategoryInternal("__metadata");

[joth, 2011/07/26 09:53:17]

static const?

+#ifdef USE_UNRELIABLE_NOW
+  TimeTicks now = TimeTicks::HighResNow();

[jbates, 2011/07/26 20:57:00]

can we replace the timestamp with 0 for metadata events or would that trip up
the javascript range calculation?

+#else
+  TimeTicks now = TimeTicks::Now();
+#endif
+  for(base::hash_map<PlatformThreadId, std::string>::iterator it =
+          thread_names_.begin();
+      it != thread_names_.end();
+      it++) {
+    logged_events_.push_back(
+        TraceEvent(static_cast<unsigned long>(base::GetCurrentProcId()),
+                   it->first,
+                   now, base::debug::TRACE_EVENT_PHASE_METADATA,
+                   metadata_category, "thread_name",
+                   "name", it->second.c_str(),
+                   NULL, 0,
+                   true));

[joth, 2011/07/26 09:53:17]

you can pass false here. (The only thing that needs copying is the arg value,
and that's always copied)

+  }
+}
+
 void TraceLog::Resurrect() {
   StaticMemorySingletonTraits<TraceLog>::Resurrect();
 }