Bug 1103915: Output absolute starting time in the captured TaskTracer profile. r=tlee

--HG--
extra : rebase_source : e258ea3548ee4d7f3d806eeb7b4a53daa9061dc1

tools/profiler/GeckoTaskTracer.cpp

@@ -9,6 +9,7 @@
 
 #include "mozilla/StaticMutex.h"
 #include "mozilla/ThreadLocal.h"
+#include "mozilla/TimeStamp.h"
 #include "mozilla/unused.h"
 
 #include "nsString.h"
@@ -26,8 +27,6 @@ static pid_t gettid()
 }
 #endif
 
-using mozilla::TimeStamp;
-
 namespace mozilla {
 namespace tasktracer {
 
@@ -35,12 +34,18 @@ static mozilla::ThreadLocal<TraceInfo*>* sTraceInfoTLS = nullptr;
 static mozilla::StaticMutex sMutex;
 static nsTArray<nsAutoPtr<TraceInfo>>* sTraceInfos = nullptr;
 static bool sIsLoggingStarted = false;
+static PRTime sStartTime;
 
-static TimeStamp sStartTime;
 static const char sJSLabelPrefix[] = "#tt#";
 
 namespace {
 
+static PRTime
+GetTimestamp()
+{
+  return PR_Now() / 1000;
+}
+
 static TraceInfo*
 AllocTraceInfo(int aTid)
 {
@@ -172,12 +177,6 @@ IsStartLogging(TraceInfo* aInfo)
   return aInfo ? aInfo->mStartLogging : false;
 }
 
-static PRInt64
-DurationFromStart()
-{
-  return static_cast<PRInt64>((TimeStamp::Now() - sStartTime).ToMilliseconds());
-}
-
 } // namespace anonymous
 
 nsCString*
@@ -291,8 +290,8 @@ LogDispatch(uint64_t aTaskId, uint64_t aParentTaskId, uint64_t aSourceEventId,
   nsCString* log = info->AppendLog();
   if (log) {
     log->AppendPrintf("%d %lld %lld %lld %d %lld",
-                      ACTION_DISPATCH, aTaskId, DurationFromStart(),
-                      aSourceEventId, aSourceEventType, aParentTaskId);
+                      ACTION_DISPATCH, aTaskId, GetTimestamp(), aSourceEventId,
+                      aSourceEventType, aParentTaskId);
   }
 }
 
@@ -309,7 +308,7 @@ LogBegin(uint64_t aTaskId, uint64_t aSourceEventId)
   nsCString* log = info->AppendLog();
   if (log) {
     log->AppendPrintf("%d %lld %lld %d %d",
-                      ACTION_BEGIN, aTaskId, DurationFromStart(), getpid(), gettid());
+                      ACTION_BEGIN, aTaskId, GetTimestamp(), getpid(), gettid());
   }
 }
 
@@ -325,8 +324,7 @@ LogEnd(uint64_t aTaskId, uint64_t aSourceEventId)
   // [2 taskId endTime]
   nsCString* log = info->AppendLog();
   if (log) {
-    log->AppendPrintf("%d %lld %lld", ACTION_END, aTaskId,
-                      DurationFromStart());
+    log->AppendPrintf("%d %lld %lld", ACTION_END, aTaskId, GetTimestamp());
   }
 }
 
@@ -386,16 +384,16 @@ void AddLabel(const char* aFormat, ...)
   nsCString* log = info->AppendLog();
   if (log) {
     log->AppendPrintf("%d %lld %lld \"%s\"", ACTION_ADD_LABEL, info->mCurTaskId,
-                      DurationFromStart(), buffer.get());
+                      GetTimestamp(), buffer.get());
   }
 }
 
 // Functions used by GeckoProfiler.
 
 void
-StartLogging(TimeStamp aStartTime)
+StartLogging()
 {
-  sStartTime = aStartTime;
+  sStartTime = GetTimestamp();
   SetLogStarted(true);
 }
 
@@ -406,7 +404,7 @@ StopLogging()
 }
 
 TraceInfoLogsType*
-GetLoggedData(TimeStamp aStartTime)
+GetLoggedData()
 {
   TraceInfoLogsType* result = new TraceInfoLogsType();
 
@@ -420,6 +418,12 @@ GetLoggedData(TimeStamp aStartTime)
   return result;
 }
 
+const PRTime
+GetStartTime()
+{
+  return sStartTime;
+}
+
 const char*
 GetJSLabelPrefix()
 {

tools/profiler/GeckoTaskTracer.h

@@ -8,7 +8,6 @@
 #define GECKO_TASK_TRACER_H
 
 #include "nsCOMPtr.h"
-#include "mozilla/TimeStamp.h"
 
 /**
  * TaskTracer provides a way to trace the correlation between different tasks
@@ -64,10 +63,13 @@ public:
 // followed by corresponding parameters.
 void AddLabel(const char* aFormat, ...);
 
-void StartLogging(mozilla::TimeStamp aStartTime);
+void StartLogging();
 void StopLogging();
 nsTArray<nsCString>* GetLoggedData(TimeStamp aStartTime);
 
+// Returns the timestamp when Task Tracer is enabled in this process.
+const PRTime GetStartTime();
+
 /**
  * Internal functions.
  */

tools/profiler/TableTicker.cpp

@@ -119,7 +119,6 @@ void TableTicker::StreamTaskTracer(JSStreamWriter& b)
       for (uint32_t i = 0; i < data->Length(); ++i) {
         b.Value((data->ElementAt(i)).get());
       }
-      mozilla::tasktracer::StartLogging(sStartTime);
     b.EndArray();
 
     b.Name("threads");
@@ -139,6 +138,9 @@ void TableTicker::StreamTaskTracer(JSStreamWriter& b)
         b.EndObject();
       }
     b.EndArray();
+
+    b.NameValue("start",
+                static_cast<double>(mozilla::tasktracer::GetStartTime()));
 #endif
   b.EndObject();
 }

tools/profiler/TableTicker.h

@@ -111,7 +111,7 @@ class TableTicker: public Sampler {
 
 #ifdef MOZ_TASK_TRACER
     if (mTaskTracer) {
-      mozilla::tasktracer::StartLogging(sStartTime);
+      mozilla::tasktracer::StartLogging();
     }
 #endif
   }