Bug 1159506 - Make GC events use TimeStamp. r=terrence

js/public/GCAPI.h

@@ -285,8 +285,8 @@ class GarbageCollectionEvent
     // Represents a single slice of a possibly multi-slice incremental garbage
     // collection.
     struct Collection {
-        int64_t startTimestamp;
-        int64_t endTimestamp;
+        double startTimestamp;
+        double endTimestamp;
     };
 
     // The set of garbage collection slices that made up this GC cycle.

js/src/gc/Statistics.cpp

@@ -931,7 +931,7 @@ Statistics::beginSlice(const ZoneGCStats& zoneStats, JSGCInvocationKind gckind,
     if (first)
         beginGC(gckind);
 
-    SliceData data(budget, reason, PRMJ_Now(), GetPageFaultCount());
+    SliceData data(budget, reason, PRMJ_Now(), JS_GetCurrentEmbedderTime(), GetPageFaultCount());
     if (!slices.append(data)) {
         // OOM testing fails if we CrashAtUnhandlableOOM here.
         aborted = true;
@@ -954,6 +954,7 @@ Statistics::endSlice()
 {
     if (!aborted) {
         slices.back().end = PRMJ_Now();
+        slices.back().endTimestamp = JS_GetCurrentEmbedderTime();
         slices.back().endFaults = GetPageFaultCount();
 
         int64_t sliceTime = slices.back().end - slices.back().start;

js/src/gc/Statistics.h

@@ -211,10 +211,12 @@ struct Statistics
     static const size_t MAX_NESTING = 20;
 
     struct SliceData {
-        SliceData(SliceBudget budget, JS::gcreason::Reason reason, int64_t start, size_t startFaults)
+        SliceData(SliceBudget budget, JS::gcreason::Reason reason, int64_t start,
+                  double startTimestamp, size_t startFaults)
           : budget(budget), reason(reason),
             resetReason(nullptr),
-            start(start), startFaults(startFaults)
+            start(start), startTimestamp(startTimestamp),
+            startFaults(startFaults)
         {
             for (auto i : mozilla::MakeRange(NumTimingArrays))
                 mozilla::PodArrayZero(phaseTimes[i]);
@@ -224,6 +226,7 @@ struct Statistics
         JS::gcreason::Reason reason;
         const char* resetReason;
         int64_t start, end;
+        double startTimestamp, endTimestamp;
         size_t startFaults, endFaults;
         PhaseTimeTable phaseTimes;
 

js/src/vm/Debugger.cpp

@@ -8056,8 +8056,8 @@ GarbageCollectionEvent::Create(JSRuntime* rt, ::js::gcstats::Statistics& stats,
         if (!data->collections.growBy(1))
             return nullptr;
 
-        data->collections.back().startTimestamp = range.front().start;
-        data->collections.back().endTimestamp = range.front().end;
+        data->collections.back().startTimestamp = range.front().startTimestamp;
+        data->collections.back().endTimestamp = range.front().endTimestamp;
     }
 
 

toolkit/devtools/shared/timeline.js

@@ -182,9 +182,6 @@ let Timeline = exports.Timeline = Class({
    */
   start: Task.async(function *({ withMemory, withTicks }) {
     let startTime = this._startTime = this.docShells[0].now();
-    // Store the start time from unix epoch so we can normalize
-    // markers from the memory actor
-    this._unixStartTime = Date.now();
 
     if (this._isRecording) {
       return startTime;
@@ -266,9 +263,6 @@ let Timeline = exports.Timeline = Class({
       return;
     }
 
-    // Normalize the start time to docshell start time, and convert it
-    // to microseconds.
-    let startTime = (this._unixStartTime - this._startTime) * 1000;
     let endTime = this.docShells[0].now();
 
     events.emit(this, "markers", collections.map(({ startTimestamp: start, endTimestamp: end }) => {
@@ -277,8 +271,8 @@ let Timeline = exports.Timeline = Class({
         causeName: reason,
         nonincrementalReason: nonincrementalReason,
         // Both timestamps are in microseconds -- convert to milliseconds to match other markers
-        start: (start - startTime) / 1000,
-        end: (end - startTime) / 1000
+        start: start,
+        end: end
       };
     }), endTime);
   },