Bug 660329 - GC: add reason for GC to GCTimer. r=igor

js/src/jsapi.cpp

@@ -2602,12 +2602,14 @@ JS_CompartmentGC(JSContext *cx, JSCompartment *comp)
     if (cx->tempPool.current == &cx->tempPool.first)
         JS_FinishArenaPool(&cx->tempPool);
 
+    GCREASON(PUBLIC_API);
     js_GC(cx, comp, GC_NORMAL);
 }
 
 JS_PUBLIC_API(void)
 JS_GC(JSContext *cx)
 {
+    GCREASON(PUBLIC_API);
     JS_CompartmentGC(cx, NULL);
 }
 

js/src/jscntxt.cpp

@@ -640,6 +640,7 @@ js_DestroyContext(JSContext *cx, JSDestroyContextMode mode)
 #endif
 
         if (last) {
+            GCREASON(LASTCONTEXT);
             js_GC(cx, NULL, GC_LAST_CONTEXT);
             DUMP_EVAL_CACHE_METER(cx);
             DUMP_FUNCTION_METER(cx);
@@ -649,10 +650,13 @@ js_DestroyContext(JSContext *cx, JSDestroyContextMode mode)
             rt->state = JSRTS_DOWN;
             JS_NOTIFY_ALL_CONDVAR(rt->stateChange);
         } else {
-            if (mode == JSDCM_FORCE_GC)
+            if (mode == JSDCM_FORCE_GC) {
+                GCREASON(DESTROYCONTEXT);
                 js_GC(cx, NULL, GC_NORMAL);
-            else if (mode == JSDCM_MAYBE_GC)
+            } else if (mode == JSDCM_MAYBE_GC) {
+                GCREASON(DESTROYCONTEXT);
                 JS_MaybeGC(cx);
+            }
             JS_LOCK_GC(rt);
             js_WaitForGC(rt);
         }
@@ -1574,6 +1578,7 @@ JSRuntime::onTooMuchMalloc()
      */
     js_WaitForGC(this);
 #endif
+    GCREASON(TOOMUCHMALLOC);
     TriggerGC(this);
 }
 

js/src/jsgc.cpp

@@ -1187,6 +1187,7 @@ ArenaList::getArenaWithFreeList(JSContext *cx, unsigned thingKind)
 #endif /* !JS_THREADSAFE */
 
     if (!chunk) {
+        GCREASON(CHUNK);
         TriggerGC(cx->runtime);
         return NULL;
     }
@@ -1349,6 +1350,7 @@ RunLastDitchGC(JSContext *cx)
 #endif
     /* The last ditch GC preserves all atoms. */
     AutoKeepAtoms keep(rt);
+    GCREASON(LASTDITCH);
     js_GC(cx, rt->gcTriggerCompartment, GC_NORMAL);
 
 #ifdef JS_THREADSAFE
@@ -1879,6 +1881,7 @@ TriggerCompartmentGC(JSCompartment *comp)
 {
     JSRuntime *rt = comp->rt;
     JS_ASSERT(!rt->gcRunning);
+    GCREASON(COMPARTMENT);
 
     if (rt->gcZeal()) {
         TriggerGC(rt);
@@ -1919,18 +1922,22 @@ MaybeGC(JSContext *cx)
     JSRuntime *rt = cx->runtime;
 
     if (rt->gcZeal()) {
+        GCREASON(MAYBEGC);
         js_GC(cx, NULL, GC_NORMAL);
         return;
     }
 
     JSCompartment *comp = cx->compartment;
     if (rt->gcIsNeeded) {
+        GCREASON(MAYBEGC);
         js_GC(cx, (comp == rt->gcTriggerCompartment) ? comp : NULL, GC_NORMAL);
         return;
     }
 
-    if (comp->gcBytes > 8192 && comp->gcBytes >= 3 * (comp->gcTriggerBytes / 4))
+    if (comp->gcBytes > 8192 && comp->gcBytes >= 3 * (comp->gcTriggerBytes / 4)) {
+        GCREASON(MAYBEGC);
         js_GC(cx, (rt->gcMode == JSGC_MODE_COMPARTMENT) ? comp : NULL, GC_NORMAL);
+    }
 }
 
 } /* namespace js */

js/src/jsgcstats.cpp

@@ -372,6 +372,10 @@ GCMarker::dumpConservativeRoots()
 
 #if defined(MOZ_GCTIMER) || defined(JSGC_TESTPILOT)
 
+volatile GCTimer::JSGCReason gcReason = GCTimer::NOREASON;
+const char *gcReasons[] = {"  API", "Maybe", "LastC", "DestC", "Compa", "LastD",
+                          "Malloc", "Alloc", "Chunk", "Shape", "  None"};
+
 jsrefcount newChunkCount = 0;
 jsrefcount destroyChunkCount = 0;
 
@@ -452,14 +456,15 @@ GCTimer::finish(bool lastGC)
                 gcFile = fopen("gcTimer.dat", "a");
 
                 fprintf(gcFile, "     AppTime,  Total,   Wait,   Mark,  Sweep, FinObj,"
-                                " FinStr, SwShapes, Destroy,    End, +Chu, -Chu\n");
+                                " FinStr, SwShapes, Destroy,    End, +Chu, -Chu, T, Reason\n");
             }
             JS_ASSERT(gcFile);
             /*               App   , Tot  , Wai  , Mar  , Swe  , FiO  , FiS  , SwS  , Des   , End */
             fprintf(gcFile, "%12.0f, %6.1f, %6.1f, %6.1f, %6.1f, %6.1f, %6.1f, %8.1f,  %6.1f, %6.1f, ",
                     appTime, gcTime, waitTime, markTime, sweepTime, sweepObjTime, sweepStringTime,
                     sweepShapeTime, destroyTime, endTime);
-            fprintf(gcFile, "%4d, %4d\n", newChunkCount, destroyChunkCount);
+            fprintf(gcFile, "%4d, %4d,", newChunkCount, destroyChunkCount);
+            fprintf(gcFile, " %s, %s\n", isCompartmental ? "C" : "G", gcReasons[gcReason]);
             fflush(gcFile);
 
             if (lastGC) {
@@ -471,6 +476,7 @@ GCTimer::finish(bool lastGC)
     }
     newChunkCount = 0;
     destroyChunkCount = 0;
+    gcReason = NOREASON;
 }
 
 #undef TIMEDIFF

js/src/jsgcstats.h

@@ -211,8 +211,27 @@ struct GCTimer
     }
 
     void finish(bool lastGC);
+
+    enum JSGCReason {
+        PUBLIC_API,
+        MAYBEGC,
+        LASTCONTEXT,
+        DESTROYCONTEXT,
+        COMPARTMENT,
+        LASTDITCH,
+        TOOMUCHMALLOC,
+        ALLOCTRIGGER,
+        CHUNK,
+        SHAPE,
+        NOREASON
+    };
 };
 
+/* We accept the possiblility of races for this variable. */
+extern volatile GCTimer::JSGCReason gcReason;
+
+#define GCREASON(x) ((gcReason == GCTimer::NOREASON) ? gcReason = GCTimer::x : gcReason = gcReason)
+
 # define GCTIMER_PARAM              , GCTimer &gcTimer
 # define GCTIMER_ARG                , gcTimer
 # define GCTIMESTAMP(stamp_name_) \
@@ -223,6 +242,7 @@ struct GCTimer
 # define GCTIMER_BEGIN(rt, comp)    GCTimer gcTimer(rt, comp)
 # define GCTIMER_END(last)          (gcTimer.finish(last))
 #else
+# define GCREASON(x)                ((void) 0)
 # define GCTIMER_PARAM
 # define GCTIMER_ARG
 # define GCTIMESTAMP(x)             ((void) 0)

js/src/jsscope.cpp

@@ -90,6 +90,7 @@ js_GenerateShape(JSRuntime *rt)
 #ifdef JS_THREADSAFE
         AutoLockGC lockIf(rt);
 #endif
+        GCREASON(SHAPE);
         TriggerGC(rt);
     }
     return shape;