Bug 778993 - Separate runtime's gcMallocBytes from compartment's gcMallocBytes (r=gwagner,till)

js/src/jscntxt.cpp

@@ -1410,14 +1410,15 @@ JSRuntime::setGCMaxMallocBytes(size_t value)
 void
 JSRuntime::updateMallocCounter(JSContext *cx, size_t nbytes)
 {
-    /* We tolerate any thread races when updating gcMallocBytes. */
-    ptrdiff_t oldCount = gcMallocBytes;
-    ptrdiff_t newCount = oldCount - ptrdiff_t(nbytes);
-    gcMallocBytes = newCount;
-    if (JS_UNLIKELY(newCount <= 0 && oldCount > 0))
-        onTooMuchMalloc();
-    else if (cx && cx->compartment)
+    if (cx && cx->compartment) {
         cx->compartment->updateMallocCounter(nbytes);
+    } else {
+        ptrdiff_t oldCount = gcMallocBytes;
+        ptrdiff_t newCount = oldCount - ptrdiff_t(nbytes);
+        gcMallocBytes = newCount;
+        if (JS_UNLIKELY(newCount <= 0 && oldCount > 0))
+            onTooMuchMalloc();
+    }
 }
 
 JS_FRIEND_API(void)

js/src/jscompartment.cpp

@@ -77,7 +77,7 @@ JSCompartment::JSCompartment(JSRuntime *rt)
     , ionCompartment_(NULL)
 #endif
 {
-    setGCMaxMallocBytes(rt->gcMaxMallocBytes * 0.9);
+    setGCMaxMallocBytes(rt->gcMaxMallocBytes / 2);
 }
 
 JSCompartment::~JSCompartment()

js/src/jsgc.cpp

@@ -3274,6 +3274,8 @@ BeginMarkPhase(JSRuntime *rt)
             any = true;
             if (c != rt->atomsCompartment)
                 c->setGCState(JSCompartment::Mark);
+
+            c->resetGCMallocBytes();
         } else {
             rt->gcIsFull = false;
         }
@@ -3281,6 +3283,9 @@ BeginMarkPhase(JSRuntime *rt)
         c->setPreservingCode(ShouldPreserveJITCode(c, currentTime));
     }
 
+    if (rt->gcIsFull)
+        rt->resetGCMallocBytes();
+
     /* Check that at least one compartment is scheduled for collection. */
     JS_ASSERT(any);
 
@@ -4036,13 +4041,8 @@ AutoGCSession::~AutoGCSession()
     runtime->gcSelectedForMarking.clearAndFree();
 #endif
 
-    /* Clear gcMallocBytes for all compartments */
-    for (CompartmentsIter c(runtime); !c.done(); c.next()) {
-        c->resetGCMallocBytes();
+    for (CompartmentsIter c(runtime); !c.done(); c.next())
         c->unscheduleGC();
-    }
-
-    runtime->resetGCMallocBytes();
 }
 
 class AutoCopyFreeListToArenas {