Bug 754588 - Set rt->gcPoke when doing xpconnect unrooting (r=mccr8)

js/src/jsapi.cpp

@@ -718,6 +718,7 @@ JSRuntime::JSRuntime()
     gcNextFullGCTime(0),
     gcJitReleaseTime(0),
     gcMode(JSGC_MODE_GLOBAL),
+    gcShouldCleanUpEverything(false),
     gcIsNeeded(0),
     gcWeakMapList(NULL),
     gcStats(thisFromCtor()),

js/src/jscntxt.h

@@ -490,6 +490,9 @@ struct JSRuntime : js::RuntimeFriendFields
     int64_t             gcJitReleaseTime;
     JSGCMode            gcMode;
 
+    /* During shutdown, the GC needs to clean up every possible object. */
+    bool                gcShouldCleanUpEverything;
+
     /*
      * These flags must be kept separate so that a thread requesting a
      * compartment GC doesn't cancel another thread's concurrent request for a

js/src/jsfriendapi.cpp

@@ -785,6 +785,12 @@ IncrementalValueBarrier(const Value &v)
     HeapValue::writeBarrierPre(v);
 }
 
+extern JS_FRIEND_API(void)
+PokeGC(JSRuntime *rt)
+{
+    rt->gcPoke = true;
+}
+
 JS_FRIEND_API(JSObject *)
 GetTestingFunctions(JSContext *cx)
 {

js/src/jsfriendapi.h

@@ -700,6 +700,9 @@ IncrementalReferenceBarrier(void *ptr);
 extern JS_FRIEND_API(void)
 IncrementalValueBarrier(const Value &v);
 
+extern JS_FRIEND_API(void)
+PokeGC(JSRuntime *rt);
+
 class ObjectPtr
 {
     JSObject *value;

js/src/jsgc.cpp

@@ -2872,7 +2872,7 @@ PurgeRuntime(JSTracer *trc)
 static bool
 ShouldPreserveJITCode(JSCompartment *c, int64_t currentTime)
 {
-    if (!c->rt->hasContexts() || !c->types.inferenceEnabled)
+    if (c->rt->gcShouldCleanUpEverything || !c->types.inferenceEnabled)
         return false;
 
     if (c->rt->alwaysPreserveCode)
@@ -3628,6 +3628,12 @@ IsDeterministicGCReason(gcreason::Reason reason)
 }
 #endif
 
+static bool
+ShouldCleanUpEverything(JSRuntime *rt, gcreason::Reason reason)
+{
+    return !rt->hasContexts() || reason == gcreason::CC_FORCED;
+}
+
 static void
 Collect(JSRuntime *rt, bool incremental, int64_t budget,
         JSGCInvocationKind gckind, gcreason::Reason reason)
@@ -3679,6 +3685,8 @@ Collect(JSRuntime *rt, bool incremental, int64_t budget,
             collectedCount++;
     }
 
+    rt->gcShouldCleanUpEverything = ShouldCleanUpEverything(rt, reason);
+
     gcstats::AutoGCSlice agc(rt->gcStats, collectedCount, compartmentCount, reason);
 
     do {
@@ -3702,14 +3710,14 @@ Collect(JSRuntime *rt, bool incremental, int64_t budget,
         }
 
         /* Need to re-schedule all compartments for GC. */
-        if (!rt->hasContexts() && rt->gcPoke)
+        if (rt->gcPoke && rt->gcShouldCleanUpEverything)
             PrepareForFullGC(rt);
 
         /*
          * On shutdown, iterate until finalizers or the JSGC_END callback
          * stop creating garbage.
          */
-    } while (!rt->hasContexts() && rt->gcPoke);
+    } while (rt->gcPoke && rt->gcShouldCleanUpEverything);
 }
 
 namespace js {
@@ -4578,4 +4586,3 @@ js_NewGCXML(JSContext *cx)
     return NewGCThing<JSXML>(cx, js::gc::FINALIZE_XML, sizeof(JSXML));
 }
 #endif
-

js/xpconnect/src/XPCJSRuntime.cpp

@@ -2270,6 +2270,9 @@ XPCRootSetElem::AddToRootSet(XPCLock *lock, XPCRootSetElem **listHead)
 void
 XPCRootSetElem::RemoveFromRootSet(XPCLock *lock)
 {
+    if (nsXPConnect *xpc = nsXPConnect::GetXPConnect())
+        js::PokeGC(xpc->GetRuntime()->GetJSRuntime());
+
     NS_ASSERTION(mSelfp, "Must be linked");
 
     XPCAutoLock autoLock(lock);