Bug 1352430 - Update the GC finalize callback to communicate the new state r=sfink r=mccr8

--HG--
extra : rebase_source : ebd661eee50bbf48f21c12e6a1c6df9015f81beb

js/src/jsapi-tests/testGCFinalizeCallback.cpp

@@ -160,15 +160,15 @@ virtual void uninit() override
 bool checkSingleGroup()
 {
     CHECK(FinalizeCalls < BufferSize);
-    CHECK(FinalizeCalls == 3);
+    CHECK(FinalizeCalls == 4);
     return true;
 }
 
 bool checkMultipleGroups()
 {
     CHECK(FinalizeCalls < BufferSize);
-    CHECK(FinalizeCalls % 2 == 1);
-    CHECK((FinalizeCalls - 1) / 2 > 1);
+    CHECK(FinalizeCalls % 3 == 1);
+    CHECK((FinalizeCalls - 1) / 3 > 1);
     return true;
 }
 
@@ -180,9 +180,10 @@ bool checkFinalizeStatus()
      * and then once more with JSFINALIZE_COLLECTION_END.
      */
 
-    for (unsigned i = 0; i < FinalizeCalls - 1; i += 2) {
-        CHECK(StatusBuffer[i] == JSFINALIZE_GROUP_START);
-        CHECK(StatusBuffer[i + 1] == JSFINALIZE_GROUP_END);
+    for (unsigned i = 0; i < FinalizeCalls - 1; i += 3) {
+        CHECK(StatusBuffer[i] == JSFINALIZE_GROUP_PREPARE);
+        CHECK(StatusBuffer[i + 1] == JSFINALIZE_GROUP_START);
+        CHECK(StatusBuffer[i + 2] == JSFINALIZE_GROUP_END);
     }
 
     CHECK(StatusBuffer[FinalizeCalls - 1] == JSFINALIZE_COLLECTION_END);

js/src/jsapi.h

@@ -563,15 +563,20 @@ typedef enum JSFinalizeStatus {
     /**
      * Called when preparing to sweep a group of zones, before anything has been
      * swept.  The collector will not yield to the mutator before calling the
-     * callback with JSFINALIZE_GROUP_END status.
+     * callback with JSFINALIZE_GROUP_START status.
+     */
+    JSFINALIZE_GROUP_PREPARE,
+
+    /**
+     * Called after preparing to sweep a group of zones. Weak references to
+     * unmarked things have been removed at this point, but no GC things have
+     * been swept. The collector may yield to the mutator after this point.
      */
     JSFINALIZE_GROUP_START,
 
     /**
-     * Called when preparing to sweep a group of zones. Weak references to
-     * unmarked things have been removed and things that are not swept
-     * incrementally have been finalized at this point.  The collector may yield
-     * to the mutator after this point.
+     * Called after sweeping a group of zones. All dead GC things have been
+     * swept at this point.
      */
     JSFINALIZE_GROUP_END,
 

js/src/jsgc.cpp

@@ -5130,7 +5130,7 @@ GCRuntime::beginSweepingSweepGroup(AutoLockForExclusiveAccess& lock)
 
     {
         gcstats::AutoPhase ap(stats(), gcstats::PHASE_FINALIZE_START);
-        callFinalizeCallbacks(&fop, JSFINALIZE_GROUP_START);
+        callFinalizeCallbacks(&fop, JSFINALIZE_GROUP_PREPARE);
         {
             gcstats::AutoPhase ap2(stats(), gcstats::PHASE_WEAK_ZONES_CALLBACK);
             callWeakPointerZonesCallbacks();
@@ -5142,6 +5142,7 @@ GCRuntime::beginSweepingSweepGroup(AutoLockForExclusiveAccess& lock)
                     callWeakPointerCompartmentCallbacks(comp);
             }
         }
+        callFinalizeCallbacks(&fop, JSFINALIZE_GROUP_START);
     }
 
     if (sweepingAtoms) {
@@ -5275,16 +5276,17 @@ GCRuntime::beginSweepingSweepGroup(AutoLockForExclusiveAccess& lock)
     sweepPhaseIndex = 0;
     sweepZone = currentSweepGroup;
     sweepActionIndex = 0;
-
-    {
-        gcstats::AutoPhase ap(stats(), gcstats::PHASE_FINALIZE_END);
-        callFinalizeCallbacks(&fop, JSFINALIZE_GROUP_END);
-    }
 }
 
 void
 GCRuntime::endSweepingSweepGroup()
 {
+    {
+        gcstats::AutoPhase ap(stats(), gcstats::PHASE_FINALIZE_END);
+        FreeOp fop(rt);
+        callFinalizeCallbacks(&fop, JSFINALIZE_GROUP_END);
+    }
+
     /* Update the GC state for zones we have swept. */
     for (GCSweepGroupIter zone(rt); !zone.done(); zone.next()) {
         MOZ_ASSERT(zone->isGCSweeping());

js/xpconnect/src/XPCJSRuntime.cpp

@@ -813,7 +813,7 @@ XPCJSRuntime::FinalizeCallback(JSFreeOp* fop,
         return;
 
     switch (status) {
-        case JSFINALIZE_GROUP_START:
+        case JSFINALIZE_GROUP_PREPARE:
         {
             MOZ_ASSERT(!self->mDoingFinalization, "bad state");
 
@@ -821,12 +821,12 @@ XPCJSRuntime::FinalizeCallback(JSFreeOp* fop,
             self->mGCIsRunning = true;
 
             self->mDoingFinalization = true;
+
             break;
         }
-        case JSFINALIZE_GROUP_END:
+        case JSFINALIZE_GROUP_START:
         {
             MOZ_ASSERT(self->mDoingFinalization, "bad state");
-            self->mDoingFinalization = false;
 
             // Sweep scopes needing cleanup
             XPCWrappedNativeScope::KillDyingScopes();
@@ -836,6 +836,13 @@ XPCJSRuntime::FinalizeCallback(JSFreeOp* fop,
 
             break;
         }
+        case JSFINALIZE_GROUP_END:
+        {
+            MOZ_ASSERT(self->mDoingFinalization, "bad state");
+            self->mDoingFinalization = false;
+
+            break;
+        }
         case JSFINALIZE_COLLECTION_END:
         {
             MOZ_ASSERT(!self->mGCIsRunning, "bad state");