Bug 678615 - remove ExplainLiveExpectedGarbage. r=smaug sr=peterv

js/xpconnect/src/XPCDebug.cpp

@@ -475,3 +475,13 @@ xpc_DumpJSObject(JSObject* obj)
 
     return true;
 }
+
+#ifdef DEBUG
+void
+xpc_PrintAllReferencesTo(void *p)
+{
+    /* p must be a JS object */
+    XPCJSRuntime* rt = nsXPConnect::GetRuntimeInstance();
+    JS_DumpHeap(rt->GetJSRuntime(), stdout, nsnull, JSTRACE_OBJECT, p, 0x7fffffff, nsnull);
+}
+#endif

js/xpconnect/src/nsXPConnect.cpp

@@ -119,9 +119,6 @@ nsXPConnect::nsXPConnect()
     mRuntime = XPCJSRuntime::newXPCJSRuntime(this);
 
     nsCycleCollector_registerRuntime(nsIProgrammingLanguage::JAVASCRIPT, this);
-#ifdef DEBUG_CC
-    mJSRoots.ops = nsnull;
-#endif
 
     char* reportableEnv = PR_GetEnv("MOZ_REPORT_ALL_JS_EXCEPTIONS");
     if (reportableEnv && *reportableEnv)
@@ -399,14 +396,14 @@ nsXPConnect::Collect(PRUint32 reason, PRUint32 kind)
     // JS objects that are part of cycles the cycle collector breaks will be
     // collected by the next JS.
     //
-    // If DEBUG_CC is not defined the cycle collector will not traverse roots
+    // If WantAllTraces() is false the cycle collector will not traverse roots
     // from category 1 or any JS objects held by them. Any JS objects they hold
     // will already be marked by the JS GC and will thus be colored black
     // themselves. Any C++ objects they hold will have a missing (untraversed)
     // edge from the JS object to the C++ object and so it will be marked black
     // too. This decreases the number of objects that the cycle collector has to
     // deal with.
-    // To improve debugging, if DEBUG_CC is defined all JS objects are
+    // To improve debugging, if WantAllTraces() is true all JS objects are
     // traversed.
 
     MOZ_ASSERT(reason < js::gcreason::NUM_REASONS);
@@ -431,37 +428,6 @@ nsXPConnect::GarbageCollect(PRUint32 reason, PRUint32 kind)
     return NS_OK;
 }
 
-#ifdef DEBUG_CC
-struct NoteJSRootTracer : public JSTracer
-{
-    NoteJSRootTracer(PLDHashTable *aObjects,
-                     nsCycleCollectionTraversalCallback& cb)
-      : mObjects(aObjects),
-        mCb(cb)
-    {
-    }
-    PLDHashTable* mObjects;
-    nsCycleCollectionTraversalCallback& mCb;
-};
-
-static void
-NoteJSRoot(JSTracer *trc, void *thing, JSGCTraceKind kind)
-{
-    if (AddToCCKind(kind)) {
-        NoteJSRootTracer *tracer = static_cast<NoteJSRootTracer*>(trc);
-        PLDHashEntryHdr *entry = PL_DHashTableOperate(tracer->mObjects, thing,
-                                                      PL_DHASH_ADD);
-        if (entry && !reinterpret_cast<PLDHashEntryStub*>(entry)->key) {
-            reinterpret_cast<PLDHashEntryStub*>(entry)->key = thing;
-            tracer->mCb.NoteRoot(nsIProgrammingLanguage::JAVASCRIPT, thing,
-                                 nsXPConnect::GetXPConnect());
-        }
-    } else if (kind != JSTRACE_STRING) {
-        JS_TraceChildren(trc, thing, kind);
-    }
-}
-#endif
-
 struct NoteWeakMapChildrenTracer : public JSTracer
 {
     NoteWeakMapChildrenTracer(nsCycleCollectionTraversalCallback &cb)
@@ -538,8 +504,7 @@ TraceWeakMapping(js::WeakMapTracer *trc, JSObject *m,
 }
 
 nsresult
-nsXPConnect::BeginCycleCollection(nsCycleCollectionTraversalCallback &cb,
+nsXPConnect::BeginCycleCollection(nsCycleCollectionTraversalCallback &cb)
-                                  bool explainLiveExpectedGarbage)
 {
     // It is important not to call GetSafeJSContext while on the
     // cycle-collector thread since this context will be destroyed
@@ -565,31 +530,6 @@ nsXPConnect::BeginCycleCollection(nsCycleCollectionTraversalCallback &cb,
         gcHasRun = true;
     }
 
-#ifdef DEBUG_CC
-    NS_ASSERTION(!mJSRoots.ops, "Didn't call FinishCycleCollection?");
-
-    if (explainLiveExpectedGarbage) {
-        // Being called from nsCycleCollector::ExplainLiveExpectedGarbage.
-
-        // Record all objects held by the JS runtime. This avoids doing a
-        // complete GC if we're just tracing to explain (from
-        // ExplainLiveExpectedGarbage), which makes the results of cycle
-        // collection identical for DEBUG_CC and non-DEBUG_CC builds.
-        if (!PL_DHashTableInit(&mJSRoots, PL_DHashGetStubOps(), nsnull,
-                               sizeof(PLDHashEntryStub), PL_DHASH_MIN_SIZE)) {
-            mJSRoots.ops = nsnull;
-
-            return NS_ERROR_OUT_OF_MEMORY;
-        }
-
-        NoteJSRootTracer trc(&mJSRoots, cb);
-        JS_TracerInit(&trc, mCycleCollectionContext->GetJSContext(), NoteJSRoot);
-        JS_TraceRuntime(&trc);
-    }
-#else
-    NS_ASSERTION(!explainLiveExpectedGarbage, "Didn't call nsXPConnect::Collect()?");
-#endif
-
     GetRuntime()->AddXPConnectRoots(cb);
 
     NoteWeakMapsTracer trc(GetRuntime()->GetJSRuntime(), TraceWeakMapping, cb);
@@ -641,13 +581,6 @@ nsXPConnect::FinishTraverse()
 nsresult
 nsXPConnect::FinishCycleCollection()
 {
-#ifdef DEBUG_CC
-    if (mJSRoots.ops) {
-        PL_DHashTableFinish(&mJSRoots);
-        mJSRoots.ops = nsnull;
-    }
-#endif
-
     return NS_OK;
 }
 
@@ -665,19 +598,6 @@ nsXPConnect::Root(void *p)
     return NS_OK;
 }
 
-#ifdef DEBUG_CC
-void
-nsXPConnect::PrintAllReferencesTo(void *p)
-{
-#ifdef DEBUG
-    XPCCallContext ccx(NATIVE_CALLER);
-    if (ccx.IsValid())
-        JS_DumpHeap(ccx.GetJSContext(), stdout, nsnull, 0, p,
-                    0x7fffffff, nsnull);
-#endif
-}
-#endif
-
 NS_IMETHODIMP
 nsXPConnect::Unlink(void *p)
 {
@@ -909,30 +829,7 @@ nsXPConnect::Traverse(void *p, nsCycleCollectionTraversalCallback &cb)
         }
     }
 
-    bool isMarked;
+    bool isMarked = markJSObject || !xpc_IsGrayGCThing(p);
-
-#ifdef DEBUG_CC
-    // Note that the conditions under which we specify GCMarked vs.
-    // GCUnmarked are different between ExplainLiveExpectedGarbage and
-    // the normal case.  In the normal case, we're saying that anything
-    // reachable from a JS runtime root is itself such a root.  This
-    // doesn't actually break anything; it really just does some of the
-    // cycle collector's work for it.  However, when debugging, we
-    // (1) actually need to know what the root is and (2) don't want to
-    // do an extra GC, so we use mJSRoots, built from JS_TraceRuntime,
-    // which produces a different result because we didn't call
-    // JS_TraceChildren to trace everything that was reachable.
-    if (mJSRoots.ops) {
-        // ExplainLiveExpectedGarbage codepath
-        PLDHashEntryHdr* entry =
-            PL_DHashTableOperate(&mJSRoots, p, PL_DHASH_LOOKUP);
-        isMarked = markJSObject || PL_DHASH_ENTRY_IS_BUSY(entry);
-    } else
-#endif
-    {
-        // Normal codepath (matches non-DEBUG_CC codepath).
-        isMarked = markJSObject || !xpc_IsGrayGCThing(p);
-    }
 
     if (cb.WantDebugInfo()) {
         char name[72];
@@ -982,8 +879,8 @@ nsXPConnect::Traverse(void *p, nsCycleCollectionTraversalCallback &cb)
 
     // There's no need to trace objects that have already been marked by the JS
     // GC. Any JS objects hanging from them will already be marked. Only do this
-    // if DEBUG_CC is not defined, else we do want to know about all JS objects
+    // if cb.WantAllTraces() is false, otherwise we do want to know about all JS
-    // to get better graphs and explanations.
+    // objects to get better graphs and explanations.
     if (!cb.WantAllTraces() && isMarked)
         return NS_OK;
 

js/xpconnect/src/xpcprivate.h

@@ -537,16 +537,12 @@ public:
     virtual void NotifyEnterCycleCollectionThread();
     virtual void NotifyLeaveCycleCollectionThread();
     virtual void NotifyEnterMainThread();
-    virtual nsresult BeginCycleCollection(nsCycleCollectionTraversalCallback &cb,
+    virtual nsresult BeginCycleCollection(nsCycleCollectionTraversalCallback &cb);
-                                          bool explainExpectedLiveGarbage);
     virtual nsresult FinishTraverse();
     virtual nsresult FinishCycleCollection();
     virtual nsCycleCollectionParticipant *ToParticipant(void *p);
     virtual bool NeedCollect();
     virtual void Collect(PRUint32 reason, PRUint32 kind);
-#ifdef DEBUG_CC
-    virtual void PrintAllReferencesTo(void *p);
-#endif
 
     XPCCallContext *GetCycleCollectionContext()
     {
@@ -598,9 +594,6 @@ private:
     // an 'after' notification without getting an 'on' notification. If we don't
     // watch out for this, we'll do an unmatched |pop| on the context stack.
     PRUint16                   mEventDepth;
-#ifdef DEBUG_CC
-    PLDHashTable             mJSRoots;
-#endif
     nsAutoPtr<XPCCallContext> mCycleCollectionContext;
 
     typedef nsBaseHashtable<nsPtrHashKey<void>, nsISupports*, nsISupports*> ScopeSet;

xpcom/base/nsCycleCollector.cpp

@@ -500,17 +500,6 @@ public:
 
 };
 
-#ifdef DEBUG_CC
-
-struct ReversedEdge {
-    PtrInfo *mTarget;
-    nsCString *mEdgeName;
-    ReversedEdge *mNext;
-};
-
-#endif
-
-
 enum NodeColor { black, white, grey };
 
 // This structure should be kept as small as possible; we may expect
@@ -532,18 +521,6 @@ public:
     size_t mBytes;
     char *mName;
     PRUint32 mLangID;
-
-    // For finding roots in ExplainLiveExpectedGarbage (when there are
-    // missing calls to suspect or failures to unlink).
-    PRUint32 mSCCIndex; // strongly connected component
-
-    // For finding roots in ExplainLiveExpectedGarbage (when nodes
-    // expected to be garbage are black).
-    ReversedEdge* mReversedEdges; // linked list
-    PtrInfo* mShortestPathToExpectedGarbage;
-    nsCString* mShortestPathToExpectedGarbageEdgeName;
-
-    nsTArray<nsCString> mEdgeNames;
 #endif
 
     PtrInfo(void *aPointer, nsCycleCollectionParticipant *aParticipant
@@ -558,11 +535,7 @@ public:
 #ifdef DEBUG_CC
         , mBytes(0),
           mName(nsnull),
-          mLangID(aLangID),
+          mLangID(aLangID)
-          mSCCIndex(0),
-          mReversedEdges(nsnull),
-          mShortestPathToExpectedGarbage(nsnull),
-          mShortestPathToExpectedGarbageEdgeName(nsnull)
 #endif
     {
     }
@@ -570,7 +543,6 @@ public:
 #ifdef DEBUG_CC
     void Destroy() {
         PL_strfree(mName);
-        mEdgeNames.~nsTArray<nsCString>();
     }
 #endif
 
@@ -766,9 +738,6 @@ struct GCGraph
     EdgePool mEdges;
     nsTArray<WeakMapping> mWeakMaps;
     PRUint32 mRootCount;
-#ifdef DEBUG_CC
-    ReversedEdge *mReversedEdges;
-#endif
 
     GCGraph() : mRootCount(0) {
     }
@@ -911,8 +880,6 @@ public:
     void RemoveSkippable(bool removeChildlessNodes);
 
 #ifdef DEBUG_CC
-    void NoteAll(GCGraphBuilder &builder);
-
     bool Exists(void *p) const
     {
         return mNormalObjects.GetEntry(p) || mCompatObjects.GetEntry(p);
@@ -1086,8 +1053,7 @@ nsPurpleBuffer::SelectPointers(GCGraphBuilder &aBuilder)
 struct nsCycleCollectionXPCOMRuntime : 
     public nsCycleCollectionLanguageRuntime 
 {
-    nsresult BeginCycleCollection(nsCycleCollectionTraversalCallback &cb,
+    nsresult BeginCycleCollection(nsCycleCollectionTraversalCallback &cb)
-                                  bool explainLiveExpectedGarbage)
     {
         return NS_OK;
     }
@@ -1103,10 +1069,6 @@ struct nsCycleCollectionXPCOMRuntime :
     }
 
     inline nsCycleCollectionParticipant *ToParticipant(void *p);
-
-#ifdef DEBUG_CC
-    virtual void PrintAllReferencesTo(void *p) {}
-#endif
 };
 
 struct nsCycleCollector
@@ -1131,11 +1093,11 @@ struct nsCycleCollector
     PRUint32 mVisitedRefCounted;
     PRUint32 mVisitedGCed;
 
-    nsPurpleBuffer mPurpleBuf;
-
     CC_BeforeUnlinkCallback mBeforeUnlinkCB;
     CC_ForgetSkippableCallback mForgetSkippableCB;
 
+    nsPurpleBuffer mPurpleBuf;
+
     void RegisterRuntime(PRUint32 langID, 
                          nsCycleCollectionLanguageRuntime *rt);
     void ForgetRuntime(PRUint32 langID);
@@ -1187,20 +1149,16 @@ struct nsCycleCollector
 
 #ifdef DEBUG_CC
     nsCycleCollectorStats mStats;
-
     FILE *mPtrLog;
+    PointerSet mExpectedGarbage;
 
     void Allocated(void *n, size_t sz);
     void Freed(void *n);
 
     void LogPurpleRemoval(void* aObject);
 
-    void ExplainLiveExpectedGarbage();
-    bool CreateReversedEdges();
-    void DestroyReversedEdges();
     void ShouldBeFreed(nsISupports *n);
     void WasFreed(nsISupports *n);
-    PointerSet mExpectedGarbage;
 #endif
 };
 
@@ -1780,9 +1738,6 @@ private:
         if (!childPi)
             return;
         mEdgeBuilder.Add(childPi);
-#ifdef DEBUG_CC
-        mCurrPi->mEdgeNames.AppendElement(edgeName);
-#endif
         if (mListener) {
             mListener->NoteEdge((PRUint64)child, edgeName.get());
         }
@@ -2183,33 +2138,6 @@ nsPurpleBuffer::RemoveSkippable(bool removeChildlessNodes)
     }
 }
 
-#ifdef DEBUG_CC
-static PLDHashOperator
-noteAllCallback(nsPtrHashKey<const void>* key, void* userArg)
-{
-    GCGraphBuilder *builder = static_cast<GCGraphBuilder*>(userArg);
-    builder->NoteXPCOMRoot(
-      static_cast<nsISupports *>(const_cast<void*>(key->GetKey())));
-    return PL_DHASH_NEXT;
-}
-
-void
-nsPurpleBuffer::NoteAll(GCGraphBuilder &builder)
-{
-    mCompatObjects.EnumerateEntries(noteAllCallback, &builder);
-
-    for (Block *b = &mFirstBlock; b; b = b->mNext) {
-        for (nsPurpleBufferEntry *e = b->mEntries,
-                              *eEnd = ArrayEnd(b->mEntries);
-            e != eEnd; ++e) {
-            if (!(uintptr_t(e->mObject) & uintptr_t(1)) && e->mObject) {
-                builder.NoteXPCOMRoot(e->mObject);
-            }
-        }
-    }
-}
-#endif
-
 void 
 nsCycleCollector::SelectPurple(GCGraphBuilder &builder)
 {
@@ -2485,11 +2413,11 @@ nsCycleCollector::CollectWhite(nsICycleCollectorListener *aListener)
 // free. This stuff is disabled unless you set an environment variable.
 ////////////////////////////////////////////////////////////////////////
 
-static bool hookedMalloc = false;
-
 #if defined(__GLIBC__) && !defined(__UCLIBC__)
 #include <malloc.h>
 
+static bool hookedMalloc = false;
+
 static void* (*old_memalign_hook)(size_t, size_t, const void *);
 static void* (*old_realloc_hook)(void *, size_t, const void *);
 static void* (*old_malloc_hook)(size_t, const void *);
@@ -2615,6 +2543,8 @@ InitMemHook(void)
 #elif defined(WIN32)
 #ifndef __MINGW32__
 
+static bool hookedMalloc = false;
+
 static int 
 AllocHook(int allocType, void *userData, size_t size, int 
           blockType, long requestNumber, const unsigned char *filename, int 
@@ -2639,6 +2569,8 @@ static void InitMemHook(void)
 
 #include <malloc/malloc.h>
 
+static bool hookedMalloc = false;
+
 static void (*old_free)(struct _malloc_zone_t *zone, void *ptr);
 
 static void
@@ -2684,14 +2616,14 @@ nsCycleCollector::nsCycleCollector() :
     mWhiteNodeCount(0),
     mVisitedRefCounted(0),
     mVisitedGCed(0),
+    mBeforeUnlinkCB(nsnull),
+    mForgetSkippableCB(nsnull),
 #ifdef DEBUG_CC
     mPurpleBuf(mParams, mStats),
-    mPtrLog(nsnull),
+    mPtrLog(nsnull)
 #else
-    mPurpleBuf(mParams),
+    mPurpleBuf(mParams)
 #endif
-   mBeforeUnlinkCB(nsnull),
-   mForgetSkippableCB(nsnull)
 {
 #ifdef DEBUG_CC
     mExpectedGarbage.Init();
@@ -3125,10 +3057,6 @@ nsCycleCollector::CleanupAfterCollection()
     Telemetry::Accumulate(Telemetry::CYCLE_COLLECTOR_VISITED_REF_COUNTED, mVisitedRefCounted);
     Telemetry::Accumulate(Telemetry::CYCLE_COLLECTOR_VISITED_GCED, mVisitedGCed);
     Telemetry::Accumulate(Telemetry::CYCLE_COLLECTOR_COLLECTED, mWhiteNodeCount);
-
-#ifdef DEBUG_CC
-    ExplainLiveExpectedGarbage();
-#endif
 }
 
 void
@@ -3172,7 +3100,7 @@ nsCycleCollector::BeginCollection(nsICycleCollectorListener *aListener)
 
     for (PRUint32 i = 0; i <= nsIProgrammingLanguage::MAX; ++i) {
         if (mRuntimes[i])
-            mRuntimes[i]->BeginCycleCollection(builder, false);
+            mRuntimes[i]->BeginCycleCollection(builder);
     }
 
     timeLog.Checkpoint("mRuntimes[*]->BeginCycleCollection()");
@@ -3348,390 +3276,6 @@ nsCycleCollector::Shutdown()
 }
 
 #ifdef DEBUG_CC
-
-static PLDHashOperator
-AddExpectedGarbage(nsPtrHashKey<const void> *p, void *arg)
-{
-    GCGraphBuilder *builder = static_cast<GCGraphBuilder*>(arg);
-    nsISupports *root =
-      static_cast<nsISupports*>(const_cast<void*>(p->GetKey()));
-    builder->NoteXPCOMRoot(root);
-    return PL_DHASH_NEXT;
-}
-
-struct SetSCCVisitor
-{
-    SetSCCVisitor(PRUint32 aIndex) : mIndex(aIndex) {}
-    bool ShouldVisitNode(PtrInfo const *pi) { return pi->mSCCIndex == 0; }
-    void VisitNode(PtrInfo *pi) { pi->mSCCIndex = mIndex; }
-private:
-    PRUint32 mIndex;
-};
-
-struct SetNonRootGreyVisitor
-{
-    bool ShouldVisitNode(PtrInfo const *pi) { return pi->mColor == white; }
-    void VisitNode(PtrInfo *pi) { pi->mColor = grey; }
-};
-
-static void
-PrintPathToExpectedGarbage(PtrInfo *pi)
-{
-    printf("  An object expected to be garbage could be "
-           "reached from it by the path:\n");
-    for (PtrInfo *path = pi, *prev = nsnull; prev != path;
-         prev = path,
-         path = path->mShortestPathToExpectedGarbage) {
-        if (prev) {
-            nsCString *edgeName = prev
-                ->mShortestPathToExpectedGarbageEdgeName;
-            printf("        via %s\n",
-                   edgeName->IsEmpty() ? "<unknown edge>"
-                                       : edgeName->get());
-        }
-        printf("    %s %p\n", path->mName, path->mPointer);
-    }
-}
-
-void
-nsCycleCollector::ExplainLiveExpectedGarbage()
-{
-    if (mScanInProgress || mCollectionInProgress)
-        Fault("can't explain expected garbage during collection itself");
-
-    if (mParams.mDoNothing) {
-        printf("nsCycleCollector: not explaining expected garbage since\n"
-               "  cycle collection disabled\n");
-        return;
-    }
-
-    mCollectionInProgress = true;
-    mScanInProgress = true;
-
-    {
-        GCGraphBuilder builder(mGraph, mRuntimes, nsnull);
-
-        // Instead of adding roots from the purple buffer, we add them
-        // from the list of nodes we were expected to collect.
-        // Put the expected garbage in *before* calling
-        // BeginCycleCollection so that we can separate the expected
-        // garbage from the NoteRoot calls in such a way that something
-        // that's in both is considered expected garbage.
-        mExpectedGarbage.EnumerateEntries(&AddExpectedGarbage, &builder);
-
-        PRUint32 expectedGarbageCount = builder.Count();
-
-        for (PRUint32 i = 0; i <= nsIProgrammingLanguage::MAX; ++i) {
-            if (mRuntimes[i])
-                mRuntimes[i]->BeginCycleCollection(builder, true);
-        }
-
-        // But just for extra information, add entries from the purple
-        // buffer too, since it may give us extra information about
-        // traversal deficiencies.
-        mPurpleBuf.NoteAll(builder);
-
-        MarkRoots(builder);
-        ScanRoots();
-
-        mScanInProgress = false;
-
-        for (PRUint32 i = 0; i <= nsIProgrammingLanguage::MAX; ++i) {
-            if (mRuntimes[i]) {
-                mRuntimes[i]->FinishTraverse();
-            }
-        }
-
-        bool describeExtraRefcounts = false;
-        bool findCycleRoots = false;
-        {
-            NodePool::Enumerator queue(mGraph.mNodes);
-            PRUint32 i = 0;
-            while (!queue.IsDone()) {
-                PtrInfo *pi = queue.GetNext();
-                if (pi->mColor == white) {
-                    findCycleRoots = true;
-                }
-
-                if (pi->mInternalRefs != pi->mRefCount &&
-                    (i < expectedGarbageCount || i >= mGraph.mRootCount)) {
-                    // This check isn't particularly useful anymore
-                    // given that we need to enter this part for i >=
-                    // mGraph.mRootCount and there are plenty of
-                    // NoteRoot roots.
-                    describeExtraRefcounts = true;
-                }
-                ++i;
-            }
-        }
-
-        if ((describeExtraRefcounts || findCycleRoots) &&
-            CreateReversedEdges()) {
-            // Note that the external references may have been external
-            // to a different node in the cycle collection that just
-            // happened, if that different node was purple and then
-            // black.
-
-            // Use mSCCIndex temporarily to track whether we've reached
-            // nodes in the breadth-first search.
-            const PRUint32 INDEX_UNREACHED = 0;
-            const PRUint32 INDEX_REACHED = 1;
-            NodePool::Enumerator etor_clear(mGraph.mNodes);
-            while (!etor_clear.IsDone()) {
-                PtrInfo *pi = etor_clear.GetNext();
-                pi->mSCCIndex = INDEX_UNREACHED;
-            }
-
-            nsDeque queue; // for breadth-first search
-            NodePool::Enumerator etor_roots(mGraph.mNodes);
-            for (PRUint32 i = 0; i < mGraph.mRootCount; ++i) {
-                PtrInfo *root_pi = etor_roots.GetNext();
-                if (i < expectedGarbageCount) {
-                    root_pi->mSCCIndex = INDEX_REACHED;
-                    root_pi->mShortestPathToExpectedGarbage = root_pi;
-                    queue.Push(root_pi);
-                }
-            }
-
-            while (queue.GetSize() > 0) {
-                PtrInfo *pi = (PtrInfo*)queue.PopFront();
-                for (ReversedEdge *e = pi->mReversedEdges; e; e = e->mNext) {
-                    if (e->mTarget->mSCCIndex == INDEX_UNREACHED) {
-                        e->mTarget->mSCCIndex = INDEX_REACHED;
-                        PtrInfo *target = e->mTarget;
-                        if (!target->mShortestPathToExpectedGarbage) {
-                            target->mShortestPathToExpectedGarbage = pi;
-                            target->mShortestPathToExpectedGarbageEdgeName =
-                                e->mEdgeName;
-                        }
-                        queue.Push(target);
-                    }
-                }
-
-                if (pi->mRefCount == PR_UINT32_MAX ||
-                    (pi->mInternalRefs != pi->mRefCount && pi->mRefCount > 0)) {
-                    if (pi->mRefCount == PR_UINT32_MAX) {
-                        printf("nsCycleCollector: %s %p was not collected due "
-                           "to \n"
-                           "  external references\n",
-                           pi->mName, pi->mPointer);
-                    }
-                    else {
-                        printf("nsCycleCollector: %s %p was not collected due "
-                               "to %d\n"
-                               "  external references (%d total - %d known)\n",
-                               pi->mName, pi->mPointer,
-                               pi->mRefCount - pi->mInternalRefs,
-                               pi->mRefCount, pi->mInternalRefs);
-                    }
-
-                    PrintPathToExpectedGarbage(pi);
-
-                    if (pi->mRefCount == PR_UINT32_MAX) {
-                        printf("  The known references to it were from:\n");
-                    }
-                    else {
-                        printf("  The %d known references to it were from:\n",
-                               pi->mInternalRefs);
-                    }
-                    for (ReversedEdge *e = pi->mReversedEdges;
-                         e; e = e->mNext) {
-                        printf("    %s %p",
-                               e->mTarget->mName, e->mTarget->mPointer);
-                        if (!e->mEdgeName->IsEmpty()) {
-                            printf(" via %s", e->mEdgeName->get());
-                        }
-                        printf("\n");
-                    }
-                    mRuntimes[pi->mLangID]->PrintAllReferencesTo(pi->mPointer);
-                }
-            }
-
-            if (findCycleRoots) {
-                // NOTE: This code changes the white nodes that are not
-                // roots to gray.
-
-                // Put the nodes in post-order traversal order from a
-                // depth-first search.
-                nsDeque DFSPostOrder;
-
-                {
-                    // Use mSCCIndex temporarily to track the DFS numbering:
-                    const PRUint32 INDEX_UNREACHED = 0;
-                    const PRUint32 INDEX_TRAVERSING = 1;
-                    const PRUint32 INDEX_NUMBERED = 2;
-
-                    NodePool::Enumerator etor_clear(mGraph.mNodes);
-                    while (!etor_clear.IsDone()) {
-                        PtrInfo *pi = etor_clear.GetNext();
-                        pi->mSCCIndex = INDEX_UNREACHED;
-                    }
-
-                    nsDeque stack;
-
-                    NodePool::Enumerator etor_roots(mGraph.mNodes);
-                    for (PRUint32 i = 0; i < mGraph.mRootCount; ++i) {
-                        PtrInfo *root_pi = etor_roots.GetNext();
-                        stack.Push(root_pi);
-                    }
-
-                    while (stack.GetSize() > 0) {
-                        PtrInfo *pi = (PtrInfo*)stack.Peek();
-                        if (pi->mSCCIndex == INDEX_UNREACHED) {
-                            pi->mSCCIndex = INDEX_TRAVERSING;
-                            for (EdgePool::Iterator child = pi->FirstChild(),
-                                                child_end = pi->LastChild();
-                                 child != child_end; ++child) {
-                                stack.Push(*child);
-                            }
-                        } else {
-                            stack.Pop();
-                            // Somebody else might have numbered it already
-                            // (since this is depth-first, not breadth-first).
-                            // This happens if a node is pushed on the stack
-                            // a second time while it is on the stack in
-                            // UNREACHED state.
-                            if (pi->mSCCIndex == INDEX_TRAVERSING) {
-                                pi->mSCCIndex = INDEX_NUMBERED;
-                                DFSPostOrder.Push(pi);
-                            }
-                        }
-                    }
-                }
-
-                // Put the nodes into strongly-connected components.
-                {
-                    NodePool::Enumerator etor_clear(mGraph.mNodes);
-                    while (!etor_clear.IsDone()) {
-                        PtrInfo *pi = etor_clear.GetNext();
-                        pi->mSCCIndex = 0;
-                    }
-
-                    PRUint32 currentSCC = 1;
-
-                    while (DFSPostOrder.GetSize() > 0) {
-                        GraphWalker<SetSCCVisitor>(SetSCCVisitor(currentSCC)).Walk((PtrInfo*)DFSPostOrder.PopFront());
-                        ++currentSCC;
-                    }
-                }
-
-                // Mark any white nodes reachable from other components as
-                // grey.
-                {
-                    NodePool::Enumerator queue(mGraph.mNodes);
-                    while (!queue.IsDone()) {
-                        PtrInfo *pi = queue.GetNext();
-                        if (pi->mColor != white)
-                            continue;
-                        for (EdgePool::Iterator child = pi->FirstChild(),
-                                            child_end = pi->LastChild();
-                             child != child_end; ++child) {
-                            if ((*child)->mSCCIndex != pi->mSCCIndex) {
-                                GraphWalker<SetNonRootGreyVisitor>(SetNonRootGreyVisitor()).Walk(*child);
-                            }
-                        }
-                    }
-                }
-
-                {
-                    NodePool::Enumerator queue(mGraph.mNodes);
-                    while (!queue.IsDone()) {
-                        PtrInfo *pi = queue.GetNext();
-                        if (pi->mColor == white) {
-                            if (pi->mLangID ==
-                                    nsIProgrammingLanguage::CPLUSPLUS &&
-                                mPurpleBuf.Exists(pi->mPointer)) {
-                                printf(
-"nsCycleCollector: %s %p in component %d\n"
-"  which was reference counted during the root/unlink/unroot phase of the\n"
-"  last collection was not collected due to failure to unlink (see other\n"
-"  warnings) or deficiency in traverse that causes cycles referenced only\n"
-"  from other cycles to require multiple rounds of cycle collection in which\n"
-"  this object was likely the reachable object\n",
-                                       pi->mName, pi->mPointer, pi->mSCCIndex);
-                            } else {
-                                printf(
-"nsCycleCollector: %s %p in component %d\n"
-"  was not collected due to missing call to suspect, failure to unlink (see\n"
-"  other warnings), or deficiency in traverse that causes cycles referenced\n"
-"  only from other cycles to require multiple rounds of cycle collection\n",
-                                       pi->mName, pi->mPointer, pi->mSCCIndex);
-                            }
-                            if (pi->mShortestPathToExpectedGarbage)
-                                PrintPathToExpectedGarbage(pi);
-                        }
-                    }
-                }
-            }
-
-            DestroyReversedEdges();
-        }
-    }
-
-    ClearGraph();
-
-    mCollectionInProgress = false;
-
-    for (PRUint32 i = 0; i <= nsIProgrammingLanguage::MAX; ++i) {
-        if (mRuntimes[i])
-            mRuntimes[i]->FinishCycleCollection();
-    }    
-}
-
-bool
-nsCycleCollector::CreateReversedEdges()
-{
-    // Count the edges in the graph.
-    PRUint32 edgeCount = 0;
-    NodePool::Enumerator countQueue(mGraph.mNodes);
-    while (!countQueue.IsDone()) {
-        PtrInfo *pi = countQueue.GetNext();
-        for (EdgePool::Iterator e = pi->FirstChild(), e_end = pi->LastChild();
-             e != e_end; ++e, ++edgeCount) {
-        }
-    }
-
-    // Allocate a pool to hold all of the edges.
-    mGraph.mReversedEdges = new ReversedEdge[edgeCount];
-    if (mGraph.mReversedEdges == nsnull) {
-        NS_NOTREACHED("allocation failure creating reversed edges");
-        return false;
-    }
-
-    // Fill in the reversed edges by scanning all forward edges.
-    ReversedEdge *current = mGraph.mReversedEdges;
-    NodePool::Enumerator buildQueue(mGraph.mNodes);
-    while (!buildQueue.IsDone()) {
-        PtrInfo *pi = buildQueue.GetNext();
-        PRInt32 i = 0;
-        for (EdgePool::Iterator e = pi->FirstChild(), e_end = pi->LastChild();
-             e != e_end; ++e) {
-            current->mTarget = pi;
-            current->mEdgeName = &pi->mEdgeNames[i];
-            current->mNext = (*e)->mReversedEdges;
-            (*e)->mReversedEdges = current;
-            ++current;
-            ++i;
-        }
-    }
-    NS_ASSERTION(current - mGraph.mReversedEdges == ptrdiff_t(edgeCount),
-                 "misallocation");
-    return true;
-}
-
-void
-nsCycleCollector::DestroyReversedEdges()
-{
-    NodePool::Enumerator queue(mGraph.mNodes);
-    while (!queue.IsDone()) {
-        PtrInfo *pi = queue.GetNext();
-        pi->mReversedEdges = nsnull;
-    }
-
-    delete mGraph.mReversedEdges;
-    mGraph.mReversedEdges = nsnull;
-}
-
 void
 nsCycleCollector::ShouldBeFreed(nsISupports *n)
 {

xpcom/base/nsCycleCollector.h

@@ -38,8 +38,6 @@
 #ifndef nsCycleCollector_h__
 #define nsCycleCollector_h__
 
-// NOTE: If you use header files to define DEBUG_CC, you must do so here
-// *and* in nsCycleCollectionParticipant.h
 //#define DEBUG_CC
 
 class nsISupports;
@@ -52,14 +50,10 @@ class nsCycleCollectionTraversalCallback;
 
 struct nsCycleCollectionLanguageRuntime
 {
-    virtual nsresult BeginCycleCollection(nsCycleCollectionTraversalCallback &cb,
+    virtual nsresult BeginCycleCollection(nsCycleCollectionTraversalCallback &cb) = 0;
-                                          bool explainLiveExpectedGarbage) = 0;
     virtual nsresult FinishTraverse() = 0;
     virtual nsresult FinishCycleCollection() = 0;
     virtual nsCycleCollectionParticipant *ToParticipant(void *p) = 0;
-#ifdef DEBUG_CC
-    virtual void PrintAllReferencesTo(void *p) = 0;
-#endif
 };
 
 // Contains various stats about the cycle collection.

xpcom/glue/nsCycleCollectionParticipant.h

@@ -40,10 +40,6 @@
 
 #include "nsISupports.h"
 
-// NOTE: If you use header files to define DEBUG_CC, you must do so here
-// *and* in nsCycleCollector.h
-//#define DEBUG_CC
-
 #define NS_CYCLECOLLECTIONPARTICIPANT_IID                                      \
 {                                                                              \
     0x9674489b,                                                                \