Changeset 190589 in webkit for trunk/Source/JavaScriptCore/heap/Heap.cpp

Timestamp:

Oct 5, 2015, 4:31:53 PM (10 years ago)

Author:

[email protected]

Message:

Unreviewed, rolling back in r190450
​https://bugs.webkit.org/show_bug.cgi?id=149727

The cause of the leak was VM shutdown, which happens in workers.

The fix is for CodeBlockSet to participate in lastChanceToFinalize,
since it's responsible for running CodeBlock destructors.

I ran the leaks tests locally and did not see any CodeBlock-related leaks.

Restored changesets:

"CodeBlock should be a GC object"
​https://bugs.webkit.org/show_bug.cgi?id=149727
​http://trac.webkit.org/changeset/190450

File:

• trunk/Source/JavaScriptCore/heap/Heap.cpp (modified) (11 diffs)

trunk/Source/JavaScriptCore/heap/Heap.cpp

@@ -383 +383 @@
     RELEASE_ASSERT(m_operationInProgress == NoOperation);
 
+    m_codeBlocks.lastChanceToFinalize();
     m_objectSpace.lastChanceToFinalize();
     releaseDelayedReleasedObjects();
@@ -521 +522 @@
     ASSERT(isValidThreadState(m_vm));
 
-    Vector<const JSCell*> rememberedSet(m_slotVisitor.markStack().size());
-    m_slotVisitor.markStack().fillVector(rememberedSet);
-
-#if ENABLE(DFG_JIT)
-    DFG::clearCodeBlockMarks(*m_vm);
-#endif
-    if (m_operationInProgress == EdenCollection)
-        m_codeBlocks.clearMarksForEdenCollection(rememberedSet);
-    else
-        m_codeBlocks.clearMarksForFullCollection();
-
     // We gather conservative roots before clearing mark bits because conservative
     // gathering uses the mark bits to determine whether a reference is valid.
@@ -539 +529 @@
     gatherScratchBufferRoots(conservativeRoots);
 
+#if ENABLE(DFG_JIT)
+    DFG::rememberCodeBlocks(*m_vm);
+#endif
+
+    if (m_operationInProgress == FullCollection) {
+        m_opaqueRoots.clear();
+        m_slotVisitor.clearMarkStack();
+    }
+
     clearLivenessData();
-
-    if (m_operationInProgress == FullCollection)
-        m_opaqueRoots.clear();
 
     m_parallelMarkersShouldExit = false;
@@ -581 +577 @@
         ParallelModeEnabler enabler(m_slotVisitor);
 
+        m_slotVisitor.donateAndDrain();
         visitExternalRememberedSet();
         visitSmallStrings();
@@ -695 +692 @@
 {
     GCPHASE(ClearLivenessData);
+    if (m_operationInProgress == FullCollection)
+        m_codeBlocks.clearMarksForFullCollection();
+
     m_objectSpace.clearNewlyAllocated();
     m_objectSpace.clearMarks();
@@ -816 +816 @@
 {
     GCPHASE(TraceCodeBlocksAndJITStubRoutines);
-    m_codeBlocks.traceMarked(m_slotVisitor);
     m_jitStubRoutines.traceMarkedStubRoutines(m_slotVisitor);
 
@@ -950 +949 @@
     // we'll end up returning to deleted code.
     RELEASE_ASSERT(!m_vm->entryScope);
+    ASSERT(m_operationInProgress == NoOperation);
 
     completeAllDFGPlans();
 
-    for (ExecutableBase* current : m_executables) {
-        if (!current->isFunctionExecutable())
-            continue;
-        static_cast<FunctionExecutable*>(current)->clearCode();
-    }
-
-    ASSERT(m_operationInProgress == FullCollection || m_operationInProgress == NoOperation);
-    m_codeBlocks.clearMarksForFullCollection();
-    m_codeBlocks.deleteUnmarkedAndUnreferenced(FullCollection);
+    for (ExecutableBase* executable : m_executables)
+        executable->clearCode();
 }
 
@@ -981 +974 @@
             continue;
 
-        // We do this because executable memory is limited on some platforms and because
-        // CodeBlock requires eager finalization.
-        ExecutableBase::clearCodeVirtual(current);
+        // Eagerly dereference the Executable's JITCode in order to run watchpoint
+        // destructors. Otherwise, watchpoints might fire for deleted CodeBlocks.
+        current->clearCode();
         std::swap(m_executables[i], m_executables.last());
         m_executables.removeLast();
@@ -1104 +1097 @@
     deleteSourceProviderCaches();
     notifyIncrementalSweeper();
-    rememberCurrentlyExecutingCodeBlocks();
+    writeBarrierCurrentlyExecutingCodeBlocks();
 
     resetAllocators();
@@ -1141 +1134 @@
     if (shouldDoFullCollection(collectionType)) {
         m_operationInProgress = FullCollection;
-        m_slotVisitor.clearMarkStack();
         m_shouldDoFullCollection = false;
         if (Options::logGC())
@@ -1258 +1250 @@
 }
 
-void Heap::rememberCurrentlyExecutingCodeBlocks()
-{
-    GCPHASE(RememberCurrentlyExecutingCodeBlocks);
-    m_codeBlocks.rememberCurrentlyExecutingCodeBlocks(this);
+void Heap::writeBarrierCurrentlyExecutingCodeBlocks()
+{
+    GCPHASE(WriteBarrierCurrentlyExecutingCodeBlocks);
+    m_codeBlocks.writeBarrierCurrentlyExecutingCodeBlocks(this);
 }