JavaScriptCore-7601.1.46.3.tar.gz

[apple/javascriptcore.git] / heap / HeapVerifier.h

diff --git a/heap/HeapVerifier.h b/heap/HeapVerifier.h
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+/*
+ * Copyright (C) 2014 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#ifndef HeapVerifier_h
+#define HeapVerifier_h
+
+#include "Heap.h"
+#include <wtf/Vector.h>
+
+namespace JSC {
+
+class JSObject;
+class MarkedBlock;
+
+struct LiveObjectData {
+    LiveObjectData(JSObject* obj, bool isConfirmedDead = false)
+        : obj(obj)
+        , isConfirmedDead(isConfirmedDead)
+    {
+    }
+
+    JSObject* obj;
+    bool isConfirmedDead;
+};
+
+struct LiveObjectList {
+    LiveObjectList(const char* name)
+        : name(name)
+        , hasLiveObjects(true)
+    {
+    }
+
+    void reset()
+    {
+        liveObjects.clear();
+        hasLiveObjects = true; // Presume to have live objects until the list is trimmed.
+    }
+
+    LiveObjectData* findObject(JSObject*);
+
+    const char* name;
+    Vector<LiveObjectData> liveObjects;
+    bool hasLiveObjects;
+};
+
+class HeapVerifier {
+public:
+    enum class Phase {
+        BeforeGC,
+        BeforeMarking,
+        AfterMarking,
+        AfterGC
+    };
+
+    HeapVerifier(Heap*, unsigned numberOfGCCyclesToRecord);
+
+    void initializeGCCycle();
+    void gatherLiveObjects(Phase);
+    void trimDeadObjects();
+    void verify(Phase);
+
+    // Scans all previously recorded LiveObjectLists and checks if the specified
+    // object was in any of those lists.
+    JS_EXPORT_PRIVATE void checkIfRecorded(JSObject*);
+
+    static const char* collectionTypeName(HeapOperation);
+    static const char* phaseName(Phase);
+
+private:
+    struct GCCycle {
+        GCCycle()
+            : before("Before Marking")
+            , after("After Marking")
+        {
+        }
+
+        HeapOperation collectionType;
+        LiveObjectList before;
+        LiveObjectList after;
+
+        const char* collectionTypeName() const
+        {
+            return HeapVerifier::collectionTypeName(collectionType);
+        }
+    };
+
+    void incrementCycle() { m_currentCycle = (m_currentCycle + 1) % m_numberOfCycles; }
+    GCCycle& currentCycle() { return m_cycles[m_currentCycle]; }
+    GCCycle& cycleForIndex(int cycleIndex)
+    {
+        ASSERT(cycleIndex <= 0 && cycleIndex > -m_numberOfCycles);
+        cycleIndex += m_currentCycle;
+        if (cycleIndex < 0)
+            cycleIndex += m_numberOfCycles;
+        ASSERT(cycleIndex < m_numberOfCycles);
+        return m_cycles[cycleIndex];
+    }
+
+    LiveObjectList* liveObjectListForGathering(Phase);
+    bool verifyButterflyIsInStorageSpace(Phase, LiveObjectList&);
+
+    static void reportObject(LiveObjectData&, int cycleIndex, HeapVerifier::GCCycle&, LiveObjectList&);
+
+    Heap* m_heap;
+    int m_currentCycle;
+    int m_numberOfCycles;
+    std::unique_ptr<GCCycle[]> m_cycles;
+};
+
+} // namespace JSC
+
+#endif // HeapVerifier