heap/HeapVerifier.h

   1 /*
   2  * Copyright (C) 2014 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef HeapVerifier_h
  27 #define HeapVerifier_h
  28
  29 #include "Heap.h"
  30 #include <wtf/Vector.h>
  31
  32 namespace JSC {
  33
  34 class JSObject;
  35 class MarkedBlock;
  36
  37 struct LiveObjectData {
  38     LiveObjectData(JSObject* obj, bool isConfirmedDead = false)
  39         : obj(obj)
  40         , isConfirmedDead(isConfirmedDead)
  41     {
  42     }
  43
  44     JSObject* obj;
  45     bool isConfirmedDead;
  46 };
  47
  48 struct LiveObjectList {
  49     LiveObjectList(const char* name)
  50         : name(name)
  51         , hasLiveObjects(true)
  52     {
  53     }
  54
  55     void reset()
  56     {
  57         liveObjects.clear();
  58         hasLiveObjects = true; // Presume to have live objects until the list is trimmed.
  59     }
  60
  61     LiveObjectData* findObject(JSObject*);
  62
  63     const char* name;
  64     Vector<LiveObjectData> liveObjects;
  65     bool hasLiveObjects;
  66 };
  67
  68 class HeapVerifier {
  69 public:
  70     enum class Phase {
  71         BeforeGC,
  72         BeforeMarking,
  73         AfterMarking,
  74         AfterGC
  75     };
  76
  77     HeapVerifier(Heap*, unsigned numberOfGCCyclesToRecord);
  78
  79     void initializeGCCycle();
  80     void gatherLiveObjects(Phase);
  81     void trimDeadObjects();
  82     void verify(Phase);
  83
  84     // Scans all previously recorded LiveObjectLists and checks if the specified
  85     // object was in any of those lists.
  86     JS_EXPORT_PRIVATE void checkIfRecorded(JSObject*);
  87
  88     static const char* collectionTypeName(HeapOperation);
  89     static const char* phaseName(Phase);
  90
  91 private:
  92     struct GCCycle {
  93         GCCycle()
  94             : before("Before Marking")
  95             , after("After Marking")
  96         {
  97         }
  98
  99         HeapOperation collectionType;
 100         LiveObjectList before;
 101         LiveObjectList after;
 102
 103         const char* collectionTypeName() const
 104         {
 105             return HeapVerifier::collectionTypeName(collectionType);
 106         }
 107     };
 108
 109     void incrementCycle() { m_currentCycle = (m_currentCycle + 1) % m_numberOfCycles; }
 110     GCCycle& currentCycle() { return m_cycles[m_currentCycle]; }
 111     GCCycle& cycleForIndex(int cycleIndex)
 112     {
 113         ASSERT(cycleIndex <= 0 && cycleIndex > -m_numberOfCycles);
 114         cycleIndex += m_currentCycle;
 115         if (cycleIndex < 0)
 116             cycleIndex += m_numberOfCycles;
 117         ASSERT(cycleIndex < m_numberOfCycles);
 118         return m_cycles[cycleIndex];
 119     }
 120
 121     LiveObjectList* liveObjectListForGathering(Phase);
 122     bool verifyButterflyIsInStorageSpace(Phase, LiveObjectList&);
 123
 124     static void reportObject(LiveObjectData&, int cycleIndex, HeapVerifier::GCCycle&, LiveObjectList&);
 125
 126     Heap* m_heap;
 127     int m_currentCycle;
 128     int m_numberOfCycles;
 129     std::unique_ptr<GCCycle[]> m_cycles;
 130 };
 131
 132 } // namespace JSC
 133
 134 #endif // HeapVerifier