heap/GCIncomingRefCountedInlines.h

   1 /*
   2  * Copyright (C) 2013 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 GCIncomingRefCountedInlines_h
  27 #define GCIncomingRefCountedInlines_h
  28
  29 #include "GCIncomingRefCounted.h"
  30 #include "Heap.h"
  31
  32 namespace JSC {
  33
  34 template<typename T>
  35 bool GCIncomingRefCounted<T>::addIncomingReference(JSCell* cell)
  36 {
  37     if (!hasAnyIncoming()) {
  38         m_encodedPointer = bitwise_cast<uintptr_t>(cell) | singletonFlag();
  39         this->setIsDeferred(true);
  40         ASSERT(hasSingleton());
  41         return true;
  42     }
  43
  44     ASSERT(Heap::heap(incomingReferenceAt(0)) == Heap::heap(cell));
  45
  46     if (hasSingleton()) {
  47         Vector<JSCell*>* vector = new Vector<JSCell*>();
  48         vector->append(singleton());
  49         vector->append(cell);
  50         m_encodedPointer = bitwise_cast<uintptr_t>(vector);
  51         ASSERT(hasVectorOfCells());
  52         return false;
  53     }
  54
  55     vectorOfCells()->append(cell);
  56     return false;
  57 }
  58
  59 template<typename T>
  60 template<typename FilterFunctionType>
  61 bool GCIncomingRefCounted<T>::filterIncomingReferences(FilterFunctionType& filterFunction)
  62 {
  63     const bool verbose = false;
  64
  65     if (verbose)
  66         dataLog("Filtering incoming references.\n");
  67
  68     if (!hasAnyIncoming()) {
  69         ASSERT(!this->isDeferred());
  70         ASSERT(this->refCount());
  71         if (verbose)
  72             dataLog("    Has no incoming.\n");
  73         return false;
  74     }
  75
  76     ASSERT(this->isDeferred());
  77
  78     if (hasSingleton()) {
  79         if (filterFunction(singleton())) {
  80             if (verbose)
  81                 dataLog("   Singleton passed.\n");
  82             return false;
  83         }
  84
  85         if (verbose)
  86             dataLog("   Removing singleton.\n");
  87         m_encodedPointer = 0;
  88         ASSERT(!hasAnyIncoming());
  89         this->setIsDeferred(false);
  90         return true;
  91     }
  92
  93     if (verbose)
  94         dataLog("   Has ", vectorOfCells()->size(), " entries.\n");
  95     for (size_t i = 0; i < vectorOfCells()->size(); ++i) {
  96         if (filterFunction(vectorOfCells()->at(i)))
  97             continue;
  98         vectorOfCells()->at(i--) = vectorOfCells()->last();
  99         vectorOfCells()->removeLast();
 100     }
 101
 102     if (vectorOfCells()->size() >= 2) {
 103         if (verbose)
 104             dataLog("   Still has ", vectorOfCells()->size(), " entries.\n");
 105         return false;
 106     }
 107
 108     if (vectorOfCells()->isEmpty()) {
 109         if (verbose)
 110             dataLog("   Removing.\n");
 111         delete vectorOfCells();
 112         m_encodedPointer = 0;
 113         ASSERT(!hasAnyIncoming());
 114         this->setIsDeferred(false);
 115         return true;
 116     }
 117
 118     if (verbose)
 119         dataLog("   Shrinking to singleton.\n");
 120     JSCell* singleton = vectorOfCells()->at(0);
 121     delete vectorOfCells();
 122     m_encodedPointer = bitwise_cast<uintptr_t>(singleton) | singletonFlag();
 123     ASSERT(hasSingleton());
 124     return false;
 125 }
 126
 127 } // namespace JSC
 128
 129 #endif // GCIncomingRefCountedInlines_h
 130