dfg/DFGSafepoint.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 DFGSafepoint_h
  27 #define DFGSafepoint_h
  28
  29 #if ENABLE(DFG_JIT)
  30
  31 #include <wtf/Vector.h>
  32
  33 namespace JSC {
  34
  35 class SlotVisitor;
  36 class VM;
  37
  38 namespace DFG {
  39
  40 class Scannable;
  41 struct Plan;
  42
  43 class Safepoint {
  44 public:
  45     class Result {
  46     public:
  47         Result()
  48             : m_didGetCancelled(false)
  49             , m_wasChecked(true)
  50         {
  51         }
  52
  53         ~Result();
  54
  55         bool didGetCancelled();
  56
  57     private:
  58         friend class Safepoint;
  59
  60         bool m_didGetCancelled;
  61         bool m_wasChecked;
  62     };
  63
  64     Safepoint(Plan&, Result&);
  65     ~Safepoint();
  66
  67     void add(Scannable*);
  68
  69     void begin();
  70
  71     void checkLivenessAndVisitChildren(SlotVisitor&);
  72     bool isKnownToBeLiveDuringGC();
  73     void cancel();
  74
  75     VM& vm() const;
  76
  77 private:
  78     Plan& m_plan;
  79     Vector<Scannable*> m_scannables;
  80     bool m_didCallBegin;
  81     Result& m_result;
  82 };
  83
  84 } } // namespace JSC::DFG
  85
  86 #endif // ENABLE(DFG_JIT)
  87
  88 #endif // DFGSafepoint_h
  89