jit/GCAwareJITStubRoutine.h

   1 /*
   2  * Copyright (C) 2012 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 GCAwareJITStubRoutine_h
  27 #define GCAwareJITStubRoutine_h
  28
  29 #include <wtf/Platform.h>
  30
  31 #if ENABLE(JIT)
  32
  33 #include "JITStubRoutine.h"
  34 #include "JSObject.h"
  35 #include "JSString.h"
  36 #include "WriteBarrier.h"
  37 #include <wtf/RefCounted.h>
  38 #include <wtf/Vector.h>
  39
  40 namespace JSC {
  41
  42 class JITStubRoutineSet;
  43
  44 // Use this stub routine if you know that your code might be on stack when
  45 // either GC or other kinds of stub deletion happen. Basicaly, if your stub
  46 // routine makes calls (either to JS code or to C++ code) then you should
  47 // assume that it's possible for that JS or C++ code to do something that
  48 // causes the system to try to delete your routine. Using this routine type
  49 // ensures that the actual deletion is delayed until the GC proves that the
  50 // routine is no longer running. You can also subclass this routine if you
  51 // want to mark additional objects during GC in those cases where the
  52 // routine is known to be executing, or if you want to force this routine to
  53 // keep other routines alive (for example due to the use of a slow-path
  54 // list which does not get reclaimed all at once).
  55 class GCAwareJITStubRoutine : public JITStubRoutine {
  56 public:
  57     GCAwareJITStubRoutine(const MacroAssemblerCodeRef&, VM&, bool isClosureCall = false);
  58     virtual ~GCAwareJITStubRoutine();
  59
  60     void markRequiredObjects(SlotVisitor& visitor)
  61     {
  62         markRequiredObjectsInternal(visitor);
  63     }
  64
  65     void deleteFromGC();
  66
  67     bool isClosureCall() const { return m_isClosureCall; }
  68
  69 protected:
  70     virtual void observeZeroRefCount();
  71
  72     virtual void markRequiredObjectsInternal(SlotVisitor&);
  73
  74 private:
  75     friend class JITStubRoutineSet;
  76
  77     bool m_mayBeExecuting;
  78     bool m_isJettisoned;
  79     bool m_isClosureCall;
  80 };
  81
  82 // Use this if you want to mark one additional object during GC if your stub
  83 // routine is known to be executing.
  84 class MarkingGCAwareJITStubRoutineWithOneObject : public GCAwareJITStubRoutine {
  85 public:
  86     MarkingGCAwareJITStubRoutineWithOneObject(
  87         const MacroAssemblerCodeRef&, VM&, const JSCell* owner, JSCell*);
  88     virtual ~MarkingGCAwareJITStubRoutineWithOneObject();
  89
  90 protected:
  91     virtual void markRequiredObjectsInternal(SlotVisitor&);
  92
  93 private:
  94     WriteBarrier<JSCell> m_object;
  95 };
  96
  97 // Helper for easily creating a GC-aware JIT stub routine. For the varargs,
  98 // pass zero or more JSCell*'s. This will either create a JITStubRoutine, a
  99 // GCAwareJITStubRoutine, or an ObjectMarkingGCAwareJITStubRoutine as
 100 // appropriate. Generally you only need to pass pointers that will be used
 101 // after the first call to C++ or JS.
 102 //
 103 // PassRefPtr<JITStubRoutine> createJITStubRoutine(
 104 //    const MacroAssemblerCodeRef& code,
 105 //    VM& vm,
 106 //    const JSCell* owner,
 107 //    bool makesCalls,
 108 //    ...);
 109 //
 110 // Note that we don't actually use C-style varargs because that leads to
 111 // strange type-related problems. For example it would preclude us from using
 112 // our custom of passing '0' as NULL pointer. Besides, when I did try to write
 113 // this function using varargs, I ended up with more code than this simple
 114 // way.
 115
 116 PassRefPtr<JITStubRoutine> createJITStubRoutine(
 117     const MacroAssemblerCodeRef&, VM&, const JSCell* owner, bool makesCalls);
 118 PassRefPtr<JITStubRoutine> createJITStubRoutine(
 119     const MacroAssemblerCodeRef&, VM&, const JSCell* owner, bool makesCalls,
 120     JSCell*);
 121
 122 } // namespace JSC
 123
 124 #endif // ENABLE(JIT)
 125
 126 #endif // GCAwareJITStubRoutine_h
 127