src/third_party/WebKit/Source/JavaScriptCore/jit/GCAwareJITStubRoutine.cpp

/*
 * Copyright (C) 2012 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. 
 */

#include "config.h"
#include "GCAwareJITStubRoutine.h"

#if ENABLE(JIT)

#include "Heap.h"
#include "JSGlobalData.h"
#include "SlotVisitor.h"
#include "Structure.h"

namespace JSC {

GCAwareJITStubRoutine::GCAwareJITStubRoutine(
    const MacroAssemblerCodeRef& code, JSGlobalData& globalData, bool isClosureCall)
    : JITStubRoutine(code)
    , m_mayBeExecuting(false)
    , m_isJettisoned(false)
    , m_isClosureCall(isClosureCall)
{
    globalData.heap.m_jitStubRoutines.add(this);
}
    
GCAwareJITStubRoutine::~GCAwareJITStubRoutine() { }

void GCAwareJITStubRoutine::observeZeroRefCount()
{
    if (m_isJettisoned) {
        // This case is needed for when the system shuts down. It may be that
        // the JIT stub routine set gets deleted before we get around to deleting
        // this guy. In that case the GC informs us that we're jettisoned already
        // and that we should delete ourselves as soon as the ref count reaches
        // zero.
        delete this;
        return;
    }
    
    ASSERT(!m_refCount);

    m_isJettisoned = true;
}

void GCAwareJITStubRoutine::deleteFromGC()
{
    ASSERT(m_isJettisoned);
    ASSERT(!m_refCount);
    ASSERT(!m_mayBeExecuting);
    
    delete this;
}

void GCAwareJITStubRoutine::markRequiredObjectsInternal(SlotVisitor&)
{
}

MarkingGCAwareJITStubRoutineWithOneObject::MarkingGCAwareJITStubRoutineWithOneObject(
    const MacroAssemblerCodeRef& code, JSGlobalData& globalData, const JSCell* owner,
    JSCell* object)
    : GCAwareJITStubRoutine(code, globalData)
    , m_object(globalData, owner, object)
{
}

MarkingGCAwareJITStubRoutineWithOneObject::~MarkingGCAwareJITStubRoutineWithOneObject()
{
}

void MarkingGCAwareJITStubRoutineWithOneObject::markRequiredObjectsInternal(SlotVisitor& visitor)
{
    visitor.append(&m_object);
}

PassRefPtr<JITStubRoutine> createJITStubRoutine(
    const MacroAssemblerCodeRef& code,
    JSGlobalData& globalData,
    const JSCell*,
    bool makesCalls)
{
    if (!makesCalls)
        return adoptRef(new JITStubRoutine(code));

    return static_pointer_cast<JITStubRoutine>(
        adoptRef(new GCAwareJITStubRoutine(code, globalData)));
}

PassRefPtr<JITStubRoutine> createJITStubRoutine(
    const MacroAssemblerCodeRef& code,
    JSGlobalData& globalData,
    const JSCell* owner,
    bool makesCalls,
    JSCell* object)
{
    if (!makesCalls)
        return adoptRef(new JITStubRoutine(code));
    
    return static_pointer_cast<JITStubRoutine>(
        adoptRef(new MarkingGCAwareJITStubRoutineWithOneObject(code, globalData, owner, object)));
}

} // namespace JSC

#endif // ENABLE(JIT)