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/*
* 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.
*/
#ifndef JITStubRoutine_h
#define JITStubRoutine_h
#include <wtf/Platform.h>
#if ENABLE(JIT)
#include "ExecutableAllocator.h"
#include "MacroAssemblerCodeRef.h"
#include <wtf/RefCounted.h>
#include <wtf/Vector.h>
namespace JSC {
class JITStubRoutineSet;
// This is a base-class for JIT stub routines, and also the class you want
// to instantiate directly if you have a routine that does not need any
// help from the GC. If in doubt, use one of the other stub routines. But
// if you know for sure that the stub routine cannot be on the stack while
// someone triggers a stub routine reset, then using this will speed up
// memory reclamation. One case where a stub routine satisfies this
// condition is if it doesn't make any calls, to either C++ or JS code. In
// such a routine you know that it cannot be on the stack when anything
// interesting happens.
// See GCAwareJITStubRoutine.h for the other stub routines.
class JITStubRoutine {
WTF_MAKE_NONCOPYABLE(JITStubRoutine);
WTF_MAKE_FAST_ALLOCATED;
public:
JITStubRoutine(const MacroAssemblerCodeRef& code)
: m_code(code)
, m_refCount(1)
{
}
// Use this if you want to pass a CodePtr to someone who insists on taking
// a RefPtr<JITStubRoutine>.
static PassRefPtr<JITStubRoutine> createSelfManagedRoutine(
MacroAssemblerCodePtr rawCodePointer)
{
return adoptRef(new JITStubRoutine(MacroAssemblerCodeRef::createSelfManagedCodeRef(rawCodePointer)));
}
virtual ~JITStubRoutine();
// MacroAssemblerCodeRef is copyable, but at the cost of reference
// counting churn. Returning a reference is a good way of reducing
// the churn.
const MacroAssemblerCodeRef& code() const { return m_code; }
static MacroAssemblerCodePtr asCodePtr(PassRefPtr<JITStubRoutine> stubRoutine)
{
if (!stubRoutine)
return MacroAssemblerCodePtr();
MacroAssemblerCodePtr result = stubRoutine->code().code();
ASSERT(!!result);
return result;
}
void ref()
{
m_refCount++;
}
void deref()
{
if (--m_refCount)
return;
observeZeroRefCount();
}
// Helpers for the GC to determine how to deal with marking JIT stub
// routines.
uintptr_t startAddress() const { return m_code.executableMemory()->startAsInteger(); }
uintptr_t endAddress() const { return m_code.executableMemory()->endAsInteger(); }
static uintptr_t addressStep() { return jitAllocationGranule; }
static bool canPerformRangeFilter()
{
#if ENABLE(EXECUTABLE_ALLOCATOR_FIXED)
return true;
#else
return false;
#endif
}
static uintptr_t filteringStartAddress()
{
#if ENABLE(EXECUTABLE_ALLOCATOR_FIXED)
return startOfFixedExecutableMemoryPool;
#else
UNREACHABLE_FOR_PLATFORM();
return 0;
#endif
}
static size_t filteringExtentSize()
{
#if ENABLE(EXECUTABLE_ALLOCATOR_FIXED)
return fixedExecutableMemoryPoolSize;
#else
UNREACHABLE_FOR_PLATFORM();
return 0;
#endif
}
static bool passesFilter(uintptr_t address)
{
if (!canPerformRangeFilter()) {
// Just check that the address doesn't use any special values that would make
// our hashtables upset.
return address >= jitAllocationGranule && address != std::numeric_limits<uintptr_t>::max();
}
if (address - filteringStartAddress() >= filteringExtentSize())
return false;
return true;
}
protected:
virtual void observeZeroRefCount();
MacroAssemblerCodeRef m_code;
unsigned m_refCount;
};
// Helper for the creation of simple stub routines that need no help from the GC.
#define FINALIZE_CODE_FOR_STUB(patchBuffer, dataLogFArguments) \
(adoptRef(new JITStubRoutine(FINALIZE_CODE((patchBuffer), dataLogFArguments))))
#define FINALIZE_CODE_FOR_DFG_STUB(patchBuffer, dataLogFArguments) \
(adoptRef(new JITStubRoutine(FINALIZE_DFG_CODE((patchBuffer), dataLogFArguments))))
} // namespace JSC
#endif // ENABLE(JIT)
#endif // JITStubRoutine_h
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