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/*
* Copyright (C) 2011 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 DFGByteCodeCache_h
#define DFGByteCodeCache_h
#include <wtf/Platform.h>
#if ENABLE(DFG_JIT)
#include "CodeBlock.h"
#include "Executable.h"
#include "JSFunction.h"
#include <wtf/HashMap.h>
namespace JSC { namespace DFG {
class CodeBlockKey {
public:
CodeBlockKey()
: m_executable(0)
, m_kind(CodeForCall) // CodeForCall = empty value
{
}
CodeBlockKey(WTF::HashTableDeletedValueType)
: m_executable(0)
, m_kind(CodeForConstruct) // CodeForConstruct = deleted value
{
}
CodeBlockKey(FunctionExecutable* executable, CodeSpecializationKind kind)
: m_executable(executable)
, m_kind(kind)
{
}
bool operator==(const CodeBlockKey& other) const
{
return m_executable == other.m_executable
&& m_kind == other.m_kind;
}
unsigned hash() const
{
return WTF::PtrHash<FunctionExecutable*>::hash(m_executable) ^ static_cast<unsigned>(m_kind);
}
FunctionExecutable* executable() const { return m_executable; }
CodeSpecializationKind kind() const { return m_kind; }
bool isHashTableDeletedValue() const
{
return !m_executable && m_kind == CodeForConstruct;
}
private:
FunctionExecutable* m_executable;
CodeSpecializationKind m_kind;
};
struct CodeBlockKeyHash {
static unsigned hash(const CodeBlockKey& key) { return key.hash(); }
static bool equal(const CodeBlockKey& a, const CodeBlockKey& b) { return a == b; }
static const bool safeToCompareToEmptyOrDeleted = true;
};
} } // namespace JSC::DFG
namespace WTF {
template<typename T> struct DefaultHash;
template<> struct DefaultHash<JSC::DFG::CodeBlockKey> {
typedef JSC::DFG::CodeBlockKeyHash Hash;
};
template<typename T> struct HashTraits;
template<> struct HashTraits<JSC::DFG::CodeBlockKey> : SimpleClassHashTraits<JSC::DFG::CodeBlockKey> { };
} // namespace WTF
namespace JSC { namespace DFG {
struct ByteCodeCacheValue {
FunctionCodeBlock* codeBlock;
bool owned;
bool oldValueOfShouldDiscardBytecode;
// All uses of this struct initialize everything manually. But gcc isn't
// smart enough to see that, so this constructor is just here to make the
// compiler happy.
ByteCodeCacheValue()
: codeBlock(0)
, owned(false)
, oldValueOfShouldDiscardBytecode(false)
{
}
};
template<bool (*filterFunction)(CodeBlock*, CodeSpecializationKind)>
class ByteCodeCache {
public:
typedef HashMap<CodeBlockKey, ByteCodeCacheValue> Map;
ByteCodeCache() { }
~ByteCodeCache()
{
Map::iterator begin = m_map.begin();
Map::iterator end = m_map.end();
for (Map::iterator iter = begin; iter != end; ++iter) {
if (!iter->value.codeBlock)
continue;
if (iter->value.owned) {
delete iter->value.codeBlock;
continue;
}
}
}
CodeBlock* get(const CodeBlockKey& key, JSScope* scope)
{
Map::iterator iter = m_map.find(key);
if (iter != m_map.end())
return iter->value.codeBlock;
ByteCodeCacheValue value;
// First see if there is already a parsed code block that still has some
// bytecode in it.
value.codeBlock = key.executable()->codeBlockWithBytecodeFor(key.kind());
if (value.codeBlock) {
value.owned = false;
} else {
// Nope, so try to parse one.
JSObject* exception;
value.owned = true;
value.codeBlock = key.executable()->produceCodeBlockFor(scope, key.kind(), exception).leakPtr();
}
// Check if there is any reason to reject this from our cache. If so, then
// poison it.
if (!!value.codeBlock && !filterFunction(value.codeBlock, key.kind())) {
if (value.owned)
delete value.codeBlock;
value.codeBlock = 0;
}
m_map.add(key, value);
return value.codeBlock;
}
private:
Map m_map;
};
} } // namespace JSC::DFG
#endif // ENABLE(DFG_JIT)
#endif // DFGByteCodeCache_h
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