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/*
* Copyright (C) 2013, 2014 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 CodeBlockSet_h
#define CodeBlockSet_h
#include "GCSegmentedArray.h"
#include "HeapOperation.h"
#include <wtf/HashSet.h>
#include <wtf/Noncopyable.h>
#include <wtf/PassRefPtr.h>
#include <wtf/PrintStream.h>
#include <wtf/RefPtr.h>
namespace JSC {
class BlockAllocator;
class CodeBlock;
class Heap;
class JSCell;
class SlotVisitor;
// CodeBlockSet tracks all CodeBlocks. Every CodeBlock starts out with one
// reference coming in from GC. The GC is responsible for freeing CodeBlocks
// once they hasOneRef() and nobody is running code from that CodeBlock.
class CodeBlockSet {
WTF_MAKE_NONCOPYABLE(CodeBlockSet);
public:
CodeBlockSet(BlockAllocator&);
~CodeBlockSet();
// Add a CodeBlock. This is only called by CodeBlock constructors.
void add(PassRefPtr<CodeBlock>);
// Clear mark bits for certain CodeBlocks depending on the type of collection.
void clearMarksForEdenCollection(const Vector<const JSCell*>&);
// Clear all mark bits for all CodeBlocks.
void clearMarksForFullCollection();
// Mark a pointer that may be a CodeBlock that belongs to the set of DFG
// blocks. This is defined in CodeBlock.h.
void mark(CodeBlock* candidateCodeBlock);
void mark(void* candidateCodeBlock);
// Delete all code blocks that are only referenced by this set (i.e. owned
// by this set), and that have not been marked.
void deleteUnmarkedAndUnreferenced(HeapOperation);
void remove(CodeBlock*);
// Trace all marked code blocks. The CodeBlock is free to make use of
// mayBeExecuting.
void traceMarked(SlotVisitor&);
// Add all currently executing CodeBlocks to the remembered set to be
// re-scanned during the next collection.
void rememberCurrentlyExecutingCodeBlocks(Heap*);
// Visits each CodeBlock in the heap until the visitor function returns true
// to indicate that it is done iterating, or until every CodeBlock has been
// visited.
template<typename Functor> void iterate(Functor& functor)
{
for (auto& codeBlock : m_oldCodeBlocks) {
bool done = functor(codeBlock);
if (done)
return;
}
for (auto& codeBlock : m_newCodeBlocks) {
bool done = functor(codeBlock);
if (done)
return;
}
}
void dump(PrintStream&) const;
private:
void clearMarksForCodeBlocksInRememberedExecutables(const Vector<const JSCell*>&);
void promoteYoungCodeBlocks();
// This is not a set of RefPtr<CodeBlock> because we need to be able to find
// arbitrary bogus pointers. I could have written a thingy that had peek types
// and all, but that seemed like overkill.
HashSet<CodeBlock*> m_oldCodeBlocks;
HashSet<CodeBlock*> m_newCodeBlocks;
GCSegmentedArray<CodeBlock*> m_currentlyExecuting;
};
} // namespace JSC
#endif // CodeBlockSet_h
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