/* * 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 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(); ~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; Vector<CodeBlock*> m_currentlyExecuting; }; } // namespace JSC #endif // CodeBlockSet_h