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mhahnenberg@apple.com authored
https://bugs.webkit.org/show_bug.cgi?id=122667 Reviewed by Filip Pizlo. The issue this patch is attempting to fix is that there are places in our codebase where we acquire the ConcurrentJITLock for a particular CodeBlock, then we do some operations that can initiate a garbage collection. Garbage collection then calls some methods of CodeBlock that also take the ConcurrentJITLock (because they don't always necessarily run during garbage collection). This causes a deadlock. To fix this issue, this patch adds a new RAII-style object (DisallowGC) that stores into a thread-local field that indicates that it is unsafe to perform any operation that could trigger garbage collection on the current thread. In debug builds, ConcurrentJITLocker contains one of these DisallowGC objects so that we can eagerly detect deadlocks. This patch also adds a new type of ConcurrentJITLocker, GCSafeConcurrentJITLocker, which uses the DeferGC mechanism to prevent collections from occurring while the lock is held. * CMakeLists.txt: * GNUmakefile.list.am: * JavaScriptCore.vcxproj/JavaScriptCore.vcxproj: * JavaScriptCore.vcxproj/JavaScriptCore.vcxproj.filters: * JavaScriptCore.xcodeproj/project.pbxproj: * heap/DeferGC.cpp: Added. * heap/DeferGC.h: (JSC::DisallowGC::DisallowGC): (JSC::DisallowGC::~DisallowGC): (JSC::DisallowGC::isGCDisallowedOnCurrentThread): (JSC::DisallowGC::initialize): * jit/JITStubs.cpp: (JSC::tryCachePutByID): (JSC::tryCacheGetByID): (JSC::DEFINE_STUB_FUNCTION): * llint/LLIntSlowPaths.cpp: (JSC::LLInt::LLINT_SLOW_PATH_DECL): * runtime/ConcurrentJITLock.h: (JSC::ConcurrentJITLockerBase::ConcurrentJITLockerBase): (JSC::ConcurrentJITLockerBase::~ConcurrentJITLockerBase): (JSC::ConcurrentJITLockerBase::unlockEarly): (JSC::GCSafeConcurrentJITLocker::GCSafeConcurrentJITLocker): (JSC::ConcurrentJITLocker::ConcurrentJITLocker): * runtime/InitializeThreading.cpp: (JSC::initializeThreadingOnce): * runtime/JSCellInlines.h: (JSC::allocateCell): * runtime/Structure.cpp: (JSC::Structure::materializePropertyMap): (JSC::Structure::putSpecificValue): (JSC::Structure::createPropertyMap): * runtime/Structure.h: git-svn-id: http://svn.webkit.org/repository/webkit/trunk@157413 268f45cc-cd09-0410-ab3c-d52691b4dbfc
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