/* * Copyright (C) 2018 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. */ #pragma once #include "AllocationFailureMode.h" #include "LocalAllocator.h" #include "SecurityOriginToken.h" #include <wtf/FastMalloc.h> #include <wtf/FastTLS.h> #include <wtf/ThreadSafeRefCounted.h> #include <wtf/Vector.h> namespace JSC { class Heap; class VM; class ThreadLocalCache : public ThreadSafeRefCounted<ThreadLocalCache> { WTF_MAKE_NONCOPYABLE(ThreadLocalCache); WTF_MAKE_FAST_ALLOCATED; public: JS_EXPORT_PRIVATE static RefPtr<ThreadLocalCache> create(Heap&, SecurityOriginToken = uniqueSecurityOriginToken()); JS_EXPORT_PRIVATE virtual ~ThreadLocalCache(); static RefPtr<ThreadLocalCache> get(VM&); // This is designed to be fast enough that you could even call it before every allocation, by // optimizing for the case that you're just installing the cache that is already installed. This // assumes a relatively small number of caches or low chance of actual context switch combined // with possibly high rate of "I may have context switched" sites that call this out of paranoia. void install(VM&, RefPtr<ThreadLocalCache>* = nullptr); static LocalAllocator& allocator(VM&, size_t offset); template<typename SuccessFunc, typename FailureFunc> static void tryGetAllocator(VM&, size_t offset, const SuccessFunc&, const FailureFunc&); static ptrdiff_t offsetOfSizeInData() { return OBJECT_OFFSETOF(Data, size); } static ptrdiff_t offsetOfFirstAllocatorInData() { return OBJECT_OFFSETOF(Data, allocator); } SecurityOriginToken securityOriginToken() const { return m_securityOriginToken; } protected: JS_EXPORT_PRIVATE ThreadLocalCache(Heap&, SecurityOriginToken); private: friend class VM; struct Data { size_t size; ThreadLocalCache* cache; LocalAllocator allocator[1]; }; static Data* getImpl(VM&); Data* allocateData(); void destroyData(Data*); static LocalAllocator& allocator(Data& data, size_t offset); void installSlow(VM&, RefPtr<ThreadLocalCache>*); static void installData(VM&, Data*); LocalAllocator& allocatorSlow(VM&, size_t offset); static void destructor(void*); // When installed, we ref() the cache. Uninstalling deref()s the cache. TLS destruction deref()s // the cache. When the cache is destructed, it needs to return all of its state to the GC. I // think that just means stopAllocating(), but with some seriously heavy caveats having to do // with when it's valid to make that call. Alternatively, we could RELEASE_ASSERT that the cache // is empty when we destruct it. This is correct for caches that are kept live by GC objects and // it's correct for immortal caches. Heap& m_heap; Data* m_data { nullptr }; SecurityOriginToken m_securityOriginToken; #if USE(FAST_TLS_FOR_TLC) static const pthread_key_t tlsKey = WTF_GC_TLC_KEY; #endif }; } // namespace JSC