/* * Copyright (C) 2017-2020 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 <wtf/ForbidHeapAllocation.h> #include <wtf/Noncopyable.h> namespace JSC { template<class T> class DisallowScope { WTF_MAKE_NONCOPYABLE(DisallowScope); WTF_FORBID_HEAP_ALLOCATION; public: #if ASSERT_ENABLED DisallowScope() { auto count = T::scopeReentryCount(); T::setScopeReentryCount(++count); } ~DisallowScope() { auto count = T::scopeReentryCount(); ASSERT(count); T::setScopeReentryCount(--count); } static bool isInEffectOnCurrentThread() { return !!T::scopeReentryCount(); } #else // not ASSERT_ENABLED ALWAYS_INLINE DisallowScope() { } // We need this to placate Clang due to unused warnings. ALWAYS_INLINE static bool isInEffectOnCurrentThread() { return false; } #endif // ASSERT_ENABLED }; } // namespace JSC