| /* |
| * Copyright (C) 2009, 2010 Google 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: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * 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. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "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 THE COPYRIGHT |
| * OWNER 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 THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_CROSS_THREAD_COPIER_H_ |
| #define THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_CROSS_THREAD_COPIER_H_ |
| |
| #include <type_traits> |
| |
| #include "third_party/blink/renderer/platform/wtf/allocator/allocator.h" |
| #include "third_party/blink/renderer/platform/wtf/forward.h" |
| #include "third_party/blink/renderer/platform/wtf/wtf_size_t.h" |
| |
| namespace WTF { |
| |
| class String; |
| |
| template <typename T> |
| struct CrossThreadCopierPassThrough { |
| STATIC_ONLY(CrossThreadCopierPassThrough); |
| typedef T Type; |
| static Type Copy(const T& parameter) { return parameter; } |
| }; |
| |
| template <typename T> |
| struct CrossThreadCopierByValuePassThrough { |
| STATIC_ONLY(CrossThreadCopierByValuePassThrough); |
| typedef T Type; |
| static Type Copy(T receiver) { |
| return receiver; // This is in fact a move. |
| } |
| }; |
| |
| template <typename T, bool isArithmeticOrEnum> |
| struct CrossThreadCopierBase; |
| |
| // Arithmetic values (integers or floats) and enums can be safely copied. |
| template <typename T> |
| struct CrossThreadCopierBase<T, true> : public CrossThreadCopierPassThrough<T> { |
| STATIC_ONLY(CrossThreadCopierBase); |
| }; |
| |
| template <typename T> |
| struct CrossThreadCopier |
| : public CrossThreadCopierBase<T, |
| std::is_arithmetic<T>::value || |
| std::is_enum<T>::value> { |
| STATIC_ONLY(CrossThreadCopier); |
| }; |
| |
| // To allow a type to be passed across threads using its copy constructor, |
| // provide a specialization of CrossThreadCopier<T>. |
| // |
| // * If the type is not defined in third_party/blink/ |
| // ==> Choose one of the existing cross_thread_copier_*.h or add new one, |
| // and add a forward declaration and a CrossThreadCopier specialization |
| // for the type to the file. |
| // * If the type is defined in third_party/blink/public/ |
| // ==> Add a forward declaration and a CrossThreadCopier specialization for |
| // the type to cross_thread_copier_public.h. |
| // * If the type is defined in third_party/blink/ |
| // ==> Include cross_thread_copier.h from the header defining the type, and |
| // add a CrossThreadCopier specialization for the type to the header. |
| |
| template <typename T, wtf_size_t inlineCapacity, typename Allocator> |
| struct CrossThreadCopier<Vector<T, inlineCapacity, Allocator>> { |
| STATIC_ONLY(CrossThreadCopier); |
| static_assert(std::is_enum<T>() || std::is_arithmetic<T>(), |
| "Vectors of this type are not known to be safe to pass to " |
| "another thread."); |
| using Type = Vector<T, inlineCapacity, Allocator>; |
| static Type Copy(Type value) { return value; } |
| }; |
| |
| template <wtf_size_t inlineCapacity, typename Allocator> |
| struct CrossThreadCopier<Vector<String, inlineCapacity, Allocator>> |
| : public CrossThreadCopierPassThrough< |
| Vector<String, inlineCapacity, Allocator>> { |
| STATIC_ONLY(CrossThreadCopier); |
| }; |
| |
| template <> |
| struct CrossThreadCopier<AtomicString> |
| : public CrossThreadCopierPassThrough<AtomicString> { |
| STATIC_ONLY(CrossThreadCopier); |
| }; |
| |
| template <> |
| struct CrossThreadCopier<String> : public CrossThreadCopierPassThrough<String> { |
| STATIC_ONLY(CrossThreadCopier); |
| }; |
| |
| } // namespace WTF |
| |
| #endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_CROSS_THREAD_COPIER_H_ |