| // Copyright 2022 The Dawn & Tint Authors |
| // |
| // 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. |
| // |
| // 3. Neither the name of the copyright holder 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 HOLDER 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 SRC_DAWN_NATIVE_REFCOUNTEDWITHEXTERNALCOUNT_H_ |
| #define SRC_DAWN_NATIVE_REFCOUNTEDWITHEXTERNALCOUNT_H_ |
| |
| #include "dawn/common/RefCounted.h" |
| |
| namespace dawn::native { |
| |
| // RecCountedWithExternalCountBase is a version of RefCounted which tracks a separate |
| // refcount for calls to APIAddRef/APIRelease (refs added/removed by the application). |
| // The external refcount starts at 0, and the total refcount starts at 1 - i.e. the first |
| // ref isn't an external ref. |
| // When the external refcount drops to zero, WillDropLastExternalRef is called. and it can be called |
| // more than once. |
| // The derived class should override the behavior of WillDropLastExternalRef. |
| template <typename T> |
| class RefCountedWithExternalCountBase : public T { |
| public: |
| static constexpr bool HasExternalRefCount = true; |
| |
| using T::AddRef; |
| using T::Release; |
| using T::T; |
| |
| void APIAddRef() { |
| IncrementExternalRefCount(); |
| T::APIAddRef(); |
| } |
| |
| void APIRelease() { |
| if (mExternalRefCount.Decrement()) { |
| WillDropLastExternalRef(); |
| } |
| T::Release(); |
| } |
| |
| void IncrementExternalRefCount() { mExternalRefCount.Increment(); } |
| |
| uint64_t GetExternalRefCountForTesting() const { |
| return mExternalRefCount.GetValueForTesting(); |
| } |
| |
| protected: |
| using T::DeleteThis; |
| |
| private: |
| virtual void WillDropLastExternalRef() = 0; |
| |
| RefCount mExternalRefCount{/*initCount=*/0, /*payload=*/0}; |
| }; |
| |
| using RefCountedWithExternalCount = RefCountedWithExternalCountBase<RefCounted>; |
| |
| } // namespace dawn::native |
| |
| #endif // SRC_DAWN_NATIVE_REFCOUNTEDWITHEXTERNALCOUNT_H_ |