| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| #ifndef ParallelVectorIterator_h |
| #define ParallelVectorIterator_h |
| |
| #include <wtf/FastMalloc.h> |
| #include <wtf/Lock.h> |
| #include <wtf/Noncopyable.h> |
| |
| namespace WTF { |
| |
| template<typename VectorType> |
| class ParallelVectorIterator { |
| WTF_MAKE_NONCOPYABLE(ParallelVectorIterator); |
| WTF_MAKE_FAST_ALLOCATED; |
| public: |
| ParallelVectorIterator(VectorType& vector, size_t shardSize) |
| : m_vector(vector) |
| , m_shardSize(shardSize) |
| { |
| } |
| |
| template<typename Functor> |
| ALWAYS_INLINE void iterate(const Functor& functor) |
| { |
| for (;;) { |
| size_t begin; |
| size_t end; |
| { |
| LockHolder locker(m_lock); |
| begin = m_next; |
| if (begin == m_vector.size()) |
| return; |
| if (m_vector.size() - begin < m_shardSize) |
| end = m_vector.size(); |
| else |
| end = begin + m_shardSize; |
| RELEASE_ASSERT(end <= m_vector.size()); |
| RELEASE_ASSERT(begin < end); |
| m_next = end; |
| } |
| |
| for (size_t i = begin; i < end; ++i) |
| functor(m_vector[i]); |
| } |
| } |
| private: |
| VectorType& m_vector; |
| Lock m_lock; |
| size_t m_shardSize; |
| size_t m_next { 0 }; |
| }; |
| |
| } // namespace WTF |
| |
| using WTF::ParallelVectorIterator; |
| |
| #endif // ParallelVectorIterator_h |
| |