v8/src/unbound-queue.h

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// Copyright 2010 the V8 project authors. 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 V8_UNBOUND_QUEUE_
#define V8_UNBOUND_QUEUE_
namespace v8 {
namespace internal {
// Lock-free unbound queue for small records. Intended for
// transferring small records between a Single producer and a Single
// consumer. Doesn't have restrictions on the number of queued
// elements, so producer never blocks. Implemented after Herb
// Sutter's article:
// http://www.ddj.com/high-performance-computing/210604448
template<typename Record>
class UnboundQueue BASE_EMBEDDED {
public:
inline UnboundQueue();
inline ~UnboundQueue();
INLINE(void Dequeue(Record* rec));
INLINE(void Enqueue(const Record& rec));
INLINE(bool IsEmpty()) { return divider_ == last_; }
INLINE(Record* Peek());
private:
INLINE(void DeleteFirst());
struct Node;
Node* first_;
AtomicWord divider_; // Node*
AtomicWord last_; // Node*
DISALLOW_COPY_AND_ASSIGN(UnboundQueue);
};
} } // namespace v8::internal
#endif // V8_UNBOUND_QUEUE_