1// Copyright 2010 the V8 project authors. All rights reserved. 2// Redistribution and use in source and binary forms, with or without 3// modification, are permitted provided that the following conditions are 4// met: 5// 6// * Redistributions of source code must retain the above copyright 7// notice, this list of conditions and the following disclaimer. 8// * Redistributions in binary form must reproduce the above 9// copyright notice, this list of conditions and the following 10// disclaimer in the documentation and/or other materials provided 11// with the distribution. 12// * Neither the name of Google Inc. nor the names of its 13// contributors may be used to endorse or promote products derived 14// from this software without specific prior written permission. 15// 16// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28#ifndef V8_UNBOUND_QUEUE_ 29#define V8_UNBOUND_QUEUE_ 30 31#include "allocation.h" 32 33namespace v8 { 34namespace internal { 35 36 37// Lock-free unbound queue for small records. Intended for 38// transferring small records between a Single producer and a Single 39// consumer. Doesn't have restrictions on the number of queued 40// elements, so producer never blocks. Implemented after Herb 41// Sutter's article: 42// http://www.ddj.com/high-performance-computing/210604448 43template<typename Record> 44class UnboundQueue BASE_EMBEDDED { 45 public: 46 inline UnboundQueue(); 47 inline ~UnboundQueue(); 48 49 INLINE(void Dequeue(Record* rec)); 50 INLINE(void Enqueue(const Record& rec)); 51 INLINE(bool IsEmpty()) { return divider_ == last_; } 52 INLINE(Record* Peek()); 53 54 private: 55 INLINE(void DeleteFirst()); 56 57 struct Node; 58 59 Node* first_; 60 AtomicWord divider_; // Node* 61 AtomicWord last_; // Node* 62 63 DISALLOW_COPY_AND_ASSIGN(UnboundQueue); 64}; 65 66 67} } // namespace v8::internal 68 69#endif // V8_UNBOUND_QUEUE_ 70