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 namespace v8 { 32 namespace internal { 33 34 35 // Lock-free unbound queue for small records. Intended for 36 // transferring small records between a Single producer and a Single 37 // consumer. Doesn't have restrictions on the number of queued 38 // elements, so producer never blocks. Implemented after Herb 39 // Sutter's article: 40 // http://www.ddj.com/high-performance-computing/210604448 41 template<typename Record> 42 class UnboundQueue BASE_EMBEDDED { 43 public: 44 inline UnboundQueue(); 45 inline ~UnboundQueue(); 46 47 INLINE(void Dequeue(Record* rec)); 48 INLINE(void Enqueue(const Record& rec)); 49 INLINE(bool IsEmpty()) { return divider_ == last_; } 50 INLINE(Record* Peek()); 51 52 private: 53 INLINE(void DeleteFirst()); 54 55 struct Node; 56 57 Node* first_; 58 AtomicWord divider_; // Node* 59 AtomicWord last_; // Node* 60 61 DISALLOW_COPY_AND_ASSIGN(UnboundQueue); 62 }; 63 64 65 } } // namespace v8::internal 66 67 #endif // V8_UNBOUND_QUEUE_ 68
