CPU profiler: make code events handling scalable.

src/unbound-queue.h

+// 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

[Søren Thygesen Gjesse, 2010/05/21 06:44:08]

Maybe emphasize single.

[mnaganov (inactive), 2010/05/22 05:26:44]

Capitalized 'Single' -- now easier to spot.

+// 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_; }
+
+ 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_