97681be4e5
This change fixes data race described in the bug by adding Acquire_Load to SamplingCircularQueue::StartDequeue and Acquire_Store to SamplingCircularQueue::Enqueue. Also the queue implementation imposed a constraint on the records it stored: the first AtomicWord in each record was a marker. For that purpose TickSampleEventRecord had filter field of type int. This approach is error prone, e.g. on x64 sizeof(AtomicWord) is 8 while sizeof(int) is 4. Moreover the queue needs such marker only at the beginning of chunk. I changed the queue so that it stores the marker explicitly as the first Cell in chunk and removed the filter field. BUG=251218 R=loislo@chromium.org, yangguo@chromium.org Review URL: https://codereview.chromium.org/19642002 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15750 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
63 lines
2.5 KiB
C++
63 lines
2.5 KiB
C++
// Copyright 2011 the V8 project authors. All rights reserved.
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following
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// disclaimer in the documentation and/or other materials provided
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// with the distribution.
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// * Neither the name of Google Inc. nor the names of its
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// contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#ifndef V8_CIRCULAR_QUEUE_INL_H_
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#define V8_CIRCULAR_QUEUE_INL_H_
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#include "circular-queue.h"
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namespace v8 {
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namespace internal {
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void* SamplingCircularQueue::Enqueue() {
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if (producer_pos_->enqueue_pos == producer_pos_->next_chunk_pos) {
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if (producer_pos_->enqueue_pos == buffer_ + buffer_size_) {
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producer_pos_->next_chunk_pos = buffer_;
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producer_pos_->enqueue_pos = buffer_;
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}
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Acquire_Store(producer_pos_->next_chunk_pos, kEnqueueStarted);
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// Skip marker.
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producer_pos_->enqueue_pos += 1;
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producer_pos_->next_chunk_pos += chunk_size_;
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}
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void* result = producer_pos_->enqueue_pos;
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producer_pos_->enqueue_pos += record_size_;
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return result;
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}
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void SamplingCircularQueue::WrapPositionIfNeeded(
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SamplingCircularQueue::Cell** pos) {
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if (*pos == buffer_ + buffer_size_) *pos = buffer_;
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}
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} } // namespace v8::internal
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#endif // V8_CIRCULAR_QUEUE_INL_H_
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