
The methodology used to generate this CL is documented in https://crbug.com/1098010#c34. An earlier version of this CL, https://crrev.com/c/3879904, was reverted due to an issue that was resolved with https://crrev.com/c/3881211. No-Try: true Bug: 1098010 Change-Id: Ibd6ffb97e66835bc299fe7b85876c3e2927b2345 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3883841 Auto-Submit: Avi Drissman <avi@chromium.org> Owners-Override: Avi Drissman <avi@chromium.org> Reviewed-by: Mark Mentovai <mark@chromium.org> Commit-Queue: Mark Mentovai <mark@chromium.org> Cr-Commit-Position: refs/heads/main@{#1044747}
32 lines
992 B
C++
32 lines
992 B
C++
// Copyright 2012 The Chromium Authors
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef BASE_ATOMIC_SEQUENCE_NUM_H_
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#define BASE_ATOMIC_SEQUENCE_NUM_H_
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#include <atomic>
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namespace base {
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// AtomicSequenceNumber is a thread safe increasing sequence number generator.
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// Its constructor doesn't emit a static initializer, so it's safe to use as a
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// global variable or static member.
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class AtomicSequenceNumber {
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public:
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constexpr AtomicSequenceNumber() = default;
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AtomicSequenceNumber(const AtomicSequenceNumber&) = delete;
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AtomicSequenceNumber& operator=(const AtomicSequenceNumber&) = delete;
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// Returns an increasing sequence number starts from 0 for each call.
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// This function can be called from any thread without data race.
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inline int GetNext() { return seq_.fetch_add(1, std::memory_order_relaxed); }
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private:
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std::atomic_int seq_{0};
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};
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} // namespace base
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#endif // BASE_ATOMIC_SEQUENCE_NUM_H_
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