44 lines
1.1 KiB
C++
44 lines
1.1 KiB
C++
// Copyright (c) Facebook, Inc. and its affiliates.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#pragma once
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#include <folly/synchronization/Baton.h>
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/// Simple implementation of a latch synchronization primitive, for testing.
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class Latch {
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public:
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explicit Latch(size_t limit) : limit_{limit} {}
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void wait() {
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baton_.wait();
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}
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bool timed_wait(std::chrono::milliseconds timeout) {
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return baton_.timed_wait(timeout);
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}
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void post() {
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auto const old = count_.fetch_add(1);
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if (old == limit_ - 1) {
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baton_.post();
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}
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}
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private:
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folly::Baton<> baton_;
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std::atomic<size_t> count_{0};
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const size_t limit_{0};
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};
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