63 lines
2.1 KiB
C++
63 lines
2.1 KiB
C++
// Copyright 2010-2017 Google
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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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#ifndef OR_TOOLS_BASE_NOTIFICATION_H_
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#define OR_TOOLS_BASE_NOTIFICATION_H_
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#include <atomic>
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#include <condition_variable> // NOLINT
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#include <mutex> // NOLINT
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namespace absl {
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// -----------------------------------------------------------------------------
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// Notification
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// -----------------------------------------------------------------------------
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class Notification {
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public:
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// Initializes the "notified" state to unnotified.
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Notification() : notified_yet_(false) {}
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Notification(const Notification&) = delete;
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Notification& operator=(const Notification&) = delete;
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~Notification();
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// Notification::HasBeenNotified()
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//
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// Returns the value of the notification's internal "notified" state.
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bool HasBeenNotified() const;
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// Notification::WaitForNotification()
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//
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// Blocks the calling thread until the notification's "notified" state is
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// `true`. Note that if `Notify()` has been previously called on this
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// notification, this function will immediately return.
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void WaitForNotification();
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// Notification::Notify()
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//
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// Sets the "notified" state of this notification to `true` and wakes waiting
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// threads. Note: do not call `Notify()` multiple times on the same
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// `Notification`; calling `Notify()` more than once on the same notification
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// results in undefined behavior.
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void Notify();
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private:
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std::mutex mutex_;
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std::condition_variable condition_;
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std::atomic<bool> notified_yet_; // written under mutex_
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};
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} // namespace absl
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#endif // OR_TOOLS_BASE_NOTIFICATION_H_
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