src/bthread/countdown_event.h

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// to you under the Apache License, Version 2.0 (the
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//
//   http://www.apache.org/licenses/LICENSE-2.0
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// bthread - An M:N threading library to make applications more concurrent.

// Date: 2016/06/03 13:06:40

#ifndef BTHREAD_COUNTDOWN_EVENT_H
#define BTHREAD_COUNTDOWN_EVENT_H

#include "bthread/bthread.h"

namespace bthread {

// A synchronization primitive to wait for multiple signallers.
class CountdownEvent {
public:
    CountdownEvent(int initial_count = 1);
    ~CountdownEvent();

    // Increase current counter by |v|
    void add_count(int v = 1);

    // Reset the counter to |v|
    void reset(int v = 1);

    // Decrease the counter by |sig|
    // when flush is true, after signal we need to call bthread_flush
    void signal(int sig = 1, bool flush = false);

    // Block current thread until the counter reaches 0.
    // Returns 0 on success, error code otherwise.
    // This method never returns EINTR.
    int wait();

    // Block the current thread until the counter reaches 0 or duetime has expired
    // Returns 0 on success, error code otherwise. ETIMEDOUT is for timeout.
    // This method never returns EINTR.
    int timed_wait(const timespec& duetime);

private:
    int *_butex;
    bool _wait_was_invoked;
};

}  // namespace bthread

#endif  // BTHREAD_COUNTDOWN_EVENT_H