asyncsleep.hpp

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//    OpenVPN -- An application to securely tunnel IP networks
//               over a single port, with support for SSL/TLS-based
//               session authentication and key exchange,
//               packet encryption, packet authentication, and
//               packet compression.
//
//    Copyright (C) 2012- OpenVPN Inc.
//
//    SPDX-License-Identifier: MPL-2.0 OR AGPL-3.0-only WITH openvpn3-openssl-exception
//
 
// Interruptible sleep
 
#ifndef OPENVPN_COMMON_ASYNCSLEEP_H
#define OPENVPN_COMMON_ASYNCSLEEP_H
 
#include <algorithm>
#include <chrono>
#include <thread>
 
#include <openvpn/common/stop.hpp>
 
namespace openvpn {
 
// returns false if Stop signal prevented full wait
inline bool async_sleep_milliseconds(int milliseconds, Stop *async_stop)
{
    const int milliseconds_per_retry = 250;
    volatile bool stop = false;
 
    // allow asynchronous stop
    Stop::Scope stop_scope(async_stop, [&stop]()
                           { stop = true; });
 
    while (milliseconds > 0 && !stop)
    {
        const int ms = std::min(milliseconds, milliseconds_per_retry);
        std::this_thread::sleep_for(std::chrono::milliseconds(ms));
        milliseconds -= ms;
    }
 
    return !stop;
}
 
} // namespace openvpn
 
#endif