locker.h

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2018, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */
/*
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#pragma once
namespace rp::hal
{
class Locker
{
   public:
    enum LOCK_STATUS
    {
        LOCK_OK = 1,
        LOCK_TIMEOUT = -1,
        LOCK_FAILED = 0
    };

    Locker()
    {
#ifdef _WIN32
        _lock = nullptr;
#endif
        init();
    }

    ~Locker() { release(); }
    Locker::LOCK_STATUS lock(unsigned long timeout = 0xFFFFFFFF)
    {
#ifdef _WIN32
        switch (WaitForSingleObject(
            _lock, timeout == 0xFFFFFFF ? INFINITE : (DWORD)timeout))
        {
            case WAIT_ABANDONED:
                return LOCK_FAILED;
            case WAIT_OBJECT_0:
                return LOCK_OK;
            case WAIT_TIMEOUT:
                return LOCK_TIMEOUT;
        }

#else
#ifdef _MACOS
        if (timeout != 0)
        {
            if (pthread_mutex_lock(&_lock) == 0) return LOCK_OK;
        }
#else
        if (timeout == 0xFFFFFFFF)
        {
            if (pthread_mutex_lock(&_lock) == 0) return LOCK_OK;
        }
#endif
        else if (timeout == 0)
        {
            if (pthread_mutex_trylock(&_lock) == 0) return LOCK_OK;
        }
#ifndef _MACOS
        else
        {
            timespec wait_time;
            timeval now;
            gettimeofday(&now, nullptr);

            wait_time.tv_sec = timeout / 1000 + now.tv_sec;
            wait_time.tv_nsec = (timeout % 1000) * 1000000 + now.tv_usec * 1000;

            if (wait_time.tv_nsec >= 1000000000)
            {
                ++wait_time.tv_sec;
                wait_time.tv_nsec -= 1000000000;
            }
            switch (pthread_mutex_timedlock(&_lock, &wait_time))
            {
                case 0:
                    return LOCK_OK;
                case ETIMEDOUT:
                    return LOCK_TIMEOUT;
            }
        }
#endif
#endif

        return LOCK_FAILED;
    }

    void unlock()
    {
#ifdef _WIN32
        ReleaseMutex(_lock);
#else
        pthread_mutex_unlock(&_lock);
#endif
    }

#ifdef _WIN32
    HANDLE getLockHandle() { return _lock; }
#else
    pthread_mutex_t* getLockHandle() { return &_lock; }
#endif

   protected:
    void init()
    {
#ifdef _WIN32
        _lock = CreateMutex(nullptr, FALSE, nullptr);
#else
        pthread_mutex_init(&_lock, nullptr);
#endif
    }

    void release()
    {
        unlock();  // force unlock before release
#ifdef _WIN32

        if (_lock) CloseHandle(_lock);
        _lock = nullptr;
#else
        pthread_mutex_destroy(&_lock);
#endif
    }

#ifdef _WIN32
    HANDLE _lock;
#else
    pthread_mutex_t _lock;
#endif
};

class AutoLocker
{
   public:
    AutoLocker(Locker& l) : _binded(l) { _binded.lock(); }
    void forceUnlock() { _binded.unlock(); }
    ~AutoLocker() { _binded.unlock(); }
    Locker& _binded;
};
}