ZeroTierOne/node/Mutex.hpp

/*
 * Copyright (c)2019 ZeroTier, Inc.
 *
 * Use of this software is governed by the Business Source License included
 * in the LICENSE.TXT file in the project's root directory.
 *
 * Change Date: 2026-01-01
 *
 * On the date above, in accordance with the Business Source License, use
 * of this software will be governed by version 2.0 of the Apache License.
 */
/****/

#ifndef ZT_MUTEX_HPP
#define ZT_MUTEX_HPP

#include "Constants.hpp"

#ifdef __UNIX_LIKE__

#include <pthread.h>
#include <stdint.h>
#include <stdlib.h>

namespace ZeroTier {

// libpthread based mutex lock
class Mutex {
  public:
    Mutex()
    {
        pthread_mutex_init(&_mh, (const pthread_mutexattr_t*)0);
    }

    ~Mutex()
    {
        pthread_mutex_destroy(&_mh);
    }

    inline void lock() const
    {
        pthread_mutex_lock(&((const_cast<Mutex*>(this))->_mh));
    }

    inline void unlock() const
    {
        pthread_mutex_unlock(&((const_cast<Mutex*>(this))->_mh));
    }

    class Lock {
      public:
        Lock(Mutex& m) : _m(&m)
        {
            m.lock();
        }

        Lock(const Mutex& m) : _m(const_cast<Mutex*>(&m))
        {
            _m->lock();
        }

        ~Lock()
        {
            _m->unlock();
        }

      private:
        Mutex* const _m;
    };

  private:
    Mutex(const Mutex&)
    {
    }
    const Mutex& operator=(const Mutex&)
    {
        return *this;
    }

    pthread_mutex_t _mh;
};

}   // namespace ZeroTier

#endif

#ifdef __WINDOWS__

#include <stdlib.h>
#include <windows.h>

namespace ZeroTier {

// Windows critical section based lock
class Mutex {
  public:
    Mutex()
    {
        InitializeCriticalSection(&_cs);
    }

    ~Mutex()
    {
        DeleteCriticalSection(&_cs);
    }

    inline void lock()
    {
        EnterCriticalSection(&_cs);
    }

    inline void unlock()
    {
        LeaveCriticalSection(&_cs);
    }

    inline void lock() const
    {
        (const_cast<Mutex*>(this))->lock();
    }

    inline void unlock() const
    {
        (const_cast<Mutex*>(this))->unlock();
    }

    class Lock {
      public:
        Lock(Mutex& m) : _m(&m)
        {
            m.lock();
        }

        Lock(const Mutex& m) : _m(const_cast<Mutex*>(&m))
        {
            _m->lock();
        }

        ~Lock()
        {
            _m->unlock();
        }

      private:
        Mutex* const _m;
    };

  private:
    Mutex(const Mutex&)
    {
    }
    const Mutex& operator=(const Mutex&)
    {
        return *this;
    }

    CRITICAL_SECTION _cs;
};

}   // namespace ZeroTier

#endif   // _WIN32

#endif