QoreThreadLock.h

/* -*- mode: c++; indent-tabs-mode: nil -*- */
/*
    QoreThreadLock.h

    Qore Programming Language

    Copyright (C) 2003 - 2018 Qore Technologies, s.r.o.

    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
    to deal in the Software without restriction, including without limitation
    the rights to use, copy, modify, merge, publish, distribute, sublicense,
    and/or sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in
    all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.

    Note that the Qore library is released under a choice of three open-source
    licenses: MIT (as above), LGPL 2+, or GPL 2+; see README-LICENSE for more
    information.
*/

#ifndef _QORE_QORETHREADLOCK_H

#define _QORE_QORETHREADLOCK_H

#include <cassert>
#include <csignal>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <pthread.h>


class QoreThreadLock {
    friend class QoreCondition;

private:
    pthread_mutex_t ptm_lock;

    DLLLOCAL QoreThreadLock& operator=(const QoreThreadLock&);

    DLLLOCAL void init(const pthread_mutexattr_t* pma = 0) {
#ifndef NDEBUG
        int rc =
#endif
        pthread_mutex_init(&ptm_lock, pma);
        assert(!rc);
    }

public:
    DLLLOCAL QoreThreadLock() {
        init();
    }

    DLLLOCAL QoreThreadLock(const pthread_mutexattr_t* ma) {
        init(ma);
    }

    DLLLOCAL ~QoreThreadLock() {
        pthread_mutex_destroy(&ptm_lock);
    }

    DLLLOCAL QoreThreadLock(const QoreThreadLock&) {
        init();
    }


    DLLLOCAL void lock() {
#ifndef NDEBUG
        int rc =
#endif
        pthread_mutex_lock(&ptm_lock);
        assert(!rc);
    }


    DLLLOCAL void unlock() {
#ifndef NDEBUG
        int rc =
#endif
        pthread_mutex_unlock(&ptm_lock);
        assert(!rc);
    }


    DLLLOCAL int trylock() {
        return pthread_mutex_trylock(&ptm_lock);
    }
};


class AutoLocker {
private:
    DLLLOCAL AutoLocker(const AutoLocker&);

    DLLLOCAL AutoLocker& operator=(const AutoLocker&);

    DLLLOCAL void *operator new(size_t);

protected:
    QoreThreadLock* lck;

public:
    DLLLOCAL AutoLocker(QoreThreadLock* l) : lck(l) {
        lck->lock();
    }

    DLLLOCAL AutoLocker(QoreThreadLock& l) : lck(&l) {
        lck->lock();
    }


    DLLLOCAL AutoLocker(QoreThreadLock* l, bool already_locked) : lck(l) {
        if (!already_locked) {
            lck->lock();
        }
    }


    DLLLOCAL AutoLocker(QoreThreadLock& l, bool already_locked) : lck(&l) {
        if (!already_locked) {
            lck->lock();
        }
    }

    DLLLOCAL ~AutoLocker() {
        lck->unlock();
    }
};


class AutoUnlocker {
private:
    DLLLOCAL AutoUnlocker(const AutoUnlocker&);

    DLLLOCAL AutoUnlocker& operator=(const AutoUnlocker&);

    DLLLOCAL void *operator new(size_t);

protected:
    QoreThreadLock* lck;

public:
    DLLLOCAL AutoUnlocker(QoreThreadLock* l) : lck(l) {
        if (lck)
            lck->unlock();
    }

    DLLLOCAL AutoUnlocker(QoreThreadLock& l) : lck(&l) {
        lck->unlock();
    }

    DLLLOCAL ~AutoUnlocker() {
        if (lck)
            lck->lock();
    }
};


class SafeLocker {
private:
    DLLLOCAL SafeLocker(const SafeLocker&);

    DLLLOCAL SafeLocker& operator=(const SafeLocker&);

    DLLLOCAL void *operator new(size_t);

protected:
    QoreThreadLock* lck;

    bool locked;

public:
    DLLLOCAL SafeLocker(QoreThreadLock* l) : lck(l) {
        lck->lock();
        locked = true;
    }

    DLLLOCAL SafeLocker(QoreThreadLock& l) : lck(&l) {
        lck->lock();
        locked = true;
    }

    DLLLOCAL ~SafeLocker() {
        if (locked)
            lck->unlock();
    }

    DLLLOCAL void lock() {
        assert(!locked);
        lck->lock();
        locked = true;
    }

    DLLLOCAL void unlock() {
        assert(locked);
        locked = false;
        lck->unlock();
    }

    DLLLOCAL void stay_locked() {
        assert(locked);
        locked = false;
    }

    DLLLOCAL void relock() {
        assert(!locked);
        lck->lock();
        locked = true;
    }
};


class OptLocker {
private:
   DLLLOCAL OptLocker(const OptLocker&);

   DLLLOCAL OptLocker& operator=(const OptLocker&);

   DLLLOCAL void *operator new(size_t);

protected:
   QoreThreadLock* lck;

public:
   DLLLOCAL OptLocker(QoreThreadLock* l) : lck(l) {
      if (lck)
         lck->lock();
   }

   DLLLOCAL ~OptLocker() {
      if (lck)
         lck->unlock();
   }
};

#endif // _QORE_QORETHREADLOCK_H