include/qore/QoreRWLock.h (4311)

/* -*- mode: c++; indent-tabs-mode: nil -*- */
/*
  QoreRWLock.cc

  simple pthreads-based read-write lock

  Qore Programming Language

  Copyright 2003 - 2011 David Nichols

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
  
  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.
  
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#ifndef _QORE_QORERWLOCK_H
#define _QORE_QORERWLOCK_H

#include <pthread.h>


class QoreRWLock {
protected:
   pthread_rwlock_t m;

   DLLLOCAL QoreRWLock& operator=(const QoreRWLock&);

public:
   DLLLOCAL QoreRWLock() {
#ifndef NDEBUG
      int rc =
#endif
      pthread_rwlock_init(&m, 0);
      assert(!rc);
   }

   DLLLOCAL ~QoreRWLock() {
#ifndef NDEBUG
      int rc =
#endif
      pthread_rwlock_destroy(&m);
      assert(!rc);
   }

   DLLLOCAL int rdlock() {
      return pthread_rwlock_rdlock(&m);
   }

   DLLLOCAL int wrlock() {
      return pthread_rwlock_wrlock(&m);
   }

   DLLLOCAL int tryrdlock() {
      return pthread_rwlock_tryrdlock(&m);
   }

   DLLLOCAL int trywrlock() {
      return pthread_rwlock_trywrlock(&m);
   }

   DLLLOCAL int unlock() {
      return pthread_rwlock_unlock(&m);
   }
};


class QoreAutoRWReadLocker {
private:
   DLLLOCAL QoreAutoRWReadLocker(const QoreAutoRWReadLocker&);
   
   DLLLOCAL QoreAutoRWReadLocker& operator=(const QoreAutoRWReadLocker&);
   
   DLLLOCAL void *operator new(size_t);

protected:
   QoreRWLock *l;

public:
   DLLLOCAL QoreAutoRWReadLocker(QoreRWLock &n_l) : l(&n_l) {
      l->rdlock();
   }

   DLLLOCAL QoreAutoRWReadLocker(QoreRWLock *n_l) : l(n_l) {
      l->rdlock();
   }

   DLLLOCAL ~QoreAutoRWReadLocker() {
      l->unlock();
   }
};


class QoreAutoRWWriteLocker {
private:
   DLLLOCAL QoreAutoRWWriteLocker(const QoreAutoRWWriteLocker&);
   
   DLLLOCAL QoreAutoRWWriteLocker& operator=(const QoreAutoRWWriteLocker&);
   
   DLLLOCAL void *operator new(size_t);

protected:
   QoreRWLock *l;

public:
   DLLLOCAL QoreAutoRWWriteLocker(QoreRWLock &n_l) : l(&n_l) {
      l->wrlock();
   }

   DLLLOCAL QoreAutoRWWriteLocker(QoreRWLock *n_l) : l(n_l) {
      l->wrlock();
   }

   DLLLOCAL ~QoreAutoRWWriteLocker() {
      l->unlock();
   }
};

#endif // #ifndef _QORE_QORERWLOCK_H