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livetrax/libs/pbd/pbd/semutils.h

70 lines
1.6 KiB
C++

/*
Copyright (C) 2010 Paul Davis
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef __pbd_semutils_h__
#define __pbd_semutils_h__
#if (defined PLATFORM_WINDOWS && !defined USE_PTW32_SEMAPHORE)
#define WINDOWS_SEMAPHORE 1
#endif
#ifdef WINDOWS_SEMAPHORE
#include <windows.h>
#else
#include <pthread.h>
#include <semaphore.h>
#endif
#include "pbd/libpbd_visibility.h"
namespace PBD {
class LIBPBD_API Semaphore {
private:
#ifdef WINDOWS_SEMAPHORE
HANDLE _sem;
#elif __APPLE__
sem_t* _sem;
sem_t* ptr_to_sem() const { return _sem; }
#else
mutable sem_t _sem;
sem_t* ptr_to_sem() const { return &_sem; }
#endif
public:
Semaphore (const char* name, int val);
~Semaphore ();
#ifdef WINDOWS_SEMAPHORE
int signal ();
int wait ();
int reset ();
#else
int signal () { return sem_post (ptr_to_sem()); }
int wait () { return sem_wait (ptr_to_sem()); }
int reset () { int rv = 0 ; while (sem_trywait (ptr_to_sem()) == 0) ++rv; return rv; }
#endif
};
}
#endif /* __pbd_semutils_h__ */