77 lines
2.0 KiB
C++
77 lines
2.0 KiB
C++
/*
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* Copyright (C) 2010-2013 Paul Davis <paul@linuxaudiosystems.com>
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* Copyright (C) 2013 John Emmas <john@creativepost.co.uk>
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* Copyright (C) 2015-2017 Robin Gareus <robin@gareus.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#ifndef __pbd_semutils_h__
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#define __pbd_semutils_h__
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#if (defined PLATFORM_WINDOWS && !defined USE_PTW32_SEMAPHORE)
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#define WINDOWS_SEMAPHORE 1
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#endif
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#ifdef WINDOWS_SEMAPHORE
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# include <windows.h>
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#elif defined USE_FUTEX_SEMAPHORE
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# include <atomic>
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#else
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# include <pthread.h>
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# include <semaphore.h>
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#endif
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#include "pbd/libpbd_visibility.h"
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namespace PBD {
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class LIBPBD_API Semaphore {
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private:
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#ifdef WINDOWS_SEMAPHORE
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HANDLE _sem;
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#elif __APPLE__
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sem_t* _sem;
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sem_t* ptr_to_sem() const { return _sem; }
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#elif defined USE_FUTEX_SEMAPHORE
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int _futex;
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std::atomic<int> _value;
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#else
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mutable sem_t _sem;
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sem_t* ptr_to_sem() const { return &_sem; }
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#endif
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public:
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Semaphore (const char* name, int val);
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~Semaphore ();
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#if defined WINDOWS_SEMAPHORE || defined USE_FUTEX_SEMAPHORE
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int signal ();
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int wait ();
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int reset ();
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#else
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int signal () { return sem_post (ptr_to_sem()); }
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int wait () { return sem_wait (ptr_to_sem()); }
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int reset () { int rv = 0 ; while (sem_trywait (ptr_to_sem()) == 0) ++rv; return rv; }
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#endif
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};
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}
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#endif /* __pbd_semutils_h__ */
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