81 lines
1.9 KiB
C
81 lines
1.9 KiB
C
/* ****************************************************************************
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* utils/mutex.c -- mutex internals.
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* Copyright (C) 2017 Thomas "Cakeisalie5" Touhey <thomas@touhey.fr>
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*
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* This file is part of libcasio.
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* libcasio is free software; you can redistribute it and/or modify it
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* under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation; either version 3.0 of the License,
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* or (at your option) any later version.
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*
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* libcasio 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.
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* See the GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with libcasio; if not, see <http://www.gnu.org/licenses/>.
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* ************************************************************************* */
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#include "../internals.h"
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/**
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* casio_init_mutex:
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* Initialize a mutex.
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*
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* @arg mutex the mutex to initialize.
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*/
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void CASIO_EXPORT casio_init_mutex(casio_mutex_t *mutex)
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{
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*mutex = 0;
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}
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/**
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* casio_lock_mutex:
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* Lock a mutex.
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*
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* @arg mutex the mutex to lock.
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* @return the error code (0 if ok).
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*/
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int CASIO_EXPORT casio_lock_mutex(casio_mutex_t *mutex)
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{
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int err;
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if (!*mutex) goto unlocked;
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if ((err = casio_sleep(0))) return (err);
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while (*(volatile casio_mutex_t*)mutex)
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casio_sleep(5);
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unlocked:
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*mutex = 1;
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return (0);
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}
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/**
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* casio_trylock_mutex:
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* Try to lock a mutex.
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*
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* @arg mutex the mutex to lock.
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* @return the error code (0 if ok).
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*/
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int CASIO_EXPORT casio_trylock_mutex(casio_mutex_t *mutex)
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{
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if (*mutex) return (casio_error_lock);
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*mutex = 1;
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return (0);
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}
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/**
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* casio_unlock_mutex:
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* Unlock a mutex.
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*
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* @arg mutex the mutex to unlock.
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*/
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void CASIO_EXPORT casio_unlock_mutex(casio_mutex_t *mutex)
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{
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*mutex = 0;
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}
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