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Diffstat (limited to 'examples/alsa_timed_audio/thread_signal.c')
| -rw-r--r-- | examples/alsa_timed_audio/thread_signal.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/examples/alsa_timed_audio/thread_signal.c b/examples/alsa_timed_audio/thread_signal.c new file mode 100644 index 00000000..c7cab3e7 --- /dev/null +++ b/examples/alsa_timed_audio/thread_signal.c @@ -0,0 +1,182 @@ +/****************************************************************************** + + Copyright (c) 2018, Intel Corporation + All rights reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are met: + + 1. Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. + + 2. Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. + + 3. Neither the name of the Intel Corporation nor the names of its + contributors may be used to endorse or promote products derived from + this software without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + POSSIBILITY OF SUCH DAMAGE. + +******************************************************************************/ + +#include <thread_signal.h> +#include <sdk.h> + +#include <pthread.h> +#include <stdlib.h> +#include <errno.h> + +struct isaudk_signal +{ + pthread_cond_t cond; + pthread_mutex_t mutex; + bool signaled; +}; + +isaudk_signal_error_t +isaudk_create_signal( struct isaudk_signal **signal ) +{ + int err; + + *signal = (struct isaudk_signal *) + malloc((size_t) sizeof( **signal )); + if( *signal == NULL ) + return ISAUDK_SIGNAL_SYSERROR; + + err = pthread_cond_init( &(*signal)->cond, NULL ); + if( err != 0 ) + return ISAUDK_SIGNAL_SYSERROR; + + err = pthread_mutex_init( &(*signal)->mutex, NULL ); + if( err != 0 ) + return ISAUDK_SIGNAL_SYSERROR; + + return ISAUDK_SIGNAL_OK; +} + +isaudk_signal_error_t +isaudk_free_signal( isaudk_signal_t signal ) +{ + int err; + + err = pthread_mutex_lock( &signal->mutex ); + if( err ) + return ISAUDK_SIGNAL_SYSERROR; + + err = pthread_cond_destroy( &signal->cond ); + if( err ) + return ISAUDK_SIGNAL_SYSERROR; + + err = pthread_mutex_destroy( &signal->mutex ); + if( err ) + return ISAUDK_SIGNAL_SYSERROR; + + free(( void * ) signal ); + + return ISAUDK_SIGNAL_OK; +} + +#define NS_PER_SEC (1000000000LL) +#define MS_PER_SEC (1000) +#define NS_PER_MS (NS_PER_SEC/MS_PER_SEC) + +static inline void +timespec_add_ns( struct timespec *ts, unsigned ns ) +{ + ts->tv_nsec += ns % NS_PER_SEC; + ts->tv_sec += ns / NS_PER_SEC; + if( ts->tv_nsec >= NS_PER_SEC ) { + ts->tv_nsec -= NS_PER_SEC; + ts->tv_sec += 1; + } +} + +#include <stdio.h> + +// Wait for signal, *wait* == 0: forever, *wait* != 0: *wait* milliseconds +isaudk_signal_error_t +isaudk_signal_wait( isaudk_signal_t signal, unsigned wait ) +{ + int err; + isaudk_signal_error_t retval = ISAUDK_SIGNAL_OK; + + err = pthread_mutex_lock( &signal->mutex ); + if( err != 0 ) + return ISAUDK_SIGNAL_SYSERROR; + + while( !signal->signaled ) + { + if( wait != 0 ) + { + struct timespec timeout; + + err = clock_gettime( CLOCK_REALTIME, &timeout ); + if( err != 0 ) + { + retval = ISAUDK_SIGNAL_SYSERROR; + goto done; + } + timespec_add_ns( &timeout, wait*NS_PER_MS ); + + err = pthread_cond_timedwait + ( &signal->cond, &signal->mutex, &timeout ); + } + else + { + err = pthread_cond_wait + ( &signal->cond, &signal->mutex ); + } + if( err == ETIMEDOUT ) + goto done; + } + + signal->signaled = false; + +done: + err = pthread_mutex_unlock( &signal->mutex ); + if( err != 0 ) + return ISAUDK_SIGNAL_SYSERROR; + + return retval; +} + +isaudk_signal_error_t +isaudk_signal_send( isaudk_signal_t signal ) +{ + int err; + isaudk_signal_error_t retval = ISAUDK_SIGNAL_OK; + + err = pthread_mutex_lock( &signal->mutex ); + if( err != 0 ) + { + retval = ISAUDK_SIGNAL_SYSERROR; + goto done; + } + + signal->signaled = true; + err = pthread_cond_broadcast( &signal->cond ); + if( err != 0 ) + { + retval = ISAUDK_SIGNAL_SYSERROR; + goto done; + } + +done: + err = pthread_mutex_unlock( &signal->mutex ); + if( err != 0 ) + return ISAUDK_SIGNAL_SYSERROR; + + return ISAUDK_SIGNAL_OK; +} |