_WCRTLINK int sem_timedwait( sem_t *sem, const struct timespec *abstime )
{
int ret;
struct timespec reltime;
if( sem == NULL ) {
_RWD_errno = EINVAL;
return( -1 );
}
if( __decrement_if_positive( &sem->value ) )
return( 0 );
do {
clock_gettime( CLOCK_MONOTONIC, &reltime );
reltime.tv_sec = abstime->tv_sec - reltime.tv_sec;
reltime.tv_nsec = abstime->tv_nsec - reltime.tv_nsec;
if(reltime.tv_nsec < 0) {
reltime.tv_sec--;
reltime.tv_nsec += 1E+9;
}
ret = __futex( &sem->value, FUTEX_WAIT_PRIVATE, 0, &reltime );
if(ret == -ETIMEDOUT) {
_RWD_errno = ETIMEDOUT;
return( -1 );
}
} while( !__decrement_if_positive( &sem->value ) );
return( 0 );
}
_WCRTLINK int sem_wait( sem_t *sem )
{
if( sem == NULL ) {
_RWD_errno = EINVAL;
return( -1 );
}
if( __decrement_if_positive( &sem->value ) )
return( 0 );
do {
__futex( &sem->value, FUTEX_WAIT_PRIVATE, 0, NULL );
} while( !__decrement_if_positive( &sem->value ) );
return( 0 );
}
_WCRTLINK int sem_trywait( sem_t *sem )
{
struct timespec timer;
int ret;
if( sem == NULL ) {
_RWD_errno = EINVAL;
return( -1 );
}
timer.tv_sec = 0;
timer.tv_nsec = 0;
if( __decrement_if_positive( &sem->value ) )
return( 0 );
do {
ret = __futex( &sem->value, FUTEX_WAIT_PRIVATE, 0, &timer );
} while( ret == 0 && !__decrement_if_positive( &sem->value ) );
if( ret == 0 )
return( 0 );
_RWD_errno = EAGAIN;
return( -1 );
}
int __futex_wake(volatile void *ftx, int count)
{
return __futex(ftx, FUTEX_WAKE, count, 0);
}
// This used to be in <sys/atomics.h>.
extern "C" int __futex_wait(volatile void* ftx, int value, const struct timespec* timeout) {
return __futex(ftx, FUTEX_WAIT, value, timeout);
}
// This used to be in <sys/atomics.h>.
extern "C" int __futex_wake(volatile void* ftx, int count) {
return __futex(ftx, FUTEX_WAKE, count, NULL);
}
