int pthread_rwlock_tryrdlock(
pthread_rwlock_t *rwlock
)
{
POSIX_RWLock_Control *the_rwlock;
ISR_lock_Context lock_context;
Thread_Control *executing;
the_rwlock = _POSIX_RWLock_Get( rwlock, &lock_context );
if ( the_rwlock == NULL ) {
return EINVAL;
}
executing = _Thread_Executing;
_CORE_RWLock_Seize_for_reading(
&the_rwlock->RWLock,
executing,
false, /* do not wait for the rwlock */
0,
&lock_context
);
return _POSIX_RWLock_Translate_core_RWLock_return_code(
(CORE_RWLock_Status) executing->Wait.return_code
);
}
int pthread_rwlock_timedrdlock(
pthread_rwlock_t *rwlock,
const struct timespec *abstime
)
{
POSIX_RWLock_Control *the_rwlock;
Thread_queue_Context queue_context;
Watchdog_Interval ticks;
bool do_wait;
TOD_Absolute_timeout_conversion_results timeout_status;
Status_Control status;
/*
* POSIX requires that blocking calls with timeouts that take
* an absolute timeout must ignore issues with the absolute
* time provided if the operation would otherwise succeed.
* So we check the abstime provided, and hold on to whether it
* is valid or not. If it isn't correct and in the future,
* then we do a polling operation and convert the STATUS_UNAVAILABLE
* status into the appropriate error.
*
* If the timeout status is TOD_ABSOLUTE_TIMEOUT_INVALID,
* TOD_ABSOLUTE_TIMEOUT_IS_IN_PAST, or TOD_ABSOLUTE_TIMEOUT_IS_NOW,
* then we should not wait.
*/
timeout_status = _TOD_Absolute_timeout_to_ticks( abstime, &ticks );
do_wait = ( timeout_status == TOD_ABSOLUTE_TIMEOUT_IS_IN_FUTURE );
the_rwlock = _POSIX_RWLock_Get( rwlock, &queue_context );
if ( the_rwlock == NULL ) {
return EINVAL;
}
status = _CORE_RWLock_Seize_for_reading(
&the_rwlock->RWLock,
_Thread_Executing,
do_wait,
ticks,
&queue_context
);
if ( !do_wait && status == STATUS_UNAVAILABLE ) {
if ( timeout_status == TOD_ABSOLUTE_TIMEOUT_INVALID ) {
return EINVAL;
}
if (
timeout_status == TOD_ABSOLUTE_TIMEOUT_IS_IN_PAST
|| timeout_status == TOD_ABSOLUTE_TIMEOUT_IS_NOW
) {
return ETIMEDOUT;
}
}
return _POSIX_Get_error( status );
}
int pthread_rwlock_tryrdlock(
pthread_rwlock_t *rwlock
)
{
POSIX_RWLock_Control *the_rwlock;
Thread_queue_Context queue_context;
Status_Control status;
the_rwlock = _POSIX_RWLock_Get( rwlock, &queue_context );
if ( the_rwlock == NULL ) {
return EINVAL;
}
status = _CORE_RWLock_Seize_for_reading(
&the_rwlock->RWLock,
_Thread_Executing,
false, /* do not wait for the rwlock */
&queue_context
);
return _POSIX_Get_error( status );
}
