int _POSIX_Mutex_Lock_support(
pthread_mutex_t *mutex,
bool wait,
Watchdog_Interval timeout
)
{
POSIX_Mutex_Control *the_mutex;
Thread_queue_Context queue_context;
Thread_Control *executing;
Status_Control status;
the_mutex = _POSIX_Mutex_Get( mutex, &queue_context );
if ( the_mutex == NULL ) {
return EINVAL;
}
executing = _Thread_Executing;
_Thread_queue_Context_set_relative_timeout( &queue_context, timeout );
switch ( the_mutex->protocol ) {
case POSIX_MUTEX_PRIORITY_CEILING:
status = _CORE_ceiling_mutex_Seize(
&the_mutex->Mutex,
executing,
wait,
_POSIX_Mutex_Lock_nested,
&queue_context
);
break;
case POSIX_MUTEX_NO_PROTOCOL:
status = _CORE_recursive_mutex_Seize(
&the_mutex->Mutex.Recursive,
POSIX_MUTEX_NO_PROTOCOL_TQ_OPERATIONS,
executing,
wait,
_POSIX_Mutex_Lock_nested,
&queue_context
);
break;
default:
_Assert( the_mutex->protocol == POSIX_MUTEX_PRIORITY_INHERIT );
status = _CORE_recursive_mutex_Seize(
&the_mutex->Mutex.Recursive,
CORE_MUTEX_TQ_PRIORITY_INHERIT_OPERATIONS,
executing,
wait,
_POSIX_Mutex_Lock_nested,
&queue_context
);
break;
}
return _POSIX_Get_error( status );
}
int _Mutex_recursive_Acquire_timed(
struct _Mutex_recursive_Control *_mutex,
const struct timespec *abstime
)
{
Mutex_recursive_Control *mutex;
Thread_queue_Context queue_context;
ISR_Level level;
Thread_Control *executing;
Thread_Control *owner;
mutex = _Mutex_recursive_Get( _mutex );
_Thread_queue_Context_initialize( &queue_context );
_Thread_queue_Context_ISR_disable( &queue_context, level );
executing = _Mutex_Queue_acquire_critical( &mutex->Mutex, &queue_context );
owner = mutex->Mutex.Queue.Queue.owner;
if ( __predict_true( owner == NULL ) ) {
mutex->Mutex.Queue.Queue.owner = executing;
_Thread_Resource_count_increment( executing );
_Mutex_Queue_release( &mutex->Mutex, level, &queue_context );
return 0;
} else if ( owner == executing ) {
++mutex->nest_level;
_Mutex_Queue_release( &mutex->Mutex, level, &queue_context );
return 0;
} else {
Watchdog_Interval ticks;
switch ( _TOD_Absolute_timeout_to_ticks( abstime, CLOCK_REALTIME, &ticks ) ) {
case TOD_ABSOLUTE_TIMEOUT_INVALID:
_Mutex_Queue_release( &mutex->Mutex, level, &queue_context );
return EINVAL;
case TOD_ABSOLUTE_TIMEOUT_IS_IN_PAST:
case TOD_ABSOLUTE_TIMEOUT_IS_NOW:
_Mutex_Queue_release( &mutex->Mutex, level, &queue_context );
return ETIMEDOUT;
default:
break;
}
_Thread_queue_Context_set_relative_timeout( &queue_context, ticks );
_Mutex_Acquire_slow( &mutex->Mutex, owner, executing, level, &queue_context );
return STATUS_GET_POSIX( _Thread_Wait_get_status( executing ) );
}
}
int _POSIX_Condition_variables_Wait_support(
pthread_cond_t *cond,
pthread_mutex_t *mutex,
const struct timespec *abstime
)
{
POSIX_Condition_variables_Control *the_cond;
Thread_queue_Context queue_context;
int error;
int mutex_error;
Per_CPU_Control *cpu_self;
Thread_Control *executing;
Watchdog_Interval timeout;
bool already_timedout;
TOD_Absolute_timeout_conversion_results status;
if ( mutex == NULL ) {
return EINVAL;
}
the_cond = _POSIX_Condition_variables_Get( cond, &queue_context );
if ( the_cond == NULL ) {
return EINVAL;
}
already_timedout = false;
if ( abstime != NULL ) {
/*
* 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 UNSATISFIED
* status into the appropriate error.
*/
_Assert( the_cond->clock );
status = _TOD_Absolute_timeout_to_ticks(abstime, the_cond->clock, &timeout);
if ( status == TOD_ABSOLUTE_TIMEOUT_INVALID )
return EINVAL;
if ( status == TOD_ABSOLUTE_TIMEOUT_IS_IN_PAST ||
status == TOD_ABSOLUTE_TIMEOUT_IS_NOW ) {
already_timedout = true;
} else {
_Thread_queue_Context_set_relative_timeout( &queue_context, timeout );
}
} else {
_Thread_queue_Context_set_no_timeout( &queue_context );
}
_POSIX_Condition_variables_Acquire_critical( the_cond, &queue_context );
if (
the_cond->mutex != POSIX_CONDITION_VARIABLES_NO_MUTEX
&& the_cond->mutex != *mutex
) {
_POSIX_Condition_variables_Release( the_cond, &queue_context );
return EINVAL;
}
the_cond->mutex = *mutex;
cpu_self = _Thread_Dispatch_disable_critical( &queue_context.Lock_context );
executing = _Per_CPU_Get_executing( cpu_self );
if ( !already_timedout ) {
_Thread_queue_Context_set_expected_level( &queue_context, 2 );
_Thread_queue_Enqueue_critical(
&the_cond->Wait_queue.Queue,
POSIX_CONDITION_VARIABLES_TQ_OPERATIONS,
executing,
STATES_WAITING_FOR_CONDITION_VARIABLE,
&queue_context
);
} else {
_POSIX_Condition_variables_Release( the_cond, &queue_context );
executing->Wait.return_code = STATUS_TIMEOUT;
}
mutex_error = pthread_mutex_unlock( mutex );
if ( mutex_error != 0 ) {
/*
* Historically, we ignored the unlock status since the behavior
* is undefined by POSIX. But GNU/Linux returns EPERM in this
* case, so we follow their lead.
*/
_Assert( mutex_error == EINVAL || mutex_error == EPERM );
_Thread_queue_Extract( executing );
_Thread_Dispatch_enable( cpu_self );
return EPERM;
}
/*
* Switch ourself out because we blocked as a result of the
* _Thread_queue_Enqueue_critical().
*/
_Thread_Dispatch_enable( cpu_self );
error = _POSIX_Get_error_after_wait( executing );
/*
* If the thread is interrupted, while in the thread queue, by
* a POSIX signal, then pthread_cond_wait returns spuriously,
* according to the POSIX standard. It means that pthread_cond_wait
* returns a success status, except for the fact that it was not
* woken up a pthread_cond_signal() or a pthread_cond_broadcast().
*/
if ( error == EINTR ) {
error = 0;
}
/*
* When we get here the dispatch disable level is 0.
*/
mutex_error = pthread_mutex_lock( mutex );
if ( mutex_error != 0 ) {
_Assert( mutex_error == EINVAL );
return EINVAL;
}
return error;
}
ssize_t _POSIX_Message_queue_Receive_support(
mqd_t mqdes,
char *msg_ptr,
size_t msg_len,
unsigned int *msg_prio,
bool wait,
Watchdog_Interval timeout
)
{
POSIX_Message_queue_Control *the_mq;
Thread_queue_Context queue_context;
size_t length_out;
bool do_wait;
Thread_Control *executing;
Status_Control status;
the_mq = _POSIX_Message_queue_Get( mqdes, &queue_context );
if ( the_mq == NULL ) {
rtems_set_errno_and_return_minus_one( EBADF );
}
if ( ( the_mq->oflag & O_ACCMODE ) == O_WRONLY ) {
_ISR_lock_ISR_enable( &queue_context.Lock_context.Lock_context );
rtems_set_errno_and_return_minus_one( EBADF );
}
if ( msg_len < the_mq->Message_queue.maximum_message_size ) {
_ISR_lock_ISR_enable( &queue_context.Lock_context.Lock_context );
rtems_set_errno_and_return_minus_one( EMSGSIZE );
}
/*
* Now if something goes wrong, we return a "length" of -1
* to indicate an error.
*/
length_out = -1;
/*
* A timed receive with a bad time will do a poll regardless.
*/
if ( wait ) {
do_wait = ( the_mq->oflag & O_NONBLOCK ) == 0;
} else {
do_wait = wait;
}
_CORE_message_queue_Acquire_critical(
&the_mq->Message_queue,
&queue_context
);
if ( the_mq->open_count == 0 ) {
_CORE_message_queue_Release( &the_mq->Message_queue, &queue_context );
rtems_set_errno_and_return_minus_one( EBADF );
}
/*
* Now perform the actual message receive
*/
executing = _Thread_Executing;
_Thread_queue_Context_set_relative_timeout( &queue_context, timeout );
status = _CORE_message_queue_Seize(
&the_mq->Message_queue,
executing,
msg_ptr,
&length_out,
do_wait,
&queue_context
);
if ( msg_prio != NULL ) {
*msg_prio = _POSIX_Message_queue_Priority_from_core(
executing->Wait.count
);
}
if ( status != STATUS_SUCCESSFUL ) {
rtems_set_errno_and_return_minus_one( _POSIX_Get_error( status ) );
}
return length_out;
}
