int _POSIX_Condition_variables_Signal_support(
pthread_cond_t *cond,
bool is_broadcast
)
{
register POSIX_Condition_variables_Control *the_cond;
Objects_Locations location;
Thread_Control *the_thread;
the_cond = _POSIX_Condition_variables_Get( cond, &location );
switch ( location ) {
case OBJECTS_LOCAL:
do {
the_thread = _Thread_queue_Dequeue( &the_cond->Wait_queue );
if ( !the_thread )
the_cond->Mutex = POSIX_CONDITION_VARIABLES_NO_MUTEX;
} while ( is_broadcast && the_thread );
_Thread_Enable_dispatch();
return 0;
#if defined(RTEMS_MULTIPROCESSING)
case OBJECTS_REMOTE:
#endif
case OBJECTS_ERROR:
break;
}
return EINVAL;
}
void _POSIX_Thread_Exit(
Thread_Control *the_thread,
void *value_ptr
)
{
Thread_Control *unblocked;
POSIX_API_Control *api;
bool previous_life_protection;
api = the_thread->API_Extensions[ THREAD_API_POSIX ];
_Assert( _Debug_Is_thread_dispatching_allowed() );
previous_life_protection = _Thread_Set_life_protection( true );
_Thread_Disable_dispatch();
the_thread->Wait.return_argument = value_ptr;
/*
* Process join
*/
if ( api->detachstate == PTHREAD_CREATE_JOINABLE ) {
unblocked = _Thread_queue_Dequeue( &api->Join_List );
if ( unblocked ) {
do {
*(void **)unblocked->Wait.return_argument = value_ptr;
} while ( (unblocked = _Thread_queue_Dequeue( &api->Join_List )) );
} else {
_Thread_Set_state( the_thread, STATES_WAITING_FOR_JOIN_AT_EXIT );
_Thread_Enable_dispatch();
/* now waiting for thread to arrive */
_Thread_Disable_dispatch();
}
}
/*
* Now shut down the thread
*/
_Thread_Close( the_thread, _Thread_Executing );
_Thread_Enable_dispatch();
_Thread_Set_life_protection( previous_life_protection );
}
void _Thread_queue_Flush(
Thread_queue_Control *the_thread_queue,
#if defined(RTEMS_MULTIPROCESSING)
Thread_queue_Flush_callout remote_extract_callout,
#else
Thread_queue_Flush_callout remote_extract_callout __attribute__((unused)),
#endif
uint32_t status
)
{
Thread_Control *the_thread;
while ( (the_thread = _Thread_queue_Dequeue( the_thread_queue )) ) {
#if defined(RTEMS_MULTIPROCESSING)
if ( !_Objects_Is_local_id( the_thread->Object.id ) )
( *remote_extract_callout )( the_thread );
else
#endif
the_thread->Wait.return_code = status;
}
}
void _POSIX_Thread_Exit(
Thread_Control *the_thread,
void *value_ptr
)
{
Objects_Information *the_information;
Thread_Control *unblocked;
POSIX_API_Control *api;
the_information = _Objects_Get_information_id( the_thread->Object.id );
api = the_thread->API_Extensions[ THREAD_API_POSIX ];
/*
* The_information has to be non-NULL. Otherwise, we couldn't be
* running in a thread of this API and class.
*
* NOTE: Lock and unlock in different order so we do not throw a
* fatal error when locking the allocator mutex. And after
* we unlock, we want to defer the context switch until we
* are ready to be switched out. Otherwise, an ISR could
* occur and preempt us out while we still hold the
* allocator mutex.
*/
_RTEMS_Lock_allocator();
_Thread_Disable_dispatch();
the_thread->Wait.return_argument = value_ptr;
/*
* Process join
*/
if ( api->detachstate == PTHREAD_CREATE_JOINABLE ) {
unblocked = _Thread_queue_Dequeue( &api->Join_List );
if ( unblocked ) {
do {
*(void **)unblocked->Wait.return_argument = value_ptr;
} while ( (unblocked = _Thread_queue_Dequeue( &api->Join_List )) );
} else {
_Thread_Set_state(
the_thread,
STATES_WAITING_FOR_JOIN_AT_EXIT | STATES_TRANSIENT
);
_RTEMS_Unlock_allocator();
_Thread_Enable_dispatch();
/* now waiting for thread to arrive */
_RTEMS_Lock_allocator();
_Thread_Disable_dispatch();
}
}
/*
* Now shut down the thread
*/
_Thread_Close( the_information, the_thread );
_POSIX_Threads_Free( the_thread );
_RTEMS_Unlock_allocator();
_Thread_Enable_dispatch();
}
CORE_mutex_Status _CORE_mutex_Surrender(
CORE_mutex_Control *the_mutex,
#if defined(RTEMS_MULTIPROCESSING)
Objects_Id id,
CORE_mutex_API_mp_support_callout api_mutex_mp_support
#else
Objects_Id id __attribute__((unused)),
CORE_mutex_API_mp_support_callout api_mutex_mp_support __attribute__((unused))
#endif
)
{
Thread_Control *the_thread;
Thread_Control *holder;
holder = the_mutex->holder;
/*
* The following code allows a thread (or ISR) other than the thread
* which acquired the mutex to release that mutex. This is only
* allowed when the mutex in quetion is FIFO or simple Priority
* discipline. But Priority Ceiling or Priority Inheritance mutexes
* must be released by the thread which acquired them.
*/
if ( the_mutex->Attributes.only_owner_release ) {
if ( !_Thread_Is_executing( holder ) )
return CORE_MUTEX_STATUS_NOT_OWNER_OF_RESOURCE;
}
/* XXX already unlocked -- not right status */
if ( !the_mutex->nest_count )
return CORE_MUTEX_STATUS_SUCCESSFUL;
the_mutex->nest_count--;
if ( the_mutex->nest_count != 0 ) {
/*
* All error checking is on the locking side, so if the lock was
* allowed to acquired multiple times, then we should just deal with
* that. The RTEMS_DEBUG is just a validation.
*/
#if defined(RTEMS_DEBUG)
switch ( the_mutex->Attributes.lock_nesting_behavior ) {
case CORE_MUTEX_NESTING_ACQUIRES:
return CORE_MUTEX_STATUS_SUCCESSFUL;
#if defined(RTEMS_POSIX_API)
case CORE_MUTEX_NESTING_IS_ERROR:
/* should never occur */
return CORE_MUTEX_STATUS_NESTING_NOT_ALLOWED;
#endif
case CORE_MUTEX_NESTING_BLOCKS:
/* Currently no API exercises this behavior. */
break;
}
#else
/* must be CORE_MUTEX_NESTING_ACQUIRES or we wouldn't be here */
return CORE_MUTEX_STATUS_SUCCESSFUL;
#endif
}
/*
* Formally release the mutex before possibly transferring it to a
* blocked thread.
*/
if ( _CORE_mutex_Is_inherit_priority( &the_mutex->Attributes ) ||
_CORE_mutex_Is_priority_ceiling( &the_mutex->Attributes ) ) {
CORE_mutex_Status pop_status =
_CORE_mutex_Pop_priority( the_mutex, holder );
if ( pop_status != CORE_MUTEX_STATUS_SUCCESSFUL )
return pop_status;
holder->resource_count--;
/*
* Whether or not someone is waiting for the mutex, an
* inherited priority must be lowered if this is the last
* mutex (i.e. resource) this task has.
*/
if ( holder->resource_count == 0 &&
holder->real_priority != holder->current_priority ) {
_Thread_Change_priority( holder, holder->real_priority, true );
}
}
the_mutex->holder = NULL;
the_mutex->holder_id = 0;
/*
* Now we check if another thread was waiting for this mutex. If so,
* transfer the mutex to that thread.
*/
if ( ( the_thread = _Thread_queue_Dequeue( &the_mutex->Wait_queue ) ) ) {
#if defined(RTEMS_MULTIPROCESSING)
if ( !_Objects_Is_local_id( the_thread->Object.id ) ) {
the_mutex->holder = NULL;
the_mutex->holder_id = the_thread->Object.id;
the_mutex->nest_count = 1;
( *api_mutex_mp_support)( the_thread, id );
} else
#endif
{
the_mutex->holder = the_thread;
the_mutex->holder_id = the_thread->Object.id;
the_mutex->nest_count = 1;
switch ( the_mutex->Attributes.discipline ) {
case CORE_MUTEX_DISCIPLINES_FIFO:
case CORE_MUTEX_DISCIPLINES_PRIORITY:
break;
case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT:
_CORE_mutex_Push_priority( the_mutex, the_thread );
the_thread->resource_count++;
break;
case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING:
_CORE_mutex_Push_priority( the_mutex, the_thread );
the_thread->resource_count++;
if (the_mutex->Attributes.priority_ceiling <
the_thread->current_priority){
_Thread_Change_priority(
the_thread,
the_mutex->Attributes.priority_ceiling,
false
);
}
break;
}
}
} else
the_mutex->lock = CORE_MUTEX_UNLOCKED;
return CORE_MUTEX_STATUS_SUCCESSFUL;
}
void _CORE_message_queue_Seize(
CORE_message_queue_Control *the_message_queue,
Thread_Control *executing,
Objects_Id id,
void *buffer,
size_t *size_p,
bool wait,
Watchdog_Interval timeout
)
{
ISR_Level level;
CORE_message_queue_Buffer_control *the_message;
executing->Wait.return_code = CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL;
_ISR_Disable( level );
the_message = _CORE_message_queue_Get_pending_message( the_message_queue );
if ( the_message != NULL ) {
the_message_queue->number_of_pending_messages -= 1;
_ISR_Enable( level );
*size_p = the_message->Contents.size;
executing->Wait.count =
_CORE_message_queue_Get_message_priority( the_message );
_CORE_message_queue_Copy_buffer(
the_message->Contents.buffer,
buffer,
*size_p
);
#if !defined(RTEMS_SCORE_COREMSG_ENABLE_BLOCKING_SEND)
/*
* There is not an API with blocking sends enabled.
* So return immediately.
*/
_CORE_message_queue_Free_message_buffer(the_message_queue, the_message);
return;
#else
{
Thread_Control *the_thread;
/*
* There could be a thread waiting to send a message. If there
* is not, then we can go ahead and free the buffer.
*
* NOTE: If we note that the queue was not full before this receive,
* then we can avoid this dequeue.
*/
the_thread = _Thread_queue_Dequeue( &the_message_queue->Wait_queue );
if ( !the_thread ) {
_CORE_message_queue_Free_message_buffer(
the_message_queue,
the_message
);
return;
}
/*
* There was a thread waiting to send a message. This code
* puts the messages in the message queue on behalf of the
* waiting task.
*/
_CORE_message_queue_Set_message_priority(
the_message,
the_thread->Wait.count
);
the_message->Contents.size = (size_t) the_thread->Wait.option;
_CORE_message_queue_Copy_buffer(
the_thread->Wait.return_argument_second.immutable_object,
the_message->Contents.buffer,
the_message->Contents.size
);
_CORE_message_queue_Insert_message(
the_message_queue,
the_message,
_CORE_message_queue_Get_message_priority( the_message )
);
return;
}
#endif
}
if ( !wait ) {
_ISR_Enable( level );
executing->Wait.return_code = CORE_MESSAGE_QUEUE_STATUS_UNSATISFIED_NOWAIT;
return;
}
_Thread_queue_Enter_critical_section( &the_message_queue->Wait_queue );
executing->Wait.queue = &the_message_queue->Wait_queue;
executing->Wait.id = id;
executing->Wait.return_argument_second.mutable_object = buffer;
executing->Wait.return_argument = size_p;
/* Wait.count will be filled in with the message priority */
_ISR_Enable( level );
_Thread_queue_Enqueue(
&the_message_queue->Wait_queue,
executing,
STATES_WAITING_FOR_MESSAGE,
timeout
);
}
CORE_message_queue_Status _CORE_message_queue_Broadcast(
CORE_message_queue_Control *the_message_queue,
const void *buffer,
size_t size,
#if defined(RTEMS_MULTIPROCESSING)
Objects_Id id,
CORE_message_queue_API_mp_support_callout api_message_queue_mp_support,
#else
Objects_Id id __attribute__((unused)),
CORE_message_queue_API_mp_support_callout api_message_queue_mp_support __attribute__((unused)),
#endif
uint32_t *count
)
{
Thread_Control *the_thread;
uint32_t number_broadcasted;
Thread_Wait_information *waitp;
if ( size > the_message_queue->maximum_message_size ) {
return CORE_MESSAGE_QUEUE_STATUS_INVALID_SIZE;
}
/*
* If there are pending messages, then there can't be threads
* waiting for us to send them a message.
*
* NOTE: This check is critical because threads can block on
* send and receive and this ensures that we are broadcasting
* the message to threads waiting to receive -- not to send.
*/
if ( the_message_queue->number_of_pending_messages != 0 ) {
*count = 0;
return CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL;
}
/*
* There must be no pending messages if there is a thread waiting to
* receive a message.
*/
number_broadcasted = 0;
while ((the_thread =
_Thread_queue_Dequeue(&the_message_queue->Wait_queue))) {
waitp = &the_thread->Wait;
number_broadcasted += 1;
_CORE_message_queue_Copy_buffer(
buffer,
waitp->return_argument_second.mutable_object,
size
);
*(size_t *) the_thread->Wait.return_argument = size;
#if defined(RTEMS_MULTIPROCESSING)
if ( !_Objects_Is_local_id( the_thread->Object.id ) )
(*api_message_queue_mp_support) ( the_thread, id );
#endif
}
*count = number_broadcasted;
return CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL;
}
CORE_message_queue_Status _CORE_message_queue_Submit(
CORE_message_queue_Control *the_message_queue,
void *buffer,
size_t size,
Objects_Id id,
CORE_message_queue_API_mp_support_callout api_message_queue_mp_support,
CORE_message_queue_Submit_types submit_type,
boolean wait,
Watchdog_Interval timeout
)
{
ISR_Level level;
CORE_message_queue_Buffer_control *the_message;
Thread_Control *the_thread;
if ( size > the_message_queue->maximum_message_size ) {
return CORE_MESSAGE_QUEUE_STATUS_INVALID_SIZE;
}
/*
* Is there a thread currently waiting on this message queue?
*/
if ( the_message_queue->number_of_pending_messages == 0 ) {
the_thread = _Thread_queue_Dequeue( &the_message_queue->Wait_queue );
if ( the_thread ) {
_CORE_message_queue_Copy_buffer(
buffer,
the_thread->Wait.return_argument,
size
);
*(size_t *)the_thread->Wait.return_argument_1 = size;
the_thread->Wait.count = submit_type;
#if defined(RTEMS_MULTIPROCESSING)
if ( !_Objects_Is_local_id( the_thread->Object.id ) )
(*api_message_queue_mp_support) ( the_thread, id );
#endif
return CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL;
}
}
/*
* No one waiting on the message queue at this time, so attempt to
* queue the message up for a future receive.
*/
if ( the_message_queue->number_of_pending_messages <
the_message_queue->maximum_pending_messages ) {
the_message =
_CORE_message_queue_Allocate_message_buffer( the_message_queue );
/*
* NOTE: If the system is consistent, this error should never occur.
*/
if ( !the_message ) {
return CORE_MESSAGE_QUEUE_STATUS_UNSATISFIED;
}
_CORE_message_queue_Copy_buffer(
buffer,
the_message->Contents.buffer,
size
);
the_message->Contents.size = size;
the_message->priority = submit_type;
_CORE_message_queue_Insert_message(
the_message_queue,
the_message,
submit_type
);
return CORE_MESSAGE_QUEUE_STATUS_SUCCESSFUL;
}
/*
* No message buffers were available so we may need to return an
* overflow error or block the sender until the message is placed
* on the queue.
*/
if ( !wait ) {
return CORE_MESSAGE_QUEUE_STATUS_TOO_MANY;
}
/*
* Do NOT block on a send if the caller is in an ISR. It is
* deadly to block in an ISR.
*/
if ( _ISR_Is_in_progress() ) {
return CORE_MESSAGE_QUEUE_STATUS_UNSATISFIED;
}
/*
* WARNING!! executing should NOT be used prior to this point.
* Thus the unusual choice to open a new scope and declare
* it as a variable. Doing this emphasizes how dangerous it
* would be to use this variable prior to here.
*/
{
Thread_Control *executing = _Thread_Executing;
_ISR_Disable( level );
_Thread_queue_Enter_critical_section( &the_message_queue->Wait_queue );
executing->Wait.queue = &the_message_queue->Wait_queue;
executing->Wait.id = id;
executing->Wait.return_argument = buffer;
executing->Wait.option = size;
executing->Wait.count = submit_type;
_ISR_Enable( level );
_Thread_queue_Enqueue( &the_message_queue->Wait_queue, timeout );
}
return CORE_MESSAGE_QUEUE_STATUS_UNSATISFIED_WAIT;
}
CORE_RWLock_Status _CORE_RWLock_Release(
CORE_RWLock_Control *the_rwlock,
Thread_Control *executing
)
{
ISR_Level level;
Thread_Control *next;
/*
* If unlocked, then OK to read.
* Otherwise, we have to block.
* If locked for reading and no waiters, then OK to read.
* If any thread is waiting, then we wait.
*/
_ISR_Disable( level );
if ( the_rwlock->current_state == CORE_RWLOCK_UNLOCKED){
_ISR_Enable( level );
executing->Wait.return_code = CORE_RWLOCK_UNAVAILABLE;
return CORE_RWLOCK_SUCCESSFUL;
}
if ( the_rwlock->current_state == CORE_RWLOCK_LOCKED_FOR_READING ) {
the_rwlock->number_of_readers -= 1;
if ( the_rwlock->number_of_readers != 0 ) {
/* must be unlocked again */
_ISR_Enable( level );
return CORE_RWLOCK_SUCCESSFUL;
}
}
/* CORE_RWLOCK_LOCKED_FOR_WRITING or READING with readers */
executing->Wait.return_code = CORE_RWLOCK_SUCCESSFUL;
/*
* Implicitly transition to "unlocked" and find another thread interested
* in obtaining this rwlock.
*/
the_rwlock->current_state = CORE_RWLOCK_UNLOCKED;
_ISR_Enable( level );
next = _Thread_queue_Dequeue( &the_rwlock->Wait_queue );
if ( next ) {
if ( next->Wait.option == CORE_RWLOCK_THREAD_WAITING_FOR_WRITE ) {
the_rwlock->current_state = CORE_RWLOCK_LOCKED_FOR_WRITING;
return CORE_RWLOCK_SUCCESSFUL;
}
/*
* Must be CORE_RWLOCK_THREAD_WAITING_FOR_READING
*/
the_rwlock->number_of_readers += 1;
the_rwlock->current_state = CORE_RWLOCK_LOCKED_FOR_READING;
/*
* Now see if more readers can be let go.
*/
while ( 1 ) {
next = _Thread_queue_First( &the_rwlock->Wait_queue );
if ( !next ||
next->Wait.option == CORE_RWLOCK_THREAD_WAITING_FOR_WRITE )
return CORE_RWLOCK_SUCCESSFUL;
the_rwlock->number_of_readers += 1;
_Thread_queue_Extract( &the_rwlock->Wait_queue, next );
}
}
/* indentation is to match _ISR_Disable at top */
return CORE_RWLOCK_SUCCESSFUL;
}