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Diffstat (limited to 'cpukit/score/src/coremsgbroadcast.c')
-rw-r--r-- | cpukit/score/src/coremsgbroadcast.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/cpukit/score/src/coremsgbroadcast.c b/cpukit/score/src/coremsgbroadcast.c new file mode 100644 index 0000000000..1d6340991c --- /dev/null +++ b/cpukit/score/src/coremsgbroadcast.c @@ -0,0 +1,111 @@ +/* + * CORE Message Queue Handler + * + * DESCRIPTION: + * + * This package is the implementation of the CORE Message Queue Handler. + * This core object provides task synchronization and communication functions + * via messages passed to queue objects. + * + * COPYRIGHT (c) 1989-1999. + * On-Line Applications Research Corporation (OAR). + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.com/license/LICENSE. + * + * $Id$ + */ + +#include <rtems/system.h> +#include <rtems/score/chain.h> +#include <rtems/score/isr.h> +#include <rtems/score/object.h> +#include <rtems/score/coremsg.h> +#include <rtems/score/states.h> +#include <rtems/score/thread.h> +#include <rtems/score/wkspace.h> +#if defined(RTEMS_MULTIPROCESSING) +#include <rtems/score/mpci.h> +#endif + +/*PAGE + * + * _CORE_message_queue_Broadcast + * + * This function sends a message for every thread waiting on the queue and + * returns the number of threads made ready by the message. + * + * Input parameters: + * the_message_queue - message is submitted to this message queue + * buffer - pointer to message buffer + * size - size in bytes of message to send + * id - id of message queue + * api_message_queue_mp_support - api specific mp support callout + * count - area to store number of threads made ready + * + * Output parameters: + * count - number of threads made ready + * CORE_MESSAGE_QUEUE_SUCCESSFUL - if successful + * error code - if unsuccessful + */ + +CORE_message_queue_Status _CORE_message_queue_Broadcast( + CORE_message_queue_Control *the_message_queue, + void *buffer, + uint32_t size, + Objects_Id id, + CORE_message_queue_API_mp_support_callout api_message_queue_mp_support, + uint32_t *count +) +{ + Thread_Control *the_thread; + uint32_t number_broadcasted; + Thread_Wait_information *waitp; + uint32_t constrained_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; + + constrained_size = size; + if ( size > the_message_queue->maximum_message_size ) + constrained_size = the_message_queue->maximum_message_size; + + _CORE_message_queue_Copy_buffer( + buffer, + waitp->return_argument, + constrained_size + ); + + *(uint32_t *)the_thread->Wait.return_argument_1 = 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; +} |