get_message_queue_paramT_get_message_queue_paramGetMessageQueueParamGetMessageQueueParamget_message_queue_param (算子名称)

名称

get_message_queue_paramT_get_message_queue_paramGetMessageQueueParamGetMessageQueueParamget_message_queue_param — Query message queue parameters or information about the queue.

参数签名

get_message_queue_param( : : QueueHandle, GenParamName : GenParamValue)

描述

get_message_queue_paramget_message_queue_paramGetMessageQueueParamGetMessageQueueParamGetMessageQueueParamget_message_queue_param queries current values of message queue parameters or other information about the queue status.

Multiple queries can be carried out with a single get_message_queue_paramget_message_queue_paramGetMessageQueueParamGetMessageQueueParamGetMessageQueueParamget_message_queue_param call, passing multiple parameter names to parameter GenParamNameGenParamNameGenParamNameGenParamNamegenParamNamegen_param_name. The parameter values are returned in GenParamValueGenParamValueGenParamValueGenParamValuegenParamValuegen_param_value in the same order as the parameter names requested by the caller.

Currently, following parameter names are supported:

'is_empty'"is_empty""is_empty""is_empty""is_empty""is_empty":: Returns 1 if the queue is empty, 0 otherwise.
'message_num'"message_num""message_num""message_num""message_num""message_num":: Returns the number of messages currently stored in the queue.
'max_message_num'"max_message_num""max_message_num""max_message_num""max_message_num""max_message_num":: Returns the current value of the 'max_message_num'"max_message_num""max_message_num""max_message_num""max_message_num""max_message_num" parameter of the message queue, as it was set using set_message_queue_paramset_message_queue_paramSetMessageQueueParamSetMessageQueueParamSetMessageQueueParamset_message_queue_param. The default value -1 stands for no limit.

运行信息

多线程类型:可重入(与非独占操作符并行运行)。
多线程作用域:全局(可以从任何线程调用)。
未经并行化处理。

参数表

QueueHandleQueueHandleQueueHandleQueueHandlequeueHandlequeue_handle (input_control) message_queue → (handle)

Message queue handle.

Number of elements: QueueHandle == 1

Restriction: QueueHandle != 0

GenParamNameGenParamNameGenParamNameGenParamNamegenParamNamegen_param_name (input_control) string(-array) → (string)

Names of the queue parameters or info queries.

Number of elements: GenParamName == GenParamValue

Default: 'max_message_num' "max_message_num" "max_message_num" "max_message_num" "max_message_num" "max_message_num"

List of values: 'is_empty'"is_empty""is_empty""is_empty""is_empty""is_empty", 'max_message_num'"max_message_num""max_message_num""max_message_num""max_message_num""max_message_num", 'message_num'"message_num""message_num""message_num""message_num""message_num"

GenParamValueGenParamValueGenParamValueGenParamValuegenParamValuegen_param_value (output_control) tuple(-array) → (string / integer / real)

Values of the queue parameters or info queries.

Number of elements: GenParamName == GenParamValue

例程 (HDevelop)

create_message_queue (QueueHandle)
set_message_queue_param ( QueueHandle, 'max_message_num', 10)
* ...
get_message_queue_param( QueueHandle, 'message_num', Num)

结果

If all 该算子 parameters are valid, get_message_queue_paramget_message_queue_paramGetMessageQueueParamGetMessageQueueParamGetMessageQueueParamget_message_queue_param returns 2 ( H_MSG_TRUE) . Otherwise an exception is raised.

可能的前置算子

create_message_queuecreate_message_queueCreateMessageQueueCreateMessageQueueCreateMessageQueuecreate_message_queue, enqueue_messageenqueue_messageEnqueueMessageEnqueueMessageEnqueueMessageenqueue_message, dequeue_messagedequeue_messageDequeueMessageDequeueMessageDequeueMessagedequeue_message

参考其它

create_message_queuecreate_message_queueCreateMessageQueueCreateMessageQueueCreateMessageQueuecreate_message_queue, clear_message_queueclear_message_queueClearMessageQueueClearMessageQueueClearMessageQueueclear_message_queue, enqueue_messageenqueue_messageEnqueueMessageEnqueueMessageEnqueueMessageenqueue_message, dequeue_messagedequeue_messageDequeueMessageDequeueMessageDequeueMessagedequeue_message, set_message_queue_paramset_message_queue_paramSetMessageQueueParamSetMessageQueueParamSetMessageQueueParamset_message_queue_param, create_messagecreate_messageCreateMessageCreateMessageCreateMessagecreate_message, clear_messageclear_messageClearMessageClearMessageClearMessageclear_message, set_message_tupleset_message_tupleSetMessageTupleSetMessageTupleSetMessageTupleset_message_tuple, get_message_tupleget_message_tupleGetMessageTupleGetMessageTupleGetMessageTupleget_message_tuple, set_message_objset_message_objSetMessageObjSetMessageObjSetMessageObjset_message_obj, get_message_objget_message_objGetMessageObjGetMessageObjGetMessageObjget_message_obj

模块

Foundation

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