RTEMS 4.9.3 On-Line Library

Message Manager Building a MESSAGE_QUEUE_RECEIVE Option Set

RTEMS C User's Guide

10.2.4: Building a MESSAGE_QUEUE_RECEIVE Option Set

In general, an option is built by a bitwise OR of the desired option components. The set of valid options for the rtems_message_queue_receive directive are listed in the following table:

RTEMS_WAIT - task will wait for a message (default)
RTEMS_NO_WAIT - task should not wait

An option listed as a default is not required to appear in the option OR list, although it is a good programming practice to specify default options. If all defaults are desired, the option RTEMS_DEFAULT_OPTIONS should be specified on this call.

This example demonstrates the option parameter needed to poll for a message to arrive. The option parameter passed to the rtems_message_queue_receive directive should be RTEMS_NO_WAIT.

RTEMS C User's Guide