RTEMS 4.9.2 On-Line Library

Region Manager Acquiring a Segment

RTEMS C User's Guide

14.3.4: Acquiring a Segment

The rtems_region_get_segment directive attempts to acquire a segment from a specified region. If the region has enough available free memory, then a segment is returned successfully to the caller. When the segment cannot be allocated, one of the following situations applies:

By default, the calling task will wait forever to acquire the segment.
Specifying the RTEMS_NO_WAIT option forces an immediate return with an error status code.
Specifying a timeout limits the interval the task will wait before returning with an error status code.

If the task waits for the segment, then it is placed in the region's task wait queue in either FIFO or task priority order. All tasks waiting on a region are returned an error when the message queue is deleted.

RTEMS C User's Guide