RTEMS 4.9.0 On-Line Library

Semaphore Manager T_RSEM Structure

RTEMS ITRON 3.0 API User's Guide

3.2.4: T_RSEM Structure

The T_RSEM structure is filled in by the ref_sem service with status and state information on a semaphore. The structure is defined as follows:

/*
 *  Reference Semaphore (ref_sem) Structure
 */

typedef struct t_rsem {
  VP      exinf;    /* extended information */
  BOOL_ID wtsk;     /* indicates whether there is a waiting task */
  INT     semcnt;   /* current semaphore count */
  /* additional implementation dependent information may be included */
} T_RSEM;

exinf: is for any extended information that the implementation may define. This implementation does not use this field.
wtsk: is TRUE when there is one or more task waiting on the semaphore. It is FALSE if no tasks are currently waiting. The meaning of this field is allowed to vary between ITRON implementations. It may have the ID of a waiting task, the number of tasks waiting, or a boolean indication that one or more tasks are waiting.
semcnt: is the current semaphore count.

The information in this table is very volatile and should be used with caution in an application.

RTEMS ITRON 3.0 API User's Guide