RTEMS 4.7.2 On-Line Library

Message Buffer Manager T_CMBF Structure

RTEMS ITRON 3.0 API User's Guide

6.2.1: T_CMBF Structure

The T_CMBF structure is used to define the characteristics of a message buffer and passed as an argument to the cre_mbf routine. This structure is defined as:


typedef struct t_cmbf {
  VP      exinf;   /* extended information */
  ATR     mbfatr;  /* message buffer attributes */
  INT     bufsz;   /* buffer size (in bytes) */
  INT     maxmsz;  /* maximum message size (in bytes) */
  /* (CPU and/or implementation-dependent information may also be
  included) */
} T_CMBF;

where the meaning of each field is:

exinf: is for any extended information that the implementation may define. This implementation does not use this field.
mbfatr: is the attributes for the message buffer. The only attributes which can be specified is whether tasks wait in FIFO (TA_TFIFO) or priority (TA_TPRI) order.
bufsz: is the size of the message buffer. Since some control data are needed to manage each messages in the message buffer, bufsz is usually larger than the total of all message sizes in this buffer.
maxmsz: is the maximum message size.

RTEMS ITRON 3.0 API User's Guide