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RTEMS 4.7.1 On-Line Library


Eventflags Manager T_CFLG Structure

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4.2.2: T_CFLG Structure

The T_CFLG structire is used to define the characteristics of an eventflag and passed as an argument to the cre_flg service. The structure is defined as follows:


/*
 * Create Eventflags (cre_flg) Structure
 */

typedef struct t_cflg {
  VP exinf;     /* extended information */
  ATR flgatr;   /* eventflag attribute */
  UINT iflgptn; /* initial eventflag */
  /* additional implementation dependent information may be included */
} T_CFLG;

/*
 *  flgatr - Eventflag Attribute Values
 */


/* multiple tasks are not allowed to wait (Wait Single Task)*/

#define TA_WSGL 0x00

/* multiple tasks are allowed to wait (Wait Multiple Task) */

#define TA_WMUL 0x08

/* wfmode */
#define TWF_ANDW 0x00 /* AND wait */
#define TWF_ORW 0x02 /* OR wait */
#define TWF_CLR 0x01 /* clear specification */

where the meaning of each field is:

exinf
may be used freely by the user for including extended information about the eventflag to be created. Information set here may be accessed by ref_flg. If a larger region is desired for including user information, or if the user wishes to change the contents of this information, the usr should allocate memory area and set the address of this memory packet to exinf. The OS does not take care of the contents of exinf. This implementation does not use this field.
flgatr
is the attributes for this eventflag. The lower bits of flgatr represent system attributes, while the upper bits represent implementation-dependent attributes.
iflgptn
is the initial eventflag pattern. (CPU and/or implementation-dependent information may also be included)


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