Outline

Create eventflag.

C format

 ER      cre_flg (ID flgid, T_CFLG *pk_cflg );

 ER_ID   acre_flg ( T_CFLG *pk_cflg );

Parameter(s)

I/O	Parameter	Description
I	ID flgid;	ID number of the eventflag.
I	T_CFLG *pk_cflg;	Pointer to the packet containing the eventflag creation information.

[Eventflag creation information packet : T_CFLG]

typedef struct t_cflg { ATR flgatr; /*Eventflag attribute*/ FLGPTN iflgptn; /*Initial bit pattern*/ } T_CFLG;

Explanation

This service call can be called from tasks that belong to Trusted Domain.

The cre_flg creates a eventflag with eventflag ID indicated by flgid according to the content of pk_cflg. The acre_flg creates a eventflag according to the content of pk_cflg, and returns the created eventflag ID.

1 ) Eventflag attribute (flgatr)
The following are specified for flgatr.

   flgatr := ( ( TA_TFIFO || TA_TPRI  | ( TA_WSGL || TA_WMUL ) | [TA_CLR] )

- TA_TFIFO ( = 0x0000)
Task wait queue is managed in FIFO order.

- TA_TPRI ( = 0x0001)
Task wait queue is managed in task current priority order. Among tasks with the same priority, they are queued in FIFO order.
When TA_CLR attribute is not specified, even if there is the TA_TPRI attribute specified, the queue is managed in the same way as for the TA_TFIFO attribute. This behavior falls outside mITRON4.0 specification.

- TA_WSGL ( = 0x0000)
Does not permit multiple tasks to wait for the eventflag.

- TA_WMUL ( = 0x0002)
Permit multiple tasks to wait for the eventflag.

- TA_CLR ( = 0x0004)
All the bits of the eventflag are cleared when wai_flg, pol_flg, ipol_flg or twai_flg ends normally.

2 ) Initial bit pattern (iflgptn)
Specify initial eventflag bit pattern.

Return value

Macro	Value	Description
-	Positive value	Normal completion of acre_flg. (Created eventflag ID)
E_OK	0	Normal completion of cre_flg.
E_RSATR	-11	Reserved attribute - Either of bits in flgatr except bit0, bit1 and bit2 is 1.
E_PAR	-17	Parameter error. - pk_cflg == NULL
E_ID	-18	Invalid ID number. (only for cre_flg) - flgid < 0 - flgid > VTMAX_FLG
E_CTX	-25	Context error. - This service call was issued in the CPU locked state. - This service call was issued from non-task. - This service call was issued in the status "PSW.IPL > kernel interrupt mask level".
E_MACV	-26	Memory access violation. - Stack pointer points out of user stack for invoking task. - The operand-read access to the area indicated by pk_cflg has not been permitted to the invoking task.
E_OACV	-27	Object access violation. - The invoking task does not belong to trusted domain.
E_NOID	-34	No ID number available.(only for acre_flg)
E_OBJ	-41	Object state error. (only for cre_flg) - The eventflag specified by flgid exists.