pol_sem/ipol_sem | CS+ V5.00.00

pol_sem

ipol_sem

Outline

Acquire semaphore resource (polling).

C format
 ER      pol_sem (ID semid);
 ER      isem_sem (ID semid);
Parameter(s)
I/O

Parameter

Description
I
 ID      semid;
ID number of the semaphore.
Explanation

This service call acquires a resource from the semaphore specified by parameter semid (subtracts 1 from the semaphore counter).

If a resource could not be acquired from the target semaphore (semaphore counter is set to 0) when this service call is issued, the counter manipulation processing is not performed but "E_TMOUT" is returned.

Return value

Macro

Value

Description

E_OK

0

Normal completion.

E_ID

-18

Invalid ID number.

- semid < 0

- semid > VTMAX_SEM

E_CTX

-25

Context error.

- This service call was issued in the CPU locked state.

- This service call was issued in the status "PSW.IPL > kernel interrupt mask level".

Note When the ipol_sem is issued from task or the pol_sem is issued from non-task, the context error is not detected and normal operation of the system is not guaranteed.

E_TMOUT

-50

Polling failure.

Macro	Value	Description
E_OK	0	Normal completion.
E_ID	-18	Invalid ID number. - semid < 0 - semid > VTMAX_SEM
E_CTX	-25	Context error. - This service call was issued in the CPU locked state. - This service call was issued in the status "PSW.IPL > kernel interrupt mask level". Note When the ipol_sem is issued from task or the pol_sem is issued from non-task, the context error is not detected and normal operation of the system is not guaranteed.
E_TMOUT	-50	Polling failure.