Outline

Release semaphore resource.

C format

 ER      sig_sem (ID semid);

 ER      isig_sem (ID semid);

Parameter(s)

I/O	Parameter	Description
I	ID semid;	ID number of the semaphore to which resource is released.

Explanation

These service calls return the resource to the semaphore specified by parameter semid (adds 0x1 to the semaphore counter).

If a task is queued in the wait queue of the target semaphore when this service call is issued, the counter manipulation processing is not performed but the resource is passed to the relevant task (first task of wait queue).

As a result, the relevant task is unlinked from the wait queue and is moved from the WAITING state (WAITING state for a semaphore resource) to the READY state, or from the WAITING-SUSPENDED state to the SUSPENDED state.

Note With the RI850V4, the maximum possible number of semaphore resources (maximum resource count) is defined during configuration. If the number of resources exceeds the specified maximum resource count, this service call therefore does not return the acquired resources (addition to the semaphore counter value) but returns E_QOVR.

Return value

Macro	Value	Description
E_OK	0	Normal completion.
E_ID	-18	Invalid ID number. - semid < 0x0 - semid > Maximum ID number
E_CTX	-25	Context error. - This service call was issued in the CPU locked state.
E_NOEXS	-42	Non-existent object. - Specified semaphore is not registered.
E_QOVR	-43	Queue overflow. - Resource count exceeded maximum resource count.