IPC@CHIP Documentation - SC12 @CHIP-RTOS V1.10

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RTOS Semaphore Services
Interrupt 0xAD service 0x18: RTX_RELEASE_SEM, Release a resource semaphore
Parameters
AH
BX
Down count (unwind) a resource semaphore's "use count".
0x18 (= RTX_RELEASE_SEM)
ID of the resource semaphore acquired from RTX_CREATE_SEM
Return Value
Comments
DX =0 success AX: 0
DX!=0 failure AX: contains error code
The resource's use count is decremented by one if the calling task presently owns this resource
semaphore (otherwise error code -12, "not owner"). The resource is not freed until the use count
reaches zero, at which point the caller no longer "owns" this semaphore.
Once freed, the resource will immediately be given to the task (if any) which is waiting at the head of this
resource semaphore's wait queue. An immediate task switch occurs if this waiting task is higher priority
than the calling task that just gave up ownership of this semaphore.
Note: Attempting to use this function on a counting semaphore will fail with error code -12.
Related Topics
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RTX_FREE_RES Free resource semaphore
RTX_RESERVE_RES Reserve resource semaphore
RTOS Semaphore Services
Interrupt 0xAD service 0x19: RTX_RESERVE_RES, Get use of a resource semaphore
Parameters
AH
Reserves a resource semaphore.
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