CBL_SEMAPHORE_ACQUIRE

Acquires one of the resources represented by the semaphore by decrementing the associated count.

Syntax:

call "CBL_SEMAPHORE_ACQUIRE" using by value semaphore-handle
                                   by value flags
                                  [by value timeout]

Parameters:

	Using call prototype (see Key)	Picture
`semaphore-handle`	cblt-pointer	usage pointer
`flags`	cblt-os-flags	pic x(4) comp-5 or pic x(8) comp-5 (64-bit native programs only)
`timeout`	cblt-os-size	pic x(4) comp-5

Using call prototype (see Key)

Picture

semaphore-handle

cblt-pointer

usage pointer

flags

cblt-os-flags

pic x(4) comp-5

pic x(8) comp-5 (64-bit native programs only)

timeout

cblt-os-size

pic x(4) comp-5

On Entry:

semaphore-handle

Semaphore handle.

flags

A value that determines the action of the routine if the count is zero:

Bit 0

Block the thread/process until the count is non-zero, then the count is decremented and the call returns.

If no timeout is supplied (i.e. bit 1 = 0) then return immediately, no decrement

If timeout supplied (i.e. bit 1=1 ) then block until count is non-zero or timeout duration has expired. If the timeout expires, return error code 1010 ("no resources available"), else decrement count and return

Bit 1

0	No timeout parameter supplied
1	Timeout parameter is supplied and used if bit 0=1

Remaining bits

Reserved. Must be set to zero.

timeout

The timeout value in milliseconds. A value of zero returns immediately. This parameter is mandatory if bit 1=1 for the flags parameter; otherwise, it is optional.

On Exit:

return-code: A value of 0 indicates that the call was successful. Any other value indicates an error. See RETURN-CODE Values For Synchronization Routines

Comments:

Behavior is undefined if semaphore-handle is invalid.