FN_SEMWAIT()
 Wait on a semaphore (decrement)
------------------------------------------------------------------------------
 Syntax
 
      fn_semWait( <nHandle> [, nTimeout ] ) -> nRc
 
 Arguments

     <nHandle> is the semaphore handle, returned from a previous call
     to fn_semOpen().

     <nTimeOut> is an optional parameter telling how long you wish to
     wait on this semaphore.  This is a numeric indicating the number
     of clock ticks (approx 1/18 sec ) to wait.  A zero (the default)
     means "don't wait."

 Returns

     nRc, a numeric, as follows:

           0 - success
         254 - timeout failure
         255 - invalid semaphore handle

 Description

     See the description for the fn_semOpen() function.

 Examples

    fn_semOpen( "Semaphore Test", nInitVal, @nHandle, @nOpenCnt )

    nRc := fn_semWait( nHandle )
    IF nRc == 254
       QOUT( "All slots for this resource are currently in use" )
       QUIT
    ENDIF


 Source: N:\SRC\SYNCHRO\SEMA.PRG

 Author: Glenn Scott