Function

sleep invokes the sleep callable service to suspend running of the calling thread (process) until either the number of seconds specified by number has elapsed, or a signal is delivered to the calling thread to invoke a signal-catching function or end the thread.

Parameters

number

The number of seconds to suspend the process. For more information on signals, see Using the REXX signal services.

Usage notes

1. The suspension can actually be longer than the requested time, due to the scheduling of other activity by the system.
2. The sleep service suspends the thread running for a specified number of seconds, or until a signal is delivered to the calling thread that invokes a signal-catching function or ends the thread. An unblocked signal received during this time prematurely wakes up the thread. The appropriate signal-handling function is invoked to handle the signal. When that signal-handling function returns, the sleep service returns immediately, even if there is sleep time remaining.
3. The sleep service returns a zero in RETVAL if it has slept for the number of seconds specified. If the time specified by number has not elapsed when the sleep service is interrupted because of the delivery of a signal, the sleep service returns the unslept amount of time (the requested time minus the time actually slept when the signal was delivered) in seconds. Any time consumed by signal-catching functions is not reflected in the value returned by the sleep service.
4. The following are usage notes for a SIGALRM signal generated by the alarm or kill calls during the execution of the sleep call:
   • If the calling thread has SIGALRM blocked prior to calling the sleep service, the sleep service does not return when SIGALRM is generated, and the SIGALRM signal is left pending when sleep returns.
   • If the calling process has SIGALRM ignored when the SIGALRM signal is generated, then the sleep service does not return and the SIGALRM signal is ignored.
   • If the calling process has SIGALRM set to a signal-catching function, that function interrupts the sleep service and receives control. The sleep service returns any unslept amount of time, as it does for any other type of signal.
5. An EC6 abend is generated when the caller's PSW key or RB state prevents signals from being delivered.