sleep(+Seconds)

Seconds

Positive number (integer or float).

Description

sleep/1 causes the calling thread to be suspended for the given number of seconds. Other threads will be unaffected.

Modes and Determinism

• sleep(+) is det

Exceptions

(4) instantiation fault

Seconds is uninstantiated.

(5) type error

Seconds is not an integer or float.

Examples

    ?- sleep(0.3).
                         % short sleep
    Yes (0.00s cpu).     % appears after 0.3 seconds.


    ?- sleep(63072000).
                         % long sleep
    Yes (0.00s cpu).     % appears after 2 years.


    ?- engine_create(E,[thread]),
       engine_resume_thread(E, (sleep(3),writeln(sleep_done))),
       writeln(thread_started),
       engine_join(E, block, S).
    thread_started
    sleep_done           % appears after 3 seconds
    Yes (0.00s cpu)

See Also