The timeout package, which may be loaded by the query
| ?- use_module(library(timeout)).
contains the predicate:
time_out(:Goal, +Time, ?Result)
The Goal is executed as if by call/1. If computing any
solution takes more than Time milliseconds, the goal will be
aborted and Result unified with the atom time_out. If the
goal succeeds within the specified time, Result is unified with
the atom success. Time must be a number between (not
including) 0 and 2147483647.
The time is measured in process virtual time on UNIX. On Windows NT/2000/XP, as of SICStus 3.10, thread virtual time is used, which is the same as process virtual time for single-threaded processes. On Windows 95/98/ME the time is measured in real time (wall time), due to limitations in those operating systems.
The precision of the time out interval is usually not better than
several tens of milliseconds. This is due to limitations in the timing
mechanisms used to implement library(timeout).
time_out/3 is implemented by raising and handling
time_out exceptions, so any exception handler in the scope of
Goal must be prepared to pass on time_out exceptions.
The following incorrect example shows what can happen otherwise:
| ?- time_out(on_exception(Q,(repeat,false),true), 1000, Res).
Q = time_out,
Res = success