"John Macdonald" <[EMAIL PROTECTED]> wrote > At first glance, this
doesn't need a thread - a
> Instead of
> sleep, though, I'd use a pipeline and read it with
> a non-blocking read until there is no data. ...
++ For the lateral thinking. Definitely a valid solution to the problem, as
given. So I'll change the problem prevent it: the slow fn is a 3rd-party
blob with no access to source code and no progress indication.
sub slow_fn {
print "starting slow operation: this sometimes takes half an hour!\n";
my $tid = thread { slow_fn_imp @_ };
$start = time;
loop {
wait $tid | timeout(60);
return $tid.result if $tid.done;
print "... $(time-$start) seconds\n";
}
}
Still a bit too complex for my taste: perhaps we can use C<timeout> to
generate exceptions:
my lazy::threaded $result := { slow_fn_imp @_ };
loop {
timeout(60);
return $result;
CATCH Timeout { print "...$(time)\n" }
}
At last, no C<tid>! (Reminder: the suggested semantics of the threaded
variable were that a FETCH to it blocks until the result of the thread is
available).
Dave.
