NAME¶
Mail::SpamAssassin::Timeout - safe, reliable timeouts in perl
SYNOPSIS¶
# non-timeout code...
my $t = Mail::SpamAssassin::Timeout->new({ secs => 5, deadline => $when });
$t->run(sub {
# code to run with a 5-second timeout...
});
if ($t->timed_out()) {
# do something...
}
# more non-timeout code...
DESCRIPTION¶
This module provides a safe, reliable and clean API to provide alarm(2)-based
timeouts for perl code.
Note that $SIG{ALRM} is used to provide the timeout, so this will not interrupt
out-of-control regular expression matches.
Nested timeouts are supported.
PUBLIC METHODS¶
- my $t = Mail::SpamAssassin::Timeout->new({ ... options
... });
- Constructor. Options include:
- secs => $seconds
- time interval, in seconds. Optional; if neither
"secs" nor "deadline" is specified, no timeouts will
be applied.
- deadline => $unix_timestamp
- Unix timestamp (seconds since epoch) when a timeout is
reached in the latest. Optional; if neither secs nor
deadline is specified, no timeouts will be applied. If both are
specified, the shorter interval of the two prevails.
- $t->run($coderef)
- Run a code reference within the currently-defined timeout.
The timeout is as defined by the secs and deadline parameters
to the constructor.
Returns whatever the subroutine returns, or "undef" on timeout. If
the timer times out, "$t-<gt" timed_out()> will
return 1.
Time elapsed is not cumulative; multiple runs of "run" will
restart the timeout from scratch. On the other hand, nested timers do
observe outer timeouts if they are shorter, resignalling a timeout to the
level which established them, i.e. code running under an inner timer can
not exceed the time limit established by an outer timer. When restarting
an outer timer on return, elapsed time of a running code is taken into
account.
- $t->run_and_catch($coderef)
- Run a code reference, as per
"$t-<gt"run()>, but also catching any
"die()" calls within the code reference.
Returns "undef" if no "die()" call was executed and $@
was unset, or the value of $@ if it was set. (The timeout event doesn't
count as a "die()".)
- $t->timed_out()
- Returns 1 if the most recent code executed in
"run()" timed out, or "undef" if it did not.
- $t->reset()
- If called within a "run()" code reference, causes
the current alarm timer to be restored to its original setting (useful
after our alarm setting was clobbered by some underlying module).
