Thoughts?
I can override CORE::GLOBAL::time() and I've done this before with a
closure (ala Time::Mock), but how would one implement accelerated time
for testing a multi-process program?
I'm also dealing with possibly sleep(), alarm() and other timing issues,
as well as maybe Time::HiRes::time(). I can probably work my way
around the sleep() and such.
All of the processes are in perl, starting from fork-opens.
If I use Time::HiRes::time() multiplied by some accelerating factor,
would one process appear to get ahead of the other? (A quick test
shows not, at least on this system with that code.) I don't have any
particular sync requirements, but I'm curious if there's prior art or
know pitfalls here.
use Time::HiRes ();
BEGIN {
my $htime = \&Time::HiRes::time;
my $time_start = $htime->();
my $timesub = sub () {
$time_start + ($htime->() - $time_start) * 10_000;
};
*Time::HiRes::time = $timesub;
*CORE::GLOBAL::time = sub () {
return(sprintf("%0.0f", $timesub->()));
};
# TODO override sleep and T::HR::sleep, etc
}
I was thinking there needs to be a shared filehandle with a stream of
time on it similar to the below, but with various time() and sleep()
methods overridden. Calls to time() or sleep() would peel-off lines,
thus keeping everyone in sync. It becomes impossible for two things to
happen at the same time (and I think I'm seeing the child blocking the
parent's reads.)
use Time::HiRes qw(sleep);
my $pid = open(my $fh, "-|");
unless($pid) {
$| = 1;
while(1) {
print Time::HiRes::time(), "\n";
sleep(0.01);
}
exit;
}
if(fork) {
while(my $line = <$fh>) {
warn "parent $line";
}
}
else {
while(my $line = <$fh>) {
warn "child $line";
}
}
--Eric
--
"But as to modern architecture, let us drop it and let us take
modernistic out and shoot it at sunrise."
--F.L. Wright
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