On Tue, Mar 28, 2006 at 08:22:25PM +1000 Adam Kennedy wrote:
> Tassilo von Parseval wrote:
> >Hi,
> >
> >I was told that Test::More patches should now go to this list so here we
> >go.
> >
> >The attached patch serves as a draft for enabling test-scripts that fork
> >without the test-counter getting confused. It does so by using a
> >Storable imaged shared between the processes. The patch however does
> >need some modification because there's a race condition in there. It
> >uses lock_nstore and lock_retrieve to store the current test-metrics
> >thusly:
>
> To get back to the subject at hand, can you explain what the
> implications of this might be for portability, given the universality of
> Test::More.
>
> Wouldn't this patch introduce IPC and forking portability issues to
> Test::More, when it currently does have these issues (that I'm aware of).
Forking issues no, IPC issues yes. My patch doesn't make Test::More
fork, it only adds means of synchronizing processes that were forked in
a test-script.
The only unportable part is the locking of the Storable image. Ideally
this should get factored out in two methods acquire_lock() and
release_lock(), thusly:
sub acquire_lock {
my $self = shift;
if (HAVE_FLOCK) {
flock $self->{Forked} => LOCK_EX;
} elsif (HAVE_EXCL_SYSOPEN) {
select undef, undef, undef, 0.05
while not sysopen my $lockf, $self->{Lockfile}, O_CREAT|O_EXCL;
} elsif (HAVE_WHATEVER_OTHER_METHOD) {
...
} ...
}
sub release_lock {
my $self = shift;
if (HAVE_FLOCK) {
flock $self->{Forked} => LOCK_UN;
} elsif (HAVE_EXCL_SYSOPEN) {
unlink $self->{Lockfile};
} ...
}
> Do you think this might work better, or could be implemented as, a
> seperate Test::Fork type module?
It certainly could be done. But it would essentially share 90% of its
code with Test::Builder. It's simple really: Either my proposed method
is robust in which case it can go into Test-Simple. Or it isn't. Then
there's no need to implement it as a separate module. :-)
Cheers,
Tassilo
--
use bigint;
$n=71423350343770280161397026330337371139054411854220053437565440;
$m=-8,;;$_=$n&(0xff)<<$m,,$_>>=$m,,print+chr,,while(($m+=8)<=200);
