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Postings from October 1999
Some random reactions:
> When built with the appropriate options, perl provides facilities for
Which options? Maybe it should be explicit, or at least link to where
someone could find out.
> async is not exported by default--if you want it, you need to ask for
> it when you use the Thread module. (If you don't, the code in the
Should have an example of a use statement that "asks for" async.
> Perl code must never access a variable simultaneously in two or more
> threads. The only way to safely do this is to lock the variable you're
> accessing with the lock() function. lock() is advisory, in that it
> only blocks other locks rather than actual access to a
> variable. Locks are dynamically scoped, much like the way local works,
> and stay locked until the lock goes out of scope.
Maybe I'm a dumbass, but what happens here:
use vars qw($GLOBVAR);
sub something_that_locks_globvar {
lock($GLOBVAR);
}
lock($GLOBVAR);
something_that_locks_globvar();
Does this lock up permanently since the lock() was done already in the
main scope and then re-tried in a subroutine? Consider that I may not be
the only fool that wonders about this... Is it a candidate for the docs?
> The single exception is locking subroutines. If a thread locks a
> subroutine, perl will prevent any other thread from entering it until
> the lock is released.
What is the syntax for locking a subroutine? lock(\&sub), or what?
Other than that it looks like fun stuff! Good job.
-sam