=head1 NAME
-Thread::Semaphore - thread-safe semaphores
+threads::shared::semaphore - thread-safe semaphores
=head1 SYNOPSIS
- use Thread::Semaphore;
- my $s = new Thread::Semaphore;
+ use threads::shared::semaphore;
+ my $s = new threads::shared::semaphore;
$s->up; # Also known as the semaphore V -operation.
# The guarded section is here
$s->down; # Also known as the semaphore P -operation.
# The default semaphore value is 1.
- my $s = new Thread::Semaphore($initial_value);
+ my $s = new threads::shared::semaphore($initial_value);
$s->up($up_value);
$s->down($up_value);
control access to anything you care to use them for.
Semaphores don't limit their values to zero or one, so they can be used to
-control access to some resource that may have more than one of. (For
-example, filehandles) Increment and decrement amounts aren't fixed at one
+control access to some resource that there may be more than one of. (For
+example, filehandles). Increment and decrement amounts aren't fixed at one
either, so threads can reserve or return multiple resources at once.
=head1 FUNCTIONS AND METHODS
=item down NUMBER
The C<down> method decreases the semaphore's count by the specified number,
-or one if no number has been specified. If the semaphore's count would drop
+or by one if no number has been specified. If the semaphore's count would drop
below zero, this method will block until such time that the semaphore's
count is equal to or larger than the amount you're C<down>ing the
semaphore's count by.
=item up NUMBER
The C<up> method increases the semaphore's count by the number specified,
-or one if no number's been specified. This will unblock any thread blocked
+or by one if no number has been specified. This will unblock any thread blocked
trying to C<down> the semaphore if the C<up> raises the semaphore count
-above what the C<down>s are trying to decrement it by.
+above the amount that the C<down>s are trying to decrement it by.
=back
sub down {
my $s = shift;
- lock($s);
+ lock($$s);
my $inc = @_ ? shift : 1;
- cond_wait $s until $$s >= $inc;
+ cond_wait $$s until $$s >= $inc;
$$s -= $inc;
}
sub up {
my $s = shift;
- lock($s);
+ lock($$s);
my $inc = @_ ? shift : 1;
- ($$s += $inc) > 0 and cond_broadcast $s;
+ ($$s += $inc) > 0 and cond_broadcast $$s;
}
1;