1 package threads::shared::queue;
10 threads::shared::queue - thread-safe queues
14 use threads::shared::queue;
15 my $q = new threads::shared::queue;
16 $q->enqueue("foo", "bar");
17 my $foo = $q->dequeue; # The "bar" is still in the queue.
18 my $foo = $q->dequeue_nb; # returns "bar", or undef if the queue was
20 my $left = $q->pending; # returns the number of items still in the queue
24 A queue, as implemented by C<threads::shared::queue> is a thread-safe
25 data structure much like a list. Any number of threads can safely
26 add elements to the end of the list, or remove elements from the head
27 of the list. (Queues don't permit adding or removing elements from
28 the middle of the list).
30 =head1 FUNCTIONS AND METHODS
36 The C<new> function creates a new empty queue.
40 The C<enqueue> method adds a list of scalars on to the end of the queue.
41 The queue will grow as needed to accommodate the list.
45 The C<dequeue> method removes a scalar from the head of the queue and
46 returns it. If the queue is currently empty, C<dequeue> will block the
47 thread until another thread C<enqueue>s a scalar.
51 The C<dequeue_nb> method, like the C<dequeue> method, removes a scalar from
52 the head of the queue and returns it. Unlike C<dequeue>, though,
53 C<dequeue_nb> won't block if the queue is empty, instead returning
58 The C<pending> method returns the number of items still in the queue.
64 L<threads>, L<threads::shared>
71 return bless \@q, $class;
77 cond_wait @$q until @$q;
78 cond_signal @$q if @$q > 1;
91 push @$q, @_ and cond_signal @$q;