Thread::Queue - thread-safe queues (5.005-threads)
This Perl installation is using the old unsupported "5.005 threads". Use of the old threads model is discouraged.
For the whole story about the development of threads in Perl,
and why you should not be using "old threads" unless you know what you're doing,
see the CAVEAT of the
use Thread::Queue; my $q = new Thread::Queue; $q->enqueue("foo", "bar"); my $foo = $q->dequeue; # The "bar" is still in the queue. my $foo = $q->dequeue_nb; # returns "bar", or undef if the queue was # empty my $left = $q->pending; # returns the number of items still in the queue
A queue, as implemented by
Thread::Queue is a thread-safe data structure much like a list. Any number of threads can safely add elements to the end of the list, or remove elements from the head of the list. (Queues don't permit adding or removing elements from the middle of the list)
new function creates a new empty queue.
enqueue method adds a list of scalars on to the end of the queue. The queue will grow as needed to accomodate the list.
dequeue method removes a scalar from the head of the queue and returns it. If the queue is currently empty,
dequeue will block the thread until another thread
enqueues a scalar.
dequeue_nb method, like the
dequeue method, removes a scalar from the head of the queue and returns it. Unlike
dequeue_nb won't block if the queue is empty, instead returning
pending method returns the number of items still in the queue. (If there can be multiple readers on the queue it's best to lock the queue before checking to make sure that it stays in a consistent state)