Thread::Queue - thread-safe queues
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 queueA 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).
The new function creates a new empty queue.
The enqueue method adds a list of scalars on to the end of the queue. The queue will grow as needed to accommodate the list.
The 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.
The dequeue_nb method, like the dequeue method, removes a scalar from the head of the queue and returns it. Unlike dequeue, though, dequeue_nb won't block if the queue is empty, instead returning undef.
The pending method returns the number of items still in the queue.