NAME

Coro::PriorityQueue

SYNOPSIS

    use Coro::PriorityQueue;
    use Coro;

    my $queue = Coro::PriorityQueue->new(10);

    my $producer = async {
        foreach my $i (1 .. 10) {
            $queue->insert($i);
        }

        $queue->shutdown;
    };

    my $consumer = async {
        while (1) {
            my $i = $queue->remove or last;
            printf("%d * 2 = %d\n", $i, $i * 2);
        }
    };

    $producer->join, $consumer->join;

DESCRIPTION

Priority queues automatically order their contents according to the inserted item's priority. Calling code must ensure that their queue items are comparable via this strategy (e.g. by overloading the <=> operator).

Underneath, this is implemented as a simple array heap, using Coro::Semaphore to control access.

METHODS

new($max)

Creates a new queue that can store $max items.

insert($item)

Inserts an item into the queue. Will block the thread until a slot is available if necessary. If the queue has been shut down, croaks.

It is an error to insert undef into the queue.

remove

Removes and returns an item from the queue. Blocks until an item becomes available if necessary. If the queue is shutdown, returns undefined immediately.

count

Returns the number of items currently stored.

is_empty

Returns true if the queue is empty.

is_full

Returns true if the queue is full.

shutdown

Shuts down the queue, after which no items may be inserted. Items already in the queue can be pulled normally until empty, after which further calls to remove will return undefined.

AUTHOR

Jeff Ober <jeffober@gmail.com>