Loop8ack.AsyncTicketLock

An asynchronous class that functions as a lock based on provided ticket objects instead of the current thread. Only one ticket object can hold the lock at a time, accesses with the same ticket object are allowed, accesses with other ticket objects are not allowed.

I addressed the original idea in the following forum topic:
https://mycsharp.de/forum/threads/124593/async-task-synchronisation

Special thanks to gfoidl, who contributed the basic implementation and who gave me advice and support.

How to Use

Enter/Release with using

var ticketLock = new AsyncTicketLock();
var ticket = new object();

// async
using (await ticketLock.EnterAsync(ticket))
{
    // Do work
}

// sync
if (ticketLock.TryEnter(ticket, out var releaser))
{
    using (releaser)
    {
        // ...
    }
}

Enter/Release manually

var ticketLock = new AsyncTicketLock();
var ticket = new object();

// async
await ticketLock.EnterAsync(ticket);
// Do work
ticketLock.Release(ticket); // true

// sync
if (ticketLock.TryEnter(ticket))
{
    ticketLock.TryEnter(new object()); // false

    ticketLock.Release(ticket);
}

Nested lock

var ticketLock = new AsyncTicketLock();
var ticket = new object();

await ticketLock.EnterAsync(ticket);
await ticketLock.EnterAsync(ticket);
await ticketLock.EnterAsync(ticket);
await ticketLock.EnterAsync(ticket);

ticketLock.Release(ticket, 2); // returns 2
ticketLock.Release(ticket);    // returns true
ticketLock.Release(ticket, 2); // returns 1
ticketLock.ReleaseAll(ticket); // returns false

With timeout

var ticketLock = new AsyncTicketLock();
var ticket1 = new object();
var ticket2 = new object();

await ticketLock.EnterAsync(ticket1);

// TimeoutException after one second
await ticketLock.EnterAsync(ticket2, TimeSpan.FromSeconds(1));

With maximum entered count

var ticketLock = new AsyncTicketLock(3);
var ticket = new object();

ticketLock.TryEnter(ticket); // true
ticketLock.TryEnter(ticket); // true
ticketLock.TryEnter(ticket); // true
ticketLock.TryEnter(ticket); // false

ticketLock.Release(ticket, 2);

ticketLock.TryEnter(ticket); // true
ticketLock.TryEnter(ticket); // true
ticketLock.TryEnter(ticket); // false

Release Notes

1.1.0

Added support for MaxEnteredCount parameter: Users can now limit the number of times a ticket object can enter the lock.

License

This project is licensed under the MIT License.

loop8ack/AsyncTicketLock