AsyncUtilities 0.5.0

AsyncUtilities

A collection of somewhat useful utilities for async programming:

• Non-generic ValueTask
• StripedAsyncLock<TKey>
• Striped<TKey, TLock>
• CancelableTaskCompletionSource

Install

Install-Package AsyncUtilities

Usage

<a id="valueTask">ValueTask</a>

The non-generic ValueTask can be useful in async methods that are invoked very frequently, are likely to complete synchronously but unlike ValueTask<TResult> don't return a result. Usually these method will await another async method that does return a ValueTask<TResult>, for example:

async ValueTask DrawAsync(string name)
{
    var pen = await GetAsync<Pen>("pen");
    var apple = await Getsync<Apple>("apple");
    
    var applePen = pen.JamIn(apple);
    applePen.Draw();
}

async ValueTask<T> GetItemAsync<T>(string name)
{
    var item = GetFromCache<T>(name);
    if (item != null)
    {
        return item;
    }
    
    return await GetFromDbAsync<T>(name);
}

<a id="stripedasynclock">StripedAsyncLock</a>

StripedAsyncLock<TKey> can be used to reduce contention on an AsyncLock by dividing it into more granular stripes. This allows different operations to lock separate stripes concurrently instead of locking the entire lock altogether:

StripedAsyncLock<string> _lock = new StripedAsyncLock<string>(stripes: 100);
Cache _cache = new Cache();

async Task<T> GetOrCreateItem<T>(string name) where T : new()
{
    var item = _cache.Get<T>(name);
    if (item != null)
    {
        return item;
    }
    
    using (await _lock.LockAsync(name))
    {
        var item = _cache.Get<T>(name);
        if (item != null)
        {
            return item;
        }
        
        item = new T();
        _cache.Set(item;
        return item;
    }
}

License

AsyncUtilities is licensed under the MIT license.