AsyncKeyedLock 7.1.3

.NET 5.0 This package targets .NET 5.0. The package is compatible with this framework or higher. .NET Standard 2.0 This package targets .NET Standard 2.0. The package is compatible with this framework or higher. 
dotnet add package AsyncKeyedLock --version 7.1.3                

                    
                

            
NuGet\Install-Package AsyncKeyedLock -Version 7.1.3
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package. 
<PackageReference Include="AsyncKeyedLock" Version="7.1.3" />
For projects that support PackageReference, copy this XML node into the project file to reference the package. 
paket add AsyncKeyedLock --version 7.1.3                

                    
                

            
#r "nuget: AsyncKeyedLock, 7.1.3"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package. 
// Install AsyncKeyedLock as a Cake Addin
#addin nuget:?package=AsyncKeyedLock&version=7.1.3

// Install AsyncKeyedLock as a Cake Tool
#tool nuget:?package=AsyncKeyedLock&version=7.1.3

AsyncKeyedLock AsyncKeyedLock

GitHub Workflow Status NuGet NuGet Codacy Grade Codecov

An asynchronous .NET Standard 2.0 library that allows you to lock based on a key (keyed semaphores), limiting concurrent threads sharing the same key to a specified number, with optional pooling for reducing memory allocations.

For example, suppose you were processing financial transactions, but while working on one account you wouldn't want to concurrently process a transaction for the same account. Of course, you could just add a normal lock, but then you can only process one transaction at a time. If you're processing a transaction for account A, you may want to also be processing a separate transaction for account B. That's where AsyncKeyedLock comes in: it allows you to lock but only if the key matches.

The library uses two very different methods for locking, AsyncKeyedLocker which uses an underlying ConcurrentDictionary that's cleaned up after use and StripedAsyncKeyedLocker which uses a technique called striped locking. Both have their advantages and disadvantages, and in order to help you choose you are highly recommended to read about it in the wiki.

A simple non-keyed lock is also available through AsyncNonKeyedLocker.

Installation and usage

Using this library is straightforward. Here's a simple example for using AsyncKeyedLocker:

private static readonly AsyncKeyedLocker<string> _asyncKeyedLocker = new();

...

using (await _asyncKeyedLocker.LockAsync("test123"))
{
  ...
}

or with timeouts:

private static readonly AsyncKeyedLocker<string> _asyncKeyedLocker = new();
private const _timeout = 100;

...

using (var releaser = await _asyncKeyedLocker.LockOrNullAsync("test123", _timeout))
{
  if (releaser is not null)
  {
    ...
  }
}

This libary also supports conditional locking, whether for AsyncKeyedLocker, StripedAsyncKeyedLocker or AsyncNonKeyedLocker. This could provide a workaround for reentrancy in some scenarios for example in recursion:

double factorial = Factorial(number);

public static double Factorial(int number, bool isFirst = true)
{
  using (await _asyncKeyedLocker.ConditionalLockAsync("test123", isFirst))
  {
    if (number == 0)
      return 1;
    return number * Factorial(number-1, false);
  }
}

For more help with AsyncKeyedLocker, or for examples with StripedAsyncKeyedLocker or AsyncNonKeyedLocker (for simple, non-keyed locking), please take a look at our wiki.

Pooling change in v7.0.0

Prior to AsyncKeyedLock 7.0.0, pooling was disabled by default and you needed to specify a pool size in order to enable it. Since v7.0.0, pooling is enabled by default with an initial fill of 1 and a pool size of 20. In order to disable pooling (not recommended), you need to now specify a pool size of 0 within AsyncKeyedLockOptions. Read more about pooling in our wiki.

Benchmarks

This library has been extensively benchmarked against several other options and our benchmarks run publicly and transparently on Github Actions.

Credits

Check out our list of contributors!

Product Compatible and additional computed target framework versions.
.NET net5.0 is compatible.  net5.0-windows was computed.  net6.0 is compatible.  net6.0-android was computed.  net6.0-ios was computed.  net6.0-maccatalyst was computed.  net6.0-macos was computed.  net6.0-tvos was computed.  net6.0-windows was computed.  net7.0 is compatible.  net7.0-android was computed.  net7.0-ios was computed.  net7.0-maccatalyst was computed.  net7.0-macos was computed.  net7.0-tvos was computed.  net7.0-windows was computed.  net8.0 is compatible.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed.  net9.0 is compatible. 
.NET Core netcoreapp2.0 was computed.  netcoreapp2.1 was computed.  netcoreapp2.2 was computed.  netcoreapp3.0 was computed.  netcoreapp3.1 was computed. 
.NET Standard netstandard2.0 is compatible.  netstandard2.1 is compatible. 
.NET Framework net461 was computed.  net462 was computed.  net463 was computed.  net47 was computed.  net471 was computed.  net472 was computed.  net48 was computed.  net481 was computed. 
MonoAndroid monoandroid was computed. 
MonoMac monomac was computed. 
MonoTouch monotouch was computed. 
Tizen tizen40 was computed.  tizen60 was computed. 
Xamarin.iOS xamarinios was computed. 
Xamarin.Mac xamarinmac was computed. 
Xamarin.TVOS xamarintvos was computed. 
Xamarin.WatchOS xamarinwatchos was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

NuGet packages (41)

Showing the top 5 NuGet packages that depend on AsyncKeyedLock:

Package Downloads
EasyCaching.Core

EasyCaching is a open source caching library that contains basic usages and some advanced usages of caching which can help us to handle caching more easier!
Volo.Abp.DistributedLocking.Abstractions

Package Description
EFCoreSecondLevelCacheInterceptor

Entity Framework Core Second Level Caching Library.
N3O.Umbraco.Extensions

TODO
ZhileTime.Hope.DistributedLocking.Abstractions

Package Description

GitHub repositories (14)

Showing the top 5 popular GitHub repositories that depend on AsyncKeyedLock:

Repository Stars
jellyfin/jellyfin
The Free Software Media System
abpframework/abp
Open-source web application framework for ASP.NET Core! Offers an opinionated architecture to build enterprise software solutions with best practices on top of the .NET. Provides the fundamental infrastructure, cross-cutting-concern implementations, startup templates, application modules, UI themes, tooling and documentation.
Tyrrrz/DiscordChatExporter
Exports Discord chat logs to a file
stefanprodan/AspNetCoreRateLimit
ASP.NET Core rate limiting middleware
microsoft/kiota
OpenAPI based HTTP Client code generator
Version Downloads Last updated
7.1.3 13,761 11/10/2024
7.0.2 53,031 10/13/2024
7.0.1 167,493 8/20/2024
7.0.0 89,047 7/21/2024
7.0.0-rc3 122 7/20/2024
7.0.0-rc2 118 7/20/2024
7.0.0-rc1 146 6/29/2024
7.0.0-beta 121 6/29/2024
7.0.0-alpha 118 6/29/2024
6.4.2 281,466 4/21/2024
6.4.1 1,205 4/21/2024
6.4.0 632 4/20/2024
6.3.4 1,245,109 1/23/2024
6.3.4-rc 570 1/23/2024
6.3.4-beta 548 1/23/2024
6.3.3 16,527 1/14/2024
6.3.2 1,241 1/14/2024
6.3.0 1,362 1/14/2024
6.2.6 18,781 1/1/2024
6.2.5 1,454 12/30/2023
6.2.4 72,447 12/6/2023
6.2.3 4,920 12/3/2023
6.2.3-beta 768 12/2/2023
6.2.2 757,899 10/9/2023
6.2.1 1,959,538 4/10/2023
6.2.0 95,115 2/25/2023
6.1.1 63,792 1/27/2023
6.1.1-rc 1,111 1/27/2023
6.1.1-beta 1,074 1/27/2023
6.1.0 17,992 1/26/2023
6.0.5 44,149 1/2/2023
6.0.5-alpha 1,088 12/30/2022
6.0.4 2,580 12/30/2022
6.0.4-rc6 1,074 12/30/2022
6.0.4-rc5 1,108 12/30/2022
6.0.4-rc3 1,076 12/30/2022
6.0.4-rc 1,041 12/29/2022
6.0.4-beta 1,095 12/29/2022
6.0.4-alpha 1,142 12/29/2022
6.0.3 3,086 12/29/2022
6.0.2 29,545 12/18/2022
6.0.1 2,456 12/17/2022 6.0.1 is deprecated because it has critical bugs.
5.1.2 3,567 12/16/2022
5.1.1 11,568 12/13/2022
5.1.0 4,206 12/3/2022
5.0.4 10,673 11/27/2022
5.0.3 2,994 11/26/2022
5.0.3-rc 1,099 11/26/2022
5.0.2-rc 1,052 11/26/2022
5.0.1 3,472 11/19/2022
4.0.2 6,942 11/13/2022
3.2.3 3,832 10/26/2022
3.2.1 2,828 10/23/2022
3.2.0 2,490 10/23/2022
3.0.1 3,027 10/18/2022
3.0.0 2,817 10/16/2022
2.0.3 16,944 6/29/2022 2.0.3 is deprecated because it has critical bugs.
2.0.2 17,775 3/13/2022 2.0.2 is deprecated because it has critical bugs.
2.0.1 2,905 3/13/2022 2.0.1 is deprecated because it has critical bugs.
2.0.0 2,979 3/11/2022 2.0.0 is deprecated because it has critical bugs.
1.1.0 4,160 12/11/2021 1.1.0 is deprecated because it has critical bugs.
1.0.1 2,942 11/22/2021
1.0.0 2,794 11/22/2021

Performance improvements for timeout-based locking and StripedAsyncKeyedLocker; fixes in ConditionalLocks.