AsyncKeyedLock 7.1.7

.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 7.1.7
                    


                    

                
NuGet\Install-Package AsyncKeyedLock -Version 7.1.7
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="7.1.7" />
For projects that support PackageReference, copy this XML node into the project file to reference the package. 
<PackageVersion Include="AsyncKeyedLock" Version="7.1.7" />
                    


                            Directory.Packages.props
                        

                    

                
<PackageReference Include="AsyncKeyedLock" />
                    


                            Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package. 
paket add AsyncKeyedLock --version 7.1.7
                    


                    

                
#r "nuget: AsyncKeyedLock, 7.1.7"
#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. 
#:package AsyncKeyedLock@7.1.7
#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package. 
#addin nuget:?package=AsyncKeyedLock&version=7.1.7
                    


                            Install as a Cake Addin
                        

                    

                
#tool nuget:?package=AsyncKeyedLock&version=7.1.7
                    


                            Install as a Cake Tool

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.  net9.0-android was computed.  net9.0-browser was computed.  net9.0-ios was computed.  net9.0-maccatalyst was computed.  net9.0-macos was computed.  net9.0-tvos was computed.  net9.0-windows was computed.  net10.0 was computed.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
.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 (43)

Showing the top 5 NuGet packages that depend on AsyncKeyedLock:

Package Downloads
Volo.Abp.DistributedLocking.Abstractions

Package Description
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!
EFCoreSecondLevelCacheInterceptor

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

TODO
ZhileTime.Hope.DistributedLocking.Abstractions

Package Description

GitHub repositories (17)

Showing the top 17 popular GitHub repositories that depend on AsyncKeyedLock:

Repository Stars
jellyfin/jellyfin
The Free Software Media System - Server Backend & API
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
Saves Discord chat logs to a file
microsoft/kiota
OpenAPI based HTTP Client code generator
ZiggyCreatures/FusionCache
FusionCache is an easy to use, fast and robust hybrid cache with advanced resiliency features.
stefanprodan/AspNetCoreRateLimit
ASP.NET Core rate limiting middleware
dotnetcore/EasyCaching
:boom: EasyCaching is an open source caching library that contains basic usages and some advanced usages of caching which can help us to handle caching more easier!
smartstore/Smartstore
A modular, scalable and ultra-fast open-source all-in-one eCommerce platform built on ASP.NET Core 7
VahidN/EFCoreSecondLevelCacheInterceptor
EF Core Second Level Cache Interceptor
omeryanar/FileExplorer
Windows File Explorer alternative with tab browsing
ForNeVeR/Cesium
C compiler for the CLI platform
trimble-oss/dba-dash
DBA Dash - SQL Server Monitoring Tool
ShokoAnime/Shokofin
Repository for Shokofin, a plugin that brings Shoko to Jellyfin.
vesoapp/veso
Open source media server.
VahidN/DNTCommon.Web.Core
DNTCommon.Web.Core provides common scenarios' solutions for ASP.NET Core applications.
sa-es-ir/DotNet.RateLimit
A Distributed RateLimit for Controller-Actions and Minimal API.
microsoft/Vipr
Client Library Generation Toolkit
Version Downloads Last Updated
7.1.7 70,188 10/4/2025
7.1.6 1,423,248 4/12/2025
7.1.5-alpha 195 4/12/2025
7.1.4 882,707 11/22/2024
7.1.4-preview 201 11/22/2024
7.1.3 442,076 11/10/2024
7.0.2 199,749 10/13/2024
7.0.1 1,250,297 8/20/2024
7.0.0 152,288 7/21/2024
7.0.0-rc3 228 7/20/2024
7.0.0-rc2 227 7/20/2024
7.0.0-rc1 250 6/29/2024
7.0.0-beta 232 6/29/2024
7.0.0-alpha 225 6/29/2024
6.4.2 537,423 4/21/2024
6.4.1 2,246 4/21/2024
6.4.0 1,671 4/20/2024
6.3.4 3,001,855 1/23/2024
6.3.4-rc 683 1/23/2024
6.3.4-beta 645 1/23/2024
6.3.3 24,291 1/14/2024
6.3.2 2,209 1/14/2024
6.3.0 2,328 1/14/2024
6.2.6 25,112 1/1/2024
6.2.5 2,445 12/30/2023
6.2.4 121,599 12/6/2023
6.2.3 7,624 12/3/2023
6.2.3-beta 857 12/2/2023
6.2.2 1,251,094 10/9/2023
6.2.1 2,493,977 4/10/2023
6.2.0 117,996 2/25/2023
6.1.1 72,435 1/27/2023
6.1.1-rc 1,267 1/27/2023
6.1.1-beta 1,219 1/27/2023
6.1.0 22,361 1/26/2023
6.0.5 53,366 1/2/2023
6.0.5-alpha 1,259 12/30/2022
6.0.4 3,519 12/30/2022
6.0.4-rc6 1,215 12/30/2022
6.0.4-rc5 1,251 12/30/2022
6.0.4-rc3 1,227 12/30/2022
6.0.4-rc 1,210 12/29/2022
6.0.4-beta 1,260 12/29/2022
6.0.4-alpha 1,294 12/29/2022
6.0.3 4,033 12/29/2022
6.0.2 33,818 12/18/2022
6.0.1 3,481 12/17/2022 6.0.1 is deprecated because it has critical bugs.
5.1.2 4,557 12/16/2022
5.1.1 13,555 12/13/2022
5.1.0 5,571 12/3/2022
5.0.4 11,638 11/27/2022
5.0.3 3,987 11/26/2022
5.0.3-rc 1,261 11/26/2022
5.0.2-rc 1,217 11/26/2022
5.0.1 4,457 11/19/2022
4.0.2 8,730 11/13/2022
3.2.3 4,782 10/26/2022
3.2.1 3,779 10/23/2022
3.2.0 3,432 10/23/2022
3.0.1 3,975 10/18/2022
3.0.0 3,773 10/16/2022
2.0.3 18,029 6/29/2022 2.0.3 is deprecated because it has critical bugs.
2.0.2 19,104 3/13/2022 2.0.2 is deprecated because it has critical bugs.
2.0.1 3,931 3/13/2022 2.0.1 is deprecated because it has critical bugs.
2.0.0 4,014 3/11/2022 2.0.0 is deprecated because it has critical bugs.
1.1.0 5,241 12/11/2021 1.1.0 is deprecated because it has critical bugs.
1.0.1 3,966 11/22/2021
1.0.0 4,715 11/22/2021

Minor optimization; dependency update.