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.
There is a newer version of this package available.
See the version list below for details. 
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 (15)

Showing the top 5 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
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
7.1.4 54,319 11/22/2024
7.1.4-preview 87 11/22/2024
7.1.3 39,078 11/10/2024
7.0.2 74,134 10/13/2024
7.0.1 222,952 8/20/2024
7.0.0 99,390 7/21/2024
7.0.0-rc3 129 7/20/2024
7.0.0-rc2 126 7/20/2024
7.0.0-rc1 159 6/29/2024
7.0.0-beta 127 6/29/2024
7.0.0-alpha 125 6/29/2024
6.4.2 306,639 4/21/2024
6.4.1 1,423 4/21/2024
6.4.0 837 4/20/2024
6.3.4 1,425,856 1/23/2024
6.3.4-rc 576 1/23/2024
6.3.4-beta 554 1/23/2024
6.3.3 17,628 1/14/2024
6.3.2 1,438 1/14/2024
6.3.0 1,559 1/14/2024
6.2.6 19,136 1/1/2024
6.2.5 1,654 12/30/2023
6.2.4 76,141 12/6/2023
6.2.3 5,379 12/3/2023
6.2.3-beta 777 12/2/2023
6.2.2 799,519 10/9/2023
6.2.1 1,989,729 4/10/2023
6.2.0 95,993 2/25/2023
6.1.1 64,151 1/27/2023
6.1.1-rc 1,115 1/27/2023
6.1.1-beta 1,078 1/27/2023
6.1.0 18,192 1/26/2023
6.0.5 44,630 1/2/2023
6.0.5-alpha 1,092 12/30/2022
6.0.4 2,778 12/30/2022
6.0.4-rc6 1,078 12/30/2022
6.0.4-rc5 1,112 12/30/2022
6.0.4-rc3 1,080 12/30/2022
6.0.4-rc 1,045 12/29/2022
6.0.4-beta 1,099 12/29/2022
6.0.4-alpha 1,146 12/29/2022
6.0.3 3,284 12/29/2022
6.0.2 29,801 12/18/2022
6.0.1 2,657 12/17/2022 6.0.1 is deprecated because it has critical bugs.
5.1.2 3,763 12/16/2022
5.1.1 11,765 12/13/2022
5.1.0 4,443 12/3/2022
5.0.4 10,869 11/27/2022
5.0.3 3,194 11/26/2022
5.0.3-rc 1,103 11/26/2022
5.0.2-rc 1,056 11/26/2022
5.0.1 3,683 11/19/2022
4.0.2 7,240 11/13/2022
3.2.3 4,029 10/26/2022
3.2.1 3,024 10/23/2022
3.2.0 2,695 10/23/2022
3.0.1 3,226 10/18/2022
3.0.0 3,013 10/16/2022
2.0.3 17,139 6/29/2022 2.0.3 is deprecated because it has critical bugs.
2.0.2 17,973 3/13/2022 2.0.2 is deprecated because it has critical bugs.
2.0.1 3,097 3/13/2022 2.0.1 is deprecated because it has critical bugs.
2.0.0 3,175 3/11/2022 2.0.0 is deprecated because it has critical bugs.
1.1.0 4,355 12/11/2021 1.1.0 is deprecated because it has critical bugs.
1.0.1 3,136 11/22/2021
1.0.0 3,066 11/22/2021

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