GM.DistributedLock 1.0.2

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GM.DistributedLock

A small, provider-agnostic distributed lock for .NET. Depend on one interface — IDistributedLock — with TryAcquire (single shot) and Acquire (blocking with retry), each returning an IAsyncDisposable handle that releases on dispose and is owner-safe (it never releases a lock that expired and was re-acquired by someone else). Ships a single-process in-memory implementation; add a real backend with GM.DistributedLock.Redis. Targets .NET 10.

Packages

The two packages version and release together (lockstep):

dotnet add package GM.DistributedLock          # in-process
dotnet add package GM.DistributedLock.Redis     # + Redis backend

Quick start

Register

using GM.DistributedLock;         // in-process
builder.Services.AddGMDistributedLock();

// or, cross-process:
using GM.DistributedLock.Redis;
builder.Services.AddGMRedisDistributedLock(o => o.ConnectionString = "localhost:6379");
// or bind from configuration: AddGMRedisDistributedLock(builder.Configuration, "Redis");

Use it

Inject IDistributedLock — the same code works with either backend:

public class PayoutJob(IDistributedLock locks)
{
    public async Task RunAsync(Guid accountId)
    {
        // Block up to 30s, retrying every 200ms, holding the lock for at most 60s.
        await using var handle = await locks.AcquireAsync(
            resource: $"payout:{accountId}",
            expiry: TimeSpan.FromSeconds(60),
            wait: TimeSpan.FromSeconds(30),
            retryInterval: TimeSpan.FromMilliseconds(200));

        // ... critical section: only one worker runs this per account ...
    }   // lock released here
}

Prefer a non-blocking attempt? Use TryAcquireAsync, which returns null when the lock is held:

await using var handle = await locks.TryAcquireAsync($"report:{id}", TimeSpan.FromMinutes(5));
if (handle is null) return; // someone else is already generating it

The interface

Task<ILockHandle?> TryAcquireAsync(string resource, TimeSpan expiry, CancellationToken ct = default);
Task<ILockHandle>  AcquireAsync(string resource, TimeSpan expiry, TimeSpan wait, TimeSpan retryInterval, CancellationToken ct = default);

AcquireAsync throws LockAcquisitionException if it can't take the lock within wait. Every lock has an expiry (TTL) so a crashed holder can't wedge the resource forever.

The Redis provider targets a single Redis endpoint (SET NX PX + owner-checked release), which is the right trade-off for the vast majority of apps. It is not a multi-node Redlock quorum.

Repository layout

GM.DistributedLock/              # IDistributedLock, ILockHandle, in-memory implementation
GM.DistributedLock.Redis/        # Redis implementation (StackExchange.Redis)
tests/GM.DistributedLock.Tests/  # xUnit tests for the in-memory lock

Building & testing

dotnet build -c Release
dotnet test  -c Release

Releasing

Versioning is automated from Conventional Commits — see CONTRIBUTING.md. Both packages share one version (Directory.Build.props) and publish together to nuget.org on each release.

License

MIT — see LICENSE.