Skip to content

Only create a single publish channel #1620

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
danielmarbach merged 5 commits into from
Jun 11, 2025
Merged

Only create a single publish channel #1620

Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
53dbe79
Use a single publish channel with atomic swaps
danielmarbach Jun 6, 2025
52c757f
Cosmetics
danielmarbach Jun 6, 2025
50fb15c
Few tweaks
danielmarbach Jun 6, 2025
993abbb
Simplify implementation
danielmarbach Jun 6, 2025
0fc8473
Remove null-forgiving
danielmarbach Jun 10, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
78 changes: 46 additions & 32 deletions src/NServiceBus.Transport.RabbitMQ/Connection/ChannelProvider.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,25 +3,15 @@
namespace NServiceBus.Transport.RabbitMQ
{
using System;
using System.Collections.Concurrent;
using System.Threading;
using System.Threading.Tasks;
using global::RabbitMQ.Client;
using global::RabbitMQ.Client.Events;
using Logging;

class ChannelProvider : IAsyncDisposable
class ChannelProvider(ConnectionFactory connectionFactory, TimeSpan retryDelay, IRoutingTopology routingTopology)
: IAsyncDisposable
{
public ChannelProvider(ConnectionFactory connectionFactory, TimeSpan retryDelay, IRoutingTopology routingTopology)
{
this.connectionFactory = connectionFactory;
this.retryDelay = retryDelay;

this.routingTopology = routingTopology;

channels = new ConcurrentQueue<ConfirmsAwareChannel>();
}

public async Task Initialize(CancellationToken cancellationToken = default) => connection = await CreateConnectionWithShutdownListener(cancellationToken).ConfigureAwait(false);

async Task<IConnection> CreateConnectionWithShutdownListener(CancellationToken cancellationToken)
Expand Down Expand Up @@ -60,7 +50,7 @@ async Task ReconnectSwallowingExceptions(string? connectionName, CancellationTok

var newConnection = await CreateConnectionWithShutdownListener(cancellationToken).ConfigureAwait(false);

// A race condition is possible where CreatePublishConnection is invoked during Dispose
// A race condition is possible where CreatePublishConnection is invoked during Dispose
// where the returned connection isn't disposed so invoking Dispose to be sure
if (cancellationToken.IsCancellationRequested)
{
Expand Down Expand Up @@ -94,32 +84,57 @@ protected virtual void FireAndForget(Func<CancellationToken, Task> action, Cance

public async ValueTask<ConfirmsAwareChannel> GetPublishChannel(CancellationToken cancellationToken = default)
{
if (channels.TryDequeue(out var channel) && !channel.IsClosed)
if (publishChannel is { IsOpen: true })
{
return channel;
return publishChannel;
}

if (channel is not null)
try
{
await channel.DisposeAsync()
.ConfigureAwait(false);
}
await publishChannelSemaphore.WaitAsync(cancellationToken).ConfigureAwait(false);
if (publishChannel is { IsOpen: true })
{
return publishChannel;
}

channel = new ConfirmsAwareChannel(connection, routingTopology);
await channel.Initialize(cancellationToken).ConfigureAwait(false);
var oldChannel = publishChannel;
if (oldChannel is not null)
{
await oldChannel.DisposeAsync().ConfigureAwait(false);
}

return channel;
var newChannel = new ConfirmsAwareChannel(connection, routingTopology);
await newChannel.Initialize(cancellationToken).ConfigureAwait(false);
publishChannel = newChannel;
return newChannel;
}
finally
{
publishChannelSemaphore.Release();
}
}

public ValueTask ReturnPublishChannel(ConfirmsAwareChannel channel, CancellationToken cancellationToken = default)
public async ValueTask ReturnPublishChannel(ConfirmsAwareChannel channel, CancellationToken cancellationToken = default)
{
if (channel.IsOpen)
{
channels.Enqueue(channel);
return ValueTask.CompletedTask;
return;
}

return channel.DisposeAsync();
try
{
await publishChannelSemaphore.WaitAsync(cancellationToken).ConfigureAwait(false);

if (ReferenceEquals(publishChannel, channel))
{
await channel.DisposeAsync().ConfigureAwait(false);
publishChannel = null;
}
}
finally
{
publishChannelSemaphore.Release();
}
}

#pragma warning disable PS0018
Expand All @@ -137,20 +152,19 @@ public async ValueTask DisposeAsync()
var oldConnection = Interlocked.Exchange(ref connection, null);
oldConnection?.Dispose();

foreach (var channel in channels)
var oldChannel = Interlocked.Exchange(ref publishChannel, null);
if (oldChannel is not null)
{
await channel.DisposeAsync().ConfigureAwait(false);
await oldChannel.DisposeAsync().ConfigureAwait(false);
}

disposed = true;
}

readonly ConnectionFactory connectionFactory;
readonly TimeSpan retryDelay;
readonly IRoutingTopology routingTopology;
readonly ConcurrentQueue<ConfirmsAwareChannel> channels;
readonly CancellationTokenSource stoppingTokenSource = new();
volatile IConnection? connection;
readonly SemaphoreSlim publishChannelSemaphore = new(1, 1);
volatile ConfirmsAwareChannel? publishChannel;
bool disposed;

static readonly ILog Logger = LogManager.GetLogger(typeof(ChannelProvider));
Expand Down