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Investigate & fix SemaphoreFullException #1819

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7d81edc
Investigate & fix `SemaphoreFullException`
lukebakken Mar 27, 2025
e633973
Make copy
lukebakken Mar 27, 2025
71ccda0
* Add queue arguments to test to simulate nacks.
lukebakken Mar 27, 2025
4c844e1
* Consolidate duplicated code.
lukebakken Mar 27, 2025
ab1f358
* Remove TCS from `_confirmsTaskCompletionSources` if there is an `Op…
lukebakken Mar 28, 2025
6c0488e
* Consistently use `TryRemove`
lukebakken Mar 28, 2025
0ae8d39
* Remove use of `Debug.Assert`
lukebakken Apr 8, 2025
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19 changes: 14 additions & 5 deletions projects/RabbitMQ.Client/Impl/AsyncRpcContinuations.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -30,7 +30,6 @@
//---------------------------------------------------------------------------

using System;
using System.Diagnostics;
using System.Runtime.CompilerServices;
using System.Threading;
using System.Threading.Tasks;
Expand Down Expand Up @@ -280,10 +279,20 @@ protected override async Task DoHandleCommandAsync(IncomingCommand cmd)
{
if (cmd.CommandId == ProtocolCommandId.BasicCancelOk)
{
Debug.Assert(_consumerTag == new BasicCancelOk(cmd.MethodSpan)._consumerTag);
await _consumerDispatcher.HandleBasicCancelOkAsync(_consumerTag, CancellationToken)
.ConfigureAwait(false);
_tcs.SetResult(true);
var result = new BasicCancelOk(cmd.MethodSpan);
if (_consumerTag == result._consumerTag)
{
await _consumerDispatcher.HandleBasicCancelOkAsync(_consumerTag, CancellationToken)
.ConfigureAwait(false);
_tcs.SetResult(true);
}
else
{
string msg = string.Format("Consumer tag '{0}' does not match expected consumer tag for basic.cancel operation {1}",
result._consumerTag, _consumerTag);
var ex = new InvalidOperationException(msg);
_tcs.SetException(ex);
}
}
else
{
Expand Down
33 changes: 21 additions & 12 deletions projects/RabbitMQ.Client/Impl/Channel.PublisherConfirms.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -32,7 +32,6 @@
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Diagnostics;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading;
Expand Down Expand Up @@ -148,13 +147,14 @@ private async Task MaybeConfirmSelect(CancellationToken cancellationToken)
enqueued = Enqueue(k);

var method = new ConfirmSelect(false);

await ModelSendAsync(in method, k.CancellationToken)
.ConfigureAwait(false);

bool result = await k;
Debug.Assert(result);

return;
if (false == await k)
{
throw new InvalidOperationException(InternalConstants.BugFound);
}
}
finally
{
Expand All @@ -180,12 +180,14 @@ private void HandleAck(ulong deliveryTag, bool multiple)
{
if (multiple)
{
foreach (KeyValuePair<ulong, TaskCompletionSource<bool>> pair in _confirmsTaskCompletionSources)
foreach (KeyValuePair<ulong, TaskCompletionSource<bool>> pair in _confirmsTaskCompletionSources.ToArray())
{
if (pair.Key <= deliveryTag)
{
pair.Value.SetResult(true);
_confirmsTaskCompletionSources.Remove(pair.Key, out _);
if (_confirmsTaskCompletionSources.TryRemove(pair.Key, out TaskCompletionSource<bool>? tcs))
{
tcs.SetResult(true);
}
}
}
}
Expand All @@ -206,18 +208,20 @@ private void HandleNack(ulong deliveryTag, bool multiple, bool isReturn)
{
if (multiple)
{
foreach (KeyValuePair<ulong, TaskCompletionSource<bool>> pair in _confirmsTaskCompletionSources)
foreach (KeyValuePair<ulong, TaskCompletionSource<bool>> pair in _confirmsTaskCompletionSources.ToArray())
{
if (pair.Key <= deliveryTag)
{
pair.Value.SetException(new PublishException(pair.Key, isReturn));
_confirmsTaskCompletionSources.Remove(pair.Key, out _);
if (_confirmsTaskCompletionSources.TryRemove(pair.Key, out TaskCompletionSource<bool>? tcs))
{
tcs.SetException(new PublishException(pair.Key, isReturn));
}
}
}
}
else
{
if (_confirmsTaskCompletionSources.Remove(deliveryTag, out TaskCompletionSource<bool>? tcs))
if (_confirmsTaskCompletionSources.TryRemove(deliveryTag, out TaskCompletionSource<bool>? tcs))
{
tcs.SetException(new PublishException(deliveryTag, isReturn));
}
Expand Down Expand Up @@ -380,6 +384,11 @@ private async Task MaybeEndPublisherConfirmationTracking(PublisherConfirmationIn
await publisherConfirmationInfo.MaybeWaitForConfirmationAsync(cancellationToken)
.ConfigureAwait(false);
}
catch (OperationCanceledException)
{
_confirmsTaskCompletionSources.TryRemove(publisherConfirmationInfo.PublishSequenceNumber, out _);
throw;
}
finally
{
publisherConfirmationInfo.Dispose();
Expand Down
58 changes: 22 additions & 36 deletions projects/RabbitMQ.Client/Impl/Channel.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -234,8 +234,7 @@ await ModelSendAsync(in method, k.CancellationToken)
.ConfigureAwait(false);
}

bool result = await k;
Debug.Assert(result);
AssertResultIsTrue(await k);

await ConsumerDispatcher.WaitForShutdownAsync()
.ConfigureAwait(false);
Expand Down Expand Up @@ -387,8 +386,7 @@ await ModelSendAsync(in method, k.CancellationToken)

try
{
bool result = await k;
Debug.Assert(result);
AssertResultIsTrue(await k);

await MaybeConfirmSelect(cancellationToken)
.ConfigureAwait(false);
Expand Down Expand Up @@ -465,6 +463,14 @@ await c.HandleCommandAsync(cmd)
}
}

private static void AssertResultIsTrue(bool result)
{
if (false == result)
{
throw new InvalidOperationException(InternalConstants.BugFound);
}
}

[MethodImpl(MethodImplOptions.AggressiveInlining)]
protected ValueTask ModelSendAsync<T>(in T method, CancellationToken cancellationToken) where T : struct, IOutgoingAmqpMethod
{
Expand Down Expand Up @@ -978,8 +984,7 @@ await ModelSendAsync(in method, k.CancellationToken)
await ModelSendAsync(in method, k.CancellationToken)
.ConfigureAwait(false);

bool result = await k;
Debug.Assert(result);
AssertResultIsTrue(await k);
}
catch
{
Expand Down Expand Up @@ -1108,9 +1113,7 @@ await ModelSendAsync(in method, k.CancellationToken)

try
{
bool result = await k;
Debug.Assert(result);
return;
AssertResultIsTrue(await k);
}
catch (OperationCanceledException)
{
Expand Down Expand Up @@ -1143,9 +1146,7 @@ await ModelSendAsync(in method, k.CancellationToken)

try
{
bool result = await k;
Debug.Assert(result);
return;
AssertResultIsTrue(await k);
}
catch (OperationCanceledException)
{
Expand Down Expand Up @@ -1187,9 +1188,7 @@ await ModelSendAsync(in method, k.CancellationToken)

try
{
bool result = await k;
Debug.Assert(result);
return;
AssertResultIsTrue(await k);
}
catch (OperationCanceledException)
{
Expand Down Expand Up @@ -1240,9 +1239,7 @@ await ModelSendAsync(in method, k.CancellationToken)

try
{
bool result = await k;
Debug.Assert(result);
return;
AssertResultIsTrue(await k);
}
catch (OperationCanceledException)
{
Expand Down Expand Up @@ -1286,8 +1283,7 @@ await ModelSendAsync(in method, k.CancellationToken)

try
{
bool result = await k;
Debug.Assert(result);
AssertResultIsTrue(await k);
}
catch (OperationCanceledException)
{
Expand Down Expand Up @@ -1332,8 +1328,7 @@ await ModelSendAsync(in method, k.CancellationToken)

try
{
bool result = await k;
Debug.Assert(result);
AssertResultIsTrue(await k);
}
catch (OperationCanceledException)
{
Expand Down Expand Up @@ -1456,8 +1451,7 @@ await ModelSendAsync(in method, k.CancellationToken)

try
{
bool result = await k;
Debug.Assert(result);
AssertResultIsTrue(await k);
}
catch (OperationCanceledException)
{
Expand Down Expand Up @@ -1587,9 +1581,7 @@ await ModelSendAsync(in method, k.CancellationToken)

try
{
bool result = await k;
Debug.Assert(result);
return;
AssertResultIsTrue(await k);
}
catch (OperationCanceledException)
{
Expand Down Expand Up @@ -1621,9 +1613,7 @@ await ModelSendAsync(in method, k.CancellationToken)

try
{
bool result = await k;
Debug.Assert(result);
return;
AssertResultIsTrue(await k);
}
catch (OperationCanceledException)
{
Expand Down Expand Up @@ -1655,9 +1645,7 @@ await ModelSendAsync(in method, k.CancellationToken)

try
{
bool result = await k;
Debug.Assert(result);
return;
AssertResultIsTrue(await k);
}
catch (OperationCanceledException)
{
Expand Down Expand Up @@ -1689,9 +1677,7 @@ await ModelSendAsync(in method, k.CancellationToken)

try
{
bool result = await k;
Debug.Assert(result);
return;
AssertResultIsTrue(await k);
}
catch (OperationCanceledException)
{
Expand Down
73 changes: 56 additions & 17 deletions projects/Test/Integration/TestFloodPublishing.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,7 @@
//---------------------------------------------------------------------------

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Diagnostics;
using System.Threading;
Expand All @@ -43,7 +44,7 @@ namespace Test.Integration
{
public class TestFloodPublishing : IntegrationFixture
{
private static readonly TimeSpan FiveSeconds = TimeSpan.FromSeconds(5);
private static readonly TimeSpan ElapsedMax = TimeSpan.FromSeconds(10);
private readonly byte[] _body = GetRandomBody(2048);

public TestFloodPublishing(ITestOutputHelper output) : base(output)
Expand Down Expand Up @@ -92,31 +93,68 @@ public async Task TestUnthrottledFloodPublishing()
return Task.CompletedTask;
};

var publishTasks = new List<Task>();
var queueArguments = new Dictionary<string, object>
{
["x-max-length"] = 131072,
["x-overflow"] = "reject-publish"
};

QueueDeclareOk q = await _channel.QueueDeclareAsync(queue: string.Empty,
passive: false, durable: false, exclusive: true, autoDelete: true, arguments: queueArguments);
string queueName = q.QueueName;

var exceptions = new ConcurrentBag<Exception>();

async Task WaitPublishTasksAsync(ICollection<ValueTask> publishTasks)
{
foreach (ValueTask pt in publishTasks)
{
try
{
await pt;
}
catch (Exception ex)
{
exceptions.Add(ex);
}
}

publishTasks.Clear();
}

var stopwatch = Stopwatch.StartNew();
int i = 0;
int publishCount = 0;
try
{
for (i = 0; i < 65535 * 64; i++)
var tasks = new List<Task>();
for (int j = 0; j < 8; j++)
{
if (i % 65536 == 0)
tasks.Add(Task.Run(async () =>
{
if (stopwatch.Elapsed > FiveSeconds)
var publishTasks = new List<ValueTask>();
for (int i = 0; i < 65536; i++)
{
break;
}
}
if (stopwatch.Elapsed > ElapsedMax)
{
await WaitPublishTasksAsync(publishTasks);
return;
}

publishCount++;
publishTasks.Add(_channel.BasicPublishAsync(CachedString.Empty, CachedString.Empty, _body).AsTask());
Interlocked.Increment(ref publishCount);
publishTasks.Add(_channel.BasicPublishAsync(exchange: string.Empty, routingKey: queueName, mandatory: true,
body: _body));

if (i % 500 == 0)
{
await Task.WhenAll(publishTasks).WaitAsync(ShortSpan);
publishTasks.Clear();
}
if (i % 128 == 0)
{
await WaitPublishTasksAsync(publishTasks);
}
}

await WaitPublishTasksAsync(publishTasks);
}));
}

await Task.WhenAll(tasks).WaitAsync(WaitSpan);
}
finally
{
Expand All @@ -127,7 +165,8 @@ public async Task TestUnthrottledFloodPublishing()
Assert.False(sawUnexpectedShutdown);
if (IsVerbose)
{
_output.WriteLine("[INFO] published {0} messages in {1}", publishCount, stopwatch.Elapsed);
_output.WriteLine("[INFO] published {0} messages in {1}, exceptions: {2}",
publishCount, stopwatch.Elapsed, exceptions.Count);
}
}

Expand Down