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[S.N.Quic] Observe exceptions in ResettableValueTaskSource #114226

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Merged
merged 4 commits into from
Apr 15, 2025
Merged

[S.N.Quic] Observe exceptions in ResettableValueTaskSource #114226

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d92daa7
Observe exceptions in ResettableValueTaskSource
antonfirsov Apr 3, 2025
00383c4
Merge branch 'main' into quic-exceptions-1
antonfirsov Apr 4, 2025
2c6cd10
Update src/libraries/System.Net.Quic/src/System/Net/Quic/Internal/Res…
antonfirsov Apr 8, 2025
9de51bb
Merge branch 'main' into quic-exceptions-1
antonfirsov Apr 8, 2025
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38 changes: 22 additions & 16 deletions src/libraries/System.Net.Quic/src/System/Net/Quic/Internal/ResettableValueTaskSource.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -52,7 +52,7 @@ public ResettableValueTaskSource()
public Action<object?> CancellationAction { init { _cancellationAction = value; } }

/// <summary>
/// Returns <c>true</c> is this task source has entered its final state, i.e. <see cref="TrySetResult(bool)"/> or <see cref="TrySetException(Exception, bool)"/>
/// Returns <c>true</c> is this task source has entered its final state, i.e. <see cref="TrySetResult(bool)"/> or <see cref="TrySetException(Exception)"/>
/// was called with <c>final</c> set to <c>true</c> and the result was propagated.
/// </summary>
public bool IsCompleted => (State)Volatile.Read(ref Unsafe.As<State, byte>(ref _state)) == State.Completed;
Expand Down Expand Up @@ -173,6 +173,7 @@ private bool TryComplete(Exception? exception, bool final)
// Unblock the current task source and in case of a final also the final task source.
if (exception is not null)
{
Debug.Assert(final);
// Set up the exception stack trace for the caller.
exception = exception.StackTrace is null ? ExceptionDispatchInfo.SetCurrentStackTrace(exception) : exception;
if (state is State.None or State.Awaiting)
Expand All @@ -192,7 +193,7 @@ private bool TryComplete(Exception? exception, bool final)
if (_finalTaskSource.TryComplete(exception))
{
// Signal the final task only if we don't have another result in the value task source.
// In that case, the final task will be signalled after the value task result is retrieved.
// In that case, the final task will be signaled after the value task result is retrieved.
if (state != State.Ready)
{
_finalTaskSource.TrySignal(out _);
Expand Down Expand Up @@ -226,15 +227,14 @@ public bool TrySetResult(bool final = false)
}

/// <summary>
/// Tries to transition from <see cref="State.Awaiting"/> to either <see cref="State.Ready"/> or <see cref="State.Completed"/>, depending on the value of <paramref name="final"/>.
/// Only the first call is able to do that with the exception of <c>TrySetResult()</c> followed by <c>TrySetResult(true)</c>, which will both return <c>true</c>.
/// Tries to transition from <see cref="State.Awaiting"/> to <see cref="State.Completed"/>, setting an exception.
/// Only the first call is able to do that.
/// </summary>
/// <param name="final">Whether this is the final transition to <see cref="State.Completed" /> or just a transition into <see cref="State.Ready"/> from which the task source can be reset back to <see cref="State.None"/>.</param>
/// <param name="exception">The exception to set as a result of the value task.</param>
/// <returns><c>true</c> if this is the first call that set the result; otherwise, <c>false</c>.</returns>
public bool TrySetException(Exception exception, bool final = false)
public bool TrySetException(Exception exception)
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Just for the explanation: the bool final = false was here to have the "same" signature as TrySetResult and in the past we did have non-final exceptions (from cancellation).

It could have also gone the other way by making final mandatory to all calls to TrySetResult and TrySetException.

Anyway, this is not a hill I want to die on, so keep the change as-is if you prefer it this way.

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I don't plan to do further refactors in this PR, just leaving my take: It would be better to make it mandatory on TrySetResult() so it's easier to see what the call sites are doing. We can add it back to TrySetException when/if it turns out to be needed again, till then I don't see the value.

{
return TryComplete(exception, final);
return TryComplete(exception, final: true);
}

ValueTaskSourceStatus IValueTaskSource.GetStatus(short token)
Expand Down Expand Up @@ -297,6 +297,7 @@ private struct FinalTaskSource
private bool _isCompleted;
private bool _isSignaled;
private Exception? _exception;
private Task? _signaledTask;

public FinalTaskSource()
{
Expand All @@ -312,9 +313,9 @@ public Task GetTask(object? keepAlive)
{
if (_isSignaled)
{
return _exception is null
? Task.CompletedTask
: Task.FromException(_exception);
_signaledTask ??= _exception is null ? Task.CompletedTask : Task.FromException(_exception);
_ = _signaledTask.Exception; // Observe the exception.
return _signaledTask;
}

_finalTaskSource = new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously);
Expand All @@ -339,6 +340,7 @@ public bool TryComplete(Exception? exception = null)

_exception = exception;
_isCompleted = true;

return true;
}

Expand All @@ -350,13 +352,17 @@ public bool TrySignal(out Exception? exception)
return false;
}

if (_exception is not null)
{
_finalTaskSource?.SetException(_exception);
}
else
if (_finalTaskSource is not null)
{
_finalTaskSource?.SetResult();
if (_exception is not null)
{
_finalTaskSource.SetException(_exception);
_ = _finalTaskSource.Task.Exception; // Observe the exception.
}
else
{
_finalTaskSource.SetResult();
}
}

exception = _exception;
Expand Down
20 changes: 10 additions & 10 deletions src/libraries/System.Net.Quic/src/System/Net/Quic/QuicStream.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -430,7 +430,7 @@ public ValueTask WriteAsync(ReadOnlyMemory<byte> buffer, bool completeWrites, Ca
exception = Volatile.Read(ref _sendException);
if (exception is not null)
{
_sendTcs.TrySetException(exception, final: true);
_sendTcs.TrySetException(exception);
}
}
// SEND_COMPLETE expected, buffer and lock will be released then.
Expand Down Expand Up @@ -487,15 +487,15 @@ public void Abort(QuicAbortDirection abortDirection, long errorCode)

if (abortDirection.HasFlag(QuicAbortDirection.Read))
{
_receiveTcs.TrySetException(ThrowHelper.GetOperationAbortedException(SR.net_quic_reading_aborted), final: true);
_receiveTcs.TrySetException(ThrowHelper.GetOperationAbortedException(SR.net_quic_reading_aborted));
}
if (abortDirection.HasFlag(QuicAbortDirection.Write))
{
var exception = ThrowHelper.GetOperationAbortedException(SR.net_quic_writing_aborted);
Interlocked.CompareExchange(ref _sendException, exception, null);
if (Interlocked.CompareExchange(ref _sendLocked, 1, 0) == 0)
{
_sendTcs.TrySetException(_sendException, final: true);
_sendTcs.TrySetException(_sendException);
Volatile.Write(ref _sendLocked, 0);
}
}
Expand Down Expand Up @@ -585,7 +585,7 @@ private unsafe int HandleEventSendComplete(ref SEND_COMPLETE_DATA data)
Exception? exception = Volatile.Read(ref _sendException);
if (exception is not null)
{
_sendTcs.TrySetException(exception, final: true);
_sendTcs.TrySetException(exception);
}
if (data.Canceled == 0)
{
Expand All @@ -604,12 +604,12 @@ private unsafe int HandleEventPeerSendShutdown()
}
private unsafe int HandleEventPeerSendAborted(ref PEER_SEND_ABORTED_DATA data)
{
_receiveTcs.TrySetException(ThrowHelper.GetStreamAbortedException((long)data.ErrorCode), final: true);
_receiveTcs.TrySetException(ThrowHelper.GetStreamAbortedException((long)data.ErrorCode));
return QUIC_STATUS_SUCCESS;
}
private unsafe int HandleEventPeerReceiveAborted(ref PEER_RECEIVE_ABORTED_DATA data)
{
_sendTcs.TrySetException(ThrowHelper.GetStreamAbortedException((long)data.ErrorCode), final: true);
_sendTcs.TrySetException(ThrowHelper.GetStreamAbortedException((long)data.ErrorCode));
return QUIC_STATUS_SUCCESS;
}
private unsafe int HandleEventSendShutdownComplete(ref SEND_SHUTDOWN_COMPLETE_DATA data)
Expand Down Expand Up @@ -639,8 +639,8 @@ private unsafe int HandleEventShutdownComplete(ref SHUTDOWN_COMPLETE_DATA data)
(shutdownByApp: false, closedRemotely: false) => ThrowHelper.GetExceptionForMsQuicStatus(data.ConnectionCloseStatus, (long)data.ConnectionErrorCode),
};
_startedTcs.TrySetException(exception);
_receiveTcs.TrySetException(exception, final: true);
_sendTcs.TrySetException(exception, final: true);
_receiveTcs.TrySetException(exception);
_sendTcs.TrySetException(exception);
}
_startedTcs.TrySetException(ThrowHelper.GetOperationAbortedException());
_shutdownTcs.TrySetResult();
Expand Down Expand Up @@ -766,11 +766,11 @@ unsafe void StreamShutdown(QUIC_STREAM_SHUTDOWN_FLAGS flags, long errorCode)
{
if (flags.HasFlag(QUIC_STREAM_SHUTDOWN_FLAGS.ABORT_RECEIVE) && !_receiveTcs.IsCompleted)
{
_receiveTcs.TrySetException(ThrowHelper.GetOperationAbortedException(SR.net_quic_reading_aborted), final: true);
_receiveTcs.TrySetException(ThrowHelper.GetOperationAbortedException(SR.net_quic_reading_aborted));
}
if (flags.HasFlag(QUIC_STREAM_SHUTDOWN_FLAGS.ABORT_SEND) && !_sendTcs.IsCompleted)
{
_sendTcs.TrySetException(ThrowHelper.GetOperationAbortedException(SR.net_quic_writing_aborted), final: true);
_sendTcs.TrySetException(ThrowHelper.GetOperationAbortedException(SR.net_quic_writing_aborted));
}
}
}
Expand Down
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