[QUIC] Notify quic streams on connection abort

[CarnaViire]

Algorithm and thoughts:

The only one who knows the Connection was aborted is the Connection itself. Connection's SHUTDOWN_INITIATED_BY_PEER will be immediately followed by Stream's SHUTDOWN_COMPLETED -- which we treat as EndOfStream, hence the issue #32050. As soon as we get Connection's SHUTDOWN_INITIATED_BY_PEER, we want to notify all the Connection's Streams that the Connection was aborted, so the Streams would abort all outstanding operations with the correct exception, and throw on subsequent ones, and ignore Stream's SHUTDOWN_COMPLETED.

This can be done by maintaining a list of Streams inside Connection. There are two problems I see with that: allowing Streams be garbage collected and removing Streams from the list on Stream's Dispose and/or garbage collection.

The first one I solved with WeakReferences.

For the second one I see two possible solutions:

• having a timer inside the Connection that would periodically clean up garbage collected and/or disposed Streams from the list (which I didn't like)
• making Stream to add itself in ctor and remove itself on Dispose. That is what I implemented, but it still is not pretty - because this way Stream also has a link back to Connection. But HTTP/2 also seems to have similar two-way links.

I'm opening that as I already have the working code, but I would be happy to hear other ideas.

Fixes #32050

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Issue Details

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Algorithm and thoughts:

The only one who knows the Connection was aborted is the Connection itself. Connection's SHUTDOWN_INITIATED_BY_PEER will be immediately followed by Stream's SHUTDOWN_COMPLETED -- which we treat as EndOfStream, hence the issue #32050. As soon as we get Connection's SHUTDOWN_INITIATED_BY_PEER, we want to notify all the Connection's Streams that the Connection was aborted, so the Streams would abort all outstanding operations with the correct exception, and throw on subsequent ones, and ignore Stream's SHUTDOWN_COMPLETED.

This can be done by maintaining a list of Streams inside Connection. There are two problems I see with that: allowing Streams be garbage collected and removing Streams from the list on Stream's Dispose and/or garbage collection.

The first one I solved with WeakReferences.

For the second one I see two possible solutions:

• having a timer inside the Connection that would periodically clean up garbage collected and/or disposed Streams from the list (which I didn't like)
• making Stream to add itself in ctor and remove itself on Dispose. That is what I implemented, but it still is not pretty - because this way Stream also has a link back to Connection. But HTTP/2 also seems to have similar two-way links.

I'm opening that as I already have the working code, but I would be happy to hear other ideas.

Fixes #32050

Author:	CarnaViire
Assignees:	-
Labels:	area-System.Net
Milestone:	-

[geoffkizer]

Couldn't we do something like this:

(1) When we get SHUTDOWN_INITIATED_BY_PEER on the connection, set a flag on the connection (we may already do this?)
(2) When we get SHUTDOWN_COMPLETED on the stream, check the flag from (1) and if it's true, abort the stream

I assume we'll get SHUTDOWN_COMPLETED for all open streams promptly after we get SHUTDOWN_INITIATED_BY_PEER...

[CarnaViire]

Closing for now as this may be solved in a better way using microsoft/msquic#1581