Fix Register/Deregister race on Signal #431
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mlsmaycon
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Aug 22, 2022
pulsastrix
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Dec 24, 2023
This PR fixes a race condition that happens when agents connect to a Signal stream, multiple times within a short amount of time. Common on slow and unstable internet connections. Every time an agent establishes a new connection to Signal, Signal creates a Stream and writes an entry to the registry of connected peers storing the stream. Every time an agent disconnects, Signal removes the stream from the registry. Due to unstable connections, the agent could detect a broken connection, and attempt to reconnect to Signal. Signal will override the stream, but it might detect the old broken connection later, causing peer deregistration. It will deregister the peer leaving the client thinking it is still connected, rejecting any messages.
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This PR fixes a race condition that happens
when agents connect to a Signal stream, multiple
times within a short amount of time. Common on
slow and unstable internet connections.
Every time an agent establishes a new connection
to Signal, Signal creates a Stream and writes an entry
to the registry of connected peers storing the stream.
Every time an agent disconnects, Signal removes the
stream from the registry.
Due to unstable connections, the agent could detect
a broken connection, and attempt to reconnect to Signal.
Signal will override the stream, but it might detect
the old broken connection later, causing peer deregistration.
It will deregister the peer leaving the client thinking
it is still connected, rejecting any messages.