Defer main loop start until after the header is sent - #2020
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A previous commit moved _frameHandler.initialize(this) before
sendHeader() in AMQConnection.start() to fix a race where the I/O
thread could dereference a still-null connection reference on a fast
broker reply. For SocketFrameHandler, though, initialize() also
starts the MainLoop thread, which begins blocking-reading the socket
right away.
That reader thread now runs concurrently with the header write. For
TLS sockets the handshake is lazy and triggered by whichever
operation touches the socket first, read or write. When the peer
certificate is rejected, the thread that loses the race can see a
generic SocketException ("Connection or outbound has closed") instead
of the real SSLHandshakeException, since the other thread already
tore down the connection. This showed up as a flaky
SslContextFactoryTest failure on CI.
Split the two concerns: FrameHandler.initialize() still runs before
sendHeader(), so the connection reference is set in time for an
early reply, but a new FrameHandler.startProcessing() hook - called
only after sendHeader() succeeds - is now responsible for actually
starting a dedicated reader thread. SocketFrameHandler moves its
connection.startMainLoop() call there. Netty and NIO ignore the new
hook, since they already read asynchronously and aren't affected by
this race.
References #2018
acogoluegnes
marked this pull request as ready for review
July 9, 2026 16:46
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A previous commit moved _frameHandler.initialize(this) before sendHeader() in AMQConnection.start() to fix a race where the I/O thread could dereference a still-null connection reference on a fast broker reply. For SocketFrameHandler, though, initialize() also starts the MainLoop thread, which begins blocking-reading the socket right away.
That reader thread now runs concurrently with the header write. For TLS sockets the handshake is lazy and triggered by whichever operation touches the socket first, read or write. When the peer certificate is rejected, the thread that loses the race can see a generic SocketException ("Connection or outbound has closed") instead of the real SSLHandshakeException, since the other thread already tore down the connection. This showed up as a flaky SslContextFactoryTest failure on CI.
Split the two concerns: FrameHandler.initialize() still runs before sendHeader(), so the connection reference is set in time for an early reply, but a new FrameHandler.startProcessing() hook - called only after sendHeader() succeeds - is now responsible for actually starting a dedicated reader thread. SocketFrameHandler moves its connection.startMainLoop() call there. Netty and NIO ignore the new hook, since they already read asynchronously and aren't affected by this race.
References #2018