Brad Arant
cfc0b19418
shutdown() only sets shutDown=true and expects the fifo to drain normally before eventReceived()'s keepAlive check (!shutDown || (fifo.size() > 0 && !readHangup)) lets the connection close - correct for a graceful QUIT/LOGOUT reply that just needs a few more successful writes to flush, but exactly backwards for the give-up path: the whole reason that path was reached is that the front of the fifo can never be sent. Leaving it queued meant keepAlive stayed true forever, resetSocket() kept re-arming EPOLLWRNORM because fifo wasn't empty, the very next write attempt hit the identical stall immediately, and shutdown() got called again - forever, at whatever rate the kernel could fire EPOLLWRNORM. Confirmed live on a real internet-facing server (Zephora's game server, an ordinary port-scanner connection was enough to trigger it): one socket logged "consecutive writes made zero progress - giving up and shutting down" 2.4 million+ times in under 4 milliseconds, pegging a worker thread at 100% CPU indefinitely. The give-up path now clears the undeliverable fifo entry before calling shutdown(), so keepAlive correctly evaluates to just !shutDown (now false) on the next cycle and the connection actually tears down.