From d30278cbfa30871df44d1f672ebb8f7f02dd363f Mon Sep 17 00:00:00 2001 From: Dmitry Kropachev Date: Sat, 14 Feb 2026 07:59:18 -0400 Subject: [PATCH] Fix EventletConnection close() race causing EBADF errors (#614) EventletConnection.close() uses blocking kill() which mostly prevents races, but if close() is called from a non-eventlet thread the greenthread may not be interrupted as expected. - Add is_closed/is_defunct guards in handle_read() and handle_write() error paths to silently exit during shutdown - Set last_error in close() when connected_event is not yet set to prevent factory() from returning a dead connection - Set last_error on server-initiated close (EOF) in handle_read() --- cassandra/io/eventletreactor.py | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/cassandra/io/eventletreactor.py b/cassandra/io/eventletreactor.py index 234a4a574c..7205f2f25b 100644 --- a/cassandra/io/eventletreactor.py +++ b/cassandra/io/eventletreactor.py @@ -148,7 +148,10 @@ def close(self): msg = "Connection to %s was closed" % self.endpoint if self.last_error: msg += ": %s" % (self.last_error,) - self.error_all_requests(ConnectionShutdown(msg)) + shutdown_exc = ConnectionShutdown(msg) + self.error_all_requests(shutdown_exc) + if not self.connected_event.is_set(): + self.last_error = shutdown_exc # don't leave in-progress operations hanging self.connected_event.set() @@ -185,6 +188,8 @@ def handle_read(self): self.process_io_buffer() else: log.debug("Connection %s closed by server", self) + self.last_error = ConnectionShutdown( + "Connection to %s was closed by server" % self.endpoint) self.close() return