Problem analysis for new issue: When a client connection is rejected by the server, the connection is closed. Depending on the timing, the client will detect the connection break either while sending the request to the server, or when it is trying to read back the response.
In the first case, an exception is thrown while calling the server.connect() method, and an error connection is returned to the client (see mir_default_connect() in mir_client_library.cpp). The client can then successfully call mir_connection_release() on the error connection. In the second case, an exception is thrown while trying to read back the server response, causing the client stack to force completion of pending RPC calls (the connect() call). The client ends up with an invalid connection object, but not an error connection object. Calling mir_connection_release() on this object blocks, because, although an exception is thrown by the server.disconnect() method, the disconnect_wait_handle is not updated. This happens because in MirSocketRpcChannel::notify_disconnected() the pending RPC calls are not forced to complete, since the channel has already been marked as 'disconnected' by the previous connect failure. This bug is an instance of calling a function that talks to the server after a connection break has been detected in a previous call. Note that if the break is first detected while calling the funcion, then the call doesn't block, since this is the first time we call MirSocketRpcChannel::notify_disconnected() and the pending RPC calls are forced to complete. See https://code.launchpad.net/~afrantzis/mir/fix-1201436-more/+merge/191784 for a suggested solution. ** Changed in: mir Status: Triaged => In Progress ** Branch linked: lp:~afrantzis/mir/fix-1201436-more -- You received this bug notification because you are a member of UbuntuKylin Members, which is subscribed to a duplicate bug report (1220493). https://bugs.launchpad.net/bugs/1201436 Title: Intermittent hang in ClientPidTestFixture.authorizer_may_prevent_connection_of_clients test Status in Mir: In Progress Bug description: I noticed some Intermittent hangs in the ClientPidTestFixture.authorizer_may_prevent_connection_of_clients tests. They are present on both Android and the desktop, although they are much more easily reproducible on an Android device. Run each test with --gtest_repeat=N to catch this (and even then may need multiple runs). To manage notifications about this bug go to: https://bugs.launchpad.net/mir/+bug/1201436/+subscriptions -- Mailing list: https://launchpad.net/~ubuntukylin-members Post to : [email protected] Unsubscribe : https://launchpad.net/~ubuntukylin-members More help : https://help.launchpad.net/ListHelp
