{"action":"created","issue":{"url":"https://api.github.com/repos/synergy/synergy/issues/5157","labels_url":"https://api.github.com/repos/synergy/synergy/issues/5157/labels{/name}","comments_url":"https://api.github.com/repos/synergy/synergy/issues/5157/comments","events_url":"https://api.github.com/repos/synergy/synergy/issues/5157/events","html_url":"https://github.com/synergy/synergy/issues/5157","id":122343373,"number":5157,"title":"Assert in xcb_io.c / seg fault when rapidly switching screens","user":{"login":"james-fowler","id":16144277,"avatar_url":"https://avatars.githubusercontent.com/u/16144277?v=3","gravatar_id":"","url":"https://api.github.com/users/james-fowler","html_url":"https://github.com/james-fowler","followers_url":"https://api.github.com/users/james-fowler/followers","following_url":"https://api.github.com/users/james-fowler/following{/other_user}","gists_url":"https://api.github.com/users/james-fowler/gists{/gist_id}","starred_url":"https://api.github.com/users/james-fowler/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/james-fowler/subscriptions","organizations_url":"https://api.github.com/users/james-fowler/orgs","repos_url":"https://api.github.com/users/james-fowler/repos","events_url":"https://api.github.com/users/james-fowler/events{/privacy}","received_events_url":"https://api.github.com/users/james-fowler/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":3,"created_at":"2015-12-15T19:13:23Z","updated_at":"2015-12-16T00:27:34Z","closed_at":null,"body":"When moving the mouse rapidly across screens, my synergy client is crashing  \r\n\r\n    ....\r\n    [2015-12-15T13:30:35] DEBUG: open clipboard 0\r\n    [2015-12-15T13:30:35] INFO: entering screen\r\n    synergyc: ../../src/xcb_io.c:254: poll_for_event: Assertion `dpy->xcb->event_owner ==  XlibOwnsEventQueue && !dpy->xcb->event_waiter' failed.\r\n    Aborted\r\n\r\nor occasionally \r\n\r\n    ....\r\n    [2015-12-15T13:48:18] DEBUG: open clipboard 1\r\n    [2015-12-15T13:48:18] DEBUG: close clipboard 1\r\n    [2015-12-15T13:48:18] INFO: entering screen\r\n    Segmentation fault\r\n\r\nThis is more or less repeatable for me, under the following setup:\r\n\r\n* both client and server are run with ***-f -d DEBUG***\r\n* big chunk of text (around a dozen lines from a terminal) is copied to clipboard on the client\r\n* server is left of client\r\n* spin mouse (trackball with pointer speed maxed in settings) rapidly left to right, traversing across both systems and wrapping around several times a second\r\n* keep trying, usually will happen within thirty seconds (sometimes happens much sooner, originally caught this by accident while tweaking pointer speed)\r\n* both client and server are Ubuntu 15.10 \r\n* client is fresh unmodified build of the current synergy [master](https://github.com/synergy/synergy/commit/7a207b4a54bf0b9c0199cfc04f9d44497a0ee372)\r\n* server is built from https://github.com/james-fowler/synergy/tree/FixClipboard\r\n\r\n\r\nSmells like something timing related, possibly with multi-step clipboard stuff getting started on entry into the client but not having time to complete before leaving (and potentially wrapping back in)? \r\n\r\nIt's plausible that the increased debug output is introducing delay which contributes to the issue, however I was able to duplicate the seg fault without it (***synergyc -f server_name***).  \r\n\r\nI've reproduced this dozens of times.  I have only seen it crash the client (not the server), and I'm fairly certain it only happens when the client has set the clipboard.  Spent a few minutes trying to break it with clipboard copied from the server side and it wouldn't break.\r\n\r\nI would expect this to occur exceedingly rarely, if at all, in normal use - there's not a lot of practical need for spinning your cursor through all your screens several times a second - but it still would be nice to understand why this is happening, and ideally get it fixed. \r\n\r\n-- James"},"comment":{"url":"https://api.github.com/repos/synergy/synergy/issues/comments/164944255","html_url":"https://github.com/synergy/synergy/issues/5157#issuecomment-164944255","issue_url":"https://api.github.com/repos/synergy/synergy/issues/5157","id":164944255,"user":{"login":"XinyuHou","id":9194706,"avatar_url":"https://avatars.githubusercontent.com/u/9194706?v=3","gravatar_id":"","url":"https://api.github.com/users/XinyuHou","html_url":"https://github.com/XinyuHou","followers_url":"https://api.github.com/users/XinyuHou/followers","following_url":"https://api.github.com/users/XinyuHou/following{/other_user}","gists_url":"https://api.github.com/users/XinyuHou/gists{/gist_id}","starred_url":"https://api.github.com/users/XinyuHou/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/XinyuHou/subscriptions","organizations_url":"https://api.github.com/users/XinyuHou/orgs","repos_url":"https://api.github.com/users/XinyuHou/repos","events_url":"https://api.github.com/users/XinyuHou/events{/privacy}","received_events_url":"https://api.github.com/users/XinyuHou/received_events","type":"User","site_admin":false},"created_at":"2015-12-16T00:27:34Z","updated_at":"2015-12-16T00:27:34Z","body":"@james-fowler \r\nWe are planning to release v1.7.6 soon which is currently under beta testing."}}