This problem with synergyc is actually synergy's own defect related to using X11 from multiple threads. The connection to the kernel schedule is seen because a race condition in the application is turning out badly more often than it used to. But the right fix for this problem is in synergy.
I just added this fix as a comment to the upstream report at http://sourceforge.net/tracker/index.php?func=detail&aid=1930587&group_id=59275&atid=490467 This problem is caused by a bad assumption in the use of poll or select on the X11 socket connection when waiting for an event in CXWindowsEventQueueBuffer::waitForEvent*(). The assumption is that any new event will wake the thread when the socket becomes ready to read. The flaw in that reasoning is that Xlib will read the data for several events at once if it is available. The calls to XSendEvent and XFlush in CXWindowsEventQueueBuffer::flush can read data from the X11 socket and put it in an Xlib buffer. That will change the XPending and isEmpty status without ever finishing the poll or select call. The flush function can be called either from another thread via addEvent or in the direct call to flush in waitForEvent itself. The severity of these problems will vary greatly with changes to the scheduling of threads and the X server. It is not surprising that they show up more often with some kernels than with others. The attached diffs fix the two cases. The call to flush in waitForEvent is followed by a new call to isEmpty to check if the flush caused any events to be read. The call to flush in addEvent is followed by writing a character to the write side of a pipe. The poll or select call in waitForEvent then waits for a readable state on either the X11 socket or the pipe. ** Attachment added: "fix for lag of synergyc on input" http://launchpadlibrarian.net/13995863/synergy_diffs -- 2.6.24-8 Introduces Network Issue https://bugs.launchpad.net/bugs/194029 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
