When XInitThreads() function is invoked, the application will hang up as long as you press any key to input some messages in Qt4 application. Reproducible with the following program. #include <QApplication> #include <QLineEdit> #include <QDialog> #include <X11/Xlib.h> int main(int argc, char *argv[]) { XInitThreads(); QApplication app(argc, argv); QDialog dialog; QLineEdit lineEdit(&dialog); dialog.show(); return app.exec(); } Compile against Qt4, run, select the text input box and type a character. The application will lock. Running under gdb gives the following stack-trace: #0 0x0000003f68a0d524 in __lll_lock_wait () from /lib64/libpthread.so.0 #1 0x0000003f68a08e1a in _L_lock_1034 () from /lib64/libpthread.so.0 #2 0x0000003f68a08cdc in pthread_mutex_lock () from /lib64/libpthread.so.0 #3 0x0000003f69e35163 in ?? () from /usr/lib64/libX11.so.6 #4 0x0000003f69e99e7d in XkbGetUpdatedMap () from /usr/lib64/libX11.so.6 #5 0x0000003f69e99f75 in XkbGetMap () from /usr/lib64/libX11.so.6 #6 0x0000003f69e95ce1 in ?? () from /usr/lib64/libX11.so.6 #7 0x0000003f69e963fb in XkbLookupKeySym () from /usr/lib64/libX11.so.6 #8 0x0000003f69e964cb in XLookupString () from /usr/lib64/libX11.so.6 #9 0x0000003f69e6e7ec in _XimLocalFilter () from /usr/lib64/libX11.so.6 #10 0x0000003f69e281d4 in XFilterEvent () from /usr/lib64/libX11.so.6 #11 0x00002aaaaaff48d3 in ?? () from /usr/lib64/qt4/lib64/libQtGui.so.4 #12 0x00002aaaaac803c0 in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib64/qt4/lib64/libQtGui.so.4 #13 0x00002aaaaaca1d87 in ?? () from /usr/lib64/qt4/lib64/libQtGui.so.4 #14 0x00002aaaab4ae058 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/lib64/libQtCore.so.4 #15 0x00002aaaab4ae169 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/lib64/libQtCore.so.4 #16 0x00002aaaab4b05db in QCoreApplication::exec() () from /usr/lib64/qt4/lib64/libQtCore.so.4 #17 0x0000000000400ab8 in main () It would appear that the function at line 3 is trying to lock a mutex that has previously been locked.
This request was evaluated by Red Hat Product Management for inclusion in the current release of Red Hat Enterprise Linux. Because the affected component is not scheduled to be updated in the current release, Red Hat is unfortunately unable to address this request at this time. Red Hat invites you to ask your support representative to propose this request, if appropriate and relevant, in the next release of Red Hat Enterprise Linux.
This bug/component is not included in scope for RHEL-5.11.0 which is the last RHEL5 minor release. This Bugzilla will soon be CLOSED as WONTFIX (at the end of RHEL5.11 development phase (Apr 22, 2014)). Please contact your account manager or support representative in case you need to escalate this bug.
Thank you for submitting this request for inclusion in Red Hat Enterprise Linux 5. We've carefully evaluated the request, but are unable to include it in RHEL5 stream. If the issue is critical for your business, please provide additional business justification through the appropriate support channels (https://access.redhat.com/site/support).