<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW --- - The tutorial should have a section on error handling" href="https://bugs.freedesktop.org/show_bug.cgi?id=78140#c3">Comment # 3</a> on <a class="bz_bug_link bz_status_NEW " title="NEW --- - The tutorial should have a section on error handling" href="https://bugs.freedesktop.org/show_bug.cgi?id=78140">bug 78140</a> from <a class="email" href="mailto:psychon@znc.in" title="Uli Schlachter <psychon@znc.in>"> Uli Schlachter</a> <pre>(In reply to <a href="show_bug.cgi?id=78140#c2">comment #2</a>) > I should be able to put together at least a prototype myself but I need to > ask a few more questions. Thanks a lot! > Do I need to call xcb_connection_has_error after absolutely every function > that gets passed a connection? Nope. Nothing bad happens when you use an xcb_connection_t that is an error state. Must functions will just return e.g. NULL (however, no one ever expects e.g. xcb_get_setup() to return NULL, so other code can still crash...). > Is there a function to get an error string for each error (keep in mind that > one may want to sometimes localize error messages so this is not as easy as > it seems). Nope, and I wouldn't want to add one exactly because of things like localization. I guess you are expected to write your own function that translates the ~5 error codes that are currently in-use into a string and that returns something like "unknown error 42" for other values. E.g. qt does the following: <a href="https://qt.gitorious.org/qt/qtbase/source/d52b00e1d3cc60c81b54a89d6da488dc4bbce384:src/plugins/platforms/xcb/qxcbconnection.cpp#L95-126">https://qt.gitorious.org/qt/qtbase/source/d52b00e1d3cc60c81b54a89d6da488dc4bbce384:src/plugins/platforms/xcb/qxcbconnection.cpp#L95-126</a> > How do I check for errors with the xcb_disconnect function (I know that > free(3) does not give errors but what about close(2))? There just are no errors. :-) Also, there aren't many sensible things that can be done if close(), pthread_mutex_destroy() or pthread_cond_destroy() fail (AFAIR on some systems close() can fail and still have closed the FD already, so retrying would be unsafe in multi-threaded programs anyway). So if any errors occur during xcb_disconnect(), you'll get a memory / file descriptor leak.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are the assignee for the bug.</li> </ul> </body> </html>