The sane library and/or its backends don't seem to "clean up" after themselves by restoring signal handlers and/or signal masks. This isn't a problem for a simple application that only serves as a front end for libsane, but does cause problems in a modular application where libsane may not always be loaded. For instance, if I wrap libsane and access it indirectly through some component technology, when the component that uses libsane is unloaded, the signal handlers installed by libsane and its backends will still be installed. Of course, the library is no longer loaded in the process memory space so the function pointers used for the signal handlers are no longer valid. If a signal for that signal handler is then received, it causes a SIGSEGV. This can easily happen if you use a sane backend that sets a SIGCHLD signal handler, unload the component consuming libsane, and then use system(3) to launch a shell command.Is this a problem or is there something I'm missing here? Does anyone have any advice on the "correct" way to work around this problem? Thanks!-- Ryan _________________________________________________________________ Use Messenger to talk to your IM friends, even those on Yahoo! http://ideas.live.com/programpage.aspx?versionId=7adb59de-a857-45ba-81cc-685ee3e858fe -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.alioth.debian.org/pipermail/sane-devel/attachments/20060911/5bfc879d/attachment.html From r...@keenan.dk Tue Sep 12 12:26:40 2006 From: r...@keenan.dk (=?iso-8859-1?Q?Ren=E9_Kjellerup?=) Date: Tue Sep 12 18:52:13 2006 Subject: [sane-devel] Requesting progress on CanoScan 4200F Message-ID: <000d01c6d666$b3459d50$9d701005@rkj>
Hi' I know that as of yet the CanoScan 4200F is Unsupported by SANE http://www.sane-project.org/unsupported/canon-4200f.html All I wish to know is, is there somebody working On writing a backend, or is there plans for it to be included in the plustek or genesys backend? If not, then I could use some guidence on howto use libusb and the SANE API to write a backend, if anyone would be so kind. High hopes from Ren? Kjellerup
