Status: New Owner: ---- Labels: Version Type-Bug Priority-Medium OpSys-Any Dist-Any Arch-Any Desktop-Any GUI-Any
New issue 226 by x1f3o3...@gmail.com: SIGSEGV handler overwritten (for too long) http://code.google.com/p/gambas/issues/detail?id=226 1) Describe the problem. "main/gbx/gbx_stream_memory.c" In "static int stream_read(STREAM *stream, char *buffer, int len)" the current SIGSEGV signal handler is replaced by CHECK_enter(). This is probably done to catch errors during memory access. However, a problem arises when using a library which also uses a SIGSEGV handler, and at the same time uses a background thread which depends on that particular handler. I was not yet able to test this further, but when the background thread crashes the gambas signal handler seems to receive the error, it will therefore crash. You get a signal #11 error from gambas. The same problem also applies to the "type@()" functions. 2) GIVE THE FOLLOWING INFORMATIONS (if they are appropriate): Version: TRUNK Revision: All, at the time of writing r4384 Operating system: All, tested on Linux Distribution: All, tested on ArchLinux Architecture: All, tested on x86_64 GUI component: All Desktop used: All 3) Provide a little project that reproduces the bug or the crash. 4) If your project needs a database, try to provide it, or part of it. Not necessary yet 5) Explain clearly how to reproduce the bug or the crash. 1. Create a thread in an "extern" function and set up a SIGSEGV handler a2. In the thread, do something to trigger the SIGSEGV handler a3. In the SIGSEGV handler handle the error and continue execution b2. Try to access memory using a pointer from your gambas application 4. *Crash* A possible solution would be to add an "unsafe" mode which would disable the CHECK_* signal handlers. An alternative would be to warn the user if an error handler was already installed before, then continue without error handling. As a temporary solution I wrote my own set of memory access functions in another library which simply work like the "type@" functions. However, this requires unnecessary support code. It also means that you have to carry a module or classname around. However, this probably affects other functions using the CHECK_*() functions too. ------------------------------------------------------------------------------ This SF email is sponsosred by: Try Windows Azure free for 90 days Click Here http://p.sf.net/sfu/sfd2d-msazure _______________________________________________ Gambas-user mailing list Gambas-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/gambas-user
