On Thu, 3 Apr 2003 Tushar_Oza@xxxxxxxx wrote: > Yes... Infact I do have printfs that count moduleAttach's > And print 'em out. So it is decremented to zero and I assume the library is > unloaded. > > At that point, I need the registered handlers to be "unregistered" (in some > way) > If not, the executable has a seg fault (core dump) > > Makes sense? ;-) If you're asking me, you're really pressing your luck. You probably no more about this stuff than I do, but maybe I have more experience resolving problems. I guess that if the library's unloaded, it's not open any more. The lsof command can tell you what files are open. You might need a sleep(600); at some crucial point. Have you tried gdb on this? It works best if you compile with debugging options. > > -----Original Message----- > From: John [mailto:red@xxxxxxxxxxxxxxxxxxxxxxx] > Sent: Thursday, April 03, 2003 7:59 PM > To: redhat-devel-list@xxxxxxxxxx > Subject: Re: pthread_atfork() problem on Linux9 > > > On Thu, 3 Apr 2003 Tushar_Oza@xxxxxxxx wrote: > > > Hello, > > > > A brief description of the problem we see on Linux 9 follows: > > > > Please let me know if any of you have seen this problem or know how to > > tackle it! > > > > > > I have a "mylib.so" that calls: > > > > _init() > > { > > pthread_atfork(NULL, ParentHdlr, ChildHdlr); > > } > > > > _fini() > > { > > // do nothing > + printf(unloading\n"); > > } > > > > > > Another executable mytest.c does the following: > > > > main() > > { > > void *libHandle = NULL; > > > > libHandle = dlopen("mylib.so", RTLD_NOW); > > // dlopen() call succeeds so I have not included my error checking > > code here > > dlclose(libHandle); > > libHandle = NULL; > > ... > > printf("\n In mytest.c: Before fork \n"); > > > > if ((pid = fork()) < 0) > > { > > printf("Fork failed\n"); > > } > > > > printf("Something after fork\n"); > > } > > > > > > Note that the fork() is called after the dlclose() > > And mytest.c is NOT linked with mylib.so > > > > The problem is mytest.c causes a SEGMENTATION FAULT on Linux9. Seems > > to work fine on Linux 8 and below. > > > > We suspect that the atfork() handler functions registered at _init are > > lost And that causes the seg fault before the fork() since it cant > > find the handlers anymore as the library has been closed. > > > > Any help is appreciated. Thanks! > >From the man page on my system: > > dlclose decrements the reference count on the dynamic library handle > handle. If the reference count drops to zero and no other loaded libraries > use symbols in it, then the dynamic library is unloaded. If the dynamic > library exports a routine named _fini, then that routine is called just > before the library is unloaded. > > > I think unloading is legitimate. Try my patch to see whether it happens. > > -- Please, reply only to the list. _______________________________________________ Redhat-devel-list mailing list Redhat-devel-list@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/redhat-devel-list
