Hi Stefan, On Thu, Mar 14, 2013 at 11:44 AM, Stefan Puiu <stefan.puiu@xxxxxxxxx> wrote: > Hi Michael (and list!), > > I was trying to detect some memory leaks in some shared libraries > (plugins) that are loaded and unloaded during a normal run in our > application, and needed a way to ensure that valgrind could find the > symbols from libraries after they were unloaded. The best bet for that > was the RTLD_NODELETE flag to dlopen(), which results in the shared > library not getting unloaded. There's a small caveat, though: > destructors (functions marked with "__attribute__((destructor))") are > not called when calling dlclose() - that's the behavior I'm seeing on > the ancient glibc we use (2.3.3). > > As far as I read the current manpage, this information is not clearly > stated - the fact that static variables are not reinitialized when > reloading the library is at most a hint that constructors/destructors > won't follow the normal workflow either. I think adding some > clarifications about this makes sense. What do you think? What you say sounds reasonable, but I'd like to verify. Are you able to provide a very simple program for testing this, and a demo script of how to demonstrate it? Thanks, Michael > diff --git a/man3/dlopen.3 b/man3/dlopen.3 > index b1f21be..92950fa 100644 > --- a/man3/dlopen.3 > +++ b/man3/dlopen.3 > @@ -159,9 +159,10 @@ references in subsequently loaded libraries. > Do not unload the library during > .BR dlclose (). > Consequently, the library's static variables are not reinitialized > -if the library is reloaded with > +(and constructor routines are not called) if the library is reloaded > +with > .BR dlopen () > -at a later time. > +at a later time. Also, destructor routines are not called. > This flag is not specified in POSIX.1-2001. > .\" (But it is present on Solaris.) > .TP > > Thanks, > Stefan. -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Author of "The Linux Programming Interface"; http://man7.org/tlpi/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
