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? 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. -- 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
