On Wed, Feb 08, 2017 at 10:31:53PM +0100, Joerg Sonnenberger wrote: > On Wed, Feb 08, 2017 at 05:08:49PM +0100, Martin Husemann wrote: > > I would like to adopt a hack like FreeBSD did here: > > > > https://lists.freebsd.org/pipermail/svn-src-head/2010-August/019849.html > > > > This allows dynamically loaded shared libraries to install > > pthread_atexit handlers. Currently there is no way for the lib to > > deinstall the handler in time, and later fork()s would crash the app. > > > > The same behaviour (auto deinstall the handlers) has been implemented > > in Linux and Solaris as well. > > > > I don't like the solution, but now solving it differently sounds painfull > > as well. > > > > What do others think? > > The FreeBSD way is not acceptable at all. It violates core assumptions > for all the ways TLS can be used. The claims are not correct either, > since pthread_[gs]etspecific can be used correctly from shared > libraries. The only implementation choice that is somewhat reasonable is > to just mark the DSO as busy.
Sorry, wrong rant. That was for the TLS destructor problem where similar crude hacks exist. The FreeBSD "solution" is still wrong. Introducing __pthread_cxa_finalize or even a public interface for that is fine. Iterating over all text segments to guess what handlers to remove is definitely not fine. Joerg
