On 2013/01/12 07:29, Jilles Tjoelker wrote: > On Fri, Jan 11, 2013 at 10:49:38PM +0200, Konstantin Belousov wrote: >> http://people.freebsd.org/~kib/misc/rtld-sigblock.3.patch > The new fields td_sigblock_ptr and td_sigblock_val are in the part that > is zeroed for new threads, while the code in rtld appears to expect them > to be copied (on fork, vfork and pthread_create). The fields are > correctly zeroed on exec. > > Sharing the magic variable between threads means that one thread holding > an rtld lock will block signals for all other threads as well. This is > different from how the normal signal mask works but I don't know whether > it may break things. However, the patch depends on it in some way > because sigtd() does not know about fast sigblock and will therefore > happily select a thread that is fast-sigblocking to handle a signal > directed at the process. > > Although libthr's postpone approach is somewhat ugly, it does not depend > on any non-standard kernel features and does not delay the default > action. Would it be possible to move that code to libc to make things > easier for rtld? It looks like this requires teaching libc about various > threading concepts, though. Long time ago, if i remembered correctly, kib said that he wanted to merge libthr code into libc, I don't know its state.
> Something feels ugly about not allowing applications to use this, > although I don't know how it would work. On the other hand, the strange > signal state created by this and implicit assumptions that the duration > will be short may be a reason to restrict its use to a relatively small > piece of code. > True, it seems it is for short duration. _______________________________________________ freebsd-toolchain@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-toolchain To unsubscribe, send any mail to "freebsd-toolchain-unsubscr...@freebsd.org"
