[libc-commits] [PATCH] D76676: [libc] Unblock SIGABRT before raising in abort

Siva Chandra via Phabricator via libc-commits libc-commits at lists.llvm.org
Fri Apr 3 10:47:31 PDT 2020


sivachandra added inline comments.


================
Comment at: libc/src/stdlib/abort.cpp:34
+  // interrupted by any async signals. The user handler will be run once we
+  // unblock if it was blocked previously.
+  sigset_t set;
----------------
MaskRay wrote:
> abrachet wrote:
> > MaskRay wrote:
> > > Another thread may concurrently install a signal handler for SIGABRT or unblock SIGABRT. There needs to be a lock.
> > Yes this was discussed, we need a recursive lock here but also in sigaction, we don't have those yet. I don't personally think the benefits are worth that complexity anyway though.
> This suggests that the patches should be applied in a better way. If a mutex is implemented before improving abort, then we don't need to care about this.
> 
> I think a non-recursive mutex suffices here.
Perfect is the enemy of the good: https://en.wikipedia.org/wiki/Perfect_is_the_enemy_of_good
FWIW, this albeit incomplete implementation allowed us to make progress with other pieces. Not to claim other pieces are complete or perfect. As I said in another post, the quest for perfection hinders progress, and more importantly, hinders our own learning.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D76676/new/

https://reviews.llvm.org/D76676





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