On Sat, Oct 6, 2018 at 8:55 PM Thomas Koenig <tkoe...@netcologne.de> wrote:
> Hi Jerry, > > > Agree it should be fixed. I would think a mutex lock should work. Lock, > > issue error message, unlock. Even if there is recursion, since there is > > at least one error somewhere, It should be OK to pause the world to > > issue the error, and come back and finish. AS I think about it, maybe > > one global lock variable so that only one thread can get it at a time > > and others wait until it is unlcoked to proceed with their lock and > error. > > > Would there be a problem with some sort of endless loop waiting for the > > unlock? > > I think that as long as we > > a) make the lock recursive > > b) make sure to unlock it afterwards > > we should be fine, we also should not enter an endless loop on > the rare case of aa double error. > > I can prepare a patch, unless somebody else wants to do it. > The error handling functions can be called from a signal handler, so they need to be async-signal-safe. See a list e.g. at http://www.man7.org/linux/man-pages/man7/signal-safety.7.html . Notably, none of the pthread mutex functions are there. And come to think of it, neither are pthread_{g,s}etspecific(), so my idea of using TLS a few messages earlier in this thread is probably not Ok either.. -- Janne Blomqvist
