On 9 October 2018 at 12:16, Paolo Bonzini <pbonz...@redhat.com> wrote: > On 08/10/2018 18:40, Kevin Wolf wrote: >>> >>> I'm pretty confident this analysis of the problem is correct: >>> unfortunately I have no idea what the right way to fix it is... >> Yes, I agree with your analysis. If __thread variables can be destructed >> before pthread_key_create() destructors are called (and in particular if >> the former are implemented in terms of the latter), this implies at >> least two rules: >> >> 1. The Notfier itself can't be a TLS variable >> >> 2. The notifier callback can't access any TLS variables >> >> Of course, with these restrictions, qemu_thread_atexit_*() with its >> existing API is as useless as it could be. > > Yup, we have to stop using pthread_key_create. Luckily, these days > there is always qemu_thread_start that wraps the thread, so we can call > qemu_thread_atexit_run from there, and change exit_key to a thread-local > NotifierList.
We would also need to catch exits via qemu_thread_exit(), right? We probably also need to handle the main thread specially, via atexit(). This seems to be pretty much what we already do in util/qemu-thread-win32.c... thanks -- PMM
