Re: [Qemu-block] [Qemu-devel] [PATCH] tests: Disable test-bdrv-drain

[Peter Maydell]

On 9 October 2018 at 12:16, Paolo Bonzini <address@hidden> 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