On Wed, Feb 20, 2019 at 05:06:25PM +0100, Marc-André Lureau wrote:
> Another thread may acquire the glib context (temporarily) before
> g_main_context_push_thread_default().
>
> This can happen with the following qemu_chr_fe_set_handlers()
> modifications.
>
> Unfortunately, g_main_context_wait() is deprecated in glib
> 2.58 (apparently it was a broken interface). Use a polling loop.
>
> Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> ---
> iothread.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/iothread.c b/iothread.c
> index e615b7ae52..93cc3aa875 100644
> --- a/iothread.c
> +++ b/iothread.c
> @@ -70,6 +70,11 @@ static void *iothread_run(void *opaque)
> if (iothread->running && atomic_read(&iothread->worker_context)) {
> GMainLoop *loop;
>
> + /* we may race with another thread acquiring the context */
> + while (!g_main_context_acquire(iothread->worker_context)) {
> + g_usleep(10000);
> + }
Could you help explain why need this explicitly? Since AFAIU
g_main_loop_run() below will do context acquire too so IIUC you're
taking it twice (while g_main_context_acquire should allow it to
happen, though)?
> +
> g_main_context_push_thread_default(iothread->worker_context);
> iothread->main_loop =
> g_main_loop_new(iothread->worker_context, TRUE);
> @@ -80,6 +85,8 @@ static void *iothread_run(void *opaque)
> g_main_loop_unref(loop);
>
> g_main_context_pop_thread_default(iothread->worker_context);
> +
> + g_main_context_release(iothread->worker_context);
> }
> }
>
> --
> 2.21.0.rc1
>
>
Regards,
--
Peter Xu
