Re: compiler optimization causing issues with glib

[Mike <puffy taco gmail com>]

On Wed, May 30, 2012 at 6:43 AM, Simon McVittie
<simon mcvittie collabora co uk> wrote:
> On 24/05/12 17:20, Mike wrote:
>> I am using glib 2.26.0
> [...]
>>
>> The application I'm having issues with uses gdbus
> [...]
>> - Thread stuck in futex wait inside kernel

When I've attached GDB (or done SysRq), it's the gdbus thread that is stuck.

> If your application is calling GDBus APIs from more than one thread
> (it's unclear from your message whether it is or not), you should
> certainly upgrade. GDBus earlier than 2.32 has known thread-safety bugs,
> notably <https://bugzilla.gnome.org/show_bug.cgi?id=665211>.

I use g_dbus_connection_emit_signal in the callback from
g_child_watch_add.  Does that occur in the main loop?  Does the gdbus
thread ever call back in to my code, or does it also go through the
main loop?

> If you can't upgrade all the way to 2.32 right now for whatever reason,
> 2.28 or 2.30, or perhaps even a later 2.26.x version, would still be an
> improvement: for instance,
> <https://bugzilla.gnome.org/show_bug.cgi?id=651268> and
> <https://bugzilla.gnome.org/show_bug.cgi?id=662100> were both fixed
> since 2.28.0.

I did attempt 2.28.0, same issue.  I'll just have to upgrade my host
tools and build 2.32.  Still of course unclear whether I'm looking at
a kernel or userspace issue.  The part that bothers me the most is
that simply sending a SIGCHLD to the gdbus thread causes it to wake up
and function.

Mike