Re: [Qemu-devel] [PATCH] osdep: initialize glib threads in all QEMU tools

[Stefan Hajnoczi <stefanha@gmail.com>]

On Tue, Oct 08, 2013 at 11:58:31AM +0200, Stefan Hajnoczi wrote:
> glib versions prior to 2.31.0 require an explicit g_thread_init() call
> to enable multi-threading.
> 
> Failure to initialize threading causes glib to take single-threaded code
> paths without synchronization.  For example, the g_slice allocator will
> crash due to race conditions.
> 
> Fix this for all QEMU tool programs (qemu-nbd, qemu-io, qemu-img) by
> moving the g_thread_init() call from vl.c:main() into a new
> osdep.c:thread_init() constructor function.
> 
> thread_init() has __attribute__((constructor)) and is automatically
> invoked by the runtime during startup.
> 
> We can now drop the "simple" trace backend's g_thread_init() call since
> thread_init() already called it.
> 
> Note that we must keep coroutine-gthread.c's g_thread_init() call which
> is located in a constructor function.  There is no guarantee for
> constructor function ordering so thread_init() may only be called later.
> 
> Reported-by: Mario de Chenno <mario.dechenno@unina2.it>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  trace/simple.c |  9 ---------
>  util/osdep.c   | 18 ++++++++++++++++++
>  vl.c           |  8 --------
>  3 files changed, 18 insertions(+), 17 deletions(-)

Applied to my block tree, we need this for QEMU 2.0:
https://github.com/stefanha/qemu/commits/block

Stefan