On 12/18/23 13:23, Daniel P. Berrangé wrote:
The first thread to issue a client RPC request will own the event loop execution, sitting in the virNetClientIOEventLoop function.
It releases the client lock while running:
virNetClientUnlock() g_main_loop_run() virNetClientLock()
If a second thread arrives with an RPC request, it will queue it for the first thread to process. To inform the first thread that there's a new request it calls g_main_loop_quit() to break it out of the main loop.
This works if the first thread is in g_main_loop_run() at that time. There is a small window of opportunity, however, where the first thread has released the client lock, but not yet got into g_main_loop_run(). If that happens, the wakeup from the second thread is lost.
This patch deals with that by changing the way the wakeup is performed. Instead of directly calling g_main_loop_quit(), the second thread creates an idle source to run the quit function from within the first thread. This guarantees that the first thread will see the wakeup.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> ---
src/rpc/virnetclient.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
Reviewed-by: Michal Privoznik <mprivozn@redhat.com> Michal