[Qemu-devel] [PATCH v2 4/5] iothread: push gcontext earlier in the thread_fn

[Peter Xu]

We were pushing the context until right before running the gmainloop.
Now since we have everything unconditionally, we can move this
earlier.

One benefit is that now it's done even before init_done_sem, so as
long as the iothread user calls iothread_create() and completes, we
know that the thread stack is ready.

Signed-off-by: Peter Xu <address@hidden>
---
 iothread.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/iothread.c b/iothread.c
index 9abdbace66..045825a348 100644
--- a/iothread.c
+++ b/iothread.c
@@ -53,7 +53,12 @@ static void *iothread_run(void *opaque)
     IOThread *iothread = opaque;
 
     rcu_register_thread();
-
+    /*
+     * We should do this as soon as we enter the thread, because the
+     * function will silently fail if it fails to acquire the
+     * gcontext.
+     */
+    g_main_context_push_thread_default(iothread->worker_context);
     my_iothread = iothread;
     iothread->thread_id = qemu_get_thread_id();
     qemu_sem_post(&iothread->init_done_sem);
@@ -66,12 +71,11 @@ static void *iothread_run(void *opaque)
          * changed in previous aio_poll()
          */
         if (iothread->running && atomic_read(&iothread->run_gcontext)) {
-            g_main_context_push_thread_default(iothread->worker_context);
             g_main_loop_run(iothread->main_loop);
-            g_main_context_pop_thread_default(iothread->worker_context);
         }
     }
 
+    g_main_context_pop_thread_default(iothread->worker_context);
     rcu_unregister_thread();
     return NULL;
 }
-- 
2.17.1