From 38a2a92899b4f351cb7f4c002428a064819a565a Mon Sep 17 00:00:00 2001
From: Stefan Hajnoczi <stefanha@redhat.com>
Date: Fri, 22 Dec 2017 11:08:47 +0100
Subject: [PATCH 29/42] iothread: delay the context release to finalize

RH-Author: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: <20171222110900.24813-8-stefanha@redhat.com>
Patchwork-id: 78489
O-Subject: [RHV7.5 qemu-kvm-rhev PATCH 07/20] iothread: delay the context release to finalize
Bugzilla: 1519721
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Jeffrey Cody <jcody@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

From: Peter Xu <peterx@redhat.com>

When gcontext is used with iothread, the context will be destroyed
during iothread_stop().  That's not good since sometimes we would like
to keep the resources until iothread is destroyed, but we may want to
stop the thread before that point.

Delay the destruction of gcontext to iothread finalize.  Then we can do:

  iothread_stop(thread);
  some_cleanup_on_resources();
  iothread_destroy(thread);

We may need this patch if we want to run chardev IOs in iothreads and
hopefully clean them up correctly.  For more specific information,
please see 2b316774f6 ("qemu-char: do not operate on sources from
finalize callbacks").

Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-id: 20170928025958.1420-5-peterx@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit 5b3ac23fee97fc1a79ad2bb1cf3a1ce518d27905)
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 iothread.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/iothread.c b/iothread.c
index b3c092b..27a4288 100644
--- a/iothread.c
+++ b/iothread.c
@@ -71,8 +71,6 @@ static void *iothread_run(void *opaque)
             g_main_loop_unref(loop);
 
             g_main_context_pop_thread_default(iothread->worker_context);
-            g_main_context_unref(iothread->worker_context);
-            iothread->worker_context = NULL;
         }
     }
 
@@ -117,6 +115,10 @@ static void iothread_instance_finalize(Object *obj)
     IOThread *iothread = IOTHREAD(obj);
 
     iothread_stop(iothread);
+    if (iothread->worker_context) {
+        g_main_context_unref(iothread->worker_context);
+        iothread->worker_context = NULL;
+    }
     qemu_cond_destroy(&iothread->init_done_cond);
     qemu_mutex_destroy(&iothread->init_done_lock);
     if (!iothread->ctx) {
-- 
1.8.3.1