Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging

# gpg: Signature made Tue 03 Oct 2017 19:53:34 BST
# gpg:                using RSA key 0x9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/block-pull-request:
  aio: fix assert when remove poll during destroy
  iothread: delay the context release to finalize
  iothread: export iothread_stop()
  iothread: provide helpers for internal use
  qom: provide root container for internal objs

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

5 files changed, 75 insertions, 11 deletions

diff --git a/include/qom/object.h b/include/qom/object.h
index f3e5cff..e0d9824 100644
--- a/include/qom/object.h
+++ b/include/qom/object.h
@@ -1214,6 +1214,17 @@ Object *object_get_root(void);
 Object *object_get_objects_root(void);
 
 /**
+ * object_get_internal_root:
+ *
+ * Get the container object that holds internally used object
+ * instances.  Any object which is put into this container must not be
+ * user visible, and it will not be exposed in the QOM tree.
+ *
+ * Returns: the internal object container
+ */
+Object *object_get_internal_root(void);
+
+/**
  * object_get_canonical_path_component:
  *
  * Returns: The final component in the object's canonical path.  The canonical
diff --git a/include/sysemu/iothread.h b/include/sysemu/iothread.h
index d2985b3..110329b 100644
--- a/include/sysemu/iothread.h
+++ b/include/sysemu/iothread.h
@@ -46,4 +46,13 @@ AioContext *iothread_get_aio_context(IOThread *iothread);
 void iothread_stop_all(void);
 GMainContext *iothread_get_g_main_context(IOThread *iothread);
 
+/*
+ * Helpers used to allocate iothreads for internal use.  These
+ * iothreads will not be seen by monitor clients when query using
+ * "query-iothreads".
+ */
+IOThread *iothread_create(const char *id, Error **errp);
+void iothread_stop(IOThread *iothread);
+void iothread_destroy(IOThread *iothread);
+
 #endif /* IOTHREAD_H */
diff --git a/iothread.c b/iothread.c
index 59d0850..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;
         }
     }
 
@@ -80,13 +78,10 @@ static void *iothread_run(void *opaque)
     return NULL;
 }
 
-static int iothread_stop(Object *object, void *opaque)
+void iothread_stop(IOThread *iothread)
 {
-    IOThread *iothread;
-
-    iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD);
-    if (!iothread || !iothread->ctx || iothread->stopping) {
-        return 0;
+    if (!iothread->ctx || iothread->stopping) {
+        return;
     }
     iothread->stopping = true;
     aio_notify(iothread->ctx);
@@ -94,6 +89,17 @@ static int iothread_stop(Object *object, void *opaque)
         g_main_loop_quit(iothread->main_loop);
     }
     qemu_thread_join(&iothread->thread);
+}
+
+static int iothread_stop_iter(Object *object, void *opaque)
+{
+    IOThread *iothread;
+
+    iothread = (IOThread *)object_dynamic_cast(object, TYPE_IOTHREAD);
+    if (!iothread) {
+        return 0;
+    }
+    iothread_stop(iothread);
     return 0;
 }
 
@@ -108,7 +114,11 @@ static void iothread_instance_finalize(Object *obj)
 {
     IOThread *iothread = IOTHREAD(obj);
 
-    iothread_stop(obj, NULL);
+    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) {
@@ -328,7 +338,7 @@ void iothread_stop_all(void)
         aio_context_release(ctx);
     }
 
-    object_child_foreach(container, iothread_stop, NULL);
+    object_child_foreach(container, iothread_stop_iter, NULL);
 }
 
 static gpointer iothread_g_main_context_init(gpointer opaque)
@@ -354,3 +364,19 @@ GMainContext *iothread_get_g_main_context(IOThread *iothread)
 
     return iothread->worker_context;
 }
+
+IOThread *iothread_create(const char *id, Error **errp)
+{
+    Object *obj;
+
+    obj = object_new_with_props(TYPE_IOTHREAD,
+                                object_get_internal_root(),
+                                id, errp, NULL);
+
+    return IOTHREAD(obj);
+}
+
+void iothread_destroy(IOThread *iothread)
+{
+    object_unparent(OBJECT(iothread));
+}
diff --git a/qom/object.c b/qom/object.c
index 3e18537..6a7bd92 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -1370,6 +1370,17 @@ Object *object_get_objects_root(void)
     return container_get(object_get_root(), "/objects");
 }
 
+Object *object_get_internal_root(void)
+{
+    static Object *internal_root;
+
+    if (!internal_root) {
+        internal_root = object_new("container");
+    }
+
+    return internal_root;
+}
+
 static void object_get_child_property(Object *obj, Visitor *v,
                                       const char *name, void *opaque,
                                       Error **errp)
diff --git a/util/aio-posix.c b/util/aio-posix.c
index 2d51239..5946ac0 100644
--- a/util/aio-posix.c
+++ b/util/aio-posix.c
@@ -223,7 +223,14 @@ void aio_set_fd_handler(AioContext *ctx,
             return;
         }
 
-        g_source_remove_poll(&ctx->source, &node->pfd);
+        /* If the GSource is in the process of being destroyed then
+         * g_source_remove_poll() causes an assertion failure.  Skip
+         * removal in that case, because glib cleans up its state during
+         * destruction anyway.
+         */
+        if (!g_source_is_destroyed(&ctx->source)) {
+            g_source_remove_poll(&ctx->source, &node->pfd);
+        }
 
         /* If the lock is held, just mark the node as deleted */
         if (qemu_lockcnt_count(&ctx->list_lock)) {