[Spice-devel] [PATCH spice-gtk v2 19/19] session: disconnect in idle

[Marc-André Lureau]

This is a workaround for existing clients such as virt-viewer that do
not hold a reference to their sessions when calling
spice_session_disconnect() and crash now that channels are removed from
session during the call. They expect disconnection events to be deferred
instead, let's defer actual disconnection to idle time for public
disconnect API for compatibility reasons (it is still recommended to fix
client code, for eventual future iterations)
---
 gtk/spice-session-priv.h |  2 +-
 gtk/spice-session.c      | 72 ++++++++++++++++++++++++++++++------------------
 2 files changed, 46 insertions(+), 28 deletions(-)

diff --git a/gtk/spice-session-priv.h b/gtk/spice-session-priv.h
index 2c2be63..18c88ab 100644
--- a/gtk/spice-session-priv.h
+++ b/gtk/spice-session-priv.h
@@ -97,7 +97,7 @@ struct _SpiceSessionPrivate {
     GList             *migration_left;
     SpiceSessionMigration migration_state;
     gboolean          full_migration; /* seamless migration indicator */
-    gboolean          disconnecting;
+    guint             disconnecting;
     gboolean          migrate_wait_init;
     guint             after_main_init;
     gboolean          migration_copy;
diff --git a/gtk/spice-session.c b/gtk/spice-session.c
index e2a3de3..b59d5cd 100644
--- a/gtk/spice-session.c
+++ b/gtk/spice-session.c
@@ -173,6 +173,31 @@ static void spice_session_init(SpiceSession *session)
 }
 
 static void
+session_disconnect(SpiceSession *self)
+{
+    SpiceSessionPrivate *s;
+    struct channel *item;
+    RingItem *ring, *next;
+
+    s = self->priv;
+    s->cmain = NULL;
+
+    for (ring = ring_get_head(&s->channels); ring != NULL; ring = next) {
+        next = ring_next(&s->channels, ring);
+        item = SPICE_CONTAINEROF(ring, struct channel, link);
+        spice_session_channel_destroy(self, item->channel);
+    }
+
+    s->connection_id = 0;
+
+    g_free(s->name);
+    s->name = NULL;
+    memset(s->uuid, 0, sizeof(s->uuid));
+
+    spice_session_abort_migration(self);
+}
+
+static void
 spice_session_dispose(GObject *gobject)
 {
     SpiceSession *session = SPICE_SESSION(gobject);
@@ -180,11 +205,12 @@ spice_session_dispose(GObject *gobject)
 
     SPICE_DEBUG("session dispose");
 
-    spice_session_disconnect(session);
+    session_disconnect(session);
 
     g_warn_if_fail(s->migration == NULL);
     g_warn_if_fail(s->migration_left == NULL);
     g_warn_if_fail(s->after_main_init == 0);
+    g_warn_if_fail(s->disconnecting == 0);
 
     g_clear_object(&s->audio_manager);
     g_clear_object(&s->desktop_integration);
@@ -1299,7 +1325,7 @@ gboolean spice_session_connect(SpiceSession *session)
     s = session->priv;
     g_return_val_if_fail(!s->disconnecting, FALSE);
 
-    spice_session_disconnect(session);
+    session_disconnect(session);
 
     s->client_provided_sockets = FALSE;
 
@@ -1334,7 +1360,7 @@ gboolean spice_session_open_fd(SpiceSession *session, int fd)
     s = session->priv;
     g_return_val_if_fail(!s->disconnecting, FALSE);
 
-    spice_session_disconnect(session);
+    session_disconnect(session);
 
     s->client_provided_sockets = TRUE;
 
@@ -1487,7 +1513,7 @@ void spice_session_abort_migration(SpiceSession *session)
 end:
     g_list_free(s->migration_left);
     s->migration_left = NULL;
-    spice_session_disconnect(s->migration);
+    session_disconnect(s->migration);
     g_object_unref(s->migration);
     s->migration = NULL;
 
@@ -1526,7 +1552,7 @@ void spice_session_channel_migrate(SpiceSession *session, SpiceChannel *channel)
 
     if (g_list_length(s->migration_left) == 0) {
         CHANNEL_DEBUG(channel, "migration: all channel migrated, success");
-        spice_session_disconnect(s->migration);
+        session_disconnect(s->migration);
         g_object_unref(s->migration);
         s->migration = NULL;
         spice_session_set_migration_state(session, SPICE_SESSION_MIGRATION_NONE);
@@ -1625,6 +1651,18 @@ gboolean spice_session_get_read_only(SpiceSession *self)
     return self->priv->read_only;
 }
 
+static gboolean session_disconnect_idle(SpiceSession *self)
+{
+    SpiceSessionPrivate *s = self->priv;
+
+    session_disconnect(self);
+    s->disconnecting = 0;
+
+    g_object_unref(self);
+
+    return FALSE;
+}
+
 /**
  * spice_session_disconnect:
  * @session:
@@ -1634,37 +1672,17 @@ gboolean spice_session_get_read_only(SpiceSession *self)
 void spice_session_disconnect(SpiceSession *session)
 {
     SpiceSessionPrivate *s;
-    struct channel *item;
-    RingItem *ring, *next;
 
     g_return_if_fail(SPICE_IS_SESSION(session));
-    g_return_if_fail(session->priv != NULL);
 
     s = session->priv;
 
     SPICE_DEBUG("session: disconnecting %d", s->disconnecting);
-    if (s->disconnecting)
+    if (s->disconnecting != 0)
         return;
 
     g_object_ref(session);
-    s->disconnecting = TRUE;
-    s->cmain = NULL;
-
-    for (ring = ring_get_head(&s->channels); ring != NULL; ring = next) {
-        next = ring_next(&s->channels, ring);
-        item = SPICE_CONTAINEROF(ring, struct channel, link);
-        spice_session_channel_destroy(session, item->channel);
-    }
-
-    s->connection_id = 0;
-
-    g_free(s->name);
-    s->name = NULL;
-    memset(s->uuid, 0, sizeof(s->uuid));
-
-    spice_session_abort_migration(session);
-    s->disconnecting = FALSE;
-    g_object_unref(session);
+    s->disconnecting = g_idle_add((GSourceFunc)session_disconnect_idle, session);
 }
 
 /**
-- 
1.9.3