Ticket #625: 0001-hal-detect-Add-logic-to-wait-for-hal-to-startup.patch

src/modules/module-hal-detect.c

@@ -708 +708 @@
 
     if (!libhal_ctx_init(hal_context, &error)) {
         pa_log_error("Couldn't connect to hald: %s: %s", error.name, error.message);
+        /* Attempting to free an invalid context will result in a SIGABRT */
+        hal_context = NULL;
         goto fail;
     }
 
@@ -722 +724 @@
     return NULL;
 }
 
+static pa_bool_t connect_and_register(DBusConnection *connection, void *data)
+{
+    DBusError error;
+    struct userdata *u = (struct userdata *)data;
+
+    if (u->context)
+    return TRUE;
+
+    if (!(u->context = hal_context_new(pa_dbus_connection_get(u->connection))))
+    return FALSE;
+
+    dbus_error_init(&error);
+
+    hal_device_add_all(u);
+
+    libhal_ctx_set_user_data(u->context, u);
+    libhal_ctx_set_device_added(u->context, device_added_cb);
+    libhal_ctx_set_device_removed(u->context, device_removed_cb);
+    libhal_ctx_set_device_new_capability(u->context, new_capability_cb);
+    libhal_ctx_set_device_lost_capability(u->context, lost_capability_cb);
+
+    if (!libhal_device_property_watch_all(u->context, &error)) {
+        pa_log_error("Error monitoring device list: %s: %s", error.name, error.message);
+        goto fail;
+    }
+
+    if (!dbus_connection_add_filter(pa_dbus_connection_get (u->connection), filter_cb, u, NULL)) {
+        pa_log_error("Failed to add filter function");
+        goto fail;
+    }
+
+    if (pa_dbus_add_matches(
+                pa_dbus_connection_get (u->connection), &error,
+                "type='signal',sender='org.freedesktop.Hal',interface='org.freedesktop.Hal.Device.AccessControl',member='ACLAdded'",
+                "type='signal',sender='org.freedesktop.Hal',interface='org.freedesktop.Hal.Device.AccessControl',member='ACLRemoved'",
+                "type='signal',interface='org.pulseaudio.Server',member='DirtyGiveUpMessage'", NULL) < 0) {
+        pa_log_error("Unable to subscribe to HAL ACL signals: %s: %s", error.name, error.message);
+        goto fail;
+    }
+
+    return TRUE;
+
+fail:
+    dbus_error_free(&error);
+    return FALSE;
+}
+
+static DBusHandlerResult ownerchanged_handler(DBusConnection *connection, DBusMessage *message, void *data)
+{
+    int ret = DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+
+    if (dbus_message_is_signal(message, "org.freedesktop.DBus", "NameOwnerChanged")) {
+        DBusError error;
+        char *name, *old_owner, *new_owner;
+
+        dbus_error_init(&error);
+        dbus_message_get_args(message, &error, DBUS_TYPE_STRING, &name, DBUS_TYPE_STRING, &old_owner, DBUS_TYPE_STRING, &new_owner, DBUS_TYPE_INVALID);
+
+        if (dbus_error_is_set(&error)) {
+            pa_log_error("failed to get NameOwnerChanged args: %s (%s)", error.name, error.message);
+        } else if (name && strcmp (name, "org.freedesktop.Hal") == 0) {
+            if (!old_owner || !strlen (old_owner)) {
+                pa_log_warn ("HAL startup detected.");
+                if (connect_and_register (connection, data))
+                    dbus_connection_unregister_object_path (connection, "/org/freedesktop/DBus");
+                else
+                    pa_log_error ("Failed to connect to HAL bus.");
+            }
+
+            ret = DBUS_HANDLER_RESULT_HANDLED;
+        }
+        dbus_error_free(&error);
+    }
+
+    return ret;
+}
+
+static pa_bool_t listen_for_startup(DBusConnection *connection, void *data)
+{
+    DBusObjectPathVTable vtable = { .message_function = ownerchanged_handler, };
+    DBusError error;
+    const char MATCH_RULE[] = "sender='org.freedesktop.DBus',"
+        "interface='org.freedesktop.DBus',"
+        "type='signal',"
+        "path='/org/freedesktop/DBus',"
+        "member='NameOwnerChanged'";
+    pa_bool_t rc = FALSE;
+
+    dbus_error_init(&error);
+    dbus_bus_add_match(connection, MATCH_RULE, &error);
+    if (!dbus_error_is_set(&error)) {
+        if (dbus_connection_register_object_path (connection, "/org/freedesktop/DBus", &vtable, data))
+            rc = TRUE;
+        else
+            pa_log_error("cannot register object path.\n");
+    } else {
+        pa_log_error("Couldn't add match rule: %s (%s)\n", error.name, error.message);
+        pa_log_error("Cannot detect a HAL startup.");
+    }
+
+    dbus_error_free(&error);
+
+    return rc;
+}
+
 int pa__init(pa_module*m) {
     DBusError error;
     struct userdata *u = NULL;
-    int n = 0;
     pa_modargs *ma;
     const char *api;
 
@@ -783 +889 @@
         goto fail;
     }
 
-    if (!(u->context = hal_context_new(pa_dbus_connection_get(u->connection)))) {
-        /* pa_hal_context_new() logs appropriate errors */
-        goto fail;
+    if (!connect_and_register(pa_dbus_connection_get(u->connection), u) &&
+    !listen_for_startup(pa_dbus_connection_get(u->connection), u)) {
+    goto fail;
     }
 
-    n = hal_device_add_all(u);
-
-    libhal_ctx_set_user_data(u->context, u);
-    libhal_ctx_set_device_added(u->context, device_added_cb);
-    libhal_ctx_set_device_removed(u->context, device_removed_cb);
-    libhal_ctx_set_device_new_capability(u->context, new_capability_cb);
-    libhal_ctx_set_device_lost_capability(u->context, lost_capability_cb);
-
-    if (!libhal_device_property_watch_all(u->context, &error)) {
-        pa_log_error("Error monitoring device list: %s: %s", error.name, error.message);
-        goto fail;
-    }
-
-    if (!dbus_connection_add_filter(pa_dbus_connection_get(u->connection), filter_cb, u, NULL)) {
-        pa_log_error("Failed to add filter function");
-        goto fail;
-    }
-
-    if (pa_dbus_add_matches(
-                pa_dbus_connection_get(u->connection), &error,
-                "type='signal',sender='org.freedesktop.Hal',interface='org.freedesktop.Hal.Device.AccessControl',member='ACLAdded'",
-                "type='signal',sender='org.freedesktop.Hal',interface='org.freedesktop.Hal.Device.AccessControl',member='ACLRemoved'",
-                "type='signal',interface='org.pulseaudio.Server',member='DirtyGiveUpMessage'", NULL) < 0) {
-        pa_log_error("Unable to subscribe to HAL ACL signals: %s: %s", error.name, error.message);
-        goto fail;
-    }
-
-    pa_log_info("Loaded %i modules.", n);
-
     pa_modargs_free(ma);
 
     return 0;