unit_control: Ensure API always returns valid error codesubmit/tizen/20190807.020938accepted/tizen/unified/20190807.111823

Additionally, introduce explicit return code for asynchronous
requests - UNIT_CONTROL_REQUEST_SENT, which does only mean
that request was posted, not completed.

Change-Id: Ia5a8f7141ede8d196c8af5e3c0ec65d2058f9f73

2 files changed, 27 insertions, 19 deletions

diff --git a/include/unit_control.h b/include/unit_control.h
index 6a03450..0ec916c 100644
--- a/include/unit_control.h
+++ b/include/unit_control.h
@@ -2,6 +2,7 @@
 #define UNIT_CONTROL_H
 
 enum {
+	UNIT_CONTROL_REQUEST_SENT = 0,
 	UNIT_CONTROL_OK,
 	UNIT_CONTROL_ERROR,
 };
diff --git a/src/libactd/unit_control.c b/src/libactd/unit_control.c
index e548d0f..fd83b80 100644
--- a/src/libactd/unit_control.c
+++ b/src/libactd/unit_control.c
@@ -19,6 +19,7 @@
 #include <glib.h>
 #include <gio/gio.h>
 #include <errno.h>
+#include <stdbool.h>
 
 #include "unit_control.h"
 
@@ -104,14 +105,14 @@ const char *translate_to_systemd(const char *method)
 
 static int call_uc(GBusType bus_type, const char *method, const char *unit, int timeout_ms)
 {
-	int ret;
 	GVariant *msg = NULL;
-	GDBusConnection *bus;
-	const char *result;
+	int ret = UNIT_CONTROL_ERROR;
 
-	bus = g_bus_get_sync(bus_type, NULL, NULL);
+	GDBusConnection *bus = g_bus_get_sync(bus_type, NULL, NULL);
 	if (!bus)
-		return -1;
+		return ret;
+
+	GError *err = NULL;
 
 	if (bus_type == G_BUS_TYPE_SESSION) {
 		msg = g_dbus_connection_call_sync(bus,
@@ -124,13 +125,13 @@ static int call_uc(GBusType bus_type, const char *method, const char *unit, int
 				G_DBUS_CALL_FLAGS_NONE,
 				timeout2glib(timeout_ms),
 				NULL,
-				NULL);
+				&err);
 		if (!msg)
-			return -EBADMSG;
-
-		ret = 0;
+			goto out;
 	} else {
 		/* we assume that activationd runs on system bus and can be used as a proxy */
+		const char *result = NULL;
+
 		msg = g_dbus_connection_call_sync(bus,
 				UNIT_CONTROL_NAME,
 				UNIT_CONTROL_OBJ_PATH,
@@ -141,19 +142,24 @@ static int call_uc(GBusType bus_type, const char *method, const char *unit, int
 				G_DBUS_CALL_FLAGS_NONE,
 				timeout2glib(timeout_ms),
 				NULL,
-				NULL);
+				&err);
 		if (!msg)
-			return -EBADMSG;
+			goto out;
 
 		g_variant_get(msg, "(s)", &result);
-		if (g_strcmp0(result, "ok") == 0)
-			ret = 0;
-		else
-			ret = -1;
-
+		bool is_ok = g_strcmp0(result, "ok") == 0;
 		g_free(result);
+
+		if (!is_ok)
+			goto out;
 	}
 
+	ret = UNIT_CONTROL_OK;
+
+out:
+	if (err)
+		g_error_free(err);
+
 	return ret;
 }
 
@@ -161,14 +167,15 @@ static int call_uc_async(GBusType bus_type, const char *method, const char *unit
 {
 	GDBusConnection *bus;
 	struct generic_user_data *data = user_data;
+	int ret = UNIT_CONTROL_ERROR;
 
 	bus = g_bus_get_sync(bus_type, NULL, NULL);
 	if (!bus)
-		return -1;
+		return ret;
 
 	data = malloc(sizeof(*data));
 	if (!data)
-		return -ENOMEM;
+		return ret;
 
 	data->user_data = user_data;
 	data->cb = cb;
@@ -203,7 +210,7 @@ static int call_uc_async(GBusType bus_type, const char *method, const char *unit
 				data);
 	}
 
-	return 0;
+	return UNIT_CONTROL_REQUEST_SENT;
 }
 
 int actd_start_unit(BusType bus_type, const char *unit, int timeout_ms)