From: sooyeon <sooyeon.kim@samsung.com>
Date: Wed, 29 Jun 2022 06:44:11 +0000 (+0900)
Subject: Change return values and Fix minor issues
X-Git-Tag: submit/tizen/20220801.042437~11
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=refs%2Fchanges%2F68%2F278968%2F1;p=platform%2Fcore%2Fuifw%2Fvoice-control.git

Change return values and Fix minor issues

Change-Id: I1d10d83f58b3ec36ed3308b8906a5151b7571875
Signed-off-by: sooyeon <sooyeon.kim@samsung.com>
---

diff --git a/client/vc.c b/client/vc.c
index dd7be5a..4fed631 100644
--- a/client/vc.c
+++ b/client/vc.c
@@ -94,7 +94,7 @@ static int __vc_get_feature_enabled()
 		}
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static int __check_privilege_initialize()
@@ -1682,17 +1682,17 @@ int __vc_cb_error(int reason, int daemon_pid, char* msg)
 	vc_state_e state;
 	if (0 != vc_client_get_client_state(g_vc, &state)) {
 		SLOG(LOG_ERROR, TAG_VCC, "[ERROR] Invalid client");
-		return -1;
+		return VC_ERROR_INVALID_PARAMETER;
 	}
 
 	/* check state */
 	if (state != VC_STATE_READY) {
 		SLOG(LOG_DEBUG, TAG_VCC, "[DEBUG] State is not READY");
 		if (VC_ERROR_SERVICE_RESET != reason) {
-			SLOG(LOG_ERROR, TAG_VCC, "[ERROR] not connected client yet");
-			return -1;
+			SLOG(LOG_ERROR, TAG_VCC, "[ERROR] not connected client yet(%d)", reason);
+			return VC_ERROR_INVALID_STATE;
 		}
-		return 0;
+		return VC_ERROR_NONE;
 	}
 
 	if (VC_ERROR_SERVICE_RESET == reason) {
@@ -1711,7 +1711,7 @@ int __vc_cb_error(int reason, int daemon_pid, char* msg)
 	vc_client_set_error(g_vc, reason);
 	ecore_main_loop_thread_safe_call_async(__vc_notify_error, (void*)g_vc);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int __vc_cb_error_to_app(int pid, int reason, const char* msg)
@@ -1896,7 +1896,7 @@ int vc_set_result_cb(vc_result_cb callback, void* user_data)
 
 	vc_client_set_result_cb(g_vc, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_unset_result_cb(void)
@@ -1922,7 +1922,7 @@ int vc_unset_result_cb(void)
 
 	vc_client_set_result_cb(g_vc, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 //LCOV_EXCL_START
@@ -1933,7 +1933,7 @@ int __vc_cb_service_state(int state)
 	vc_client_get_service_state(g_vc, &before_state);
 
 	if (current_state == before_state) {
-		return 0;
+		return VC_ERROR_NONE;
 	}
 
 	SLOG(LOG_DEBUG, TAG_VCC, "Service State changed : Before(%d) Current(%d)",
@@ -1955,7 +1955,7 @@ int __vc_cb_service_state(int state)
 		SLOG(LOG_WARN, TAG_VCC, "[WARNING] Service state changed callback is null");
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int __vc_cb_manager_pid(int manager_pid)
@@ -1965,7 +1965,7 @@ int __vc_cb_manager_pid(int manager_pid)
 	/* Save service state */
 	vc_client_set_mgr_pid(g_vc, manager_pid);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 //LCOV_EXCL_STOP
 
@@ -1995,7 +1995,7 @@ int vc_set_service_state_changed_cb(vc_service_state_changed_cb callback, void*
 
 	vc_client_set_service_state_changed_cb(g_vc, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_unset_service_state_changed_cb(void)
@@ -2021,7 +2021,7 @@ int vc_unset_service_state_changed_cb(void)
 
 	vc_client_set_service_state_changed_cb(g_vc, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_set_state_changed_cb(vc_state_changed_cb callback, void* user_data)
@@ -2050,7 +2050,7 @@ int vc_set_state_changed_cb(vc_state_changed_cb callback, void* user_data)
 
 	vc_client_set_state_changed_cb(g_vc, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_unset_state_changed_cb(void)
@@ -2076,7 +2076,7 @@ int vc_unset_state_changed_cb(void)
 
 	vc_client_set_state_changed_cb(g_vc, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_set_current_language_changed_cb(vc_current_language_changed_cb callback, void* user_data)
@@ -2105,7 +2105,7 @@ int vc_set_current_language_changed_cb(vc_current_language_changed_cb callback,
 
 	vc_client_set_current_lang_changed_cb(g_vc, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_unset_current_language_changed_cb(void)
@@ -2131,7 +2131,7 @@ int vc_unset_current_language_changed_cb(void)
 
 	vc_client_set_current_lang_changed_cb(g_vc, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_set_error_cb(vc_error_cb callback, void* user_data)
@@ -2160,7 +2160,7 @@ int vc_set_error_cb(vc_error_cb callback, void* user_data)
 
 	vc_client_set_error_cb(g_vc, callback,  user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_unset_error_cb(void)
@@ -2186,7 +2186,7 @@ int vc_unset_error_cb(void)
 
 	vc_client_set_error_cb(g_vc, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_set_invocation_name(const char* name)
@@ -3244,7 +3244,7 @@ int vc_tts_set_streaming_cb(vc_tts_streaming_cb callback, void* user_data)
 
 	vc_client_set_tts_streaming_cb(g_vc, callback,	user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_tts_unset_streaming_cb(void)
@@ -3270,7 +3270,7 @@ int vc_tts_unset_streaming_cb(void)
 
 	vc_client_set_tts_streaming_cb(g_vc, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int __vc_cb_utterance_status(int utt_id, int utt_status)
@@ -3281,7 +3281,7 @@ int __vc_cb_utterance_status(int utt_id, int utt_status)
 	vc_client_get_tts_utterance_status_cb(g_vc, &callback, &user_data);
 	if (NULL == callback) {
 		SLOG(LOG_WARN, TAG_VCC, "[WARNING] Utterance status callback is null");
-		return -1;
+		return VC_ERROR_INVALID_PARAMETER;
 	}
 
 	SLOG(LOG_DEBUG, TAG_VCC, "Utterance status callback is called");
@@ -3289,7 +3289,7 @@ int __vc_cb_utterance_status(int utt_id, int utt_status)
 	callback(utt_id, (vc_tts_utterance_status_e)utt_status, user_data);
 	vc_client_not_use_callback(g_vc);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_tts_set_utterance_status_cb(vc_tts_utterance_status_cb callback, void* user_data)
@@ -3318,7 +3318,7 @@ int vc_tts_set_utterance_status_cb(vc_tts_utterance_status_cb callback, void* us
 
 	vc_client_set_tts_utterance_status_cb(g_vc, callback,  user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_tts_unset_utterance_status_cb(void)
@@ -3344,6 +3344,6 @@ int vc_tts_unset_utterance_status_cb(void)
 
 	vc_client_set_tts_utterance_status_cb(g_vc, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 //LCOV_EXCL_STOP
diff --git a/client/vc_client.c b/client/vc_client.c
index fe116b0..03e0908 100644
--- a/client/vc_client.c
+++ b/client/vc_client.c
@@ -170,14 +170,14 @@ int vc_client_create(vc_h* vc)
 
 	*vc = temp;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_destroy(vc_h vc)
 {
 	if (vc == NULL) {
 		SLOG(LOG_ERROR, TAG_VCC, "Input parameter is NULL"); //LCOV_EXCL_LINE
-		return 0;
+		return VC_ERROR_NONE;
 	}
 
 	vc_client_s *data = NULL;
@@ -203,14 +203,14 @@ int vc_client_destroy(vc_h vc)
 				free(vc);
 				data = NULL;
 				vc = NULL;
-				return 0;
+				return VC_ERROR_NONE;
 			}
 		}
 	}
 
 	SLOG(LOG_ERROR, TAG_VCC, "[ERROR] client Not found");
 
-	return -1;
+	return VC_ERROR_INVALID_PARAMETER;
 }
 
 bool vc_client_is_valid(vc_h vc)
@@ -264,12 +264,12 @@ int vc_client_get_handle(int pid, vc_h* vc)
 			SLOG(LOG_DEBUG, TAG_VCC, "[DEBUG] pid(%d), handle(%d)", pid, data->vc->handle);
 			if (pid == data->vc->handle) {
 				*vc = data->vc;
-				return 0;
+				return VC_ERROR_NONE;
 			}
 		}
 	}
 
-	return -1;
+	return VC_ERROR_INVALID_PARAMETER;
 }
 //LCOV_EXCL_STOP
 
@@ -285,7 +285,7 @@ int vc_client_set_result_cb(vc_h vc, vc_result_cb callback, void* user_data)
 	client->result_cb = callback;
 	client->result_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 //LCOV_EXCL_START
@@ -300,7 +300,7 @@ int vc_client_get_result_cb(vc_h vc, vc_result_cb* callback, void** user_data)
 	*callback = client->result_cb;
 	*user_data = client->result_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 //LCOV_EXCL_STOP
 
@@ -315,7 +315,7 @@ int vc_client_set_service_state_changed_cb(vc_h vc, vc_service_state_changed_cb
 	client->service_state_changed_cb = callback;
 	client->service_state_changed_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 //LCOV_EXCL_START
@@ -330,7 +330,7 @@ int vc_client_get_service_state_changed_cb(vc_h vc, vc_service_state_changed_cb*
 	*callback = client->service_state_changed_cb;
 	*user_data = client->service_state_changed_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 //LCOV_EXCL_STOP
 
@@ -345,7 +345,7 @@ int vc_client_set_state_changed_cb(vc_h vc, vc_state_changed_cb callback, void*
 	client->state_changed_cb = callback;
 	client->state_changed_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 //LCOV_EXCL_START
@@ -360,7 +360,7 @@ int vc_client_get_state_changed_cb(vc_h vc, vc_state_changed_cb* callback, void*
 	*callback = client->state_changed_cb;
 	*user_data = client->state_changed_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 //LCOV_EXCL_STOP
 
@@ -375,7 +375,7 @@ int vc_client_set_current_lang_changed_cb(vc_h vc, vc_current_language_changed_c
 	client->current_lang_changed_cb = callback;
 	client->current_lang_changed_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 //LCOV_EXCL_START
@@ -390,7 +390,7 @@ int vc_client_get_current_lang_changed_cb(vc_h vc, vc_current_language_changed_c
 	*callback = client->current_lang_changed_cb;
 	*user_data = client->current_lang_changed_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 //LCOV_EXCL_STOP
 
@@ -405,7 +405,7 @@ int vc_client_set_error_cb(vc_h vc, vc_error_cb callback, void* user_data)
 	client->error_cb = callback;
 	client->error_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 //LCOV_EXCL_START
@@ -420,7 +420,7 @@ int vc_client_get_error_cb(vc_h vc, vc_error_cb* callback, void** user_data)
 	*callback = client->error_cb;
 	*user_data = client->error_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 //LCOV_EXCL_STOP
 
@@ -435,7 +435,7 @@ int vc_client_set_service_state(vc_h vc, vc_service_state_e state)
 
 	client->service_state = state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_get_service_state(vc_h vc, vc_service_state_e* state)
@@ -448,7 +448,7 @@ int vc_client_get_service_state(vc_h vc, vc_service_state_e* state)
 
 	*state = client->service_state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_set_client_state(vc_h vc, vc_state_e state)
@@ -462,7 +462,7 @@ int vc_client_set_client_state(vc_h vc, vc_state_e state)
 	client->before_state = client->current_state;
 	client->current_state = state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_get_client_state(vc_h vc, vc_state_e* state)
@@ -475,7 +475,7 @@ int vc_client_get_client_state(vc_h vc, vc_state_e* state)
 
 	*state = client->current_state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_get_client_state_by_uid(unsigned int uid, vc_state_e* state)
@@ -491,12 +491,12 @@ int vc_client_get_client_state_by_uid(unsigned int uid, vc_state_e* state)
 		if (NULL != data) {
 			if (uid == data->vc->handle) {
 				*state = data->current_state;
-				return 0;
+				return VC_ERROR_NONE;
 			}
 		}
 	}
 
-	return -1;
+	return VC_ERROR_INVALID_PARAMETER;
 }
 
 int vc_client_get_before_state(vc_h vc, vc_state_e* state, vc_state_e* before_state)
@@ -510,7 +510,7 @@ int vc_client_get_before_state(vc_h vc, vc_state_e* state, vc_state_e* before_st
 	*before_state = client->before_state;
 	*state = client->current_state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_set_invocation_name(vc_h vc, const char* invocation_name)
@@ -529,7 +529,7 @@ int vc_client_set_invocation_name(vc_h vc, const char* invocation_name)
 	if (NULL != invocation_name) {
 		client->invocation_name = strdup(invocation_name);
 	}
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_get_invocation_name(vc_h vc, char** invocation_name)
@@ -542,7 +542,7 @@ int vc_client_get_invocation_name(vc_h vc, char** invocation_name)
 
 	if (NULL != client->invocation_name)
 		*invocation_name = strdup(client->invocation_name);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 //LCOV_EXCL_START
@@ -556,7 +556,7 @@ int vc_client_set_xid(vc_h vc, int xid)
 
 	client->xid = xid;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_get_xid(vc_h vc, int* xid)
@@ -569,7 +569,7 @@ int vc_client_get_xid(vc_h vc, int* xid)
 
 	*xid = client->xid;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 //LCOV_EXCL_STOP
 
@@ -582,7 +582,7 @@ int vc_client_set_is_foreground(vc_h vc, bool value)
 		return VC_ERROR_INVALID_PARAMETER;
 
 	client->is_foreground = value;
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_get_is_foreground(vc_h vc, bool* value)
@@ -595,7 +595,7 @@ int vc_client_get_is_foreground(vc_h vc, bool* value)
 
 	*value = client->is_foreground;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 //LCOV_EXCL_START
@@ -610,7 +610,7 @@ int vc_client_set_exclusive_cmd(vc_h vc, bool value)
 
 	client->exclusive_cmd = value;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_get_exclusive_cmd(vc_h vc, bool* value)
@@ -623,7 +623,7 @@ int vc_client_get_exclusive_cmd(vc_h vc, bool* value)
 
 	*value = client->exclusive_cmd;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 #endif
 //LCOV_EXCL_STOP
@@ -638,7 +638,7 @@ int vc_client_set_error(vc_h vc, int reason)
 
 	client->reason = reason;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_get_error(vc_h vc, int* reason)
@@ -651,7 +651,7 @@ int vc_client_get_error(vc_h vc, int* reason)
 
 	*reason = client->reason;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 
@@ -670,7 +670,7 @@ int vc_client_use_callback(vc_h vc)
 		return VC_ERROR_INVALID_PARAMETER;
 
 	client->cb_ref_count++;
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_not_use_callback(vc_h vc)
@@ -682,7 +682,7 @@ int vc_client_not_use_callback(vc_h vc)
 		return VC_ERROR_INVALID_PARAMETER;
 
 	client->cb_ref_count--;
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 //LCOV_EXCL_START
@@ -698,7 +698,7 @@ int vc_client_set_auth_state_changed_cb(vc_h vc, vc_auth_state_changed_cb callba
 	client->auth_state_changed_cb = callback;
 	client->auth_state_changed_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_get_auth_state_changed_cb(vc_h vc, vc_auth_state_changed_cb* callback, void** user_data)
@@ -712,7 +712,7 @@ int vc_client_get_auth_state_changed_cb(vc_h vc, vc_auth_state_changed_cb* callb
 	*callback = client->auth_state_changed_cb;
 	*user_data = client->auth_state_changed_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_unset_auth_state_changed_cb(vc_h vc)
@@ -726,7 +726,7 @@ int vc_client_unset_auth_state_changed_cb(vc_h vc)
 	client->auth_state_changed_cb = NULL;
 	client->auth_state_changed_user_data = NULL;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_set_auth_state(vc_h vc, vc_auth_state_e state)
@@ -740,7 +740,7 @@ int vc_client_set_auth_state(vc_h vc, vc_auth_state_e state)
 	client->auth_before_state = client->auth_current_state;
 	client->auth_current_state = state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_get_auth_state(vc_h vc, vc_auth_state_e* state)
@@ -753,7 +753,7 @@ int vc_client_get_auth_state(vc_h vc, vc_auth_state_e* state)
 
 	*state = client->auth_current_state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_get_before_auth_state(vc_h vc, vc_auth_state_e* before, vc_auth_state_e* current)
@@ -767,7 +767,7 @@ int vc_client_get_before_auth_state(vc_h vc, vc_auth_state_e* before, vc_auth_st
 	*before = client->auth_before_state;
 	*current = client->auth_current_state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 //LCOV_EXCL_STOP
 
@@ -781,7 +781,7 @@ int vc_client_set_mgr_pid(vc_h vc, int mgr_pid)
 
 	client->mgr_pid = mgr_pid;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_get_mgr_pid(vc_h vc, int* mgr_pid)
@@ -794,7 +794,7 @@ int vc_client_get_mgr_pid(vc_h vc, int* mgr_pid)
 
 	*mgr_pid = client->mgr_pid;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_set_tts_streaming_cb(vc_h vc, vc_tts_streaming_cb callback, void* user_data)
@@ -808,7 +808,7 @@ int vc_client_set_tts_streaming_cb(vc_h vc, vc_tts_streaming_cb callback, void*
 	client->tts_streaming_cb = callback;
 	client->tts_streaming_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_get_tts_streaming_cb(vc_h vc, vc_tts_streaming_cb* callback, void** user_data)
@@ -822,7 +822,7 @@ int vc_client_get_tts_streaming_cb(vc_h vc, vc_tts_streaming_cb* callback, void*
 	*callback = client->tts_streaming_cb;
 	*user_data = client->tts_streaming_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_set_tts_utterance_status_cb(vc_h vc, vc_tts_utterance_status_cb callback, void* user_data)
@@ -836,7 +836,7 @@ int vc_client_set_tts_utterance_status_cb(vc_h vc, vc_tts_utterance_status_cb ca
 	client->tts_utterance_status_cb = callback;
 	client->tts_utterance_status_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_client_get_tts_utterance_status_cb(vc_h vc, vc_tts_utterance_status_cb* callback, void** user_data)
@@ -850,5 +850,5 @@ int vc_client_get_tts_utterance_status_cb(vc_h vc, vc_tts_utterance_status_cb* c
 	*callback = client->tts_utterance_status_cb;
 	*user_data = client->tts_utterance_status_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
diff --git a/client/vc_data.cpp b/client/vc_data.cpp
index afc475d..d66cab3 100644
--- a/client/vc_data.cpp
+++ b/client/vc_data.cpp
@@ -127,7 +127,7 @@ int vc_data_clear_tts_data_by_uttid(int utt_id)
 	if (g_tts_data.empty()) {
 		SLOG(LOG_ERROR, TAG_VCC, "[DATA ERROR] There is no tts data");
 		pthread_mutex_unlock(&g_tts_data_mutex);
-		return -1;
+		return VC_ERROR_EMPTY;
 	}
 
 	std::list<vc_tts_data_s*>::iterator iter;
diff --git a/client/vc_mgr.c b/client/vc_mgr.c
index 1203bf6..5019344 100644
--- a/client/vc_mgr.c
+++ b/client/vc_mgr.c
@@ -151,7 +151,7 @@ static int __vc_mgr_get_feature_enabled()
 		}
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static int __check_privilege_initialize()
@@ -831,7 +831,7 @@ int vc_mgr_set_demandable_client_rule(const char* rule)
 
 	SLOG(LOG_DEBUG, TAG_VCM, "@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_unset_demandable_client_rule(void)
@@ -855,7 +855,7 @@ int vc_mgr_unset_demandable_client_rule(void)
 	}
 
 	// TODO: check return value correct or not
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_is_command_format_supported(int format, bool* support)
@@ -1139,7 +1139,7 @@ int vc_mgr_unset_command_list(void)
 	SLOG(LOG_ERROR, TAG_VCM, "@@@");
 
 	// TODO: check return value correct or not
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_command_list_from_file(const char* file_path, int type)
@@ -1381,7 +1381,7 @@ int vc_mgr_get_audio_type(char** audio_id)
 	}
 
 	// TODO: check return value correct or not
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_get_current_commands(vc_cmd_list_h* vc_cmd_list)
@@ -1474,7 +1474,7 @@ int vc_mgr_get_current_commands(vc_cmd_list_h* vc_cmd_list)
 
 	if (0 != vc_info_parser_get_client_info(&client_info_list)) {
 		SLOG(LOG_INFO, TAG_VCM, "[DEBUG] No client");
-		return 0;
+		return VC_ERROR_NONE;
 	}
 
 	if (VC_NO_FOREGROUND_PID != fg_pid) {
@@ -1533,7 +1533,7 @@ int vc_mgr_get_current_commands(vc_cmd_list_h* vc_cmd_list)
 
 			SLOG(LOG_DEBUG, TAG_VCM, "@@@");
 
-			return 0;
+			return VC_ERROR_NONE;
 		}
 	} else {
 		SLOG(LOG_INFO, TAG_VCM, "[Manager] No foreground app");
@@ -1568,7 +1568,7 @@ int vc_mgr_get_current_commands(vc_cmd_list_h* vc_cmd_list)
 	SLOG(LOG_ERROR, TAG_VCM, "@@@");
 
 	// TODO: check return value correct or not
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_recognition_mode(vc_recognition_mode_e mode)
@@ -1614,7 +1614,7 @@ int vc_mgr_set_recognition_mode(vc_recognition_mode_e mode)
 	}
 
 	vc_mgr_client_set_recognition_mode(g_vc_m, mode);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_get_recognition_mode(vc_recognition_mode_e* mode)
@@ -1649,7 +1649,7 @@ int vc_mgr_get_recognition_mode(vc_recognition_mode_e* mode)
 	}
 
 	SLOG(LOG_INFO, TAG_VCM, "@@@ [Manager] Get recognition mode = %d", *mode);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_private_data(const char* key, const char* data)
@@ -1704,7 +1704,7 @@ int vc_mgr_set_private_data(const char* key, const char* data)
 
 	SLOG(LOG_DEBUG, TAG_VCM, "@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_get_private_data(const char* key, char** data)
@@ -1769,7 +1769,7 @@ int vc_mgr_get_private_data(const char* key, char** data)
 	SLOG(LOG_DEBUG, TAG_VCM, "@@@");
 
 	// TODO: check return value correct or not
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_domain(const char* domain)
@@ -1824,7 +1824,7 @@ int vc_mgr_set_domain(const char* domain)
 
 	SLOG(LOG_DEBUG, TAG_VCM, "@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_do_action(vc_send_event_type_e type, char* send_event)
@@ -1883,7 +1883,7 @@ int vc_mgr_do_action(vc_send_event_type_e type, char* send_event)
 	}
 	SLOG(LOG_DEBUG, TAG_VCM, "@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_send_specific_engine_request(const char* engine_app_id, const char* event, const char* request)
@@ -1943,7 +1943,7 @@ int vc_mgr_send_specific_engine_request(const char* engine_app_id, const char* e
 	}
 	SLOG(LOG_DEBUG, TAG_VCM, "@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_start(bool exclusive_command_option)
@@ -2189,7 +2189,7 @@ int __vc_mgr_cb_set_volume(float volume)
 	g_cnt = 1;
 	g_m_set_volume_timer = ecore_timer_add(0.05, __vc_mgr_set_volume_timer_cb, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int __vc_mgr_set_volume(float volume)
@@ -2197,7 +2197,7 @@ int __vc_mgr_set_volume(float volume)
 	// called by app directly
 	g_volume_db = volume;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_get_recording_volume(float* volume)
@@ -2230,7 +2230,7 @@ int vc_mgr_get_recording_volume(float* volume)
 
 	*volume = g_volume_db;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int __vc_mgr_cb_set_foreground(int pid, bool value)
@@ -2265,7 +2265,7 @@ int __vc_mgr_cb_set_foreground(int pid, bool value)
 		}
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_selected_results(vc_cmd_list_h vc_cmd_list)
@@ -2324,7 +2324,7 @@ int vc_mgr_set_selected_results(vc_cmd_list_h vc_cmd_list)
 
 	SLOG(LOG_DEBUG, TAG_VCM, "@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static Eina_Bool __vc_mgr_set_select_result(void *data)
@@ -2577,7 +2577,7 @@ int vc_mgr_set_all_result_cb(vc_mgr_all_result_cb callback, void* user_data)
 
 	SLOG(LOG_INFO, TAG_VCM, "[SUCCESS] Set all result callback");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_unset_all_result_cb(void)
@@ -2605,7 +2605,7 @@ int vc_mgr_unset_all_result_cb(void)
 
 	vc_mgr_client_set_all_result_cb(g_vc_m, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_result_cb(vc_result_cb callback, void* user_data)
@@ -2636,7 +2636,7 @@ int vc_mgr_set_result_cb(vc_result_cb callback, void* user_data)
 
 	vc_mgr_client_set_result_cb(g_vc_m, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_unset_result_cb(void)
@@ -2664,7 +2664,7 @@ int vc_mgr_unset_result_cb(void)
 
 	vc_mgr_client_set_result_cb(g_vc_m, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_pre_result_cb(vc_mgr_pre_result_cb callback, void* user_data)
@@ -2695,7 +2695,7 @@ int vc_mgr_set_pre_result_cb(vc_mgr_pre_result_cb callback, void* user_data)
 
 	vc_mgr_client_set_pre_result_cb(g_vc_m, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_unset_pre_result_cb(void)
@@ -2723,7 +2723,7 @@ int vc_mgr_unset_pre_result_cb(void)
 
 	vc_mgr_client_set_pre_result_cb(g_vc_m, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_get_error_message(char** err_msg)
@@ -2795,13 +2795,13 @@ int __vc_mgr_cb_error(int reason, int daemon_pid, char* msg)
 	vc_state_e state;
 	if (0 != vc_mgr_client_get_client_state(g_vc_m, &state)) {
 		SLOG(LOG_ERROR, TAG_VCM, "[WARNING] Invalid client");
-		return -1;
+		return VC_ERROR_INVALID_PARAMETER;
 	}
 
 	/* check state */
 	if (state != VC_STATE_INITIALIZED && state != VC_STATE_READY) {
 		SLOG(LOG_ERROR, TAG_VCM, "[WARNING] not connected client yet");
-		return -1;
+		return VC_ERROR_INVALID_STATE;
 	}
 
 	vc_mgr_client_set_internal_state(g_vc_m, VC_INTERNAL_STATE_NONE);
@@ -2813,7 +2813,7 @@ int __vc_mgr_cb_error(int reason, int daemon_pid, char* msg)
 		vc_mgr_client_get_service_state(g_vc_m, &service_state);
 		if (VC_SERVICE_STATE_UPDATING == service_state) {
 			SLOG(LOG_INFO, TAG_VCM, "[INFO] VC daemon is terminated by update manager");
-			return 0;
+			return VC_ERROR_NONE;
 		}
 
 		vc_mgr_client_set_client_state(g_vc_m, VC_STATE_INITIALIZED);
@@ -2830,7 +2830,7 @@ int __vc_mgr_cb_error(int reason, int daemon_pid, char* msg)
 	vc_mgr_client_set_error_message(g_vc_m, msg);
 	__vc_mgr_notify_error(g_vc_m);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static Eina_Bool __vc_mgr_notify_state_changed(void *data)
@@ -2886,7 +2886,7 @@ int vc_mgr_set_state_changed_cb(vc_state_changed_cb callback, void* user_data)
 	vc_mgr_client_set_state_changed_cb(g_vc_m, callback, user_data);
 
 	SLOG(LOG_INFO, TAG_VCM, "[SUCCESS] Set state changed callback");
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_unset_state_changed_cb(void)
@@ -2914,7 +2914,7 @@ int vc_mgr_unset_state_changed_cb(void)
 
 	vc_mgr_client_set_state_changed_cb(g_vc_m, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int __vc_mgr_cb_service_state(int state)
@@ -2942,7 +2942,7 @@ int __vc_mgr_cb_service_state(int state)
 	if (current_state == before_state) {
 		SLOG(LOG_WARN, TAG_VCM, "Service State NOT changed : Before(%d) Current(%d)",
 			before_state, current_state);
-		return 0;
+		return VC_ERROR_NONE;
 	}
 
 	/* Save service state */
@@ -2961,7 +2961,7 @@ int __vc_mgr_cb_service_state(int state)
 		SLOG(LOG_WARN, TAG_VCM, "[WARNING] Service state changed callback is null");
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_service_state_changed_cb(vc_service_state_changed_cb callback, void* user_data)
@@ -2993,7 +2993,7 @@ int vc_mgr_set_service_state_changed_cb(vc_service_state_changed_cb callback, vo
 	vc_mgr_client_set_service_state_changed_cb(g_vc_m, callback, user_data);
 
 	SLOG(LOG_INFO, TAG_VCM, "[SUCCESS] Set service state changed callback");
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_unset_service_state_changed_cb(void)
@@ -3020,7 +3020,7 @@ int vc_mgr_unset_service_state_changed_cb(void)
 	}
 
 	vc_mgr_client_set_service_state_changed_cb(g_vc_m, NULL, NULL);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_speech_detected_cb(vc_mgr_begin_speech_detected_cb callback, void* user_data)
@@ -3052,7 +3052,7 @@ int vc_mgr_set_speech_detected_cb(vc_mgr_begin_speech_detected_cb callback, void
 	vc_mgr_client_set_speech_detected_cb(g_vc_m, callback, user_data);
 
 	SLOG(LOG_INFO, TAG_VCM, "[SUCCESS] Set speech detected callback");
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_unset_speech_detected_cb(void)
@@ -3079,7 +3079,7 @@ int vc_mgr_unset_speech_detected_cb(void)
 	}
 
 	vc_mgr_client_set_speech_detected_cb(g_vc_m, NULL, NULL);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_current_language_changed_cb(vc_current_language_changed_cb callback, void* user_data)
@@ -3111,7 +3111,7 @@ int vc_mgr_set_current_language_changed_cb(vc_current_language_changed_cb callba
 	vc_mgr_client_set_current_lang_changed_cb(g_vc_m, callback, user_data);
 
 	SLOG(LOG_INFO, TAG_VCM, "[SUCCESS] Set current language changed callback");
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_unset_current_language_changed_cb(void)
@@ -3139,7 +3139,7 @@ int vc_mgr_unset_current_language_changed_cb(void)
 
 	vc_mgr_client_set_current_lang_changed_cb(g_vc_m, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_error_cb(vc_error_cb callback, void* user_data)
@@ -3170,7 +3170,7 @@ int vc_mgr_set_error_cb(vc_error_cb callback, void* user_data)
 
 	vc_mgr_client_set_error_cb(g_vc_m, callback,  user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_unset_error_cb(void)
@@ -3198,7 +3198,7 @@ int vc_mgr_unset_error_cb(void)
 
 	vc_mgr_client_set_error_cb(g_vc_m, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int __vc_mgr_cb_dialog(int pid, const char* disp_text, const char* utt_text, bool continuous)
@@ -3217,7 +3217,7 @@ int __vc_mgr_cb_dialog(int pid, const char* disp_text, const char* utt_text, boo
 		SLOG(LOG_WARN, TAG_VCM, "[WARNING] Error callback is null");
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int __vc_mgr_cb_private_data_set(const char* key, const char* data)
@@ -3367,7 +3367,7 @@ int vc_mgr_set_dialog_request_cb(vc_mgr_dialog_request_cb callback, void* user_d
 
 	vc_mgr_client_set_dialog_request_cb(g_vc_m, callback,  user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_unset_dialog_request_cb(void)
@@ -3395,7 +3395,7 @@ int vc_mgr_unset_dialog_request_cb(void)
 
 	vc_mgr_client_set_dialog_request_cb(g_vc_m, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_private_data_set_cb(vc_mgr_private_data_set_cb callback, void* user_data)
@@ -3426,7 +3426,7 @@ int vc_mgr_set_private_data_set_cb(vc_mgr_private_data_set_cb callback, void* us
 
 	vc_mgr_client_set_private_data_set_cb(g_vc_m, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_unset_private_data_set_cb(void)
@@ -3454,7 +3454,7 @@ int vc_mgr_unset_private_data_set_cb(void)
 
 	vc_mgr_client_set_private_data_set_cb(g_vc_m, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_private_data_requested_cb(vc_mgr_private_data_requested_cb callback, void* user_data)
@@ -3485,7 +3485,7 @@ int vc_mgr_set_private_data_requested_cb(vc_mgr_private_data_requested_cb callba
 
 	vc_mgr_client_set_private_data_requested_cb(g_vc_m, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_unset_private_data_requested_cb(void)
@@ -3513,7 +3513,7 @@ int vc_mgr_unset_private_data_requested_cb(void)
 
 	vc_mgr_client_set_private_data_requested_cb(g_vc_m, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static bool __vc_mgr_check_demandable_client(int pid)
@@ -3583,7 +3583,7 @@ int __vc_mgr_request_auth_enable(int pid)
 		vc_mgr_client_set_valid_authorized_client(g_vc_m, pid);
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int __vc_mgr_request_auth_disable(int pid)
@@ -3609,7 +3609,7 @@ int __vc_mgr_request_auth_disable(int pid)
 		}
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static Eina_Bool __request_auth_start(void* data)
@@ -3644,7 +3644,7 @@ int __vc_mgr_request_auth_start(int pid)
 	/* add timer for start recording */
 	ecore_timer_add(0, __request_auth_start, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static Eina_Bool __request_auth_stop(void* data)
@@ -3670,7 +3670,7 @@ int __vc_mgr_request_auth_stop(int pid)
 	/* add timer for start recording */
 	ecore_timer_add(0, __request_auth_stop, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static Eina_Bool __request_auth_cancel(void* data)
@@ -3696,7 +3696,7 @@ int __vc_mgr_request_auth_cancel(int pid)
 	/* add timer for start recording */
 	ecore_timer_add(0, __request_auth_cancel, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_specific_engine_result_cb(vc_mgr_specific_engine_result_cb callback, void* user_data)
@@ -3726,7 +3726,7 @@ int vc_mgr_set_specific_engine_result_cb(vc_mgr_specific_engine_result_cb callba
 
 	vc_mgr_client_set_specific_engine_result_cb(g_vc_m, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 int vc_mgr_unset_specific_engine_result_cb(void)
 {
@@ -3748,7 +3748,7 @@ int vc_mgr_unset_specific_engine_result_cb(void)
 
 	vc_mgr_client_set_specific_engine_result_cb(g_vc_m, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 void __vc_mgr_cb_specific_engine_result(const char* engine_app_id, const char* event, const char* result)
@@ -3802,7 +3802,7 @@ int vc_mgr_set_feedback_audio_format_cb(vc_mgr_feedback_audio_format_cb callback
 
 	SLOG(LOG_INFO, TAG_VCM, "[SUCCESS] Set feedback audio format callback");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_unset_feedback_audio_format_cb()
@@ -3833,7 +3833,7 @@ int vc_mgr_unset_feedback_audio_format_cb()
 
 	SLOG(LOG_INFO, TAG_VCM, "[SUCCESS] Unset feedback audio format callback");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_feedback_streaming_cb(vc_mgr_feedback_streaming_cb callback, void* user_data)
@@ -3873,7 +3873,7 @@ int vc_mgr_set_feedback_streaming_cb(vc_mgr_feedback_streaming_cb callback, void
 
 	SLOG(LOG_INFO, TAG_VCM, "[SUCCESS] Set feedback streaming callback");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_unset_feedback_streaming_cb()
@@ -3910,7 +3910,7 @@ int vc_mgr_unset_feedback_streaming_cb()
 
 	SLOG(LOG_INFO, TAG_VCM, "[SUCCESS] Unset feedback streaming callback");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_set_vc_tts_streaming_cb(vc_mgr_vc_tts_streaming_cb callback, void* user_data)
@@ -3951,7 +3951,7 @@ int vc_mgr_set_vc_tts_streaming_cb(vc_mgr_vc_tts_streaming_cb callback, void* us
 
 	SLOG(LOG_INFO, TAG_VCM, "[SUCCESS] Set feedback streaming callback");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_unset_vc_tts_streaming_cb()
@@ -3989,7 +3989,7 @@ int vc_mgr_unset_vc_tts_streaming_cb()
 
 	SLOG(LOG_INFO, TAG_VCM, "[SUCCESS] Unset feedback streaming callback");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static void __tts_feedback_thread(void* data, Ecore_Thread* thread)
@@ -4143,7 +4143,7 @@ int vc_mgr_start_feedback(void)
 		SLOG(LOG_ERROR, TAG_VCM, "[ERROR] Fail to player play, ret(%d)", ret);
 	}
 #endif
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_stop_feedback(void)
@@ -4183,7 +4183,7 @@ int vc_mgr_stop_feedback(void)
 		if (0 != ret || NULL == feedback_data) {
 			/* empty queue */
 			SLOG(LOG_INFO, TAG_VCM, "[INFO] No feedback data to stop any more");
-			return 0;
+			return VC_ERROR_NONE;
 		}
 		ret = vc_mgr_data_clear_feedback_data(&feedback_data);
 		if (0 != ret) {
@@ -4489,7 +4489,7 @@ int __vc_change_system_volume(vc_system_volume_event_e volume_event)
 	}
 
 	SLOG(LOG_INFO, TAG_VCM, "[SUCCESS] Change system volume");
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int __vc_recover_system_volume()
@@ -4521,7 +4521,7 @@ int __vc_recover_system_volume()
 	}
 
 	SLOG(LOG_INFO, TAG_VCM, "[SUCCESS] Recover system volume");
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_change_system_volume(vc_system_volume_event_e event)
diff --git a/client/vc_mgr_client.c b/client/vc_mgr_client.c
index f463c48..9da3025 100644
--- a/client/vc_mgr_client.c
+++ b/client/vc_mgr_client.c
@@ -241,14 +241,14 @@ int vc_mgr_client_create(vc_h* vc)
 
 	*vc = temp;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_destroy(vc_h vc)
 {
 	if (vc == NULL) {
 		SLOG(LOG_ERROR, TAG_VCM, "Input parameter is NULL");
-		return 0;
+		return VC_ERROR_NONE;
 	}
 
 	vc_mgr_client_s *data = NULL;
@@ -285,14 +285,14 @@ int vc_mgr_client_destroy(vc_h vc)
 				data = NULL;
 				vc = NULL;
 
-				return 0;
+				return VC_ERROR_NONE;
 			}
 		}
 	}
 
 	SLOG(LOG_ERROR, TAG_VCM, "[ERROR] client Not found");
 
-	return -1;
+	return VC_ERROR_INVALID_PARAMETER;
 }
 
 bool vc_mgr_client_is_valid(vc_h vc)
@@ -342,12 +342,13 @@ int vc_mgr_client_get_handle(unsigned int uid, vc_h* vc)
 		if (NULL != data) {
 			if (uid == data->vc->handle) {
 				*vc = data->vc;
-				return 0;
+				return VC_ERROR_NONE;
 			}
 		}
 	}
 
-	return -1;
+	SLOG(LOG_ERROR, TAG_VCM, "[ERROR] Fail to find the corresponding handle.");
+	return VC_ERROR_INVALID_PARAMETER;
 }
 
 int vc_mgr_client_get_pid(vc_h vc, int* pid)
@@ -357,11 +358,11 @@ int vc_mgr_client_get_pid(vc_h vc, int* pid)
 	/* check handle */
 	if (NULL == client) {
 		SLOG(LOG_DEBUG, TAG_VCM, "[DEBUG] vc is not valid");
-		return -1;
+		return VC_ERROR_INVALID_PARAMETER;
 	}
 
 	*pid = client->pid;
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 /* set/get callback function */
@@ -376,7 +377,7 @@ int vc_mgr_client_set_all_result_cb(vc_h vc, vc_mgr_all_result_cb callback, void
 	client->all_result_cb = callback;
 	client->all_result_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_all_result_cb(vc_h vc, vc_mgr_all_result_cb* callback, void** user_data)
@@ -390,7 +391,7 @@ int vc_mgr_client_get_all_result_cb(vc_h vc, vc_mgr_all_result_cb* callback, voi
 	*callback = client->all_result_cb;
 	*user_data = client->all_result_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_result_cb(vc_h vc, vc_result_cb callback, void* user_data)
@@ -404,7 +405,7 @@ int vc_mgr_client_set_result_cb(vc_h vc, vc_result_cb callback, void* user_data)
 	client->result_cb = callback;
 	client->result_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_result_cb(vc_h vc, vc_result_cb* callback, void** user_data)
@@ -418,7 +419,7 @@ int vc_mgr_client_get_result_cb(vc_h vc, vc_result_cb* callback, void** user_dat
 	*callback = client->result_cb;
 	*user_data = client->result_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_pre_result_cb(vc_h vc, vc_mgr_pre_result_cb callback, void* user_data)
@@ -432,7 +433,7 @@ int vc_mgr_client_set_pre_result_cb(vc_h vc, vc_mgr_pre_result_cb callback, void
 	client->pre_result_cb = callback;
 	client->pre_result_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_pre_result_cb(vc_h vc, vc_mgr_pre_result_cb* callback, void** user_data)
@@ -446,7 +447,7 @@ int vc_mgr_client_get_pre_result_cb(vc_h vc, vc_mgr_pre_result_cb* callback, voi
 	*callback = client->pre_result_cb;
 	*user_data = client->pre_result_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_service_state_changed_cb(vc_h vc, vc_service_state_changed_cb callback, void* user_data)
@@ -460,7 +461,7 @@ int vc_mgr_client_set_service_state_changed_cb(vc_h vc, vc_service_state_changed
 	client->service_state_changed_cb = callback;
 	client->service_state_changed_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_service_state_changed_cb(vc_h vc, vc_service_state_changed_cb* callback, void** user_data)
@@ -474,7 +475,7 @@ int vc_mgr_client_get_service_state_changed_cb(vc_h vc, vc_service_state_changed
 	*callback = client->service_state_changed_cb;
 	*user_data = client->service_state_changed_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_state_changed_cb(vc_h vc, vc_state_changed_cb callback, void* user_data)
@@ -488,7 +489,7 @@ int vc_mgr_client_set_state_changed_cb(vc_h vc, vc_state_changed_cb callback, vo
 	client->state_changed_cb = callback;
 	client->state_changed_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_state_changed_cb(vc_h vc, vc_state_changed_cb* callback, void** user_data)
@@ -502,7 +503,7 @@ int vc_mgr_client_get_state_changed_cb(vc_h vc, vc_state_changed_cb* callback, v
 	*callback = client->state_changed_cb;
 	*user_data = client->state_changed_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_speech_detected_cb(vc_h vc, vc_mgr_begin_speech_detected_cb callback, void* user_data)
@@ -516,7 +517,7 @@ int vc_mgr_client_set_speech_detected_cb(vc_h vc, vc_mgr_begin_speech_detected_c
 	client->speech_detected_cb = callback;
 	client->speech_detected_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_speech_detected_cb(vc_h vc, vc_mgr_begin_speech_detected_cb* callback, void** user_data)
@@ -530,7 +531,7 @@ int vc_mgr_client_get_speech_detected_cb(vc_h vc, vc_mgr_begin_speech_detected_c
 	*callback = client->speech_detected_cb;
 	*user_data = client->speech_detected_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_current_lang_changed_cb(vc_h vc, vc_current_language_changed_cb callback, void* user_data)
@@ -544,7 +545,7 @@ int vc_mgr_client_set_current_lang_changed_cb(vc_h vc, vc_current_language_chang
 	client->current_lang_changed_cb = callback;
 	client->current_lang_changed_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_current_lang_changed_cb(vc_h vc, vc_current_language_changed_cb* callback, void** user_data)
@@ -558,7 +559,7 @@ int vc_mgr_client_get_current_lang_changed_cb(vc_h vc, vc_current_language_chang
 	*callback = client->current_lang_changed_cb;
 	*user_data = client->current_lang_changed_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_error_cb(vc_h vc, vc_error_cb callback, void* user_data)
@@ -572,7 +573,7 @@ int vc_mgr_client_set_error_cb(vc_h vc, vc_error_cb callback, void* user_data)
 	client->error_cb = callback;
 	client->error_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_error_cb(vc_h vc, vc_error_cb* callback, void** user_data)
@@ -586,7 +587,7 @@ int vc_mgr_client_get_error_cb(vc_h vc, vc_error_cb* callback, void** user_data)
 	*callback = client->error_cb;
 	*user_data = client->error_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_dialog_request_cb(vc_h vc, vc_mgr_dialog_request_cb callback, void* user_data)
@@ -600,7 +601,7 @@ int vc_mgr_client_set_dialog_request_cb(vc_h vc, vc_mgr_dialog_request_cb callba
 	client->diaglog_requst_cb = callback;
 	client->dialog_request_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_dialog_request_cb(vc_h vc, vc_mgr_dialog_request_cb* callback, void** user_data)
@@ -614,7 +615,7 @@ int vc_mgr_client_get_dialog_request_cb(vc_h vc, vc_mgr_dialog_request_cb* callb
 	*callback = client->diaglog_requst_cb;
 	*user_data = client->dialog_request_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 
@@ -629,7 +630,7 @@ int vc_mgr_client_set_private_data_set_cb(vc_h vc, vc_mgr_private_data_set_cb ca
 	client->private_data_set_cb = callback;
 	client->private_data_set_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_private_data_set_cb(vc_h vc, vc_mgr_private_data_set_cb* callback, void** user_data)
@@ -643,7 +644,7 @@ int vc_mgr_client_get_private_data_set_cb(vc_h vc, vc_mgr_private_data_set_cb* c
 	*callback = client->private_data_set_cb;
 	*user_data = client->private_data_set_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_private_data_requested_cb(vc_h vc, vc_mgr_private_data_requested_cb callback, void* user_data)
@@ -657,7 +658,7 @@ int vc_mgr_client_set_private_data_requested_cb(vc_h vc, vc_mgr_private_data_req
 	client->private_data_requested_cb = callback;
 	client->private_data_requested_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_private_data_requested_cb(vc_h vc, vc_mgr_private_data_requested_cb* callback, void** user_data)
@@ -671,7 +672,7 @@ int vc_mgr_client_get_private_data_requested_cb(vc_h vc, vc_mgr_private_data_req
 	*callback = client->private_data_requested_cb;
 	*user_data = client->private_data_requested_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_feedback_audio_format_cb(vc_h vc, vc_mgr_feedback_audio_format_cb callback, void* user_data)
@@ -685,7 +686,7 @@ int vc_mgr_client_set_feedback_audio_format_cb(vc_h vc, vc_mgr_feedback_audio_fo
 	client->feedback_audio_format_cb = callback;
 	client->feedback_audio_format_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_feedback_audio_format_cb(vc_h vc, vc_mgr_feedback_audio_format_cb* callback, void** user_data)
@@ -699,7 +700,7 @@ int vc_mgr_client_get_feedback_audio_format_cb(vc_h vc, vc_mgr_feedback_audio_fo
 	*callback = client->feedback_audio_format_cb;
 	*user_data = client->feedback_audio_format_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_feedback_streaming_cb(vc_h vc, vc_mgr_feedback_streaming_cb callback, void* user_data)
@@ -713,7 +714,7 @@ int vc_mgr_client_set_feedback_streaming_cb(vc_h vc, vc_mgr_feedback_streaming_c
 	client->feedback_streaming_cb = callback;
 	client->feedback_streaming_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_feedback_streaming_cb(vc_h vc, vc_mgr_feedback_streaming_cb* callback, void** user_data)
@@ -727,7 +728,7 @@ int vc_mgr_client_get_feedback_streaming_cb(vc_h vc, vc_mgr_feedback_streaming_c
 	*callback = client->feedback_streaming_cb;
 	*user_data = client->feedback_streaming_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_vc_tts_streaming_cb(vc_h vc, vc_mgr_vc_tts_streaming_cb callback, void* user_data)
@@ -741,7 +742,7 @@ int vc_mgr_client_set_vc_tts_streaming_cb(vc_h vc, vc_mgr_vc_tts_streaming_cb ca
 	client->vc_tts_streaming_cb = callback;
 	client->vc_tts_streaming_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_vc_tts_streaming_cb(vc_h vc, vc_mgr_vc_tts_streaming_cb* callback, void** user_data)
@@ -755,7 +756,7 @@ int vc_mgr_client_get_vc_tts_streaming_cb(vc_h vc, vc_mgr_vc_tts_streaming_cb* c
 	*callback = client->vc_tts_streaming_cb;
 	*user_data = client->vc_tts_streaming_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 /* set/get option */
@@ -769,7 +770,7 @@ int vc_mgr_client_set_service_state(vc_h vc, vc_service_state_e state)
 
 	client->service_state = state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_service_state(vc_h vc, vc_service_state_e* state)
@@ -782,7 +783,7 @@ int vc_mgr_client_get_service_state(vc_h vc, vc_service_state_e* state)
 
 	*state = client->service_state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_internal_state(vc_h vc, vc_internal_state_e state)
@@ -795,7 +796,7 @@ int vc_mgr_client_set_internal_state(vc_h vc, vc_internal_state_e state)
 
 	client->internal_state = state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_internal_state(vc_h vc, vc_internal_state_e* state)
@@ -808,7 +809,7 @@ int vc_mgr_client_get_internal_state(vc_h vc, vc_internal_state_e* state)
 
 	*state = client->internal_state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_client_state(vc_h vc, vc_state_e state)
@@ -822,7 +823,7 @@ int vc_mgr_client_set_client_state(vc_h vc, vc_state_e state)
 	client->before_state = client->current_state;
 	client->current_state = state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_client_state(vc_h vc, vc_state_e* state)
@@ -835,7 +836,7 @@ int vc_mgr_client_get_client_state(vc_h vc, vc_state_e* state)
 
 	*state = client->current_state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_client_state_by_uid(unsigned int uid, vc_state_e* state)
@@ -851,12 +852,12 @@ int vc_mgr_client_get_client_state_by_uid(unsigned int uid, vc_state_e* state)
 		if (NULL != data) {
 			if (uid == data->vc->handle) {
 				*state = data->current_state;
-				return 0;
+				return VC_ERROR_NONE;
 			}
 		}
 	}
 
-	return -1;
+	return VC_ERROR_INVALID_PARAMETER;
 }
 
 int vc_mgr_client_get_before_state(vc_h vc, vc_state_e* state, vc_state_e* before_state)
@@ -870,7 +871,7 @@ int vc_mgr_client_get_before_state(vc_h vc, vc_state_e* state, vc_state_e* befor
 	*before_state = client->before_state;
 	*state = client->current_state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_error(vc_h vc, int reason)
@@ -883,7 +884,7 @@ int vc_mgr_client_set_error(vc_h vc, int reason)
 
 	client->reason = reason;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_error(vc_h vc, int* reason)
@@ -896,7 +897,7 @@ int vc_mgr_client_get_error(vc_h vc, int* reason)
 
 	*reason = client->reason;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_error_message(vc_h vc, const char* err_msg)
@@ -919,7 +920,7 @@ int vc_mgr_client_set_error_message(vc_h vc, const char* err_msg)
 		}
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_error_message(vc_h vc, char** err_msg)
@@ -937,7 +938,7 @@ int vc_mgr_client_get_error_message(vc_h vc, char** err_msg)
 		}
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_enable_command_type(vc_h vc, vc_cmd_type_e cmd_type)
@@ -952,7 +953,7 @@ int vc_mgr_client_enable_command_type(vc_h vc, vc_cmd_type_e cmd_type)
 
 	client->disabled_cmd_type &= ~(1 << cmd_type);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_disable_command_type(vc_h vc, vc_cmd_type_e cmd_type)
@@ -967,7 +968,7 @@ int vc_mgr_client_disable_command_type(vc_h vc, vc_cmd_type_e cmd_type)
 
 	client->disabled_cmd_type |= (1 << cmd_type);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_disabled_command_type(vc_h vc, int* disabled_cmd_type)
@@ -982,7 +983,7 @@ int vc_mgr_client_get_disabled_command_type(vc_h vc, int* disabled_cmd_type)
 
 	*disabled_cmd_type = client->disabled_cmd_type;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_exclusive_command(vc_h vc, bool value)
@@ -995,7 +996,7 @@ int vc_mgr_client_set_exclusive_command(vc_h vc, bool value)
 
 	client->exclusive_cmd_option = value;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 bool vc_mgr_client_get_exclusive_command(vc_h vc)
@@ -1027,7 +1028,7 @@ int vc_mgr_client_set_all_result(vc_h vc, int event, const char* result_text)
 		client->all_result_text = strdup(result_text);
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_all_result(vc_h vc, int* event, char** result_text)
@@ -1045,7 +1046,7 @@ int vc_mgr_client_get_all_result(vc_h vc, int* event, char** result_text)
 		}
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_unset_all_result(vc_h vc)
@@ -1063,7 +1064,7 @@ int vc_mgr_client_unset_all_result(vc_h vc)
 		client->all_result_text = NULL;
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_audio_type(vc_h vc, const char* audio_id)
@@ -1082,13 +1083,13 @@ int vc_mgr_client_set_audio_type(vc_h vc, const char* audio_id)
 		client->audio_id = strdup(audio_id);
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_audio_type(vc_h vc, char** audio_id)
 {
 	if (NULL == audio_id)	{
-		return -1;
+		return VC_ERROR_INVALID_PARAMETER;
 	}
 
 	vc_mgr_client_s* client = __mgr_client_get(vc);
@@ -1102,7 +1103,7 @@ int vc_mgr_client_get_audio_type(vc_h vc, char** audio_id)
 	else
 		*audio_id = NULL;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_recognition_mode(vc_h vc, vc_recognition_mode_e mode)
@@ -1115,13 +1116,13 @@ int vc_mgr_client_set_recognition_mode(vc_h vc, vc_recognition_mode_e mode)
 
 	client->recognition_mode = mode;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_recognition_mode(vc_h vc, vc_recognition_mode_e* mode)
 {
 	if (NULL == mode) {
-		return -1;
+		return VC_ERROR_INVALID_PARAMETER;
 	}
 
 	vc_mgr_client_s* client = __mgr_client_get(vc);
@@ -1131,7 +1132,7 @@ int vc_mgr_client_get_recognition_mode(vc_h vc, vc_recognition_mode_e* mode)
 		return VC_ERROR_INVALID_PARAMETER;
 
 	*mode = client->recognition_mode;
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_foreground(vc_h vc, int pid, bool value)
@@ -1150,7 +1151,7 @@ int vc_mgr_client_set_foreground(vc_h vc, int pid, bool value)
 		}
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_foreground(vc_h vc, int* pid)
@@ -1162,7 +1163,7 @@ int vc_mgr_client_get_foreground(vc_h vc, int* pid)
 		return VC_ERROR_INVALID_PARAMETER;
 
 	*pid = client->foreground_pid;
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 /* utils */
@@ -1180,7 +1181,7 @@ int vc_mgr_client_use_callback(vc_h vc)
 		return VC_ERROR_INVALID_PARAMETER;
 
 	client->cb_ref_count++;
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_not_use_callback(vc_h vc)
@@ -1192,7 +1193,7 @@ int vc_mgr_client_not_use_callback(vc_h vc)
 		return VC_ERROR_INVALID_PARAMETER;
 
 	client->cb_ref_count--;
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 /* Authority */
@@ -1218,7 +1219,7 @@ int vc_mgr_client_add_authorized_client(vc_h vc, int pid)
 
 	SLOG(LOG_DEBUG, TAG_VCM, "Add authorized client - %d", pid);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_remove_authorized_client(vc_h vc, int pid)
@@ -1245,7 +1246,7 @@ int vc_mgr_client_remove_authorized_client(vc_h vc, int pid)
 				data = NULL;
 
 				SLOG(LOG_DEBUG, TAG_VCM, "Remove authorized client - %d", pid);
-				return 0;
+				return VC_ERROR_NONE;
 			}
 		}
 	}
@@ -1294,7 +1295,7 @@ int vc_mgr_client_set_valid_authorized_client(vc_h vc, int pid)
 
 	client->valid_authorized_pid = pid;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_valid_authorized_client(vc_h vc, int* pid)
@@ -1307,7 +1308,7 @@ int vc_mgr_client_get_valid_authorized_client(vc_h vc, int* pid)
 
 	*pid = client->valid_authorized_pid;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 bool vc_mgr_client_is_valid_authorized_client(vc_h vc, int pid)
@@ -1334,7 +1335,7 @@ int vc_mgr_client_set_start_by_client(vc_h vc, bool option)
 
 	client->start_by_client = option;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_start_by_client(vc_h vc, bool* option)
@@ -1347,7 +1348,7 @@ int vc_mgr_client_get_start_by_client(vc_h vc, bool* option)
 
 	*option = client->start_by_client;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_specific_engine_result_cb(vc_h vc, vc_mgr_specific_engine_result_cb callback, void* user_data)
@@ -1361,7 +1362,7 @@ int vc_mgr_client_set_specific_engine_result_cb(vc_h vc, vc_mgr_specific_engine_
 	client->specific_engine_result_cb = callback;
 	client->specific_engine_result_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_specific_engine_result_cb(vc_h vc, vc_mgr_specific_engine_result_cb* callback, void** user_data)
@@ -1375,7 +1376,7 @@ int vc_mgr_client_get_specific_engine_result_cb(vc_h vc, vc_mgr_specific_engine_
 	*callback = client->specific_engine_result_cb;
 	*user_data = client->specific_engine_result_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_set_audio_streaming_mode(vc_h vc, vc_audio_streaming_mode_e streaming_mode)
@@ -1388,7 +1389,7 @@ int vc_mgr_client_set_audio_streaming_mode(vc_h vc, vc_audio_streaming_mode_e st
 
 	client->streaming_mode = streaming_mode;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_client_get_audio_streaming_mode(vc_h vc, vc_audio_streaming_mode_e* streaming_mode)
@@ -1401,5 +1402,5 @@ int vc_mgr_client_get_audio_streaming_mode(vc_h vc, vc_audio_streaming_mode_e* s
 
 	*streaming_mode = client->streaming_mode;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
diff --git a/client/vc_mgr_data.cpp b/client/vc_mgr_data.cpp
index 8301fcd..27c96a2 100644
--- a/client/vc_mgr_data.cpp
+++ b/client/vc_mgr_data.cpp
@@ -66,7 +66,7 @@ int vc_mgr_data_get_feedback_data(vc_feedback_data_s** data)
 		*data = NULL;
 		pthread_mutex_unlock(&g_feedback_data_mutex);
 
-		return -1;
+		return VC_ERROR_EMPTY;
 	}
 
 	std::list<vc_feedback_data_s*>::iterator iter;
diff --git a/client/vc_mgr_player.c b/client/vc_mgr_player.c
index 06915f9..5bfd5be 100644
--- a/client/vc_mgr_player.c
+++ b/client/vc_mgr_player.c
@@ -78,7 +78,7 @@ static int __create_audio_out(int rate, vc_audio_channel_e channel, vc_audio_typ
 	if (AUDIO_IO_ERROR_NONE != ret) {
 		g_audio_state = AUDIO_STATE_NONE;
 		g_audio_h = NULL;
-		SLOG(LOG_ERROR, TAG_VCM, "[Player ERROR] Fail to create audio");
+		SLOG(LOG_ERROR, TAG_VCM, "[Player ERROR] Fail to create audio. ret(%d)", ret);
 		return -1;
 	} else {
 		SLOG(LOG_DEBUG, TAG_VCM, "[Player DEBUG] Create audio");
@@ -103,7 +103,7 @@ static int __destroy_audio_out()
 	int ret = -1;
 	ret = audio_out_destroy(g_audio_h);
 	if (AUDIO_IO_ERROR_NONE != ret) {
-		SLOG(LOG_ERROR, TAG_VCM, "[Player ERROR] Fail to destroy audio");
+		SLOG(LOG_ERROR, TAG_VCM, "[Player ERROR] Fail to destroy audio. ret(%d)", ret);
 		return -1;
 	} else {
 		SLOG(LOG_DEBUG, TAG_VCM, "[Player DEBUG] Destroy audio");
@@ -131,12 +131,12 @@ int vc_mgr_player_init(int rate, vc_audio_channel_e channel, vc_audio_type_e aud
 
 	ret = __create_audio_out(rate, channel, audio_type);
 	if (0 != ret) {
-		return -1;
+		return VC_ERROR_OPERATION_FAILED;
 	}
 
 	g_player_init = true;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_player_release()
@@ -167,12 +167,12 @@ int vc_mgr_player_release()
 
 	ret = __destroy_audio_out();
 	if (0 != ret) {
-		return -1;
+		return VC_ERROR_OPERATION_FAILED;
 	}
 
 	g_player_init = false;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static void __play_feedback_thread(void* data, Ecore_Thread* thread)
@@ -377,7 +377,7 @@ int vc_mgr_player_play()
 		ecore_thread_run(__play_feedback_thread, __end_play_feedback_thread, NULL, NULL);
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_mgr_player_stop()
@@ -409,5 +409,5 @@ int vc_mgr_player_stop()
 		thread_count = ecore_thread_active_get();
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
diff --git a/client/vc_setting.c b/client/vc_setting.c
index 1e99383..5f26cbe 100644
--- a/client/vc_setting.c
+++ b/client/vc_setting.c
@@ -396,7 +396,7 @@ int vc_setting_get_auto_language(bool* value)
 
 	SLOG(LOG_DEBUG, TAG_VCS, "@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_setting_set_enabled(bool value)
@@ -477,7 +477,7 @@ int vc_setting_set_enabled_changed_cb(vc_setting_enabled_changed_cb callback, vo
 
 	SLOG(LOG_DEBUG, TAG_VCS, "@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_setting_unset_enabled_changed_cb()
@@ -495,7 +495,7 @@ int vc_setting_unset_enabled_changed_cb()
 
 	SLOG(LOG_DEBUG, TAG_VCS, "@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_setting_set_current_language_changed_cb(vc_setting_current_language_changed_cb callback, void* user_data)
@@ -519,7 +519,7 @@ int vc_setting_set_current_language_changed_cb(vc_setting_current_language_chang
 
 	SLOG(LOG_DEBUG, TAG_VCS, "@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_setting_unset_current_language_changed_cb()
@@ -537,7 +537,7 @@ int vc_setting_unset_current_language_changed_cb()
 
 	SLOG(LOG_DEBUG, TAG_VCS, "@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_setting_set_engine_changed_cb(vc_setting_engine_changed_cb callback, void *user_data)
@@ -553,7 +553,7 @@ int vc_setting_set_engine_changed_cb(vc_setting_engine_changed_cb callback, void
 	g_engine_changed_user_data = user_data;
 
 	SLOG(LOG_DEBUG, TAG_VCS, "@@@");
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_setting_unset_engine_changed_cb()
@@ -570,5 +570,5 @@ int vc_setting_unset_engine_changed_cb()
 	g_engine_changed_user_data = NULL;
 
 	SLOG(LOG_DEBUG, TAG_VCS, "@@@");
-	return 0;
+	return VC_ERROR_NONE;
 }
diff --git a/client/vc_tidl.c b/client/vc_tidl.c
index 6a6caef..dbfed0d 100644
--- a/client/vc_tidl.c
+++ b/client/vc_tidl.c
@@ -200,8 +200,8 @@ static void __notify_cb(void* user_data, int pid, bundle* msg)
 	} /* VCD_METHOD_SEND_MANAGER_PID */
 	else if (0 == strncmp(VCD_METHOD_ERROR, method, strlen(VCD_METHOD_ERROR))) {
 		/* signal!!! */
-		char* reason;
-		char* daemon_pid;
+		char* reason = NULL;
+		char* daemon_pid = NULL;
 		char* err_msg = NULL;
 		
 		bundle_get_str(msg, VC_BUNDLE_REASON, &reason);
@@ -226,8 +226,8 @@ static void __notify_cb(void* user_data, int pid, bundle* msg)
 	} /* VCD_METHOD_ERROR_TO_APP */
 	else if (0 == strncmp(VC_MANAGER_METHOD_UTTERANCE_STATUS, method, strlen(VC_MANAGER_METHOD_UTTERANCE_STATUS))) {
 		/* signal!!! */
-		char* pid;
-		char* utt_id;
+		char* pid = NULL;
+		char* utt_id = NULL;
 		char* utt_status = NULL;
 
 		bundle_get_str(msg, VC_BUNDLE_PID, &pid);
@@ -262,6 +262,11 @@ void __feedback_cb(void *user_data, int utt_id, int event, rpc_port_proxy_vc_pro
 
 static int __create_notify_callback_handle(vc_tidl_info_s* info)
 {
+	if (NULL == info) {
+		SLOG(LOG_ERROR, TAG_VCC, "[ERROR] Invalid parameter");
+		return VC_ERROR_INVALID_PARAMETER;
+	}
+
 	if (NULL != info->notify_cb_h) {
 		rpc_port_proxy_vc_proxy_vc_notify_cb_dispose(info->rpc_h, info->notify_cb_h);
 		info->notify_cb_h = NULL;
@@ -281,7 +286,12 @@ static int __create_notify_callback_handle(vc_tidl_info_s* info)
 
 static int __create_feedback_callback_handle(vc_tidl_info_s* info)
 {
-	if (NULL != info) {
+	if (NULL == info) {
+		SLOG(LOG_ERROR, TAG_VCC, "[ERROR] Invalid parameter");
+		return VC_ERROR_INVALID_PARAMETER;
+	}
+
+	if (NULL != info->feedback_cb_h) {
 		rpc_port_proxy_vc_proxy_vc_feedback_cb_dispose(info->rpc_h, info->feedback_cb_h);
 		info->feedback_cb_h = NULL;
 	}
diff --git a/client/vc_widget.c b/client/vc_widget.c
index f0e3b01..5161784 100644
--- a/client/vc_widget.c
+++ b/client/vc_widget.c
@@ -86,7 +86,7 @@ static int __vc_widget_get_feature_enabled()
 		}
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 const char* vc_tag()
@@ -270,7 +270,7 @@ static int _vc_widget_wait_to_end_thread(void)
 		count++;
 	}
 	SLOG(LOG_WARN, TAG_VCW, "[Widget] prepare_thread is terminated");
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_deinitialize(vc_h vc_w)
@@ -1101,7 +1101,7 @@ int vc_widget_stop()
 		}
 	} while (0 != ret);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 #endif
 
@@ -1147,7 +1147,7 @@ int vc_widget_cancel(vc_h vc_w)
 	SLOG(LOG_DEBUG, TAG_VCW, "@@@");
 
 	// TODO: check return value correct or not
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static void __vc_widget_notify_error(void *data)
@@ -1194,13 +1194,13 @@ int __vc_widget_cb_error(int reason, int daemon_pid, char* msg)
 
 			if (0 != vc_widget_client_get_state(vc_w, &state)) {
 				SLOG(LOG_ERROR, TAG_VCW, "[WARNING] Invalid client");
-				return -1;
+				return VC_ERROR_INVALID_PARAMETER;
 			}
 
 			/* check state */
 			if (state != VC_STATE_READY) {
 				SLOG(LOG_ERROR, TAG_VCW, "[WARNING] not connected client yet");
-				return -1;
+				return VC_ERROR_INVALID_STATE;
 			}
 
 			if (VC_ERROR_SERVICE_RESET == reason) {
@@ -1221,7 +1221,7 @@ int __vc_widget_cb_error(int reason, int daemon_pid, char* msg)
 		}
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static Eina_Bool __vc_widget_start_recording(void *data)
@@ -1504,7 +1504,7 @@ int vc_widget_set_result_cb(vc_h vc_w, vc_result_cb callback, void* user_data)
 
 	vc_widget_client_set_result_cb(vc_w, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_unset_result_cb(vc_h vc_w)
@@ -1534,7 +1534,7 @@ int vc_widget_unset_result_cb(vc_h vc_w)
 
 	vc_widget_client_set_result_cb(vc_w, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_set_show_tooltip_cb(vc_h vc_w, vc_widget_show_tooltip_cb callback, void* user_data)
@@ -1567,7 +1567,7 @@ int vc_widget_set_show_tooltip_cb(vc_h vc_w, vc_widget_show_tooltip_cb callback,
 
 	vc_widget_client_set_show_tooltip_cb(vc_w, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_unset_show_tooltip_cb(vc_h vc_w)
@@ -1597,7 +1597,7 @@ int vc_widget_unset_show_tooltip_cb(vc_h vc_w)
 
 	vc_widget_client_set_show_tooltip_cb(vc_w, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_set_send_current_command_list_cb(vc_h vc_w, vc_widget_send_current_command_list_cb callback, void* user_data)
@@ -1627,7 +1627,7 @@ int vc_widget_set_send_current_command_list_cb(vc_h vc_w, vc_widget_send_current
 
 	vc_widget_client_set_send_command_list_cb(vc_w, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_unset_send_current_command_list_cb(vc_h vc_w)
@@ -1657,7 +1657,7 @@ int vc_widget_unset_send_current_command_list_cb(vc_h vc_w)
 
 	vc_widget_client_set_send_command_list_cb(vc_w, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int __vc_widget_cb_service_state(int state)
@@ -1703,7 +1703,7 @@ int __vc_widget_cb_service_state(int state)
 		}
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_set_service_state_changed_cb(vc_h vc_w, vc_service_state_changed_cb callback, void* user_data)
@@ -1733,7 +1733,7 @@ int vc_widget_set_service_state_changed_cb(vc_h vc_w, vc_service_state_changed_c
 
 	vc_widget_client_set_service_state_changed_cb(vc_w, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_unset_service_state_changed_cb(vc_h vc_w)
@@ -1763,7 +1763,7 @@ int vc_widget_unset_service_state_changed_cb(vc_h vc_w)
 
 	vc_widget_client_set_service_state_changed_cb(vc_w, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_set_state_changed_cb(vc_h vc_w, vc_state_changed_cb callback, void* user_data)
@@ -1796,7 +1796,7 @@ int vc_widget_set_state_changed_cb(vc_h vc_w, vc_state_changed_cb callback, void
 
 	vc_widget_client_set_state_changed_cb(vc_w, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_unset_state_changed_cb(vc_h vc_w)
@@ -1826,7 +1826,7 @@ int vc_widget_unset_state_changed_cb(vc_h vc_w)
 
 	vc_widget_client_set_state_changed_cb(vc_w, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_set_asr_result_cb(vc_h vc_w, vc_asr_result_cb callback, void* user_data)
@@ -1859,7 +1859,7 @@ int vc_widget_set_asr_result_cb(vc_h vc_w, vc_asr_result_cb callback, void* user
 
 	vc_widget_client_set_asr_result_cb(vc_w, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_unset_asr_result_cb(vc_h vc_w)
@@ -1889,7 +1889,7 @@ int vc_widget_unset_asr_result_cb(vc_h vc_w)
 
 	vc_widget_client_set_asr_result_cb(vc_w, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_set_current_language_changed_cb(vc_h vc_w, vc_current_language_changed_cb callback, void* user_data)
@@ -1922,7 +1922,7 @@ int vc_widget_set_current_language_changed_cb(vc_h vc_w, vc_current_language_cha
 
 	vc_widget_client_set_current_lang_changed_cb(vc_w, callback, user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_unset_current_language_changed_cb(vc_h vc_w)
@@ -1952,7 +1952,7 @@ int vc_widget_unset_current_language_changed_cb(vc_h vc_w)
 
 	vc_widget_client_set_current_lang_changed_cb(vc_w, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_set_error_cb(vc_h vc_w, vc_error_cb callback, void* user_data)
@@ -1985,7 +1985,7 @@ int vc_widget_set_error_cb(vc_h vc_w, vc_error_cb callback, void* user_data)
 
 	vc_widget_client_set_error_cb(vc_w, callback,  user_data);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_unset_error_cb(vc_h vc_w)
@@ -2015,6 +2015,6 @@ int vc_widget_unset_error_cb(vc_h vc_w)
 
 	vc_widget_client_set_error_cb(vc_w, NULL, NULL);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
diff --git a/client/vc_widget_client.c b/client/vc_widget_client.c
index c18036e..891ba75 100644
--- a/client/vc_widget_client.c
+++ b/client/vc_widget_client.c
@@ -125,14 +125,14 @@ int vc_widget_client_create(vc_h* vc)
 
 	*vc = temp;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_destroy(vc_h vc)
 {
 	if (vc == NULL) {
 		SLOG(LOG_ERROR, TAG_VCW, "Input parameter is NULL");
-		return 0;
+		return VC_ERROR_NONE;
 	}
 
 	vc_widget_s *data = NULL;
@@ -158,7 +158,7 @@ int vc_widget_client_destroy(vc_h vc)
 				vc = NULL;
 
 				pthread_mutex_unlock(&g_widget_list_mutex);
-				return 0;
+				return VC_ERROR_NONE;
 			}
 		}
 	}
@@ -166,7 +166,7 @@ int vc_widget_client_destroy(vc_h vc)
 	SLOG(LOG_ERROR, TAG_VCW, "[ERROR] widget Not found");
 
 	pthread_mutex_unlock(&g_widget_list_mutex);
-	return -1;
+	return VC_ERROR_INVALID_PARAMETER;
 }
 
 GSList* vc_widget_client_get_client_list()
@@ -230,13 +230,13 @@ int vc_widget_client_get_handle(unsigned int uid, vc_h* vc)
 			if (uid == data->vc->handle) {
 				*vc = data->vc;
 				pthread_mutex_unlock(&g_widget_list_mutex);
-				return 0;
+				return VC_ERROR_NONE;
 			}
 		}
 	}
 
 	pthread_mutex_unlock(&g_widget_list_mutex);
-	return -1;
+	return VC_ERROR_INVALID_PARAMETER;
 }
 
 /* set/get callback function */
@@ -251,7 +251,7 @@ int vc_widget_client_set_result_cb(vc_h vc, vc_result_cb callback, void* user_da
 	widget->result_cb = callback;
 	widget->result_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_get_result_cb(vc_h vc, vc_result_cb* callback, void** user_data)
@@ -265,7 +265,7 @@ int vc_widget_client_get_result_cb(vc_h vc, vc_result_cb* callback, void** user_
 	*callback = widget->result_cb;
 	*user_data = widget->result_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_set_asr_result_enabled(vc_h vc, bool enabled)
@@ -278,7 +278,7 @@ int vc_widget_client_set_asr_result_enabled(vc_h vc, bool enabled)
 
 	widget->asr_result_enabled = enabled;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_get_asr_result_enabled(vc_h vc, bool* enabled)
@@ -291,7 +291,7 @@ int vc_widget_client_get_asr_result_enabled(vc_h vc, bool* enabled)
 
 	*enabled = widget->asr_result_enabled;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_set_asr_result_cb(vc_h vc, vc_asr_result_cb callback, void* user_data)
@@ -305,7 +305,7 @@ int vc_widget_client_set_asr_result_cb(vc_h vc, vc_asr_result_cb callback, void*
 	widget->asr_result_cb = callback;
 	widget->asr_result_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_get_asr_result_cb(vc_h vc, vc_asr_result_cb* callback, void** user_data)
@@ -319,7 +319,7 @@ int vc_widget_client_get_asr_result_cb(vc_h vc, vc_asr_result_cb* callback, void
 	*callback = widget->asr_result_cb;
 	*user_data = widget->asr_result_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_set_service_state_changed_cb(vc_h vc, vc_service_state_changed_cb callback, void* user_data)
@@ -333,7 +333,7 @@ int vc_widget_client_set_service_state_changed_cb(vc_h vc, vc_service_state_chan
 	widget->service_state_changed_cb = callback;
 	widget->service_state_changed_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_get_service_state_changed_cb(vc_h vc, vc_service_state_changed_cb* callback, void** user_data)
@@ -347,7 +347,7 @@ int vc_widget_client_get_service_state_changed_cb(vc_h vc, vc_service_state_chan
 	*callback = widget->service_state_changed_cb;
 	*user_data = widget->service_state_changed_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_set_state_changed_cb(vc_h vc, vc_state_changed_cb callback, void* user_data)
@@ -361,7 +361,7 @@ int vc_widget_client_set_state_changed_cb(vc_h vc, vc_state_changed_cb callback,
 	widget->state_changed_cb = callback;
 	widget->state_changed_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_get_state_changed_cb(vc_h vc, vc_state_changed_cb* callback, void** user_data)
@@ -375,7 +375,7 @@ int vc_widget_client_get_state_changed_cb(vc_h vc, vc_state_changed_cb* callback
 	*callback = widget->state_changed_cb;
 	*user_data = widget->state_changed_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_set_show_tooltip_cb(vc_h vc, vc_widget_show_tooltip_cb callback, void* user_data)
@@ -389,7 +389,7 @@ int vc_widget_client_set_show_tooltip_cb(vc_h vc, vc_widget_show_tooltip_cb call
 	widget->show_tooltip_cb = callback;
 	widget->show_tooltip_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_get_show_tooltip_cb(vc_h vc, vc_widget_show_tooltip_cb* callback, void** user_data)
@@ -403,7 +403,7 @@ int vc_widget_client_get_show_tooltip_cb(vc_h vc, vc_widget_show_tooltip_cb* cal
 	*callback = widget->show_tooltip_cb;
 	*user_data = widget->show_tooltip_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_set_current_lang_changed_cb(vc_h vc, vc_current_language_changed_cb callback, void* user_data)
@@ -417,7 +417,7 @@ int vc_widget_client_set_current_lang_changed_cb(vc_h vc, vc_current_language_ch
 	widget->current_lang_changed_cb = callback;
 	widget->current_lang_changed_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_get_current_lang_changed_cb(vc_h vc, vc_current_language_changed_cb* callback, void** user_data)
@@ -431,7 +431,7 @@ int vc_widget_client_get_current_lang_changed_cb(vc_h vc, vc_current_language_ch
 	*callback = widget->current_lang_changed_cb;
 	*user_data = widget->current_lang_changed_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_set_error_cb(vc_h vc, vc_error_cb callback, void* user_data)
@@ -445,7 +445,7 @@ int vc_widget_client_set_error_cb(vc_h vc, vc_error_cb callback, void* user_data
 	widget->error_cb = callback;
 	widget->error_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_get_error_cb(vc_h vc, vc_error_cb* callback, void** user_data)
@@ -459,7 +459,7 @@ int vc_widget_client_get_error_cb(vc_h vc, vc_error_cb* callback, void** user_da
 	*callback = widget->error_cb;
 	*user_data = widget->error_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_set_send_command_list_cb(vc_h vc, vc_widget_send_current_command_list_cb callback, void* user_data)
@@ -473,7 +473,7 @@ int vc_widget_client_set_send_command_list_cb(vc_h vc, vc_widget_send_current_co
 	widget->send_command_list_cb = callback;
 	widget->send_command_list_user_data = user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_get_send_command_list_cb(vc_h vc, vc_widget_send_current_command_list_cb* callback, void** user_data)
@@ -487,7 +487,7 @@ int vc_widget_client_get_send_command_list_cb(vc_h vc, vc_widget_send_current_co
 	*callback = widget->send_command_list_cb;
 	*user_data = widget->send_command_list_user_data;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 
@@ -502,7 +502,7 @@ int vc_widget_client_set_service_state(vc_h vc, vc_service_state_e state)
 
 	widget->service_state = state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_get_service_state(vc_h vc, vc_service_state_e* state)
@@ -515,7 +515,7 @@ int vc_widget_client_get_service_state(vc_h vc, vc_service_state_e* state)
 
 	*state = widget->service_state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 
@@ -530,7 +530,7 @@ int vc_widget_client_set_state(vc_h vc, vc_state_e state)
 	widget->before_state = widget->current_state;
 	widget->current_state = state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_get_state(vc_h vc, vc_state_e* state)
@@ -543,7 +543,7 @@ int vc_widget_client_get_state(vc_h vc, vc_state_e* state)
 
 	*state = widget->current_state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_get_state_by_uid(unsigned int uid, vc_state_e* state)
@@ -561,13 +561,13 @@ int vc_widget_client_get_state_by_uid(unsigned int uid, vc_state_e* state)
 			if (uid == data->vc->handle) {
 				*state = data->current_state;
 				pthread_mutex_unlock(&g_widget_list_mutex);
-				return 0;
+				return VC_ERROR_NONE;
 			}
 		}
 	}
 
 	pthread_mutex_unlock(&g_widget_list_mutex);
-	return -1;
+	return VC_ERROR_INVALID_PARAMETER;
 }
 
 int vc_widget_client_get_before_state(vc_h vc, vc_state_e* state, vc_state_e* before_state)
@@ -581,7 +581,7 @@ int vc_widget_client_get_before_state(vc_h vc, vc_state_e* state, vc_state_e* be
 	*before_state = widget->before_state;
 	*state = widget->current_state;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_set_xid(vc_h vc, int xid)
@@ -594,7 +594,7 @@ int vc_widget_client_set_xid(vc_h vc, int xid)
 
 	widget->xid = xid;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_cilent_get_xid(vc_h vc, int* xid)
@@ -607,7 +607,7 @@ int vc_widget_cilent_get_xid(vc_h vc, int* xid)
 
 	*xid = widget->xid;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_set_error(vc_h vc, int reason)
@@ -620,7 +620,7 @@ int vc_widget_client_set_error(vc_h vc, int reason)
 
 	widget->reason = reason;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_get_error(vc_h vc, int* reason)
@@ -633,7 +633,7 @@ int vc_widget_client_get_error(vc_h vc, int* reason)
 
 	*reason = widget->reason;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_set_show_tooltip(vc_h vc, bool show)
@@ -646,7 +646,7 @@ int vc_widget_client_set_show_tooltip(vc_h vc, bool show)
 
 	widget->show_tooltip = show;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_get_show_tooltip(vc_h vc, bool* show)
@@ -659,7 +659,7 @@ int vc_widget_client_get_show_tooltip(vc_h vc, bool* show)
 
 	*show = widget->show_tooltip;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_get_count()
@@ -679,7 +679,7 @@ int vc_widget_client_use_callback(vc_h vc)
 		return VC_ERROR_INVALID_PARAMETER;
 
 	widget->cb_ref_count++;
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_widget_client_not_use_callback(vc_h vc)
@@ -691,6 +691,6 @@ int vc_widget_client_not_use_callback(vc_h vc)
 		return VC_ERROR_INVALID_PARAMETER;
 
 	widget->cb_ref_count--;
-	return 0;
+	return VC_ERROR_NONE;
 }
 
diff --git a/common/vc_cmd_db.c b/common/vc_cmd_db.c
index 54c1df0..8db3d37 100644
--- a/common/vc_cmd_db.c
+++ b/common/vc_cmd_db.c
@@ -79,7 +79,7 @@ int __vc_db_reset_handle(void)
 		vc_db_finalize();
 		vc_db_initialize();
 	}
-	return 0;
+	return VC_DB_ERROR_NONE;
 }
 
 static int __vc_db_transaction(sqlite3* db_handle, const char* transaction)
@@ -1731,7 +1731,7 @@ int vc_db_initialize_for_daemon(void)
 
 		g_ref_cnt++;
 		SLOG(LOG_INFO, vc_db_tag(), "[SUCCESS] DB initialization after restore for daemon");
-		return 0;
+		return VC_DB_ERROR_NONE;
 	}
 
 	is_connect = __vc_db_connect_db_for_daemon(&g_backup_path, &g_db_backup_handle);
@@ -1889,12 +1889,12 @@ int vc_db_finalize(void)
 	}
 
 	if (!g_db_handle)
-		return 0;
+		return VC_DB_ERROR_NONE;
 	db_util_close(g_db_handle);
 	g_db_handle = NULL;
 
 	if (!g_db_backup_handle)
-		return 0;
+		return VC_DB_ERROR_NONE;
 	db_util_close(g_db_backup_handle);
 	g_db_backup_handle = NULL;
 
diff --git a/common/vc_command.c b/common/vc_command.c
index 9d7f9d6..3f1b32b 100644
--- a/common/vc_command.c
+++ b/common/vc_command.c
@@ -87,7 +87,7 @@ static int __vc_cmd_get_feature_enabled()
 		}
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static int __check_privilege_initialize()
@@ -798,7 +798,7 @@ int vc_cmd_set_id(vc_cmd_h vc_command, int id)
 	cmd->id = id;
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Set id][%p] id(%d)", vc_command, cmd->id);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_get_id(vc_cmd_h vc_command, int* id)
@@ -821,7 +821,7 @@ int vc_cmd_get_id(vc_cmd_h vc_command, int* id)
 	*id = cmd->id;
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Get id][%p] id(%d)", vc_command, *id);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_set_appid(vc_cmd_h vc_command, const char* appid)
@@ -849,7 +849,7 @@ int vc_cmd_set_appid(vc_cmd_h vc_command, const char* appid)
 	cmd->appid = strdup(appid);
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Set appid][%p] appid(%s)", vc_command, cmd->appid);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_get_appid(vc_cmd_h vc_command, char** appid)
@@ -873,7 +873,7 @@ int vc_cmd_get_appid(vc_cmd_h vc_command, char** appid)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Get appid][%p] appid(%s)", vc_command, *appid);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_set_command(vc_cmd_h vc_command, const char* command)
@@ -900,7 +900,7 @@ int vc_cmd_set_command(vc_cmd_h vc_command, const char* command)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Set command][%p] Command(%s)", vc_command, cmd->command);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_get_command(vc_cmd_h vc_command, char** command)
@@ -927,7 +927,7 @@ int vc_cmd_get_command(vc_cmd_h vc_command, char** command)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Get command][%p] Command(%s)", vc_command, *command);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_set_unfixed_command(vc_cmd_h vc_command, const char* command)
@@ -953,7 +953,7 @@ int vc_cmd_set_unfixed_command(vc_cmd_h vc_command, const char* command)
 	cmd->parameter = strdup(command);
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Set unfixed command][%p] unfixed command(%s)", vc_command, cmd->parameter);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_get_unfixed_command(vc_cmd_h vc_command, char** command)
@@ -977,7 +977,7 @@ int vc_cmd_get_unfixed_command(vc_cmd_h vc_command, char** command)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Get unfixed command][%p] unfixed command(%s)", vc_command, *command);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_set_fixed_command(vc_cmd_h vc_command, const char* fixed)
@@ -1005,7 +1005,7 @@ int vc_cmd_set_fixed_command(vc_cmd_h vc_command, const char* fixed)
 	cmd->fixed = strdup(fixed);
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Set parameter][%p] fixed command(%s)", vc_command, cmd->fixed);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_get_fixed_command(vc_cmd_h vc_command, char** fixed)
@@ -1029,7 +1029,7 @@ int vc_cmd_get_fixed_command(vc_cmd_h vc_command, char** fixed)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Get fixed command][%p] fixed command(%s)", vc_command, *fixed);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_set_invocation_name(vc_cmd_h vc_command, const char* invocation_name)
@@ -1057,7 +1057,7 @@ int vc_cmd_set_invocation_name(vc_cmd_h vc_command, const char* invocation_name)
 	cmd->invocation_name = strdup(invocation_name);
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Set invocation name][%p] invocation_name(%s)", vc_command, cmd->invocation_name);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_get_invocation_name(vc_cmd_h vc_command, char** invocation_name)
@@ -1080,7 +1080,7 @@ int vc_cmd_get_invocation_name(vc_cmd_h vc_command, char** invocation_name)
 		*invocation_name = NULL;
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Get invocation name][%p] invocation_name(%s)", vc_command, *invocation_name);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_set_type(vc_cmd_h vc_command, int type)
@@ -1104,7 +1104,7 @@ int vc_cmd_set_type(vc_cmd_h vc_command, int type)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Set type][%p] type(%d)", vc_command, cmd->type);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_get_type(vc_cmd_h vc_command, int* type)
@@ -1128,7 +1128,7 @@ int vc_cmd_get_type(vc_cmd_h vc_command, int* type)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Get type][%p] type(%d)", vc_command, *type);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_set_format(vc_cmd_h vc_command, int format)
@@ -1149,7 +1149,7 @@ int vc_cmd_set_format(vc_cmd_h vc_command, int format)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Set format][%p] format(%d)", vc_command, format);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_get_format(vc_cmd_h vc_command, int* format)
@@ -1170,7 +1170,7 @@ int vc_cmd_get_format(vc_cmd_h vc_command, int* format)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Get format][%p] format(%d)", vc_command, *format);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_set_pid(vc_cmd_h vc_command, int pid)
@@ -1194,7 +1194,7 @@ int vc_cmd_set_pid(vc_cmd_h vc_command, int pid)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Set pid][%p] pid(%d)", vc_command, cmd->pid);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_get_pid(vc_cmd_h vc_command, int* pid)
@@ -1218,7 +1218,7 @@ int vc_cmd_get_pid(vc_cmd_h vc_command, int* pid)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Get pid][%p] pid(%d)", vc_command, *pid);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_set_domain(vc_cmd_h vc_command, int domain)
@@ -1242,7 +1242,7 @@ int vc_cmd_set_domain(vc_cmd_h vc_command, int domain)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Set domain] domain : %d", domain);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_get_domain(vc_cmd_h vc_command, int* domain)
@@ -1266,7 +1266,7 @@ int vc_cmd_get_domain(vc_cmd_h vc_command, int* domain)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "[Get domain] domain : %d", *domain);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 /**
@@ -1301,7 +1301,7 @@ int vc_cmd_set_result_key(vc_cmd_h vc_command, int key, int modifier)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 /**
@@ -1334,7 +1334,7 @@ int vc_cmd_get_result_key(vc_cmd_h vc_command, int* key, int* modifier)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_print_list(vc_cmd_list_h vc_cmd_list)
@@ -1367,7 +1367,7 @@ int vc_cmd_print_list(vc_cmd_list_h vc_cmd_list)
 
 	SLOG(LOG_DEBUG, TAG_VCCMD, "@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_cmd_get_nlu_json(vc_cmd_h vc_cmd, char** json)
@@ -1394,7 +1394,7 @@ int vc_cmd_get_nlu_json(vc_cmd_h vc_cmd, char** json)
 		return VC_ERROR_OPERATION_FAILED;
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static void __vc_cmd_regex_deinit(int num_regex)
diff --git a/common/vc_config_mgr.c b/common/vc_config_mgr.c
index 5436e46..aa391d3 100644
--- a/common/vc_config_mgr.c
+++ b/common/vc_config_mgr.c
@@ -124,7 +124,7 @@ int __vc_config_mgr_check_engine_is_valid(const char* engine_id)
 
 		if (!strcmp(engine_id, engine_info->uuid)) {
 			SLOG(LOG_DEBUG, vc_config_tag(), "Default engine is valid : %s", engine_id);
-			return 0;
+			return VC_ERROR_NONE;
 		}
 
 		iter = g_slist_next(iter);
@@ -164,7 +164,7 @@ int __vc_config_mgr_check_engine_is_valid(const char* engine_id)
 		return -1;
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 bool __vc_config_mgr_check_lang_is_valid(const char* engine_id, const char* language)
@@ -425,7 +425,7 @@ int __vc_config_mgr_get_engine_info()
 		return -1;
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static Eina_Bool __vc_config_mgr_engine_config_inotify_event_callback(void* data, Ecore_Fd_Handler *fd_handler)
@@ -540,7 +540,7 @@ static int __vc_config_mgr_register_engine_config_updated_event(const char* path
 	g_ino_list = g_list_append(g_ino_list, ino);
 	pthread_mutex_unlock(&vc_config_engine_mutex);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static int __vc_config_mgr_unregister_engine_config_updated_event()
@@ -569,7 +569,7 @@ static int __vc_config_mgr_unregister_engine_config_updated_event()
 		}
 	}
 	pthread_mutex_unlock(&vc_config_engine_mutex);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 Eina_Bool vc_config_mgr_inotify_event_cb(void* data, Ecore_Fd_Handler *fd_handler)
@@ -725,7 +725,7 @@ int __vc_config_set_auto_language()
 
 	if (0 == strncmp(g_config_info->language, candidate_lang, 5)) {
 		SLOG(LOG_DEBUG, vc_config_tag(), "[Config] VC language(%s) is same with display language", g_config_info->language);
-		return 0;
+		return VC_ERROR_NONE;
 	}
 
 	if (true == __vc_config_mgr_check_lang_is_valid(g_config_info->engine_id, candidate_lang)) {
@@ -813,7 +813,7 @@ int __vc_config_set_auto_language()
 		if (NULL != before_lang)	free(before_lang);
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 void __vc_config_language_changed_cb(keynode_t *key, void *data)
@@ -850,7 +850,7 @@ int vc_config_mgr_initialize(unsigned int uid)
 				pthread_mutex_unlock(&vc_config_mgr_mutex);
 				ecore_thread_main_loop_end();
 				SLOG(LOG_DEBUG, vc_config_tag(), "[WARNING] Leave critical section");
-				return 0;
+				return VC_ERROR_NONE;
 			}
 
 			iter = g_slist_next(iter);
@@ -878,7 +878,7 @@ int vc_config_mgr_initialize(unsigned int uid)
 		pthread_mutex_unlock(&vc_config_mgr_mutex);
 		ecore_thread_main_loop_end();
 		SLOG(LOG_DEBUG, vc_config_tag(), "[WARNING] Leave critical section");
-		return 0;
+		return VC_ERROR_NONE;
 	}
 
 	/* Get file name from default engine directory */
@@ -1041,7 +1041,7 @@ int vc_config_mgr_initialize(unsigned int uid)
 	pthread_mutex_unlock(&vc_config_mgr_mutex);
 	ecore_thread_main_loop_end();
 	SLOG(LOG_DEBUG, vc_config_tag(), "[WARNING] Leave critical section");
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_config_mgr_finalize(unsigned int uid)
@@ -1054,7 +1054,7 @@ int vc_config_mgr_finalize(unsigned int uid)
 		pthread_mutex_unlock(&vc_config_mgr_mutex);
 		SLOG(LOG_DEBUG, vc_config_tag(), "[WARNING] Leave critical section");
 
-		return 0;
+		return VC_ERROR_NONE;
 	}
 
 	__vc_config_release_engine();
@@ -1070,7 +1070,7 @@ int vc_config_mgr_finalize(unsigned int uid)
 	SLOG(LOG_DEBUG, vc_config_tag(), "[WARNING] Leave critical section");
 
 	SLOG(LOG_DEBUG, vc_config_tag(), "[Success] Finalize config");
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 
@@ -1108,7 +1108,7 @@ int __vc_config_mgr_register_lang_event()
 	}
 	g_lang_ref_count++;
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int __vc_config_mgr_unregister_config_event()
@@ -1130,7 +1130,7 @@ int __vc_config_mgr_unregister_config_event()
 		vconf_ignore_key_changed(VCONFKEY_LANGSET, __vc_config_language_changed_cb);
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_config_mgr_set_engine_cb(unsigned int uid, vc_config_engine_changed_cb engine_cb)
@@ -1162,7 +1162,7 @@ int vc_config_mgr_set_engine_cb(unsigned int uid, vc_config_engine_changed_cb en
 
 	pthread_mutex_unlock(&vc_config_mgr_mutex);
 	ecore_thread_main_loop_end();
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_config_mgr_unset_engine_cb(unsigned int uid)
@@ -1190,7 +1190,7 @@ int vc_config_mgr_unset_engine_cb(unsigned int uid)
 
 	pthread_mutex_unlock(&vc_config_mgr_mutex);
 	ecore_thread_main_loop_end();
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 
@@ -1223,7 +1223,7 @@ int vc_config_mgr_set_lang_cb(unsigned int uid, vc_config_lang_changed_cb lang_c
 
 	pthread_mutex_unlock(&vc_config_mgr_mutex);
 	ecore_thread_main_loop_end();
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_config_mgr_unset_lang_cb(unsigned int uid)
@@ -1251,7 +1251,7 @@ int vc_config_mgr_unset_lang_cb(unsigned int uid)
 
 	pthread_mutex_unlock(&vc_config_mgr_mutex);
 	ecore_thread_main_loop_end();
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_config_mgr_set_enabled_cb(unsigned int uid, vc_config_enabled_cb enabled_cb)
@@ -1303,7 +1303,7 @@ int vc_config_mgr_unset_enabled_cb(unsigned int uid)
 			if (uid == temp_client->uid) {
 				temp_client->enabled_cb = NULL;
 				pthread_mutex_unlock(&vc_config_mgr_mutex);
-				return 0;
+				return VC_ERROR_NONE;
 			}
 		}
 		iter = g_slist_next(iter);
@@ -1331,7 +1331,7 @@ int vc_config_mgr_get_auto_language(bool* value)
 	*value = g_config_info->auto_lang;
 	pthread_mutex_unlock(&vc_config_mgr_mutex);
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_config_mgr_set_auto_language(bool value)
@@ -1360,7 +1360,7 @@ int vc_config_mgr_set_auto_language(bool value)
 	}
 
 	pthread_mutex_unlock(&vc_config_mgr_mutex);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_config_mgr_get_engine_list(vc_config_supported_engine_cb callback, void* user_data)
@@ -1516,7 +1516,7 @@ int vc_config_mgr_set_engine(const char* engine)
 	/* Check current engine id with new engine id */
 	if (0 == strncmp(g_config_info->engine_id, engine, strlen(g_config_info->engine_id))) {
 		pthread_mutex_unlock(&vc_config_mgr_mutex);
-		return 0;
+		return VC_ERROR_NONE;
 	}
 
 	SLOG(LOG_DEBUG, vc_config_tag(), "New engine id : %s", engine);
@@ -1683,7 +1683,7 @@ int vc_config_mgr_get_language_list(vc_supported_language_cb callback, void* use
 	}
 
 	pthread_mutex_unlock(&vc_config_mgr_mutex);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_config_mgr_get_default_language(char** language)
@@ -1709,7 +1709,7 @@ int vc_config_mgr_get_default_language(char** language)
 	}
 
 	pthread_mutex_unlock(&vc_config_mgr_mutex);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 static int __vc_config_mgr_set_default_language(const char* language)
@@ -1736,7 +1736,7 @@ static int __vc_config_mgr_set_default_language(const char* language)
 		return -1;
 	}
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_config_mgr_set_default_language(const char* language)
@@ -1765,7 +1765,7 @@ int vc_config_mgr_get_enabled(bool* value)
 	*value = g_config_info->enabled;
 
 	pthread_mutex_unlock(&vc_config_mgr_mutex);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_config_mgr_set_enabled(bool value)
@@ -1786,7 +1786,7 @@ int vc_config_mgr_set_enabled(bool value)
 	g_config_info->enabled = value;
 
 	pthread_mutex_unlock(&vc_config_mgr_mutex);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int vc_config_mgr_get_nonfixed_support(bool* value)
@@ -1836,7 +1836,7 @@ int vc_config_mgr_get_nonfixed_support(bool* value)
 	}
 
 	pthread_mutex_unlock(&vc_config_mgr_mutex);
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 bool vc_config_check_default_engine_is_valid(const char* engine)
@@ -1980,7 +1980,7 @@ int __vc_config_mgr_print_engine_info()
 		SLOG(LOG_DEBUG, vc_config_tag(), "@ engine list @");
 		SLOG(LOG_DEBUG, vc_config_tag(), "  No Engine in engine directory");
 		SLOG(LOG_DEBUG, vc_config_tag(), "@@@@");
-		return 0;
+		return VC_ERROR_NONE;
 	}
 
 	/* Get a first item */
@@ -2023,7 +2023,7 @@ int __vc_config_mgr_print_engine_info()
 	}
 	SLOG(LOG_DEBUG, vc_config_tag(), "@@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
 
 int __vc_config_mgr_print_client_info()
@@ -2035,7 +2035,7 @@ int __vc_config_mgr_print_client_info()
 		SLOG(LOG_DEBUG, vc_config_tag(), "@ Client list @");
 		SLOG(LOG_DEBUG, vc_config_tag(), "  No Client");
 		SLOG(LOG_DEBUG, vc_config_tag(), "@@@@");
-		return 0;
+		return VC_ERROR_NONE;
 	}
 
 	/* Get a first item */
@@ -2054,5 +2054,5 @@ int __vc_config_mgr_print_client_info()
 	}
 	SLOG(LOG_DEBUG, vc_config_tag(), "@@@@");
 
-	return 0;
+	return VC_ERROR_NONE;
 }
diff --git a/server/vcd_client_data.c b/server/vcd_client_data.c
index 267c7c6..404d52f 100644
--- a/server/vcd_client_data.c
+++ b/server/vcd_client_data.c
@@ -69,14 +69,14 @@ int vcd_client_manager_set(int pid)
 	int ret = app_manager_get_app_id(pid, &appid);
 	if (0 != ret || NULL == appid) {
 		SLOG(LOG_ERROR, TAG_VCD, "[ERROR] fail to get app id, ret(%d), pid(%d)", ret, pid);
-		return -1;
+		return VCD_ERROR_OPERATION_FAILED;
 	}
 
 	if (-1 != g_manager.pid && NULL != g_manager.appid && 0 == strncmp(g_manager.appid, appid, strlen(g_manager.appid))) {
 		SLOG(LOG_WARN, TAG_VCD, "Same manager has already registered. It doesn't need to set manager again.");
 		if (appid)
 			free(appid);
-		return 0;
+		return VCD_ERROR_NONE;
 	}
 
 	g_manager.pid = pid;
@@ -88,7 +88,7 @@ int vcd_client_manager_set(int pid)
 
 	free(appid);
 	appid = NULL;
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_manager_unset()
@@ -97,7 +97,7 @@ int vcd_client_manager_unset()
 	g_manager.manager_cmd = false;
 	g_manager.exclusive_cmd_option = false;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_manager_unset_appid()
@@ -106,7 +106,7 @@ int vcd_client_manager_unset_appid()
 		free(g_manager.appid);
 		g_manager.appid = NULL;
 	}
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 bool vcd_client_manager_is_valid(int pid)
@@ -121,20 +121,20 @@ int vcd_client_manager_set_command(int pid)
 {
 	if (pid != g_manager.pid) {
 		SLOG(LOG_ERROR, TAG_VCD, "[Client Data ERROR] pid(%d) is NOT valid", pid);
-		return -1;
+		return VCD_ERROR_INVALID_PARAMETER;
 	}
 	g_manager.manager_cmd = true;
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_manager_unset_command(int pid)
 {
 	if (pid != g_manager.pid) {
 		SLOG(LOG_ERROR, TAG_VCD, "[Client Data ERROR] pid(%d) is NOT valid", pid);
-		return -1;
+		return VCD_ERROR_INVALID_PARAMETER;
 	}
 	g_manager.manager_cmd = false;
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 bool vcd_client_manager_is_system_command_valid(int pid)
@@ -173,7 +173,7 @@ int vcd_client_manager_set_demandable_client(int pid, GSList* client_list)
 
 	g_demandable_client = client_list;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 bool vcd_client_manager_check_demandable_client(int pid)
@@ -230,7 +230,7 @@ bool vcd_client_manager_get_exclusive()
 int vcd_client_manager_set_exclusive(bool value)
 {
 	g_manager.exclusive_cmd_option = value;
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_manager_get_pid()
@@ -243,7 +243,7 @@ int vcd_client_manager_get_appid(char** appid)
 	if (NULL != g_manager.appid)
 		*appid = strdup(g_manager.appid);
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_manager_set_result_text(const char* result)
@@ -257,7 +257,7 @@ int vcd_client_manager_set_result_text(const char* result)
 		g_result_text = strdup(result);
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 char* vcd_client_manager_get_result_text()
@@ -392,7 +392,7 @@ int vcd_client_manager_delete_tidl_info()
 	free(g_mgr_tidl_info);
 	g_mgr_tidl_info = NULL;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 manager_tidl_info_s* vcd_client_manager_get_tidl_info()
@@ -454,7 +454,7 @@ int __vcd_client_release_commands()
 	__vcd_client_release_each_commands(&(g_cur_cmd_list.foreground_cmds));
 	__vcd_client_release_each_commands(&(g_cur_cmd_list.background_cmds));
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_command_collect_command()
@@ -488,7 +488,7 @@ int vcd_client_command_collect_command()
 			SLOG(LOG_INFO, TAG_VCD, "[Client Data] No exclusive system commands");
 		}
 
-		return 0;
+		return VCD_ERROR_NONE;
 	}
 
 	/* 3. Set system command */
@@ -572,7 +572,7 @@ int vcd_client_command_collect_command()
 			g_cur_cmd_list.background_cmds = bg_cmd_list;
 		}
 	}
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_get_length()
@@ -707,7 +707,7 @@ int vcd_client_foreach_command(client_foreach_command_cb callback, void* user_da
 	} else {
 		SLOG(LOG_INFO, TAG_VCD, "[Client Data] No background commands");
 	}
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 static vc_cmd_s* __command_copy(vc_cmd_s* src_cmd)
@@ -783,7 +783,7 @@ int vcd_client_get_cmd_from_result_id(int result_id, vc_cmd_s** result)
 
 				*result = __command_copy(temp_cmd);
 
-				return 0;
+				return VCD_ERROR_NONE;
 			}
 
 			iter = g_slist_next(iter);
@@ -806,7 +806,7 @@ int vcd_client_get_cmd_from_result_id(int result_id, vc_cmd_s** result)
 				/*SLOG(LOG_DEBUG, TAG_VCD, "[Client Data] Find result pid(%d) type(%d)", *pid, *cmd_type); */
 
 				*result = __command_copy(temp_cmd);
-				return 0;
+				return VCD_ERROR_NONE;
 			}
 
 			iter = g_slist_next(iter);
@@ -826,7 +826,7 @@ int vcd_client_get_cmd_from_result_id(int result_id, vc_cmd_s** result)
 				/*SLOG(LOG_DEBUG, TAG_VCD, "[Client Data] Find result pid(%d) type(%d)", *pid, *cmd_type); */
 
 				*result = __command_copy(temp_cmd);
-				return 0;
+				return VCD_ERROR_NONE;
 			}
 
 			iter = g_slist_next(iter);
@@ -846,7 +846,7 @@ int vcd_client_get_cmd_from_result_id(int result_id, vc_cmd_s** result)
 				/*SLOG(LOG_DEBUG, TAG_VCD, "[Client Data] Find result pid(%d) type(%d)", *pid, *cmd_type); */
 
 				*result = __command_copy(temp_cmd);
-				return 0;
+				return VCD_ERROR_NONE;
 			}
 
 			iter = g_slist_next(iter);
@@ -866,7 +866,7 @@ int vcd_client_get_cmd_from_result_id(int result_id, vc_cmd_s** result)
 				/*SLOG(LOG_DEBUG, TAG_VCD, "[Client Data] Find result pid(%d) type(%d)", *pid, *cmd_type); */
 
 				*result = __command_copy(temp_cmd);
-				return 0;
+				return VCD_ERROR_NONE;
 			}
 
 			iter = g_slist_next(iter);
@@ -885,7 +885,7 @@ int vcd_client_get_cmd_from_result_id(int result_id, vc_cmd_s** result)
 
 			if (result_id == temp_cmd->id) {
 				*result = __command_copy(temp_cmd);
-				return 0;
+				return VCD_ERROR_NONE;
 			}
 
 			iter = g_slist_next(iter);
@@ -895,13 +895,13 @@ int vcd_client_get_cmd_from_result_id(int result_id, vc_cmd_s** result)
 	}
 
 	SLOG(LOG_ERROR, TAG_VCD, "[Client Data ERROR] Not find matched result");
-	return -1;
+	return VCD_ERROR_INVALID_PARAMETER;
 }
 
 int vcd_client_set_slience_detection(bool value)
 {
 	g_silence_detection = value;
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 bool vcd_client_get_slience_detection()
@@ -912,7 +912,7 @@ bool vcd_client_get_slience_detection()
 int vcd_client_set_recognition_mode(vcd_recognition_mode_e mode)
 {
 	g_recognition_mode = mode;
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 vcd_recognition_mode_e vcd_client_get_recognition_mode()
@@ -933,7 +933,7 @@ int vcd_client_set_server_dialog(int pid, bool is_server_dialog)
 	client_info->server_dialog = is_server_dialog;
 
 	SLOG(LOG_INFO, TAG_VCD, "[Client Data] Set server dialog, client pid(%d), server_dialog(%d)", pid, client_info->server_dialog);
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_get_server_dialog(int pid, bool* is_server_dialog)
@@ -949,7 +949,7 @@ int vcd_client_get_server_dialog(int pid, bool* is_server_dialog)
 	*is_server_dialog = client_info->server_dialog;
 
 	SLOG(LOG_INFO, TAG_VCD, "[Client Data] Get server dialog, client pid(%d), server_dialog(%d)", pid, *is_server_dialog);
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_append_cmd_from_type(int type, vc_cmd_list_h list)
@@ -1009,7 +1009,7 @@ int vcd_client_append_cmd_from_type(int type, vc_cmd_list_h list)
 		item = item->next;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int __show_client_list()
@@ -1066,7 +1066,7 @@ int __show_client_list()
 
 	SLOG(LOG_DEBUG, TAG_VCD, "@@@");
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int __show_command_list(GSList* cmd_group)
@@ -1101,7 +1101,7 @@ int __show_command_list(GSList* cmd_group)
 
 	SLOG(LOG_DEBUG, TAG_VCD, "@@@");
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 GSList* __client_get_item(const int pid)
@@ -1192,7 +1192,7 @@ int vcd_client_add(int pid)
 		free(info);
 		info = NULL;
 
-		return -1;
+		return VCD_ERROR_OUT_OF_MEMORY;
 	} else {
 		SLOG(LOG_INFO, TAG_VCD, "[Client Data SUCCESS] Add new client");
 	}
@@ -1200,7 +1200,7 @@ int vcd_client_add(int pid)
 #ifdef CLIENT_DATA_DEBUG
 	__show_client_list();
 #endif
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_delete(int pid)
@@ -1229,7 +1229,7 @@ int vcd_client_delete(int pid)
 	__show_client_list();
 #endif
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 GSList* __get_client_tidl_info_item(const int pid)
@@ -1318,7 +1318,7 @@ int vcd_client_add_tidl_info(int pid)
 		free(info);
 		info = NULL;
 
-		return -1;
+		return VCD_ERROR_OUT_OF_MEMORY;
 	} else {
 		SLOG(LOG_INFO, TAG_VCD, "[Client Data SUCCESS] Add new client tidl info. pid(%d)", pid);
 	}
@@ -1441,7 +1441,7 @@ int vcd_client_delete_tidl_info(int pid)
 	/*Delete handle from list*/
 	g_client_tidl_info_list = g_slist_delete_link(g_client_tidl_info_list, tmp);
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 client_tidl_info_s* vcd_client_get_tidl_info(int pid)
@@ -1452,12 +1452,12 @@ client_tidl_info_s* vcd_client_get_tidl_info(int pid)
 int vcd_client_get_tidl_list(int** pids, int* pid_count)
 {
 	if (NULL == pids || NULL == pid_count)
-		return -1;
+		return VCD_ERROR_INVALID_PARAMETER;
 
 	int count = g_slist_length(g_client_tidl_info_list);
 
 	if (0 == count)
-		return -1;
+		return VCD_ERROR_OUT_OF_MEMORY;
 
 	int *tmp;
 	tmp = (int*)calloc(count, sizeof(int));
@@ -1486,7 +1486,7 @@ int vcd_client_get_tidl_list(int** pids, int* pid_count)
 	*pids = tmp;
 	*pid_count = count;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 bool vcd_client_is_available(int pid)
@@ -1519,12 +1519,12 @@ int vcd_client_get_ref_count()
 int vcd_client_get_list(int** pids, int* pid_count)
 {
 	if (NULL == pids || NULL == pid_count)
-		return -1;
+		return VCD_ERROR_INVALID_PARAMETER;
 
 	int count = g_slist_length(g_client_list);
 
 	if (0 == count)
-		return -1;
+		return VCD_ERROR_OUT_OF_MEMORY;
 
 	int *tmp;
 	tmp = (int*)calloc(count, sizeof(int));
@@ -1553,7 +1553,7 @@ int vcd_client_get_list(int** pids, int* pid_count)
 	*pids = tmp;
 	*pid_count = count;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_set_command_type(int pid, int type)
@@ -1575,10 +1575,10 @@ int vcd_client_set_command_type(int pid, int type)
 		break;
 	default:
 		SLOG(LOG_ERROR, TAG_VCD, "[Client Data ERROR] not supported command type(%d)", type);
-		return -1;
+		return VCD_ERROR_INVALID_PARAMETER;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_unset_command_type(int pid, int type)
@@ -1600,10 +1600,10 @@ int vcd_client_unset_command_type(int pid, int type)
 		break;
 	default:
 		SLOG(LOG_ERROR, TAG_VCD, "[Client Data ERROR] not supported command type(%d)", type);
-		return -1;
+		return VCD_ERROR_INVALID_PARAMETER;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_set_exclusive_command(int pid)
@@ -1618,7 +1618,7 @@ int vcd_client_set_exclusive_command(int pid)
 
 	client_info->exclusive_cmd = true;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_unset_exclusive_command(int pid)
@@ -1633,17 +1633,17 @@ int vcd_client_unset_exclusive_command(int pid)
 
 	client_info->exclusive_cmd = false;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_save_client_info()
 {
 	if (0 != vc_info_parser_set_client_info(g_client_list)) {
 		SLOG(LOG_ERROR, TAG_VCD, "[ERROR] Fail to save client info");
-		return -1;
+		return VCD_ERROR_OPERATION_FAILED;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 /*
@@ -1709,12 +1709,12 @@ widget_info_s* __widget_get_element(int pid)
 int vcd_client_widget_get_list(int** pids, int* pid_count)
 {
 	if (NULL == pids || NULL == pid_count)
-		return -1;
+		return VCD_ERROR_INVALID_PARAMETER;
 
 	int count = g_slist_length(g_widget_list);
 
 	if (0 == count)
-		return -1;
+		return VCD_ERROR_OUT_OF_MEMORY;
 
 	int *tmp;
 	tmp = (int*)calloc(count, sizeof(int));
@@ -1742,7 +1742,7 @@ int vcd_client_widget_get_list(int** pids, int* pid_count)
 	*pids = tmp;
 	*pid_count = count;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_widget_add(int pid)
@@ -1774,7 +1774,7 @@ int vcd_client_widget_add(int pid)
 		free(info);
 		info = NULL;
 
-		return -1;
+		return VCD_ERROR_OUT_OF_MEMORY;
 	} else {
 		SLOG(LOG_INFO, TAG_VCD, "[Client Data SUCCESS] Add new widget");
 	}
@@ -1782,7 +1782,7 @@ int vcd_client_widget_add(int pid)
 #ifdef CLIENT_DATA_DEBUG
 	__show_client_list();
 #endif
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_widget_delete(int pid)
@@ -1811,7 +1811,7 @@ int vcd_client_widget_delete(int pid)
 	__show_client_list();
 #endif
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_widget_get_foreground_pid()
@@ -1828,7 +1828,7 @@ int vcd_client_widget_get_foreground_pid()
 	widget = __widget_get_element(fg_pid);
 	if (NULL == widget) {
 		SLOG(LOG_WARN, TAG_VCD, "[Client Data] Not found foreground pid of widget");
-		return -1;
+		return VCD_ERROR_INVALID_PARAMETER;
 	}
 
 	return widget->pid;
@@ -1859,7 +1859,7 @@ int vcd_client_widget_set_command(int pid)
 
 	info->widget_cmd = true;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_widget_unset_command(int pid)
@@ -1873,7 +1873,7 @@ int vcd_client_widget_unset_command(int pid)
 
 	info->widget_cmd = false;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_widget_set_asr_result_enabled(int pid, bool enable)
@@ -1887,7 +1887,7 @@ int vcd_client_widget_set_asr_result_enabled(int pid, bool enable)
 
 	info->asr_result_enabled = enable;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_widget_get_asr_result_enabled(int pid, bool* enable)
@@ -1901,7 +1901,7 @@ int vcd_client_widget_get_asr_result_enabled(int pid, bool* enable)
 
 	*enable = info->asr_result_enabled;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_widget_set_waiting_for_recording(int pid, bool waiting)
@@ -1909,25 +1909,25 @@ int vcd_client_widget_set_waiting_for_recording(int pid, bool waiting)
 
 	if (TRUE == waiting && pid != vcd_client_widget_get_foreground_pid()) {
 		SLOG(LOG_ERROR, TAG_VCD, "[Client Data ERROR] pid(%d) is NOT foreground pid", pid);
-		return -1;
+		return VCD_ERROR_INVALID_PARAMETER;
 	}
 
 	g_is_waiting_recording = waiting;
 	g_waiting_recording_pid = pid;
 	SLOG(LOG_ERROR, TAG_VCD, "[INFO] Success to set waiting for recording, pid(%d), waiting(%d)", pid, waiting);
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_client_widget_get_waiting_for_recording(int pid, bool* waiting)
 {
 	if (pid != g_waiting_recording_pid) {
 		SLOG(LOG_ERROR, TAG_VCD, "[Client Data ERROR] pid(%d) is NOT waiting pid", pid);
-		return -1;
+		return VCD_ERROR_INVALID_PARAMETER;
 	}
 
 	*waiting = g_is_waiting_recording;
 	SLOG(LOG_ERROR, TAG_VCD, "[INFO] Success to get waiting for recording, waiting(%d)", *waiting);
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 GSList* __get_widget_tidl_info_item(const int pid)
@@ -2018,7 +2018,7 @@ int vcd_client_widget_add_tidl_info(int pid)
 		free(info);
 		info = NULL;
 
-		return -1;
+		return VCD_ERROR_OUT_OF_MEMORY;
 	} else {
 		SLOG(LOG_INFO, TAG_VCD, "[Client Data SUCCESS] Add new widget tidl info. pid(%d)", pid);
 	}
@@ -2094,7 +2094,7 @@ int vcd_client_widget_delete_tidl_info(int pid)
 	/*Delete handle from list*/
 	g_widget_tidl_info_list = g_slist_delete_link(g_widget_tidl_info_list, tmp);
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 widget_tidl_info_s* vcd_client_widget_get_tidl_info(int pid)
@@ -2271,7 +2271,7 @@ int vcd_client_setting_add_tidl_info(int pid)
 		free(info);
 		info = NULL;
 
-		return -1;
+		return VCD_ERROR_OUT_OF_MEMORY;
 	} else {
 		SLOG(LOG_INFO, TAG_VCD, "[Setting Data SUCCESS] Add new setting client tidl info. pid(%d)", pid);
 	}
@@ -2347,7 +2347,7 @@ int vcd_client_setting_delete_tidl_info(int pid)
 	/*Delete handle from list*/
 	g_setting_tidl_info_list = g_slist_delete_link(g_setting_tidl_info_list, tmp);
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 setting_tidl_info_s* vcd_client_setting_get_tidl_info(int pid)
@@ -2358,12 +2358,12 @@ setting_tidl_info_s* vcd_client_setting_get_tidl_info(int pid)
 int vcd_client_setting_get_tidl_list(int** pids, int* pid_count)
 {
 	if (NULL == pids || NULL == pid_count)
-		return -1;
+		return VCD_ERROR_INVALID_PARAMETER;
 
 	int count = g_slist_length(g_setting_tidl_info_list);
 
 	if (0 == count)
-		return -1;
+		return VCD_ERROR_OUT_OF_MEMORY;
 
 	int *tmp;
 	tmp = (int*)calloc(count, sizeof(int));
@@ -2392,5 +2392,5 @@ int vcd_client_setting_get_tidl_list(int** pids, int* pid_count)
 	*pids = tmp;
 	*pid_count = count;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
diff --git a/server/vcd_config.c b/server/vcd_config.c
index cdf2f3d..2cfa477 100644
--- a/server/vcd_config.c
+++ b/server/vcd_config.c
@@ -69,7 +69,7 @@ int vcd_config_initialize(vcd_config_lang_changed_cb lang_cb, vcd_config_foregro
 
 	g_foreground_pid = VC_RUNTIME_INFO_NO_FOREGROUND;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_config_finalize()
@@ -77,7 +77,7 @@ int vcd_config_finalize()
 	vc_config_mgr_unset_lang_cb(getpid());
 	vc_config_mgr_finalize(getpid());
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_config_get_default_language(char** language)
@@ -90,7 +90,7 @@ int vcd_config_get_default_language(char** language)
 		return VCD_ERROR_OPERATION_FAILED;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_config_set_default_language(const char* language)
@@ -103,7 +103,7 @@ int vcd_config_set_default_language(const char* language)
 		return VCD_ERROR_OPERATION_FAILED;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_config_set_service_state(vcd_state_e state)
@@ -112,7 +112,7 @@ int vcd_config_set_service_state(vcd_state_e state)
 
 	SLOG(LOG_INFO, TAG_VCD, "[Config] Config is changed : %d", g_state);
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 vcd_state_e vcd_config_get_service_state()
@@ -123,7 +123,7 @@ vcd_state_e vcd_config_get_service_state()
 int vcd_config_get_foreground(int* pid)
 {
 	*pid = g_foreground_pid;
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_config_set_foreground(int pid, bool value)
@@ -135,7 +135,7 @@ int vcd_config_set_foreground(int pid, bool value)
 			g_foreground_pid = VC_RUNTIME_INFO_NO_FOREGROUND;
 		}
 	}
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_config_set_disabled_command_type(int disabled_cmd_type)
@@ -144,35 +144,35 @@ int vcd_config_set_disabled_command_type(int disabled_cmd_type)
 
 	g_disabled_command_type = disabled_cmd_type;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_config_get_command_type_enabled(int cmd_type)
 {
 	if (cmd_type <= 0 || cmd_type >= COMMAND_TYPE_MAX) {
 		SLOG(LOG_ERROR, TAG_VCD, "[ERROR] Invalid command type");
-		return 0;
+		return VCD_ERROR_NONE;
 	}
 
 	if (~(g_disabled_command_type) & (1 << cmd_type))
 		return 1;
 	else
-		return 0;
+		return VCD_ERROR_NONE;
 }
 
 int vcd_config_get_audio_streaming_mode(vcd_audio_streaming_mode_e* streaming_mode)
 {
 	*streaming_mode = g_audio_streaming_mode;
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_config_set_audio_streaming_mode(vcd_audio_streaming_mode_e streaming_mode)
 {
 	if (streaming_mode < VCD_AUDIO_STREAMING_MODE_VC_SERVICE || streaming_mode > VCD_AUDIO_STREAMING_MODE_OUTSIDE) {
 		SLOG(LOG_ERROR, TAG_VCD, "[ERROR] Invalid streaming mode(%d)", streaming_mode);
-		return -1;
+		return VCD_ERROR_INVALID_PARAMETER;
 	}
 
 	g_audio_streaming_mode = streaming_mode;
-	return 0;
+	return VCD_ERROR_NONE;
 }
diff --git a/server/vcd_engine_agent.c b/server/vcd_engine_agent.c
index 2d5bcf2..9c3c9c1 100644
--- a/server/vcd_engine_agent.c
+++ b/server/vcd_engine_agent.c
@@ -122,7 +122,7 @@ int vcd_engine_agent_init()
 
 	SLOG(LOG_INFO, TAG_VCD, "[Engine Agent SUCCESS] Engine Agent Initialize");
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_agent_release()
@@ -160,7 +160,7 @@ int vcd_engine_agent_release()
 
 	SLOG(LOG_INFO, TAG_VCD, "[Engine Agent SUCCESS] Engine Agent release");
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 bool vcd_engine_is_available_engine()
@@ -249,7 +249,7 @@ static int __internal_get_engine_info(vce_request_callback_s* callback)
 	SLOG(LOG_INFO, TAG_VCD, "Engine setting : %s", g_dynamic_engine.engine_setting_path);
 	SLOG(LOG_INFO, TAG_VCD, "@@@");
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_agent_load_current_engine(vce_request_callback_s* callback)
@@ -268,7 +268,7 @@ int vcd_engine_agent_load_current_engine(vce_request_callback_s* callback)
 
 	if (true == g_dynamic_engine.is_loaded) {
 		SLOG(LOG_ERROR, TAG_VCD, "[Engine Agent] Engine has already been loaded");
-		return 0;
+		return VCD_ERROR_NONE;
 	}
 
 	/* Get current engine info */
@@ -329,7 +329,7 @@ int vcd_engine_agent_load_current_engine(vce_request_callback_s* callback)
 
 	SLOG(LOG_INFO, TAG_VCD, "[Engine Agent] load current engine FINISH");
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_agent_unload_current_engine()
@@ -354,7 +354,7 @@ int vcd_engine_agent_unload_current_engine()
 	/* reset current engine data */
 	g_dynamic_engine.is_loaded = false;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 
@@ -386,7 +386,7 @@ int vcd_engine_set_commands()
 		SLOG(LOG_INFO, TAG_VCD, "[Engine Agent] Dynamic engine is not available");
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_recognize_start(bool silence)
@@ -411,7 +411,7 @@ int vcd_engine_recognize_start(bool silence)
 	}
 
 	SLOG(LOG_INFO, TAG_VCD, "[Engine Agent SUCCESS] Engine start");
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_recognize_audio(const void* data, unsigned int length, vce_speech_detect_e* speech_detected)
@@ -439,7 +439,7 @@ int vcd_engine_recognize_audio(const void* data, unsigned int length, vce_speech
 		}
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_recognize_stop()
@@ -461,7 +461,7 @@ int vcd_engine_recognize_stop()
 		return VCD_ERROR_OPERATION_FAILED;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_recognize_cancel()
@@ -480,7 +480,7 @@ int vcd_engine_recognize_cancel()
 		}
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_set_audio_type(const char* audio)
@@ -499,7 +499,7 @@ int vcd_engine_set_audio_type(const char* audio)
 		}
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_set_server_dialog(const char* app_id, const char* credential)
@@ -518,7 +518,7 @@ int vcd_engine_set_server_dialog(const char* app_id, const char* credential)
 		}
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_set_domain(int pid, const char* domain)
@@ -537,7 +537,7 @@ int vcd_engine_set_domain(int pid, const char* domain)
 		}
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_get_nlu_base_info(int pid, const char* key, char** value)
@@ -564,7 +564,7 @@ int vcd_engine_get_nlu_base_info(int pid, const char* key, char** value)
 		return VCD_ERROR_NONE;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_set_private_data(int pid, const char* key, const char* data)
@@ -589,7 +589,7 @@ int vcd_engine_set_private_data(int pid, const char* key, const char* data)
 		return VCD_ERROR_NONE;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_get_private_data(int pid, const char* key, char** data)
@@ -616,7 +616,7 @@ int vcd_engine_get_private_data(int pid, const char* key, char** data)
 		return VCD_ERROR_NONE;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_send_specific_engine_request(const char* engine_app_id, const char* event, const char* request)
@@ -638,7 +638,7 @@ int vcd_engine_send_specific_engine_request(const char* engine_app_id, const cha
 		return VCD_ERROR_NONE;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_process_text(int pid, const char* text)
@@ -657,7 +657,7 @@ int vcd_engine_process_text(int pid, const char* text)
 		}
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_process_list_event(int pid, const char* event)
@@ -676,7 +676,7 @@ int vcd_engine_process_list_event(int pid, const char* event)
 		}
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_process_haptic_event(int pid, const char* event)
@@ -695,7 +695,7 @@ int vcd_engine_process_haptic_event(int pid, const char* event)
 		}
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_request_tts(int pid, int utt_id, const char* text, const char* language)
@@ -719,7 +719,7 @@ int vcd_engine_request_tts(int pid, int utt_id, const char* text, const char* la
 		return VCD_ERROR_OPERATION_FAILED;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_cancel_tts(int pid, int utt_id)
@@ -741,7 +741,7 @@ int vcd_engine_cancel_tts(int pid, int utt_id)
 		return VCD_ERROR_OPERATION_FAILED;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_get_tts_audio_format(int* rate, int* channel, int* audio_type)
@@ -763,7 +763,7 @@ int vcd_engine_get_tts_audio_format(int* rate, int* channel, int* audio_type)
 		return VCD_ERROR_OPERATION_FAILED;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 
@@ -788,7 +788,7 @@ int vcd_engine_get_audio_format(const char* audio_id, vce_audio_type_e* types, i
 		return ret;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 static bool __supported_language_cb(const char* language, void* user_data)
@@ -826,7 +826,7 @@ int vcd_engine_supported_langs(GList** lang_list)
 		return ret;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 
@@ -845,7 +845,7 @@ int vcd_engine_get_current_language(char** lang)
 	/* get default language */
 	*lang = g_strdup(g_default_lang);
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_set_current_language(const char* language)
@@ -873,7 +873,7 @@ int vcd_engine_set_current_language(const char* language)
 		SLOG(LOG_INFO, TAG_VCD, "[Engine Agent] Dynamic engine is not available (Cannot start)");
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_agent_get_foreach_command(vce_cmd_h vce_command, vce_command_cb callback, void* user_data)
@@ -887,7 +887,7 @@ int vcd_engine_agent_get_command_count(vce_cmd_h vce_command, int* count)
 	SLOG(LOG_INFO, TAG_VCD, "[Engine Agent] Request command length from engine");
 
 	*count = vcd_client_get_length();
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_engine_agent_get_audio_type(char** audio_type)
diff --git a/server/vcd_server.c b/server/vcd_server.c
index d82b10b..16717a5 100644
--- a/server/vcd_server.c
+++ b/server/vcd_server.c
@@ -131,7 +131,7 @@ static int __server_recorder_callback(const void* data, const unsigned int lengt
 	if (VCD_STATE_READY == state) {
 		SLOG(LOG_DEBUG, TAG_VCD, "[Server] Ready state, but recording");
 	} else if (VCD_STATE_PROCESSING == state) {
-		return 0;
+		return VCD_ERROR_NONE;
 	}
 
 	vce_speech_detect_e speech_detected = VCE_SPEECH_DETECT_NONE;
@@ -149,7 +149,7 @@ static int __server_recorder_callback(const void* data, const unsigned int lengt
 		} else {
 			vcdc_tidl_send_error_to_manager(vcd_client_manager_get_pid(), ret, "voice_framework.error.engine.set_recording_fail");
 		}
-		return 0;
+		return VCD_ERROR_NONE;
 	}
 
 	if (VCE_SPEECH_DETECT_BEGIN == speech_detected) {
@@ -182,7 +182,7 @@ static int __server_recorder_callback(const void* data, const unsigned int lengt
 		}
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 void __server_recorder_interrupt_callback()
@@ -1363,7 +1363,7 @@ int vcd_initialize(vce_request_callback_s *callback)
 
 	SLOG(LOG_ERROR, TAG_VCD, "[Server SUCCESS] initialize");
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 bool vcd_finalize()
@@ -1844,7 +1844,7 @@ static int __reset_waiting_for_widget_recording(void)
 	}
 	// Reset flag to wait for recording from widget client
 	vcd_client_widget_set_waiting_for_recording(-1, false);
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 #if 0
@@ -1885,7 +1885,7 @@ static int __set_waiting_for_widget_recording(int pid)
 
 	// Set flag to wait for recording from widget client
 	vcd_client_widget_set_waiting_for_recording(pid, true);
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 static int __start_internal_recognition()
@@ -1954,7 +1954,7 @@ static int __start_internal_recognition()
 
 	SLOG(LOG_ERROR, TAG_VCD, "[Server Success] Start recognition(%d)", stop_by_silence);
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 static Eina_Bool __vcd_request_show_tooltip(void *data)
@@ -1996,7 +1996,7 @@ int vcd_server_mgr_start(vcd_recognition_mode_e recognition_mode, bool exclusive
 				ecore_timer_add(0, __vcd_request_show_tooltip, (void*)true);
 
 				__set_waiting_for_widget_recording(pid);
-				return 0;
+				return VCD_ERROR_NONE;
 			}
 		}
 	} else {
@@ -2446,7 +2446,7 @@ int vcd_server_set_command(int pid, vc_cmd_type_e cmd_type)
 		return VCD_ERROR_OPERATION_FAILED;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_server_unset_command(int pid, vc_cmd_type_e cmd_type)
@@ -2462,7 +2462,7 @@ int vcd_server_unset_command(int pid, vc_cmd_type_e cmd_type)
 		return VCD_ERROR_OPERATION_FAILED;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_server_set_foreground(int pid, bool value)
@@ -2478,7 +2478,7 @@ int vcd_server_set_foreground(int pid, bool value)
 		return VCD_ERROR_OPERATION_FAILED;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 static int __vcd_server_launch_manager_app()
@@ -2556,7 +2556,7 @@ int vcd_server_set_server_dialog(int pid, const char* app_id, const char* creden
 			SLOG(LOG_INFO, TAG_VCD, "[Server] Set to false for server dialog, app_id(%s)", app_id);
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_server_dialog(int pid, const char* disp_text, const char* utt_text, int continuous)
@@ -2590,7 +2590,7 @@ int vcd_server_dialog(int pid, const char* disp_text, const char* utt_text, int
 			return ret;
 		}
 	}
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_server_is_system_command_valid(int pid, int* is_sys_cmd_valid)
@@ -2607,7 +2607,7 @@ int vcd_server_is_system_command_valid(int pid, int* is_sys_cmd_valid)
 	else
 		*is_sys_cmd_valid = false;
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 static void __start_tts_request_thread(void* data, Ecore_Thread* thread)
@@ -2715,7 +2715,7 @@ int vcd_server_request_tts(int pid, const char* text, const char* language, int
 		g_tts_thread = ecore_thread_run(__start_tts_request_thread, __end_tts_request_thread, NULL, NULL);
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_server_cancel_tts(int pid, int utt_id)
@@ -2808,7 +2808,7 @@ int vcd_server_set_exclusive_command(int pid, bool value)
 		}
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_server_request_start(int pid, bool stop_by_silence)
@@ -2843,7 +2843,7 @@ int vcd_server_request_start(int pid, bool stop_by_silence)
 		return VCD_ERROR_INVALID_PARAMETER;
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_server_request_stop(int pid)
@@ -2949,7 +2949,7 @@ int vcd_server_widget_finalize(int pid)
 		if (0 == vcd_client_get_ref_count()) {
 			SLOG(LOG_ERROR, TAG_VCD, "[Server] connected client list is empty, vc-service will be terminated");
 			ecore_timer_add(0, __finalize_quit_ecore_loop, NULL);
-			return 0;
+			return VCD_ERROR_NONE;
 		}
 		return VCD_ERROR_INVALID_PARAMETER;
 	}
@@ -2962,7 +2962,7 @@ int vcd_server_widget_finalize(int pid)
 	if (0 == vcd_client_get_ref_count()) {
 		SLOG(LOG_ERROR, TAG_VCD, "[Server] connected client list is empty, vc-service will be terminated");
 		ecore_timer_add(0, __finalize_quit_ecore_loop, NULL);
-		return 0;
+		return VCD_ERROR_NONE;
 	}
 
 	bool is_waiting = false;
@@ -2988,7 +2988,7 @@ int vcd_server_widget_start_recording(int pid, bool widget_command)
 	bool waiting;
 	if (0 != vcd_client_widget_get_waiting_for_recording(pid, &waiting) || false == waiting) {
 		SLOG(LOG_ERROR, TAG_VCD, "[Server] Server is not waiting for recording, pid(%d), waiting(%d)", pid, waiting);
-		return 0;
+		return VCD_ERROR_NONE;
 	}
 
 	if (true == widget_command) {
@@ -3006,7 +3006,7 @@ int vcd_server_widget_start_recording(int pid, bool widget_command)
 		ecore_timer_add(0, __vcd_request_show_tooltip, (void*)false);
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_server_widget_start(int pid, bool stop_by_silence)
@@ -3032,7 +3032,7 @@ int vcd_server_widget_start(int pid, bool stop_by_silence)
 	/* Notify show tooltip */
 	ecore_timer_add(0, __vcd_request_show_tooltip, (void*)true);
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_server_widget_stop(int pid)
@@ -3255,7 +3255,7 @@ int vcd_send_update_status(vce_update_event_e update_event, const char* msg)
 		SLOG(LOG_ERROR, TAG_VCD, "[Server ERROR] Update event : Fail - msg(%s)", msg);
 	}
 
-	return 0;
+	return VCD_ERROR_NONE;
 }
 
 int vcd_set_private_data_set_cb(vce_private_data_set_cb callback_func)
diff --git a/server/vcd_server_data.cpp b/server/vcd_server_data.cpp
index 7a238aa..579928a 100644
--- a/server/vcd_server_data.cpp
+++ b/server/vcd_server_data.cpp
@@ -121,7 +121,7 @@ int vcd_data_get_tts_text_data(unsigned int tts_uid, vc_tts_text_data_s** data)
 		SLOG(LOG_ERROR, TAG_VCD, "[DATA ERROR] There is no tts_text data");
 		*data = NULL;
 		pthread_mutex_unlock(&g_tts_text_data_mutex);
-		return -1;
+		return VCD_ERROR_INVALID_PARAMETER;
 	}
 
 	std::list<vc_tts_text_data_s *>::iterator iter;
@@ -159,7 +159,7 @@ int vcd_data_get_first_tts_text_data(vc_tts_text_data_s** data)
 		SLOG(LOG_ERROR, TAG_VCD, "[DATA ERROR] There is no tts_text data");
 		*data = NULL;
 		pthread_mutex_unlock(&g_tts_text_data_mutex);
-		return -1;
+		return VCD_ERROR_INVALID_PARAMETER;
 	}
 
 	std::list<vc_tts_text_data_s*>::iterator iter;
diff --git a/server/vce.c b/server/vce.c
index 9a66d2d..be70147 100644
--- a/server/vce.c
+++ b/server/vce.c
@@ -58,7 +58,7 @@ static int __vce_get_feature_enabled()
 		}
 	}
 
-	return 0;
+	return VCE_ERROR_NONE;
 }
 
 static int __check_privilege_initialize()
@@ -177,7 +177,7 @@ int vce_main(int argc, char** argv, vce_request_callback_s *callback)
 	SLOG(LOG_DEBUG, TAG_VCD, "  ");
 	SLOG(LOG_DEBUG, TAG_VCD, "  ");
 
-	return 0;
+	return VCE_ERROR_NONE;
 }
 
 int vce_send_result(vce_result_event_e event, int* result_id, int count, const char* all_result, const char* non_fixed_result, const char* nlu_result, const char* msg, int* user_info, void *user_data)