ei: make ei_disconnect() public

Previously the only way to disconnect from the EIS implementation was
to call ei_unref() and release all resources. This makes it more
difficult for shared cleanup code - clients already have code in place
to deal with DEVICE_REMOVED, SEAT_REMOVED, etc. but that code has to
be triggered manually before ei_unref() is called.

OTOH where the server disconnects us, libei already unwound the state
so we would artificially generate these removed events, allowing the
client to clean up.

Make life easier for client by allowing them to ei_disconnect() and
get the benefits of our state unwinding. ei_disconnect() was already
used internally to disconnect on any error so this merely makes this
function public.

Closes #67

Part-of: <https://gitlab.freedesktop.org/libinput/libei/-/merge_requests/311>

src/libei-private.h

@@ -131,9 +131,6 @@ ei_get_interface(struct ei *ei);
 int
 ei_set_socket(struct ei *ei, int fd);
 
-void
-ei_disconnect(struct ei *ei);
-
 struct ei *
 ei_get_context(struct ei *ei);
 

src/libei.c

@@ -580,7 +580,7 @@ ei_queue_touch_up_event(struct ei_device *device, uint32_t touchid)
 	queue_event(ei_device_get_context(device), e);
 }
 
-void
+_public_ void
 ei_disconnect(struct ei *ei)
 {
 	if (ei->state == EI_STATE_DISCONNECTED ||

src/libei.h

@@ -849,6 +849,24 @@ ei_peek_event(struct ei *ei);
 uint64_t
 ei_now(struct ei *ei);
 
+/**
+ * Disconnect the current ei context from the EIS implementation.
+ *
+ * After a call to ei_disconnect(), ei_get_event() will return
+ * events to remove resources (e.g. seats and devices) as if they
+ * had been removed by the EIS implementation. The last event
+ * returned by ei_get_event() is @ref EI_EVENT_DISCONNECT after
+ * which the context should be considered inert and any
+ * remaining resources released with ei_unref().
+ *
+ * This does not free the resources associated with the ei context, use
+ * ei_unref().
+ *
+ * @since 1.4
+ */
+void
+ei_disconnect(struct ei *ei);
+
 /**
  * @ingroup libei-seat
  *

test/test-ei.c

@@ -67,7 +67,7 @@ MUNIT_TEST(test_ei_disconnect_immediately)
 	return MUNIT_OK;
 }
 
-MUNIT_TEST(test_ei_disconnect_self_immediately)
+MUNIT_TEST(test_ei_unref_self_immediately)
 {
 	_unref_(peck) *peck = peck_new();
 
@@ -93,6 +93,30 @@ MUNIT_TEST(test_ei_disconnect_self_immediately)
 	return MUNIT_OK;
 }
 
+MUNIT_TEST(test_ei_disconnect_self_immediately)
+{
+	_unref_(peck) *peck = peck_new();
+
+	peck_enable_eis_behavior(peck, PECK_EIS_BEHAVIOR_NONE);
+	peck_dispatch_until_stable(peck);
+
+	/* Disconnect before server processed CONNECT */
+	with_client(peck) {
+		ei_disconnect(ei);
+	}
+
+	peck_dispatch_until_stable(peck);
+
+	/* Expect the client to get a disconnect event */
+	with_server(peck) {
+		_unref_(eis_event) *connect =
+			peck_eis_next_event(eis, EIS_EVENT_CLIENT_CONNECT);
+		_unref_(eis_event) *disconnect =
+			peck_eis_next_event(eis, EIS_EVENT_CLIENT_DISCONNECT);
+	}
+
+	return MUNIT_OK;
+}
 
 MUNIT_TEST(test_ei_disconnect_after_connect)
 {
@@ -130,7 +154,7 @@ MUNIT_TEST(test_ei_disconnect_after_connect)
 	return MUNIT_OK;
 }
 
-MUNIT_TEST(test_ei_disconnect_self_after_connect)
+MUNIT_TEST(test_ei_unref_self_after_connect)
 {
 	_unref_(peck) *peck = peck_new();
 
@@ -154,6 +178,29 @@ MUNIT_TEST(test_ei_disconnect_self_after_connect)
 	return MUNIT_OK;
 }
 
+MUNIT_TEST(test_ei_disconnect_self_after_connect)
+{
+	_unref_(peck) *peck = peck_new();
+
+	peck_enable_eis_behavior(peck, PECK_EIS_BEHAVIOR_NONE);
+	peck_dispatch_until_stable(peck);
+
+	with_client(peck) {
+		ei_disconnect(ei);
+	}
+
+	peck_dispatch_until_stable(peck);
+
+	with_server(peck) {
+		_unref_(eis_event) *connect =
+			peck_eis_next_event(eis, EIS_EVENT_CLIENT_CONNECT);
+		_unref_(eis_event) *disconnect =
+			peck_eis_next_event(eis, EIS_EVENT_CLIENT_DISCONNECT);
+	}
+
+	return MUNIT_OK;
+}
+
 MUNIT_TEST(test_ei_disconnect_after_seat)
 {
 	_unref_(peck) *peck = peck_new();
@@ -203,9 +250,8 @@ MUNIT_TEST(test_ei_disconnect_self_after_seat)
 			peck_ei_next_event(ei, EI_EVENT_CONNECT);
 		_unref_(ei_event) *seat =
 			peck_ei_next_event(ei, EI_EVENT_SEAT_ADDED);
-		peck_drop_ei(peck);
 		/* Disconnect from client */
-		ei_unref(ei);
+		ei_disconnect(ei);
 
 		/* There is no way to disconnect from the server without
 		 * destroying the context, so we don't care about the actual
@@ -274,8 +320,7 @@ MUNIT_TEST(test_ei_disconnect_self_after_bind_before_received)
 		struct ei_seat *seat = ei_event_get_seat(event);
 		ei_seat_bind_capabilities(seat, EI_DEVICE_CAP_POINTER, NULL);
 		/* Disconnect before the server can process the bind event */
-		peck_drop_ei(peck);
-		ei_unref(ei);
+		ei_disconnect(ei);
 	}
 
 	peck_dispatch_eis(peck);
@@ -354,8 +399,7 @@ MUNIT_TEST(test_ei_disconnect_self_after_bind_after_received)
 	peck_dispatch_eis(peck);
 
 	with_client(peck) {
-		peck_drop_ei(peck);
-		ei_unref(ei);
+		ei_disconnect(ei);
 	}
 
 	peck_dispatch_eis(peck);