Fix swaywm#892

Removed additional event socket to reduce synchronisation problems
and limited workspace update requests count.

common/ipc-client.c

@@ -88,7 +88,7 @@ void free_ipc_response(struct ipc_response *response) {
 	free(response);
 }
 
-char *ipc_single_command(int socketfd, uint32_t type, const char *payload, uint32_t *len) {
+void ipc_single_command_no_response(int socketfd, uint32_t type, const char *payload, uint32_t *len) {
 	char data[ipc_header_size];
 	uint32_t *data32 = (uint32_t *)(data + sizeof(ipc_magic));
 	memcpy(data, ipc_magic, sizeof(ipc_magic));
@@ -102,6 +102,10 @@ char *ipc_single_command(int socketfd, uint32_t type, const char *payload, uint3
 	if (write(socketfd, payload, *len) == -1) {
 		sway_abort("Unable to send IPC payload");
 	}
+}
+
+char *ipc_single_command(int socketfd, uint32_t type, const char *payload, uint32_t *len) {
+	ipc_single_command_no_response(socketfd, type, payload, len);
 
 	struct ipc_response *resp = ipc_recv_response(socketfd);
 	char *response = resp->payload;

include/ipc-client.h

@@ -23,6 +23,10 @@ char *get_socketpath(void);
  * Opens the sway socket.
  */
 int ipc_open_socket(const char *socket_path);
+/**
+ * Issues a single IPC command without reading response.
+ */
+void ipc_single_command_no_response(int socketfd, uint32_t type, const char *payload, uint32_t *len);
 /**
  * Issues a single IPC command and returns the buffer. len will be updated with
  * the length of the buffer returned from sway.

include/swaybar/bar.h

@@ -15,6 +15,8 @@ struct bar {
 	int ipc_socketfd;
 	int status_read_fd;
 	pid_t status_command_pid;
+
+	int pending_ipc_requests;
 };
 
 struct output {

swaybar/bar.c

@@ -155,7 +155,6 @@ void bar_setup(struct bar *bar, const char *socket_path, const char *bar_id) {
 
 	/* connect to sway ipc */
 	bar->ipc_socketfd = ipc_open_socket(socket_path);
-	bar->ipc_event_socketfd = ipc_open_socket(socket_path);
 
 	ipc_bar_init(bar, bar_id);
 
@@ -205,7 +204,7 @@ bool dirty = true;
 
 static void respond_ipc(int fd, short mask, void *_bar) {
 	struct bar *bar = (struct bar *)_bar;
-	sway_log(L_DEBUG, "Got IPC event.");
+	sway_log(L_DEBUG, "Got IPC event or reply.");
 	dirty = handle_ipc_event(bar);
 }
 
@@ -222,7 +221,7 @@ static void respond_output(int fd, short mask, void *_output) {
 }
 
 void bar_run(struct bar *bar) {
-	add_event(bar->ipc_event_socketfd, POLLIN, respond_ipc, bar);
+	add_event(bar->ipc_socketfd, POLLIN, respond_ipc, bar);
 	add_event(bar->status_read_fd, POLLIN, respond_command, bar);
 
 	int i;
@@ -322,10 +321,6 @@ void bar_teardown(struct bar *bar) {
 		close(bar->ipc_socketfd);
 	}
 
-	if (bar->ipc_event_socketfd) {
-		close(bar->ipc_event_socketfd);
-	}
-
 	/* terminate status command process */
 	terminate_status_command(bar->status_command_pid);
 }

swaybar/ipc.c

@@ -14,7 +14,7 @@ void ipc_send_workspace_command(const char *workspace_name) {
 	char command[size];
 	sprintf(command, "workspace \"%s\"", workspace_name);
 
-	ipc_single_command(swaybar.ipc_socketfd, IPC_COMMAND, command, &size);
+	ipc_single_command_no_response(swaybar.ipc_socketfd, IPC_COMMAND, command, &size);
 }
 
 static void ipc_parse_config(struct config *config, const char *payload) {
@@ -249,7 +249,27 @@ static void ipc_parse_config(struct config *config, const char *payload) {
 	json_object_put(bar_config);
 }
 
-static void ipc_update_workspaces(struct bar *bar) {
+static void ipc_update_workspaces_request(struct bar *bar) {
+	uint32_t len = 0;
+
+	if (bar->pending_ipc_requests >= 10) {
+		sway_log(L_DEBUG, "Ignoring update request");
+		return;
+	}
+	bar->pending_ipc_requests++;
+	sway_log(L_DEBUG, "Sending update request, %d pending", bar->pending_ipc_requests);
+
+	ipc_single_command_no_response(bar->ipc_socketfd, IPC_GET_WORKSPACES, NULL, &len);
+}
+
+static void ipc_update_workspaces_response(struct bar *bar, char *res) {
+	bar->pending_ipc_requests--;
+	sway_log(L_DEBUG, "Got update response, %d pending", bar->pending_ipc_requests);
+	if (bar->pending_ipc_requests < 0) {
+		sway_log(L_DEBUG, "Unexpected update response");
+		bar->pending_ipc_requests = 0;
+	}
+
 	int i;
 	for (i = 0; i < bar->outputs->length; ++i) {
 		struct output *output = bar->outputs->items[i];
@@ -259,11 +279,8 @@ static void ipc_update_workspaces(struct bar *bar) {
 		output->workspaces = create_list();
 	}
 
-	uint32_t len = 0;
-	char *res = ipc_single_command(bar->ipc_socketfd, IPC_GET_WORKSPACES, NULL, &len);
 	json_object *results = json_tokener_parse(res);
 	if (!results) {
-		free(res);
 		return;
 	}
 
@@ -303,7 +320,6 @@ static void ipc_update_workspaces(struct bar *bar) {
 	}
 
 	json_object_put(results);
-	free(res);
 }
 
 void ipc_bar_init(struct bar *bar, const char *bar_id) {
@@ -359,22 +375,27 @@ void ipc_bar_init(struct bar *bar, const char *bar_id) {
 	free(res);
 	json_object_put(outputs);
 
+	ipc_update_workspaces_request(bar);
+	// This will handle update response, since we haven't subscribed yet
+	handle_ipc_event(bar);
+
 	const char *subscribe_json = "[ \"workspace\", \"mode\" ]";
 	len = strlen(subscribe_json);
-	res = ipc_single_command(bar->ipc_event_socketfd, IPC_SUBSCRIBE, subscribe_json, &len);
+	res = ipc_single_command(bar->ipc_socketfd, IPC_SUBSCRIBE, subscribe_json, &len);
 	free(res);
-
-	ipc_update_workspaces(bar);
 }
 
 bool handle_ipc_event(struct bar *bar) {
-	struct ipc_response *resp = ipc_recv_response(bar->ipc_event_socketfd);
+	struct ipc_response *resp = ipc_recv_response(bar->ipc_socketfd);
 	if (!resp) {
 		return false;
 	}
 	switch (resp->type) {
 	case IPC_EVENT_WORKSPACE:
-		ipc_update_workspaces(bar);
+		ipc_update_workspaces_request(bar);
+		// This should read update response, but if there are events
+		// in socket, there shouldn't be problems.
+		handle_ipc_event(bar);
 		break;
 	case IPC_EVENT_MODE: {
 		json_object *result = json_tokener_parse(resp->payload);
@@ -400,7 +421,11 @@ bool handle_ipc_event(struct bar *bar) {
 		json_object_put(result);
 		break;
 	}
+	case IPC_GET_WORKSPACES:
+		ipc_update_workspaces_response(bar, resp->payload);
+		break;
 	default:
+		sway_log(L_DEBUG, "Unknown message type: 0x%x", resp->type);
 		free_ipc_response(resp);
 		return false;
 	}