Return a closure object from wl_connection_demarshal

This way we can invoke it multiple times without having to demarshal
and build the cfi every time.

TODO

@@ -1,5 +1,9 @@
 Core wayland protocol
 
+ - The message format has to include information about number of fds
+   in the message so we can skip a message correctly.  Or we should
+   just give up on trying to recover from unknown messages.
+
  - generate pointer_focus (and drag focus) on raise/lower, move
    windows, all kinds of changes in surface stacking.
 

connection.c

@@ -45,6 +45,21 @@ struct wl_buffer {
 
 #define MASK(i) ((i) & 4095)
 
+struct wl_closure {
+	int count;
+	const struct wl_message *message;
+	ffi_type *types[20];
+	ffi_cif cif;
+	union {
+		uint32_t uint32;
+		char *string;
+		void *object;
+		uint32_t new_id;
+		struct wl_array *array;
+	} values[20];
+	void *args[20];
+};
+
 struct wl_connection {
 	struct wl_buffer in, out;
 	struct wl_buffer fds_in, fds_out;
@@ -52,6 +67,7 @@ struct wl_connection {
 	int fd;
 	void *data;
 	wl_connection_update_func_t update;
+	struct wl_closure closure;
 };
 
 static void
@@ -380,31 +396,20 @@ wl_connection_vmarshal(struct wl_connection *connection,
 	wl_connection_write(connection, args, size);
 }
 
-int
+struct wl_closure *
 wl_connection_demarshal(struct wl_connection *connection,
 			uint32_t size,
 			struct wl_hash_table *objects,
-			void (*func)(void),
-			void *data, struct wl_object *target,
 			const struct wl_message *message)
 {
-	ffi_type *types[20];
-	ffi_cif cif;
-	uint32_t *p, *next, *end, result, length;
-	int i, count, fds_tail, ret = 0;
-	union {
-		uint32_t uint32;
-		char *string;
-		void *object;
-		uint32_t new_id;
-		struct wl_array *array;
-	} values[20];
-	void *args[20];
+	uint32_t *p, *next, *end, length;
+	int i, count;
 	struct wl_object *object;
 	uint32_t buffer[64];
+	struct wl_closure *closure = &connection->closure;
 
 	count = strlen(message->signature) + 2;
-	if (count > ARRAY_LENGTH(types)) {
+	if (count > ARRAY_LENGTH(closure->types)) {
 		printf("too many args (%d)\n", count);
 		assert(0);
 	}
@@ -414,36 +419,33 @@ wl_connection_demarshal(struct wl_connection *connection,
 		assert(0);
 	}
 
-	types[0] = &ffi_type_pointer;
-	values[0].object = data;
-	args[0] =  &values[0];
+	closure->message = message;
+	closure->types[0] = &ffi_type_pointer;
+	closure->args[0] =  &closure->values[0];
 
-	types[1] = &ffi_type_pointer;
-	values[1].object = target;
-	args[1] =  &values[1];
+	closure->types[1] = &ffi_type_pointer;
+	closure->args[1] =  &closure->values[1];
 
 	wl_connection_copy(connection, buffer, size);
 	p = &buffer[2];
 	end = (uint32_t *) ((char *) (p + size));
-	fds_tail = connection->fds_in.tail;
 	for (i = 2; i < count; i++) {
 		if (p + 1 > end) {
 			printf("message too short, "
 			       "object (%d), message %s(%s)\n",
 			       *p, message->name, message->signature);
 			errno = EINVAL;
-			ret = -1;
-			goto out;
+			goto err;
 		}
 
 		switch (message->signature[i - 2]) {
 		case 'u':
 		case 'i':
-			types[i] = &ffi_type_uint32;
-			values[i].uint32 = *p++;
+			closure->types[i] = &ffi_type_uint32;
+			closure->values[i].uint32 = *p++;
 			break;
 		case 's':
-			types[i] = &ffi_type_pointer;
+			closure->types[i] = &ffi_type_pointer;
 			length = *p++;
 
 			next = p + DIV_ROUNDUP(length, sizeof *p);
@@ -452,53 +454,49 @@ wl_connection_demarshal(struct wl_connection *connection,
 				       "object (%d), message %s(%s)\n",
 				       *p, message->name, message->signature);
 				errno = EINVAL;
-				ret = -1;
-				goto out;
+				goto err;
 			}
 
 			if (length == 0) {
-				values[i].string = NULL;
+				closure->values[i].string = NULL;
 			} else {
-				values[i].string = malloc(length + 1);
-				if (values[i].string == NULL) {
+				closure->values[i].string = malloc(length + 1);
+				if (closure->values[i].string == NULL) {
 					errno = ENOMEM;
-					ret = -1;
-					goto out;
+					goto err;
 				}
-				memcpy(values[i].string, p, length);
-				values[i].string[length] = '\0';
+				memcpy(closure->values[i].string, p, length);
+				closure->values[i].string[length] = '\0';
 			}
 			p = next;
 			break;
 		case 'o':
-			types[i] = &ffi_type_pointer;
+			closure->types[i] = &ffi_type_pointer;
 			object = wl_hash_table_lookup(objects, *p);
 			if (object == NULL && *p != 0) {
 				printf("unknown object (%d), message %s(%s)\n",
 				       *p, message->name, message->signature);
 				errno = EINVAL;
-				ret = -1;
-				goto out;
+				goto err;
 			}
-			values[i].object = object;
+			closure->values[i].object = object;
 			p++;
 			break;
 		case 'n':
-			types[i] = &ffi_type_uint32;
-			values[i].new_id = *p;
+			closure->types[i] = &ffi_type_uint32;
+			closure->values[i].new_id = *p;
 			object = wl_hash_table_lookup(objects, *p);
 			if (object != NULL) {
 				printf("not a new object (%d), "
 				       "message %s(%s)\n",
 				       *p, message->name, message->signature);
 				errno = EINVAL;
-				ret = -1;
-				goto out;
+				goto err;
 			}
 			p++;
 			break;
 		case 'a':
-			types[i] = &ffi_type_pointer;
+			closure->types[i] = &ffi_type_pointer;
 			length = *p++;
 
 			next = p + DIV_ROUNDUP(length, sizeof *p);
@@ -507,58 +505,77 @@ wl_connection_demarshal(struct wl_connection *connection,
 				       "object (%d), message %s(%s)\n",
 				       *p, message->name, message->signature);
 				errno = EINVAL;
-				ret = -1;
-				goto out;
+				goto err;
 			}
 
-			values[i].array =
-				malloc(length + sizeof *values[i].array);
-			if (values[i].array == NULL) {
+			closure->values[i].array =
+				malloc(length + sizeof *closure->values[i].array);
+			if (closure->values[i].array == NULL) {
 				errno = ENOMEM;
-				ret = -1;
-				goto out;
+				goto err;
 			}
-			values[i].array->size = length;
-			values[i].array->alloc = 0;
-			values[i].array->data = values[i].array + 1;
-			memcpy(values[i].array->data, p, length);
+			closure->values[i].array->size = length;
+			closure->values[i].array->alloc = 0;
+			closure->values[i].array->data = closure->values[i].array + 1;
+			memcpy(closure->values[i].array->data, p, length);
 			p = next;
 			break;
 		case 'h':
-			types[i] = &ffi_type_uint32;
+			closure->types[i] = &ffi_type_uint32;
 			wl_buffer_copy(&connection->fds_in,
-				       &values[i].uint32,
-				       sizeof values[i].uint32);
-			connection->fds_in.tail += sizeof values[i].uint32;
+				       &closure->values[i].uint32,
+				       sizeof closure->values[i].uint32);
+			connection->fds_in.tail +=
+				sizeof closure->values[i].uint32;
 			break;
 		default:
 			printf("unknown type\n");
 			assert(0);
 			break;
 		}
-		args[i] = &values[i];
+		closure->args[i] = &closure->values[i];
 	}
 
-	ffi_prep_cif(&cif, FFI_DEFAULT_ABI, count, &ffi_type_uint32, types);
-	ffi_call(&cif, func, &result, args);
+	closure->count = i;
+	ffi_prep_cif(&closure->cif, FFI_DEFAULT_ABI,
+		     closure->count, &ffi_type_uint32, closure->types);
 
-	/* Slight hack here.  We store the tail of fds_in here and
-	 * consume will set fds_in.tail to that value */
-	connection->fds_in_tail = connection->fds_in.tail;
-	connection->fds_in.tail = fds_tail;
+	wl_connection_consume(connection, size);
 
- out:
-	count = i;
-	for (i = 2; i < count; i++) {
-		switch (message->signature[i - 2]) {
+	return closure;
+
+ err:
+	closure->count = i;
+	wl_closure_destroy(closure);
+
+	return NULL;
+}
+
+void
+wl_closure_invoke(struct wl_closure *closure,
+		  struct wl_object *target, void (*func)(void), void *data)
+{
+	int result;
+
+	closure->values[0].object = data;
+	closure->values[1].object = target;
+
+	ffi_call(&closure->cif, func, &result, closure->args);
+}
+
+void
+wl_closure_destroy(struct wl_closure *closure)
+{
+	int i;
+
+	for (i = 2; i < closure->count; i++) {
+		switch (closure->message->signature[i - 2]) {
 		case 's':
-			free(values[i].string);
+			free(closure->values[i].string);
 			break;
 		case 'a':
-			free(values[i].array);
+			free(closure->values[i].array);
 			break;
 		}
 	}
-
-	return ret;
 }

connection.h

@@ -27,6 +27,7 @@
 #include "wayland-util.h"
 
 struct wl_connection;
+struct wl_closure;
 
 #define WL_CONNECTION_READABLE 0x01
 #define WL_CONNECTION_WRITABLE 0x02
@@ -48,11 +49,15 @@ void wl_connection_vmarshal(struct wl_connection *connection,
 			    uint32_t opcode, va_list ap,
 			    const struct wl_message *message);
 
-int wl_connection_demarshal(struct wl_connection *connection,
-			    uint32_t size,
-			    struct wl_hash_table *objects,
-			    void (*func)(void),
-			    void *data, struct wl_object *target,
-			    const struct wl_message *message);
+struct wl_closure *
+wl_connection_demarshal(struct wl_connection *connection,
+			uint32_t size,
+			struct wl_hash_table *objects,
+			const struct wl_message *message);
+void
+wl_closure_invoke(struct wl_closure *closure,
+		  struct wl_object *target, void (*func)(void), void *data);
+void
+wl_closure_destroy(struct wl_closure *closure);
 
 #endif

wayland-client.c

@@ -340,6 +340,8 @@ handle_event(struct wl_display *display,
 	uint32_t p[32];
 	struct wl_listener *listener;
 	struct wl_proxy *proxy;
+	struct wl_closure *closure;
+	struct wl_message *message;
 
 	wl_connection_copy(display->connection, p, size);
 	if (id == 1)
@@ -347,17 +349,21 @@ handle_event(struct wl_display *display,
 	else
 		proxy = wl_hash_table_lookup(display->objects, id);
 
-	if (proxy != NULL)
-		wl_list_for_each(listener, &proxy->listener_list, link)
-			wl_connection_demarshal(display->connection,
-						size,
-						display->objects,
-						listener->implementation[opcode],
-						listener->data,
-						&proxy->base, 
-						&proxy->base.interface->events[opcode]);
-
-	wl_connection_consume(display->connection, size);
+	if (proxy == NULL) {
+		wl_connection_consume(display->connection, size);
+		return;
+	}
+
+	message = &proxy->base.interface->events[opcode];
+	closure = wl_connection_demarshal(display->connection,
+					  size, display->objects, message);
+
+	wl_list_for_each(listener, &proxy->listener_list, link)
+		wl_closure_invoke(closure, &proxy->base,
+				  listener->implementation[opcode],
+				  listener->data);
+
+	wl_closure_destroy(closure);
 }
 
 WL_EXPORT void

wayland-server.c

@@ -86,9 +86,11 @@ wl_client_connection_data(int fd, uint32_t mask, void *data)
 	struct wl_client *client = data;
 	struct wl_connection *connection = client->connection;
 	struct wl_object *object;
+	struct wl_closure *closure;
+	const struct wl_message *message;
 	uint32_t p[2], opcode, size;
 	uint32_t cmask = 0;
-	int len, ret;
+	int len;
 
 	if (mask & WL_EVENT_READABLE)
 		cmask |= WL_CONNECTION_READABLE;
@@ -125,24 +127,28 @@ wl_client_connection_data(int fd, uint32_t mask, void *data)
 			continue;
 		}
 
-		ret = wl_connection_demarshal(client->connection,
-					      size,
-					      client->display->objects,
-					      object->implementation[opcode],
-					      client,
-					      object, 
-					      &object->interface->methods[opcode]);
+		message = &object->interface->methods[opcode];
+		closure = wl_connection_demarshal(client->connection, size,
+						  client->display->objects,
+						  message);
+		len -= size;
 
-		if (ret < 0 && errno == EINVAL)
+		if (closure == NULL && errno == EINVAL) {
 			wl_client_post_event(client, &client->display->base,
 					     WL_DISPLAY_INVALID_METHOD,
 					     p[0], opcode);
-		if (ret < 0 && errno == ENOMEM)
+			continue;
+		} else if (closure == NULL && errno == ENOMEM) {
 			wl_client_post_event(client, &client->display->base,
 					     WL_DISPLAY_NO_MEMORY);
+			continue;
+		}
+
+		wl_closure_invoke(closure, object,
+				  object->implementation[opcode], client);
+
+		wl_closure_destroy(closure);
 
-		wl_connection_consume(connection, size);
-		len -= size;
 	}
 }