[PATCH 2/3] Modify wayland-scanner to generate inert objects
David FORT
rdp.effort at gmail.com
Wed Feb 25 06:03:34 PST 2015
As stated in the very good blog post[1] of Pekka Paalanen, server-side we can have
sometime troubles with object that the server has deleted but that the client
is still requesting. This patch complements the scanner to create some code
that will return inert objects, ie objects that will do nothing and will never
return anything else but an inert object. An example is a get_pointer() on
a wl_seat, with an unplugged mouse (and so no pointer). Instead of keeping alive
the old pointer, we could bind that inert object and wait that the client release
it (which should happen very quickly as a wl_global_remove should be in the wire).
[1]: http://ppaalanen.blogspot.fi/2014/07/wayland-protocol-design-object-lifespan.html
---
src/scanner.c | 173 +++++++++++++++++++++++++++++++++++++++++++++++++----
wayland-scanner.mk | 3 +
2 files changed, 166 insertions(+), 10 deletions(-)
diff --git a/src/scanner.c b/src/scanner.c
index 1f1e59a..dbdd1f6 100644
--- a/src/scanner.c
+++ b/src/scanner.c
@@ -39,7 +39,7 @@ enum side {
static int
usage(int ret)
{
- fprintf(stderr, "usage: ./scanner [client-header|server-header|code]\n");
+ fprintf(stderr, "usage: ./scanner [client-header|server-header|code|server-inert]\n");
fprintf(stderr, "\n");
fprintf(stderr, "Converts XML protocol descriptions supplied on "
"stdin to client headers,\n"
@@ -626,6 +626,18 @@ emit_type(struct arg *a)
}
}
+static struct arg *
+get_return_type(struct message *m)
+{
+ struct arg *a, *ret = NULL;
+
+ wl_list_for_each(a, &m->arg_list, link) {
+ if (a->type == NEW_ID)
+ ret = a;
+ }
+ return ret;
+}
+
static void
emit_stubs(struct wl_list *message_list, struct interface *interface)
{
@@ -688,11 +700,7 @@ emit_stubs(struct wl_list *message_list, struct interface *interface)
continue;
}
- ret = NULL;
- wl_list_for_each(a, &m->arg_list, link) {
- if (a->type == NEW_ID)
- ret = a;
- }
+ ret = get_return_type(m);
if (ret && ret->interface_name == NULL)
printf("static inline void *\n");
@@ -1103,8 +1111,7 @@ emit_types(struct protocol *protocol, struct wl_list *message_list)
case NEW_ID:
case OBJECT:
if (a->interface_name)
- printf("\t&%s_interface,\n",
- a->interface_name);
+ printf("\t&%s_interface,\n", a->interface_name);
else
printf("\tNULL,\n");
break;
@@ -1248,6 +1255,140 @@ emit_code(struct protocol *protocol)
}
}
+static void
+emit_inert_request(struct protocol *protocol, struct interface *interface, struct wl_list *message_list)
+{
+ struct message *m;
+ struct arg *a, *ret;
+ const char *newid_name;
+
+ wl_list_for_each(m, message_list, link) {
+ ret = get_return_type(m);
+
+ /* forward declaration for the returned object */
+ if (ret && ret->interface_name) {
+ printf("static void\n"
+ "create_inert_%s(struct wl_client *client, uint32_t version, uint32_t id);\n"
+ "\n",
+ ret->interface_name);
+ }
+
+ printf("static inline void inert_%s_%s(struct wl_client *client, struct wl_resource *resource",
+ interface->name, m->name
+ );
+
+ wl_list_for_each(a, &m->arg_list, link) {
+ if (a->type == NEW_ID) {
+ newid_name = a->name;
+
+ if (a->interface_name == NULL) {
+ printf(", const struct wl_interface *interface"
+ ", uint32_t version");
+ continue;
+ }
+ }
+
+ if (a->type == OBJECT) {
+ printf(", struct wl_resource *");
+ } else {
+ printf(", ");
+ emit_type(a);
+ }
+ printf("%s", a->name);
+ }
+
+ printf(")\n"
+ "{\n");
+
+ if (ret && ret->interface_name) {
+ printf("\tcreate_inert_%s(client, wl_resource_get_version(resource), %s);\n",
+ ret->interface_name, newid_name);
+ } else if (m->destructor) {
+ printf("\twl_resource_destroy(resource);\n");
+ }
+ printf("}\n\n");
+ }
+}
+
+static void
+emit_inert_interface(struct protocol *protocol, struct interface *i, struct wl_array *types) {
+ struct message *m;
+
+
+ if(wl_list_length(&i->request_list)) {
+ emit_inert_request(protocol, i, &i->request_list);
+
+ printf ("static const struct %s_interface inert_%s_implementation = {\n",
+ i->name, i->name);
+ wl_list_for_each(m, &i->request_list, link) {
+ printf("\tinert_%s_%s,\n", i->name, m->name);
+ }
+ printf ("};\n"
+ "\n");
+ }
+
+ printf("static inline void\n"
+ "create_inert_%s(struct wl_client *client, uint32_t version, uint32_t id) {\n",
+ i->name
+ );
+
+ if(wl_list_length(&i->request_list)) {
+ /* emit the method body only when there is requests on the object */
+ printf("\tstruct wl_resource *resource;\n"
+ "\tresource = wl_resource_create(client, &%s_interface, MIN(version, %d), id);\n"
+ "\twl_resource_set_implementation(resource, &inert_%s_implementation, NULL, wl_resource_destroy);\n",
+ i->name, i->version, i->name);
+ }
+
+ printf("}\n"
+ "\n");
+
+}
+
+
+static
+void emit_inert(struct protocol *protocol) {
+ struct interface *i;
+ struct wl_array types;
+
+ if (protocol->copyright)
+ format_copyright(protocol->copyright);
+
+ printf("#ifndef __%s_SERVER_INERT__\n"
+ "#define __%s_SERVER_INERT__\n"
+ "\n"
+ "#include \"%s-server-protocol.h\"\n"
+ "\n"
+ "#ifdef __cplusplus\n"
+ "extern \"C\" {\n"
+ "#endif\n"
+ "\n"
+ "#ifndef MIN\n"
+ "#define MIN(x,y) (((x) < (y)) ? (x) : (y))\n"
+ "#endif\n"
+ "\n",
+ protocol->uppercase_name,
+ protocol->uppercase_name,
+ //protocol->name,
+ protocol->name
+ );
+
+ wl_list_for_each(i, &protocol->interface_list, link) {
+ if (!strcmp(i->name, "wl_registry") || !strcmp(i->name, "wl_display"))
+ continue;
+
+ emit_inert_interface(protocol, i, &types);
+ }
+
+ printf("\n"
+ "#ifdef __cplusplus\n"
+ "}\n"
+ "#endif\n"
+ "\n"
+ "#endif\n");
+
+}
+
int main(int argc, char *argv[])
{
struct parse_context ctx;
@@ -1257,17 +1398,26 @@ int main(int argc, char *argv[])
enum {
CLIENT_HEADER,
SERVER_HEADER,
+ SERVER_INERT,
CODE,
} mode;
- if (argc != 2)
+ if (argc < 2) {
usage(EXIT_FAILURE);
- else if (strcmp(argv[1], "help") == 0 || strcmp(argv[1], "--help") == 0)
+ }
+
+ if (argc > 2) {
+ stdin = fopen(argv[2], "r");
+ }
+
+ if (strcmp(argv[1], "help") == 0 || strcmp(argv[1], "--help") == 0)
usage(EXIT_SUCCESS);
else if (strcmp(argv[1], "client-header") == 0)
mode = CLIENT_HEADER;
else if (strcmp(argv[1], "server-header") == 0)
mode = SERVER_HEADER;
+ else if (strcmp(argv[1], "server-inert") == 0)
+ mode = SERVER_INERT;
else if (strcmp(argv[1], "code") == 0)
mode = CODE;
else
@@ -1317,6 +1467,9 @@ int main(int argc, char *argv[])
case SERVER_HEADER:
emit_header(&protocol, SERVER);
break;
+ case SERVER_INERT:
+ emit_inert(&protocol);
+ break;
case CODE:
emit_code(&protocol);
break;
diff --git a/wayland-scanner.mk b/wayland-scanner.mk
index 0a72062..fd994e0 100644
--- a/wayland-scanner.mk
+++ b/wayland-scanner.mk
@@ -6,3 +6,6 @@
%-client-protocol.h : $(wayland_protocoldir)/%.xml
$(AM_V_GEN)$(wayland_scanner) client-header < $< > $@
+
+%-server-inert.h: $(wayland_protocoldir)/%.xml
+ $(AM_V_GEN)$(wayland_scanner) server-inert < $< > $@
\ No newline at end of file
--
1.9.1
More information about the wayland-devel
mailing list