<div dir="ltr">Does this help clean up client code? Can you give an example of how a client would use this?<br></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, Apr 2, 2014 at 10:48 AM, Jason Ekstrand <span dir="ltr"><<a href="mailto:jason@jlekstrand.net" target="_blank">jason@jlekstrand.net</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><p dir="ltr">It's worth noting that there is one small backwards-compatability issue here. Namely, if the client is built against protocol stubs from an earlier version of libwayland but links against a library built against a newer version, then all objects created by the client will report a version of 1. This is because the old api uses wl_proxy_marshal_constructor in wl_registry_bind so all objects will inherit the protocol version of wl_display which is 1. The library the client linked against is aware of the wl_proxy_version function but has no way of knowing that the library does not.</p>
<p dir="ltr">One possible solution for this is to set the version of wl_display to zero and use zero to mean "unversioned". Then, if a library wants to use something that's not strictly backwards-compatable, it can check for zero and use whatever it's non-versioned fallback is.</p>
<p dir="ltr">That said, I'm open to other suggestions.<span class="HOEnZb"><font color="#888888"><br>
--Jason Ekstrand</font></span></p><div class="HOEnZb"><div class="h5">
<div class="gmail_quote">On Apr 2, 2014 12:28 AM, "Jason Ekstrand" <<a href="mailto:jason@jlekstrand.net" target="_blank">jason@jlekstrand.net</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
This provides a standardized mechanism for tracking protocol object<br>
versions in client code. The wl_display object is created with version 1.<br>
Every time an object is created from within wl_registry_bind, it gets the<br>
bound version. Every other time an object is created, it simply inherits<br>
it's version from the parent object that created it.<br>
<br>
<br>
---<br>
I've been meaning to scratch this itch for a while. I've left it as an RFC<br>
for now because it builds, but I don't have any code to test it yet. I've<br>
got something I'm hoping to hack on this weekend that will use it. For<br>
now, feel free to comment.<br>
<br>
src/scanner.c | 29 +++++++++----<br>
src/wayland-client.c | 112 +++++++++++++++++++++++++++++++++++++++++++++++----<br>
src/wayland-client.h | 13 ++++++<br>
3 files changed, 139 insertions(+), 15 deletions(-)<br>
<br>
diff --git a/src/scanner.c b/src/scanner.c<br>
index e8bfc7c..43b3acf 100644<br>
--- a/src/scanner.c<br>
+++ b/src/scanner.c<br>
@@ -627,6 +627,14 @@ emit_stubs(struct wl_list *message_list, struct interface *interface)<br>
interface->name, interface->name, interface->name,<br>
interface->name);<br>
<br>
+ printf("static inline uint32_t\n"<br>
+ "%s_get_version(struct %s *%s)\n"<br>
+ "{\n"<br>
+ "\treturn wl_proxy_get_version((struct wl_proxy *) %s);\n"<br>
+ "}\n\n",<br>
+ interface->name, interface->name, interface->name,<br>
+ interface->name);<br>
+<br>
has_destructor = 0;<br>
has_destroy = 0;<br>
wl_list_for_each(m, message_list, link) {<br>
@@ -698,20 +706,25 @@ emit_stubs(struct wl_list *message_list, struct interface *interface)<br>
<br>
printf(")\n"<br>
"{\n");<br>
- if (ret) {<br>
+ if (ret && ret->interface_name == NULL) {<br>
printf("\tstruct wl_proxy *%s;\n\n"<br>
- "\t%s = wl_proxy_marshal_constructor("<br>
+ "\t%s = wl_proxy_marshal_constructor_versioned("<br>
"(struct wl_proxy *) %s,\n"<br>
- "\t\t\t %s_%s, ",<br>
+ "\t\t\t %s_%s, interface, version",<br>
ret->name, ret->name,<br>
interface->name,<br>
interface->uppercase_name,<br>
m->uppercase_name);<br>
-<br>
- if (ret->interface_name == NULL)<br>
- printf("interface");<br>
- else<br>
- printf("&%s_interface", ret->interface_name);<br>
+ } else if (ret) {<br>
+ printf("\tstruct wl_proxy *%s;\n\n"<br>
+ "\t%s = wl_proxy_marshal_constructor("<br>
+ "(struct wl_proxy *) %s,\n"<br>
+ "\t\t\t %s_%s, &%s_interface",<br>
+ ret->name, ret->name,<br>
+ interface->name,<br>
+ interface->uppercase_name,<br>
+ m->uppercase_name,<br>
+ ret->interface_name);<br>
} else {<br>
printf("\twl_proxy_marshal((struct wl_proxy *) %s,\n"<br>
"\t\t\t %s_%s",<br>
diff --git a/src/wayland-client.c b/src/wayland-client.c<br>
index bd40313..5608564 100644<br>
--- a/src/wayland-client.c<br>
+++ b/src/wayland-client.c<br>
@@ -59,6 +59,7 @@ struct wl_proxy {<br>
int refcount;<br>
void *user_data;<br>
wl_dispatcher_func_t dispatcher;<br>
+ uint32_t version;<br>
};<br>
<br>
struct wl_global {<br>
@@ -195,7 +196,8 @@ wl_display_create_queue(struct wl_display *display)<br>
}<br>
<br>
static struct wl_proxy *<br>
-proxy_create(struct wl_proxy *factory, const struct wl_interface *interface)<br>
+proxy_create(struct wl_proxy *factory, const struct wl_interface *interface,<br>
+ uint32_t version)<br>
{<br>
struct wl_proxy *proxy;<br>
struct wl_display *display = factory->display;<br>
@@ -211,6 +213,7 @@ proxy_create(struct wl_proxy *factory, const struct wl_interface *interface)<br>
proxy->queue = factory->queue;<br>
proxy->flags = 0;<br>
proxy->refcount = 1;<br>
+ proxy->version = version;<br>
<br>
proxy-><a href="http://object.id" target="_blank">object.id</a> = wl_map_insert_new(&display->objects, 0, proxy);<br>
<br>
@@ -243,7 +246,7 @@ wl_proxy_create(struct wl_proxy *factory, const struct wl_interface *interface)<br>
struct wl_proxy *proxy;<br>
<br>
pthread_mutex_lock(&display->mutex);<br>
- proxy = proxy_create(factory, interface);<br>
+ proxy = proxy_create(factory, interface, factory->version);<br>
pthread_mutex_unlock(&display->mutex);<br>
<br>
return proxy;<br>
@@ -269,6 +272,7 @@ wl_proxy_create_for_id(struct wl_proxy *factory,<br>
proxy->queue = factory->queue;<br>
proxy->flags = 0;<br>
proxy->refcount = 1;<br>
+ proxy->version = factory->version;<br>
<br>
wl_map_insert_at(&display->objects, 0, id, proxy);<br>
<br>
@@ -396,7 +400,7 @@ wl_proxy_add_dispatcher(struct wl_proxy *proxy,<br>
static struct wl_proxy *<br>
create_outgoing_proxy(struct wl_proxy *proxy, const struct wl_message *message,<br>
union wl_argument *args,<br>
- const struct wl_interface *interface)<br>
+ const struct wl_interface *interface, uint32_t version)<br>
{<br>
int i, count;<br>
const char *signature;<br>
@@ -410,7 +414,7 @@ create_outgoing_proxy(struct wl_proxy *proxy, const struct wl_message *message,<br>
<br>
switch (arg.type) {<br>
case 'n':<br>
- new_proxy = proxy_create(proxy, interface);<br>
+ new_proxy = proxy_create(proxy, interface, version);<br>
if (new_proxy == NULL)<br>
return NULL;<br>
<br>
@@ -435,7 +439,8 @@ create_outgoing_proxy(struct wl_proxy *proxy, const struct wl_message *message,<br>
*<br>
* For new-id arguments, this function will allocate a new wl_proxy<br>
* and send the ID to the server. The new wl_proxy will be returned<br>
- * on success or NULL on errror with errno set accordingly.<br>
+ * on success or NULL on errror with errno set accordingly. The newly<br>
+ * created proxy will inherit their version from their parent.<br>
*<br>
* \note This is intended to be used by language bindings and not in<br>
* non-generated code.<br>
@@ -449,6 +454,43 @@ wl_proxy_marshal_array_constructor(struct wl_proxy *proxy,<br>
uint32_t opcode, union wl_argument *args,<br>
const struct wl_interface *interface)<br>
{<br>
+ return wl_proxy_marshal_array_constructor_versioned(proxy, opcode,<br>
+ args, interface,<br>
+ proxy->version);<br>
+}<br>
+<br>
+<br>
+/** Prepare a request to be sent to the compositor<br>
+ *<br>
+ * \param proxy The proxy object<br>
+ * \param opcode Opcode of the request to be sent<br>
+ * \param args Extra arguments for the given request<br>
+ * \param interface The interface to use for the new proxy<br>
+ * \param version The protocol object version for the new proxy<br>
+ *<br>
+ * Translates the request given by opcode and the extra arguments into the<br>
+ * wire format and write it to the connection buffer. This version takes an<br>
+ * array of the union type wl_argument.<br>
+ *<br>
+ * For new-id arguments, this function will allocate a new wl_proxy<br>
+ * and send the ID to the server. The new wl_proxy will be returned<br>
+ * on success or NULL on errror with errno set accordingly. The newly<br>
+ * created proxy will have the version specified.<br>
+ *<br>
+ * \note This is intended to be used by language bindings and not in<br>
+ * non-generated code.<br>
+ *<br>
+ * \sa wl_proxy_marshal()<br>
+ *<br>
+ * \memberof wl_proxy<br>
+ */<br>
+WL_EXPORT struct wl_proxy *<br>
+wl_proxy_marshal_array_constructor_versioned(struct wl_proxy *proxy,<br>
+ uint32_t opcode,<br>
+ union wl_argument *args,<br>
+ const struct wl_interface *interface,<br>
+ uint32_t version)<br>
+{<br>
struct wl_closure *closure;<br>
struct wl_proxy *new_proxy = NULL;<br>
const struct wl_message *message;<br>
@@ -458,7 +500,8 @@ wl_proxy_marshal_array_constructor(struct wl_proxy *proxy,<br>
message = &proxy->object.interface->methods[opcode];<br>
if (interface) {<br>
new_proxy = create_outgoing_proxy(proxy, message,<br>
- args, interface);<br>
+ args, interface,<br>
+ version);<br>
if (new_proxy == NULL)<br>
goto err_unlock;<br>
}<br>
@@ -528,7 +571,8 @@ wl_proxy_marshal(struct wl_proxy *proxy, uint32_t opcode, ...)<br>
*<br>
* For new-id arguments, this function will allocate a new wl_proxy<br>
* and send the ID to the server. The new wl_proxy will be returned<br>
- * on success or NULL on errror with errno set accordingly.<br>
+ * on success or NULL on errror with errno set accordingly. The newly<br>
+ * created proxy will inherit their version from their parent.<br>
*<br>
* \note This should not normally be used by non-generated code.<br>
*<br>
@@ -550,6 +594,46 @@ wl_proxy_marshal_constructor(struct wl_proxy *proxy, uint32_t opcode,<br>
args, interface);<br>
}<br>
<br>
+<br>
+/** Prepare a request to be sent to the compositor<br>
+ *<br>
+ * \param proxy The proxy object<br>
+ * \param opcode Opcode of the request to be sent<br>
+ * \param interface The interface to use for the new proxy<br>
+ * \param version The protocol object version of the new proxy<br>
+ * \param ... Extra arguments for the given request<br>
+ * \return A new wl_proxy for the new_id argument or NULL on error<br>
+ *<br>
+ * Translates the request given by opcode and the extra arguments into the<br>
+ * wire format and write it to the connection buffer.<br>
+ *<br>
+ * For new-id arguments, this function will allocate a new wl_proxy<br>
+ * and send the ID to the server. The new wl_proxy will be returned<br>
+ * on success or NULL on errror with errno set accordingly. The newly<br>
+ * created proxy will have the version specified.<br>
+ *<br>
+ * \note This should not normally be used by non-generated code.<br>
+ *<br>
+ * \memberof wl_proxy<br>
+ */<br>
+WL_EXPORT struct wl_proxy *<br>
+wl_proxy_marshal_constructor_versioned(struct wl_proxy *proxy, uint32_t opcode,<br>
+ const struct wl_interface *interface,<br>
+ uint32_t version, ...)<br>
+{<br>
+ union wl_argument args[WL_CLOSURE_MAX_ARGS];<br>
+ va_list ap;<br>
+<br>
+ va_start(ap, version);<br>
+ wl_argument_from_va_list(proxy->object.interface->methods[opcode].signature,<br>
+ args, WL_CLOSURE_MAX_ARGS, ap);<br>
+ va_end(ap);<br>
+<br>
+ return wl_proxy_marshal_array_constructor_versioned(proxy, opcode,<br>
+ args, interface,<br>
+ version);<br>
+}<br>
+<br>
/** Prepare a request to be sent to the compositor<br>
*<br>
* \param proxy The proxy object<br>
@@ -730,6 +814,7 @@ wl_display_connect_to_fd(int fd)<br>
display->proxy.queue = &display->default_queue;<br>
display->proxy.flags = 0;<br>
display->proxy.refcount = 1;<br>
+ display->proxy.version = 1;<br>
<br>
display->connection = wl_connection_create(display->fd);<br>
if (display->connection == NULL)<br>
@@ -1556,6 +1641,19 @@ wl_proxy_get_user_data(struct wl_proxy *proxy)<br>
return proxy->user_data;<br>
}<br>
<br>
+/** Get the protocol object version of a proxy object<br>
+ *<br>
+ * \param proxy The proxy object<br>
+ * \return The protocol object version of the proxy<br>
+ *<br>
+ * \memberof wl_proxy<br>
+ */<br>
+WL_EXPORT uint32_t<br>
+wl_proxy_get_version(struct wl_proxy *proxy)<br>
+{<br>
+ return proxy->version;<br>
+}<br>
+<br>
/** Get the id of a proxy object<br>
*<br>
* \param proxy The proxy object<br>
diff --git a/src/wayland-client.h b/src/wayland-client.h<br>
index 2a32785..c47b8bf 100644<br>
--- a/src/wayland-client.h<br>
+++ b/src/wayland-client.h<br>
@@ -130,10 +130,22 @@ struct wl_proxy *wl_proxy_marshal_constructor(struct wl_proxy *proxy,<br>
uint32_t opcode,<br>
const struct wl_interface *interface,<br>
...);<br>
+<br>
+struct wl_proxy *wl_proxy_marshal_constructor_versioned(struct wl_proxy *proxy,<br>
+ uint32_t opcode,<br>
+ const struct wl_interface *interface,<br>
+ uint32_t version,<br>
+ ...);<br>
struct wl_proxy *<br>
wl_proxy_marshal_array_constructor(struct wl_proxy *proxy,<br>
uint32_t opcode, union wl_argument *args,<br>
const struct wl_interface *interface);<br>
+struct wl_proxy *<br>
+wl_proxy_marshal_array_constructor_versioned(struct wl_proxy *proxy,<br>
+ uint32_t opcode,<br>
+ union wl_argument *args,<br>
+ const struct wl_interface *interface,<br>
+ uint32_t version);<br>
<br>
void wl_proxy_destroy(struct wl_proxy *proxy);<br>
int wl_proxy_add_listener(struct wl_proxy *proxy,<br>
@@ -144,6 +156,7 @@ int wl_proxy_add_dispatcher(struct wl_proxy *proxy,<br>
const void * dispatcher_data, void *data);<br>
void wl_proxy_set_user_data(struct wl_proxy *proxy, void *user_data);<br>
void *wl_proxy_get_user_data(struct wl_proxy *proxy);<br>
+uint32_t wl_proxy_get_version(struct wl_proxy *proxy);<br>
uint32_t wl_proxy_get_id(struct wl_proxy *proxy);<br>
const char *wl_proxy_get_class(struct wl_proxy *proxy);<br>
void wl_proxy_set_queue(struct wl_proxy *proxy, struct wl_event_queue *queue);<br>
--<br>
1.9.0<br>
<br>
</blockquote></div>
</div></div><br>_______________________________________________<br>
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<br></blockquote></div><br><br clear="all"><br>-- <br> Jasper<br>
</div>