Compare commits

...

5 commits

Author SHA1 Message Date
Simon Ser
a9d13ecd4d Merge branch 'data-device-focus' into 'main'
protocol: add wl_data_device.{enter,leave}

Closes #37

See merge request wayland/wayland!260
2025-10-13 11:55:45 +00:00
Isaac Freund
d81525a235 client: add wl_display_dispatch_pending_single
As well as wl_display_dispatch_queue_pending_single.

The motivation is writing libwayland bindings for a dynamic language
with exceptions/non-local returns. Since it is invalid for a
wl_dispatcher_func_t callback provided to libwayland to not return,
there is no way to prevent dispatching of further events in the case of
an exception in the dynamic language event handler.

Furthermore, since creating/destroying Wayland objects in an event
handler affects the dispatching of subsequent events by libwayland,
it is not possible to collect Wayland events in a queue outside
libwayland and dispatch them one-by-one after
wl_display_dispatch_pending() returns.

Adding libwayland API to dispatch at most one pending event solves this
problem cleanly. The bindings can have libwayland dispatch a single
event, wait for wl_display_dispatch_pending_single() to return, run the
dynamic language event handler (which may longjmp away), and continue
the loop for as long as there are more events to dispatch.

References: https://codeberg.org/ifreund/janet-wayland
Signed-off-by: Isaac Freund <mail@isaacfreund.com>
2025-09-16 11:48:33 +03:00
Kyle Brenneman
4673ef7e9c connection: Add a thread ID to WAYLAND_DEBUG output.
If WAYLAND_DEBUG contains the token "thread_id", and gettid() is
available, then include the current thread ID in the output from
wl_closure_print.

If multiple threads are sending requests, then those requests can get
interleaved. That's usually fine, but for wl_surface requests and
commits, that can cause problems ranging from incorrect behavior to
protocol errors.

Being able to see which requests are sent by different threads would
make such problems much easier to diagnose.

Signed-off-by: Kyle Brenneman <kbrenneman@nvidia.com>
2025-09-15 14:45:53 +01:00
Kyle Brenneman
77730f10a0 connection: Add a function to parse WAYLAND_DEBUG tokens
Add a new function, wl_check_env_token, to scan for a token in a
comma-separated string.

Change wl_display_create in wayland-server.c and
wl_display_connect_to_fd in wayland-client.c to use that instead of a
simple substring search.

This means that WAYLAND_DEBUG will accept a value like "client,server"
but not "clientserver". But, this will make it easier to add other
tokens without worrying about overlap between them.

Signed-off-by: Kyle Brenneman <kbrenneman@nvidia.com>
2025-09-15 14:45:53 +01:00
Simon Ser
0853304bc9 protocol: add wl_data_device.{enter,leave}
Data device focus is currently indicated by wl_keyboard focus.
However some systems are lacking keyboards, in which case the
wl_seat is missing the keyboard capability and clients can't create
a wl_keyboard object.

Introduce enter and leave events so that compositors can indicate
when a client will receive selection events.

Signed-off-by: Simon Ser <contact@emersion.fr>
Closes: https://gitlab.freedesktop.org/wayland/wayland/-/issues/37
2022-08-09 21:32:18 +02:00
8 changed files with 249 additions and 12 deletions

View file

@ -46,6 +46,7 @@ have_funcs = [
'memfd_create',
'mremap',
'strndup',
'gettid',
]
foreach f: have_funcs
config_h.set('HAVE_' + f.underscorify().to_upper(), cc.has_function(f))

View file

@ -518,7 +518,7 @@
</event>
</interface>
<interface name="wl_data_offer" version="3">
<interface name="wl_data_offer" version="4">
<description summary="offer to transfer data">
A wl_data_offer represents a piece of data offered for transfer
by another client (the source client). It is used by the
@ -711,7 +711,7 @@
</event>
</interface>
<interface name="wl_data_source" version="3">
<interface name="wl_data_source" version="4">
<description summary="offer to transfer data">
The wl_data_source object is the source side of a wl_data_offer.
It is created by the source client in a data transfer and
@ -866,7 +866,7 @@
</event>
</interface>
<interface name="wl_data_device" version="3">
<interface name="wl_data_device" version="4">
<description summary="data transfer device">
There is one wl_data_device per seat which can be obtained
from the global wl_data_device_manager singleton.
@ -1006,13 +1006,12 @@
data_device.data_offer and the data_offer.offer events are
sent out immediately before this event to introduce the data
offer object. The selection event is sent to a client
immediately before receiving keyboard focus and when a new
selection is set while the client has keyboard focus. The
immediately before receiving data device focus and when a new
selection is set while the client has data device focus. The
data_offer is valid until a new data_offer or NULL is received
or until the client loses keyboard focus. Switching surface with
keyboard focus within the same client doesn't mean a new selection
will be sent. The client must destroy the previous selection
data_offer, if any, upon receiving this event.
or until the client loses data device focus. The client must
destroy the previous selection data_offer, if any, upon receiving
this event.
</description>
<arg name="id" type="object" interface="wl_data_offer" allow-null="true"
summary="selection data_offer object"/>
@ -1025,9 +1024,33 @@
This request destroys the data device.
</description>
</request>
<!-- Version 4 additions -->
<event name="enter" since="4">
<description summary="focus gained">
Notification that this seat's data device has gained focus.
The compositor must send the wl_data_device.selection event before this
event.
Before version 4, data device focus was indicated by keyboard focus.
Switching surface with keyboard focus within the same client didn't mean
a new selection event was sent.
</description>
</event>
<event name="leave" since="4">
<description summary="focus lost">
Notification that this seat's data device has lost focus.
The client will stop receiving selection events until the next enter
event.
</description>
</event>
</interface>
<interface name="wl_data_device_manager" version="3">
<interface name="wl_data_device_manager" version="4">
<description summary="data transfer interface">
The wl_data_device_manager is a singleton global object that
provides access to inter-client data transfer mechanisms such as

View file

@ -26,6 +26,8 @@
#define _GNU_SOURCE
#include "../config.h"
#include <math.h>
#include <stdlib.h>
#include <stdint.h>
@ -1491,11 +1493,56 @@ wl_closure_queue(struct wl_closure *closure, struct wl_connection *connection)
return result;
}
bool
wl_check_env_token(const char *env, const char *token)
{
const char *ptr = env;
size_t token_len;
if (env == NULL)
return false;
token_len = strlen(token);
// Scan the string for comma-separated tokens and look for a match.
while (true) {
const char *end;
size_t len;
// Skip over any leading separators.
while (*ptr == ',')
ptr++;
if (*ptr == '\x00')
return false;
end = strchr(ptr + 1, ',');
// If there isn't another separarator, then the rest of the string
// is one token.
if (end == NULL)
return (strcmp(ptr, token) == 0);
len = end - ptr;
if (len == token_len && memcmp(ptr, token, len) == 0) {
return true;
}
// Skip to the next token.
ptr += len;
}
return false;
}
void
wl_closure_print(struct wl_closure *closure, struct wl_object *target,
int send, int discarded, uint32_t (*n_parse)(union wl_argument *arg),
const char *queue_name, int color)
{
#if defined(HAVE_GETTID)
static int include_tid = -1;
#endif // defined(HAVE_GETTID)
int i;
struct argument_details arg;
const char *signature = closure->message->signature;
@ -1516,6 +1563,18 @@ wl_closure_print(struct wl_closure *closure, struct wl_object *target,
color ? WL_DEBUG_COLOR_GREEN : "",
time / 1000, time % 1000);
#if defined(HAVE_GETTID)
if (include_tid < 0) {
include_tid = wl_check_env_token(getenv("WAYLAND_DEBUG"), "thread_id");
}
if (include_tid) {
fprintf(f, "%sTID#%d ",
color ? WL_DEBUG_COLOR_CYAN : "",
(int) gettid());
}
#endif
if (queue_name) {
fprintf(f, "%s{%s} ",
color ? WL_DEBUG_COLOR_YELLOW : "",

View file

@ -268,9 +268,16 @@ int
wl_display_dispatch_queue_pending(struct wl_display *display,
struct wl_event_queue *queue);
int
wl_display_dispatch_queue_pending_single(struct wl_display *display,
struct wl_event_queue *queue);
int
wl_display_dispatch_pending(struct wl_display *display);
int
wl_display_dispatch_pending_single(struct wl_display *display);
int
wl_display_get_error(struct wl_display *display);

View file

@ -1236,7 +1236,7 @@ wl_display_connect_to_fd(int fd)
no_color = getenv("NO_COLOR");
force_color = getenv("FORCE_COLOR");
debug = getenv("WAYLAND_DEBUG");
if (debug && (strstr(debug, "client") || strstr(debug, "1"))) {
if (debug && (wl_check_env_token(debug, "client") || wl_check_env_token(debug, "1"))) {
debug_client = 1;
if (isatty(fileno(stderr)))
debug_color = 1;
@ -1882,6 +1882,34 @@ err:
return -1;
}
static int
dispatch_queue_single(struct wl_display *display, struct wl_event_queue *queue)
{
if (display->last_error)
goto err;
while (!wl_list_empty(&display->display_queue.event_list)) {
dispatch_event(display, &display->display_queue);
if (display->last_error)
goto err;
}
if (!wl_list_empty(&queue->event_list)) {
dispatch_event(display, queue);
if (display->last_error)
goto err;
return 1;
} else {
return 0;
}
err:
errno = display->last_error;
return -1;
}
/** Prepare to read events from the display's file descriptor to a queue
*
* \param display The display context object
@ -2212,6 +2240,34 @@ wl_display_dispatch_queue_pending(struct wl_display *display,
return ret;
}
/** Dispatch at most one pending event in an event queue
*
* \param display The display context object
* \param queue The event queue to dispatch
* \return The number of dispatched events (0 or 1) on success or -1 on failure
*
* Dispatch at most one pending event for objects assigned to the given
* event queue. On failure -1 is returned and errno set appropriately.
* If there are no events queued, this function returns immediately.
*
* \memberof wl_display
* \since 1.25.0
*/
WL_EXPORT int
wl_display_dispatch_queue_pending_single(struct wl_display *display,
struct wl_event_queue *queue)
{
int ret;
pthread_mutex_lock(&display->mutex);
ret = dispatch_queue_single(display, queue);
pthread_mutex_unlock(&display->mutex);
return ret;
}
/** Process incoming events
*
* \param display The display context object
@ -2272,6 +2328,25 @@ wl_display_dispatch_pending(struct wl_display *display)
&display->default_queue);
}
/** Dispatch at most one pending event in the default event queue.
*
* \param display The display context object
* \return The number of dispatched events (0 or 1) on success or -1 on failure
*
* Dispatch at most one pending event for objects assigned to the default
* event queue. On failure -1 is returned and errno set appropriately.
* If there are no events queued, this function returns immediately.
*
* \memberof wl_display
* \since 1.25.0
*/
WL_EXPORT int
wl_display_dispatch_pending_single(struct wl_display *display)
{
return wl_display_dispatch_queue_pending_single(display,
&display->default_queue);
}
/** Retrieve the last error that occurred on a display
*
* \param display The display context object

View file

@ -237,6 +237,9 @@ wl_closure_send(struct wl_closure *closure, struct wl_connection *connection);
int
wl_closure_queue(struct wl_closure *closure, struct wl_connection *connection);
bool
wl_check_env_token(const char *env, const char *token);
void
wl_closure_print(struct wl_closure *closure,
struct wl_object *target, int send, int discarded,

View file

@ -1198,7 +1198,7 @@ wl_display_create(void)
no_color = getenv("NO_COLOR");
force_color = getenv("FORCE_COLOR");
debug = getenv("WAYLAND_DEBUG");
if (debug && (strstr(debug, "server") || strstr(debug, "1"))) {
if (debug && (wl_check_env_token(debug, "server") || wl_check_env_token(debug, "1"))) {
debug_server = 1;
if (isatty(fileno(stderr)))
debug_color = 1;

View file

@ -1695,6 +1695,75 @@ TEST(global_remove)
display_destroy(d);
}
static void
dispatch_single_read_events(struct wl_display *d)
{
if (wl_display_prepare_read(d) < 0) {
return;
}
int ret = 0;
do {
ret = wl_display_flush(d);
} while (ret < 0 && (errno == EINTR || errno == EAGAIN));
assert(ret >= 0);
struct pollfd pfd[1];
pfd[0].fd = wl_display_get_fd(d);
pfd[0].events = POLLIN;
do {
ret = poll(pfd, 1, -1);
} while (ret < 0 && errno == EINTR);
assert(ret > 0);
wl_display_read_events(d);
}
static void
dispatch_single_client(void)
{
struct client *c = client_connect();
assert(wl_display_dispatch_pending_single(c->wl_display) == 0);
struct wl_registry *registry = wl_display_get_registry(c->wl_display);
dispatch_single_read_events(c->wl_display);
// [1815110.061] {Default Queue} wl_registry#3.global(1, "test", 1)
assert(wl_display_dispatch_pending_single(c->wl_display) == 1);
dispatch_single_read_events(c->wl_display);
// [1815110.067] {Default Queue} wl_registry#3.global(2, "wl_seat", 1)
assert(wl_display_dispatch_pending_single(c->wl_display) == 1);
// No more events
assert(wl_display_dispatch_pending_single(c->wl_display) == 0);
wl_registry_destroy(registry);
client_disconnect(c);
}
TEST(dispatch_single)
{
struct display *d = display_create();
struct wl_global *global = wl_global_create(d->wl_display,
&wl_seat_interface,
1, d, bind_seat);
client_create_noarg(d, dispatch_single_client);
display_run(d);
wl_global_destroy(global);
display_destroy(d);
}
static void
terminate_display(void *arg)
{