wayland/src/wayland-client-core.h

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/*
* Copyright © 2008 Kristian Høgsberg
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef WAYLAND_CLIENT_CORE_H
#define WAYLAND_CLIENT_CORE_H
#include <stdint.h>
#include "wayland-util.h"
#include "wayland-version.h"
#ifdef __cplusplus
extern "C" {
#endif
/** \class wl_proxy
*
* \brief Represents a protocol object on the client side.
*
* A wl_proxy acts as a client side proxy to an object existing in the
* compositor. The proxy is responsible for converting requests made by the
* clients with \ref wl_proxy_marshal() into Wayland's wire format. Events
* coming from the compositor are also handled by the proxy, which will in
* turn call the handler set with \ref wl_proxy_add_listener().
*
* \note With the exception of function \ref wl_proxy_set_queue(), functions
* accessing a wl_proxy are not normally used by client code. Clients
* should normally use the higher level interface generated by the scanner to
* interact with compositor objects.
*
*/
struct wl_proxy;
/** \class wl_display
*
* \brief Represents a connection to the compositor and acts as a proxy to
* the wl_display singleton object.
*
* A wl_display object represents a client connection to a Wayland
* compositor. It is created with either \ref wl_display_connect() or
* \ref wl_display_connect_to_fd(). A connection is terminated using
* \ref wl_display_disconnect().
*
* A wl_display is also used as the \ref wl_proxy for the wl_display
* singleton object on the compositor side.
*
* A wl_display object handles all the data sent from and to the
* compositor. When a \ref wl_proxy marshals a request, it will write its wire
* representation to the display's write buffer. The data is sent to the
* compositor when the client calls \ref wl_display_flush().
*
* Incoming data is handled in two steps: queueing and dispatching. In the
* queue step, the data coming from the display fd is interpreted and
* added to a queue. On the dispatch step, the handler for the incoming
* event set by the client on the corresponding \ref wl_proxy is called.
*
* A wl_display has at least one event queue, called the <em>default
* queue</em>. Clients can create additional event queues with \ref
* wl_display_create_queue() and assign \ref wl_proxy's to it. Events
* occurring in a particular proxy are always queued in its assigned queue.
* A client can ensure that a certain assumption, such as holding a lock
* or running from a given thread, is true when a proxy event handler is
* called by assigning that proxy to an event queue and making sure that
* this queue is only dispatched when the assumption holds.
*
* The default queue is dispatched by calling \ref wl_display_dispatch().
* This will dispatch any events queued on the default queue and attempt
* to read from the display fd if it's empty. Events read are then queued
* on the appropriate queues according to the proxy assignment.
*
* A user created queue is dispatched with \ref wl_display_dispatch_queue().
* This function behaves exactly the same as wl_display_dispatch()
* but it dispatches given queue instead of the default queue.
*
* A real world example of event queue usage is Mesa's implementation of
* eglSwapBuffers() for the Wayland platform. This function might need
* to block until a frame callback is received, but dispatching the default
* queue could cause an event handler on the client to start drawing
* again. This problem is solved using another event queue, so that only
* the events handled by the EGL code are dispatched during the block.
*
* This creates a problem where a thread dispatches a non-default
* queue, reading all the data from the display fd. If the application
* would call \em poll(2) after that it would block, even though there
* might be events queued on the default queue. Those events should be
* dispatched with \ref wl_display_dispatch_pending() or \ref
* wl_display_dispatch_queue_pending() before flushing and blocking.
*/
struct wl_display;
/** \class wl_event_queue
*
* \brief A queue for \ref wl_proxy object events.
*
* Event queues allows the events on a display to be handled in a thread-safe
* manner. See \ref wl_display for details.
*
*/
struct wl_event_queue;
/** Destroy proxy after marshalling
* \relates wl_proxy
*/
#define WL_MARSHAL_FLAG_DESTROY (1 << 0)
void
wl_event_queue_destroy(struct wl_event_queue *queue);
struct wl_proxy *
wl_proxy_marshal_flags(struct wl_proxy *proxy, uint32_t opcode,
const struct wl_interface *interface,
uint32_t version,
uint32_t flags, ...);
struct wl_proxy *
wl_proxy_marshal_array_flags(struct wl_proxy *proxy, uint32_t opcode,
const struct wl_interface *interface,
uint32_t version,
uint32_t flags,
union wl_argument *args);
void
wl_proxy_marshal(struct wl_proxy *p, uint32_t opcode, ...);
void
wl_proxy_marshal_array(struct wl_proxy *p, uint32_t opcode,
union wl_argument *args);
struct wl_proxy *
wl_proxy_create(struct wl_proxy *factory,
const struct wl_interface *interface);
void *
wl_proxy_create_wrapper(void *proxy);
void
wl_proxy_wrapper_destroy(void *proxy_wrapper);
struct wl_proxy *
wl_proxy_marshal_constructor(struct wl_proxy *proxy,
uint32_t opcode,
const struct wl_interface *interface,
...);
struct wl_proxy *
wl_proxy_marshal_constructor_versioned(struct wl_proxy *proxy,
uint32_t opcode,
const struct wl_interface *interface,
uint32_t version,
...);
struct wl_proxy *
wl_proxy_marshal_array_constructor(struct wl_proxy *proxy,
uint32_t opcode, union wl_argument *args,
const struct wl_interface *interface);
struct wl_proxy *
wl_proxy_marshal_array_constructor_versioned(struct wl_proxy *proxy,
uint32_t opcode,
union wl_argument *args,
const struct wl_interface *interface,
uint32_t version);
void
wl_proxy_destroy(struct wl_proxy *proxy);
int
wl_proxy_add_listener(struct wl_proxy *proxy,
void (**implementation)(void), void *data);
const void *
wl_proxy_get_listener(struct wl_proxy *proxy);
int
wl_proxy_add_dispatcher(struct wl_proxy *proxy,
wl_dispatcher_func_t dispatcher_func,
const void * dispatcher_data, void *data);
void
wl_proxy_set_user_data(struct wl_proxy *proxy, void *user_data);
void *
wl_proxy_get_user_data(struct wl_proxy *proxy);
uint32_t
wl_proxy_get_version(struct wl_proxy *proxy);
uint32_t
wl_proxy_get_id(struct wl_proxy *proxy);
proxy: Add API to tag proxy objects When an application and a toolkit share the same Wayland connection, it will receive events with each others objects. For example if the toolkit manages a set of surfaces, and the application another set, if both the toolkit and application listen to pointer focus events, they'll receive focus events for each others surfaces. In order for the toolkit and application layers to identify whether a surface is managed by itself or not, it cannot only rely on retrieving the proxy user data, without going through all it's own proxy objects finding whether it's one of them. By adding the ability to "tag" a proxy object, the toolkit and application can use the tag to identify what the user data pointer points to something known. To create a tag, the recommended way is to define a statically allocated constant char array containing some descriptive string. The tag will be the pointer to the non-const pointer to the beginning of the array. For example, to identify whether a focus event is for a surface managed by the code in question: static const char *my_tag = "my tag"; static void pointer_enter(void *data, struct wl_pointer *wl_pointer, uint32_t serial, struct wl_surface *surface, wl_fixed_t surface_x, wl_fixed_t surface_y) { struct window *window; const char * const *tag; tag = wl_proxy_get_tag((struct wl_proxy *) surface); if (tag != &my_tag) return; window = wl_surface_get_user_data(surface); ... } ... static void init_window_surface(struct window *window) { struct wl_surface *surface; surface = wl_compositor_create_surface(compositor); wl_surface_set_user_data(surface, window); wl_proxy_set_tag((struct wl_proxy *) surface, &my_tag); } Signed-off-by: Jonas Ådahl <jadahl@gmail.com>
2019-07-10 09:13:33 +02:00
void
wl_proxy_set_tag(struct wl_proxy *proxy,
const char * const *tag);
const char * const *
wl_proxy_get_tag(struct wl_proxy *proxy);
const char *
wl_proxy_get_class(struct wl_proxy *proxy);
struct wl_display *
wl_proxy_get_display(struct wl_proxy *proxy);
void
wl_proxy_set_queue(struct wl_proxy *proxy, struct wl_event_queue *queue);
struct wl_event_queue *
wl_proxy_get_queue(const struct wl_proxy *proxy);
const char *
wl_event_queue_get_name(const struct wl_event_queue *queue);
struct wl_display *
wl_display_connect(const char *name);
struct wl_display *
wl_display_connect_to_fd(int fd);
void
wl_display_disconnect(struct wl_display *display);
int
wl_display_get_fd(struct wl_display *display);
int
wl_display_dispatch(struct wl_display *display);
int
wl_display_dispatch_queue(struct wl_display *display,
struct wl_event_queue *queue);
int
wl_display_dispatch_queue_pending(struct wl_display *display,
struct wl_event_queue *queue);
int
wl_display_dispatch_pending(struct wl_display *display);
int
wl_display_get_error(struct wl_display *display);
uint32_t
wl_display_get_protocol_error(struct wl_display *display,
const struct wl_interface **interface,
uint32_t *id);
int
wl_display_flush(struct wl_display *display);
int
wl_display_roundtrip_queue(struct wl_display *display,
struct wl_event_queue *queue);
int
wl_display_roundtrip(struct wl_display *display);
struct wl_event_queue *
wl_display_create_queue(struct wl_display *display);
struct wl_event_queue *
wl_display_create_queue_with_name(struct wl_display *display,
const char *name);
int
wl_display_prepare_read_queue(struct wl_display *display,
struct wl_event_queue *queue);
int
wl_display_prepare_read(struct wl_display *display);
void
wl_display_cancel_read(struct wl_display *display);
int
wl_display_read_events(struct wl_display *display);
void
wl_log_set_handler_client(wl_log_func_t handler);
connection: Dynamically resize connection buffers When using fixed size connection buffers, if either the client or the server is sending requests faster than the other end can cope with, the connection buffers will fill up, eventually killing the connection. This can be a problem for example with Xwayland mapping a lot of windows, faster than the Wayland compositor can cope with, or a high-rate mouse flooding the Wayland client with pointer events. To avoid the issue, resize the connection buffers dynamically when they get full. Both data and fd buffers are resized on demand. The default max buffer size is controlled via the wl_display interface while each client's connection buffer size is adjustable for finer control. The purpose is to explicitly have larger connection buffers for specific clients such as Xwayland, or set a larger buffer size for the client with pointer focus to deal with a higher input events rate. v0: Manuel: Dynamically resize connection buffers - Both data and fd buffers are resized on demand. v1: Olivier 1. Add support for unbounded buffers on the client side and growable (yet limited) connection buffers on the server side. 2. Add the API to set the default maximum size and a limit for a given client. 3. Add tests for growable connection buffers and adjustable limits. v2: Additional fixes by John: 1. Fix the size calculation in ring_buffer_check_space() 2. Fix wl_connection_read() to return gracefully once it has read up to the max buffer size, rather than returning an error. 3. If wl_connection_flush() fails with EAGAIN but the transmit ring-buffer has space remaining (or can be expanded), wl_connection_queue() should store the message rather than returning an error. 4. When the receive ring-buffer is at capacity but more data is available to be read, wl_connection_read() should attempt to expand the ring-buffer in order to read the remaining data. v3: Thomas Lukaszewicz <tluk@chromium.org> Add a test for unbounded buffers v4: Add a client API as well to force bounded buffers (unbounded by default (Olivier) v5: Simplify ring_buffer_ensure_space() (Sebastian) Co-authored-by: Olivier Fourdan <ofourdan@redhat.com> Co-authored-by: John Lindgren <john@jlindgren.net> Co-authored-by: Sebastian Wick <sebastian@sebastianwick.net> Signed-off-by: Manuel Stoeckl <code@mstoeckl.com> Signed-off-by: Olivier Fourdan <ofourdan@redhat.com> Signed-off-by: John Lindgren <john@jlindgren.net> Signed-off-by: Sebastian Wick <sebastian@sebastianwick.net> Closes: https://gitlab.freedesktop.org/wayland/wayland/-/issues/237
2021-09-25 22:34:44 -04:00
void
wl_display_set_max_buffer_size(struct wl_display *display,
size_t max_buffer_size);
#ifdef __cplusplus
}
#endif
#endif