Server API¶

Server Introduction¶

The open-source reference implementation of Wayland protocol is split in two C libraries, Client API and libwayland-server. Their main responsibility is to handle the Inter-process communication (IPC) with each other, therefore guaranteeing the protocol objects marshaling and messages synchronization.

The server library is designed to work much like libwayland-client, although it is considerably complicated due to the server needing to support multiple versions of the protocol. It is best to learn libwayland-client first.

Each open socket to a client is represented by a wl_client. The equvalent of the wl_proxy that libwayland-client uses to represent an object is wl_resource for client-created objects, and wl_global for objects created by the server.

Often a server is also a client for another Wayland server, and thus must link with both libwayland-client and libwayland-server. This produces some type name conflicts (such as the client_wl_display and server_wl_display>, but the duplicate-but-not-the-same types are opaque, and accessed only inside the correct library where it came from). Naturally that means that the program writer needs to always know if a pointer to a wl_display is for the server or client side and use the corresponding functions.

union wl_argument

#include <wayland-util.h>

Protocol message argument data types.

This union represents all of the argument types in the Wayland protocol wire format. The protocol implementation uses wl_argument within its marshalling machinery for dispatching messages between a client and a compositor.

See: wl_message
See: wl_interface
See: Wire Format

Public Members

int32_t i: int

uint32_t u: uint

wl_fixed_t f: fixed

const char *s: string

struct wl_object *o: object

uint32_t n: new_id

struct wl_array *a: array

int32_t h: fd

class wl_array

#include <wayland-util.h>

Dynamic array.

A wl_array is a dynamic array that can only grow until released. It is intended for relatively small allocations whose size is variable or not known in advance. While construction of a wl_array does not require all elements to be of the same size, wl_array_for_each() does require all elements to have the same type and size.

Public Functions

void wl_array_init(struct wl_array *array)

Initializes the array.

Parameters

array: Array to initialize

void wl_array_release(struct wl_array *array)

Releases the array data.

Note

Leaves the array in an invalid state.

Parameters

array: Array whose data is to be released

void *wl_array_add(struct wl_array *array, size_t size)

Increases the size of the array by size bytes.

Return

A pointer to the beginning of the newly appended space, or NULL when resizing fails.

Parameters

array: Array whose size is to be increased
size: Number of bytes to increase the size of the array by

int wl_array_copy(struct wl_array *array, struct wl_array *source)

Copies the contents of source to array.

Return

0 on success, or -1 on failure

Parameters

array: Destination array to copy to
source: Source array to copy from

Public Members

size_t size: Array size.

size_t alloc: Allocated space.

void *data: Array data.

Iterates over an array.

This macro expresses a for-each iterator for wl_array. It assigns each element in the array to pos, which can then be referenced in a trailing code block. pos must be a pointer to the array element type, and all array elements must be of the same type and size.

See

wl_list_for_each()

Parameters

pos: Cursor that each array element will be assigned to
array: Array to iterate over

struct wl_client¶

Public Functions

void wl_client_flush(struct wl_client *client)¶

Flush pending events to the client.

Events sent to clients are queued in a buffer and written to the socket later - typically when the compositor has handled all requests and goes back to block in the event loop. This function flushes all queued up events for a client immediately.

Parameters

client: The client object

struct wl_display *wl_client_get_display(struct wl_client *client)¶

Get the display object for the given client.

Return

The display object the client is associated with.

Parameters

client: The client object

void wl_client_get_credentials(struct wl_client *client, pid_t *pid, uid_t *uid, gid_t *gid)¶

Return Unix credentials for the client.

This function returns the process ID, the user ID and the group ID for the given client. The credentials come from getsockopt() with SO_PEERCRED, on the client socket fd. All the pointers can be NULL, if the caller is not interested in a particular ID.

Parameters

client: The display object
pid: Returns the process ID
uid: Returns the user ID
gid: Returns the group ID

Be aware that for clients that a compositor forks and execs and then connects using socketpair(), this function will return the credentials for the compositor. The credentials for the socketpair are set at creation time in the compositor.

int wl_client_get_fd(struct wl_client *client)¶

Get the file descriptor for the client.

This function returns the file descriptor for the given client.

Return

The file descriptor to use for the connection

Parameters

client: The display object

Be sure to use the file descriptor from the client for inspection only. If the caller does anything to the file descriptor that changes its state, it will likely cause problems.

See also wl_client_get_credentials(). It is recommended that you evaluate whether wl_client_get_credentials() can be applied to your use case instead of this function.

If you would like to distinguish just between the client and the compositor itself from the client’s request, it can be done by getting the client credentials and by checking the PID of the client and the compositor’s PID. Regarding the case in which the socketpair() is being used, you need to be careful. Please note the documentation for wl_client_get_credentials().

This function can be used for a compositor to validate a request from a client if there are additional information provided from the client’s file descriptor. For instance, suppose you can get the security contexts from the client’s file descriptor. The compositor can validate the client’s request with the contexts and make a decision whether it permits or deny it.

struct wl_resource *wl_client_get_object(struct wl_client *client, uint32_t id)¶

Look up an object in the client name space.

This looks up an object in the client object name space by its object ID.

Return

The object or NULL if there is not object for the given ID

Parameters

client: The client object
id: The object id

void wl_client_post_implementation_error(struct wl_client *client, char const *msg, ...)¶

Report an internal server error.

Report an unspecified internal implementation error and disconnect the client.

Parameters

client: The client object
msg: A printf-style format string
...: Format string arguments

struct wl_list *wl_client_get_link(struct wl_client *client)¶

Get the link by which a client is inserted in the client list.

See

wl_client_for_each()

See

wl_display_get_client_list()

See

wl_client_from_link()

Parameters

client: The client object

struct wl_client *wl_client_from_link(struct wl_list *link)¶

Get a wl_client by its link.

See

wl_client_for_each()

See

wl_display_get_client_list()

See

wl_client_get_link()

Parameters

link: The link of a wl_client

void wl_client_add_resource_created_listener(struct wl_client *client, struct wl_listener *listener)¶

Add a listener for the client’s resource creation signal.

When a new resource is created for this client the listener will be notified, carrying the new resource as the data argument.

Parameters

client: The client object
listener: The listener to be added

void wl_client_for_each_resource(struct wl_client *client, wl_client_for_each_resource_iterator_func_t iterator, void *user_data)¶

Iterate over all the resources of a client.

The function pointed by

iterator will be called for each resource owned by the client. The user_data will be passed as the second argument of the iterator function. If the iterator function returns WL_ITERATOR_CONTINUE the iteration will continue, if it returns WL_ITERATOR_STOP it will stop.

Parameters

client: The client object
iterator: The iterator function
user_data: The user data pointer

Creating and destroying resources while iterating is safe, but new resources may or may not be picked up by the iterator.

See: wl_iterator_result

Public Members

struct wl_connection *connection¶

struct wl_event_source *source¶

struct wl_display *display¶

struct wl_resource *display_resource¶

struct wl_list link¶

struct wl_map objects¶

struct wl_priv_signal destroy_signal¶

struct ucred ucred¶

int error¶

struct wl_priv_signal resource_created_signal¶

struct wl_display

Public Functions

struct wl_client *wl_client_create(struct wl_display *display, int fd)¶

Create a client for the given file descriptor.

Given a file descriptor corresponding to one end of a socket, this function will create a

wl_client struct and add the new client to the compositors client list. At that point, the client is initialized and ready to run, as if the client had connected to the servers listening socket. When the client eventually sends requests to the compositor, the wl_client argument to the request handler will be the wl_client returned from this function.

Return

The new client object or NULL on failure.

Parameters

display: The display object
fd: The file descriptor for the socket to the client

The other end of the socket can be passed to wl_display_connect_to_fd() on the client side or used with the WAYLAND_SOCKET environment variable on the client side.

Listeners added with wl_display_add_client_created_listener() will be notified by this function after the client is fully constructed.

On failure this function sets errno accordingly and returns NULL.

struct wl_display *wl_display_create(void)¶

Create Wayland display object.

This creates the

wl_display object.

Return: The Wayland display object. Null if failed to create

void wl_display_destroy(struct wl_display *display)¶

Destroy Wayland display object.

This function emits the

wl_display destroy signal, releases all the sockets added to this display, free’s all the globals associated with this display, free’s memory of additional shared memory formats and destroy the display object.

Return

None.

Parameters

display: The Wayland display object which should be destroyed.

See: wl_display_add_destroy_listener

void wl_display_set_global_filter(struct wl_display *display, wl_display_global_filter_func_t filter, void *data)¶

Set a filter function for global objects.

Set a filter for the

wl_display to advertise or hide global objects to clients. The set filter will be used during wl_global advertisment to determine whether a global object should be advertised to a given client, and during wl_global binding to determine whether a given client should be allowed to bind to a global.

Return

None.

Parameters

display: The Wayland display object.
filter: The global filter funtion.
data: User data to be associated with the global filter.

Clients that try to bind to a global that was filtered out will have an error raised.

Setting the filter NULL will result in all globals being advertised to all clients. The default is no filter.

uint32_t wl_display_get_serial(struct wl_display *display)¶

Get the current serial number.

This function returns the most recent serial number, but does not increment it.

Parameters

display: The display object

uint32_t wl_display_next_serial(struct wl_display *display)¶

Get the next serial number.

This function increments the display serial number and returns the new value.

Parameters

display: The display object

void wl_display_destroy_clients(struct wl_display *display)¶

Destroy all clients connected to the display.

This function should be called right before

wl_display_destroy() to ensure all client resources are closed properly. Destroying a client from within wl_display_destroy_clients() is safe, but creating one will leak resources and raise a warning.

Parameters

display: The display object

int wl_display_add_socket_fd(struct wl_display *display, int sock_fd)¶

Add a socket with an existing fd to Wayland display for the clients to connect.

The existing socket fd must already be created, opened, and locked. The fd must be properly set to CLOEXEC and bound to a socket file with both bind() and listen() already called.

Return

0 if success. -1 if failed.

Parameters

display: Wayland display to which the socket should be added.
sock_fd: The existing socket file descriptor to be used

int wl_display_add_socket(struct wl_display *display, const char *name)¶

Add a socket to Wayland display for the clients to connect.

This adds a Unix socket to Wayland display which can be used by clients to connect to Wayland display.

Return

0 if success. -1 if failed.

Parameters

display: Wayland display to which the socket should be added.
name: Name of the Unix socket.

If NULL is passed as name, then it would look for WAYLAND_DISPLAY env variable for the socket name. If WAYLAND_DISPLAY is not set, then default wayland-0 is used.

The Unix socket will be created in the directory pointed to by environment variable XDG_RUNTIME_DIR. If XDG_RUNTIME_DIR is not set, then this function fails and returns -1.

The length of socket path, i.e., the path set in XDG_RUNTIME_DIR and the socket name, must not exceed the maximum length of a Unix socket path. The function also fails if the user do not have write permission in the XDG_RUNTIME_DIR path or if the socket name is already in use.

struct wl_protocol_logger *wl_display_add_protocol_logger(struct wl_display *display, wl_protocol_logger_func_t func, void *user_data)¶

Adds a new protocol logger.

When a new protocol message arrives or is sent from the server all the protocol logger functions will be called, carrying the user_data pointer, the type of the message (request or event) and the actual message. The lifetime of the messages passed to the logger function ends when they return so the messages cannot be stored and accessed later.

errno is set on error.

Return

The protol logger object on success, NULL on failure.

See

wl_protocol_logger_destroy

Parameters

display: The display object
func: The function to call to log a new protocol message
user_data: The user data pointer to pass to func

uint32_t *wl_display_add_shm_format(struct wl_display *display, uint32_t format)¶

Add support for a wl_shm pixel format.

Add the specified wl_shm format to the list of formats the wl_shm object advertises when a client binds to it. Adding a format to the list means that clients will know that the compositor supports this format and may use it for creating wl_shm buffers. The compositor must be able to handle the pixel format when a client requests it.

Return

A pointer to the wl_shm format that was added to the list or NULL if adding it to the list failed.

Parameters

display: The display object
format: The wl_shm pixel format to advertise

The compositor by default supports WL_SHM_FORMAT_ARGB8888 and WL_SHM_FORMAT_XRGB8888.

struct wl_list *wl_display_get_client_list(struct wl_display *display)¶

Get the list of currently connected clients.

This function returns a pointer to the list of clients currently connected to the display. You can iterate on the list by using the

wl_client_for_each macro. The returned value is valid for the lifetime of the display. You must not modify the returned list, but only access it.

Parameters

display: The display object

See: wl_client_for_each()
See: wl_client_get_link()
See: wl_client_from_link()

Public Members

struct wl_event_loop *loop¶

int run¶

uint32_t id¶

uint32_t serial¶

struct wl_list registry_resource_list¶

struct wl_list global_list¶

struct wl_list socket_list¶

struct wl_list client_list¶

struct wl_list protocol_loggers¶

struct wl_priv_signal destroy_signal¶

struct wl_priv_signal create_client_signal¶

struct wl_array additional_shm_formats¶

wl_display_global_filter_func_t global_filter¶

void *global_filter_data¶

Private Functions

struct wl_array *wl_display_get_additional_shm_formats(struct wl_display *display)¶

Get list of additional wl_shm pixel formats.

This function returns the list of addition wl_shm pixel formats that the compositor supports. WL_SHM_FORMAT_ARGB8888 and WL_SHM_FORMAT_XRGB8888 are always supported and not included in the array, but all formats added through

wl_display_add_shm_format() will be in the array.

Parameters

display: The display object

See: wl_display_add_shm_format()

struct wl_event_loop¶

#include <wayland-server-core.h>

An event loop context.

Usually you create an event loop context, add sources to it, and call wl_event_loop_dispatch() in a loop to process events.

See: wl_event_source

Public Functions

struct wl_event_loop *wl_event_loop_create(void)¶

Create a new event loop context.

This creates a new event loop context. Initially this context is empty. Event sources need to be explicitly added to it.

Return: A new event loop context object.

Normally the event loop is run by calling wl_event_loop_dispatch() in a loop until the program terminates. Alternatively, an event loop can be embedded in another event loop by its file descriptor, see wl_event_loop_get_fd().

void wl_event_loop_destroy(struct wl_event_loop *loop)¶

Destroy an event loop context.

This emits the event loop destroy signal, closes the event loop file descriptor, and frees

loop.

Parameters

loop: The event loop to be destroyed.

If the event loop has existing sources, those cannot be safely removed afterwards. Therefore one must call wl_event_source_remove() on all event sources before destroying the event loop context.

void wl_event_loop_dispatch_idle(struct wl_event_loop *loop)¶

Dispatch the idle sources.

See

wl_event_loop_add_idle()

Parameters

loop: The event loop whose idle sources are dispatched.

int wl_event_loop_dispatch(struct wl_event_loop *loop, int timeout)¶

Wait for events and dispatch them.

All the associated event sources are polled. This function blocks until any event source delivers an event (idle sources excluded), or the timeout expires. A timeout of -1 disables the timeout, causing the function to block indefinitely. A timeout of zero causes the poll to always return immediately.

Return

0 for success, -1 for polling error.

Parameters

loop: The event loop whose sources to wait for.
timeout: The polling timeout in milliseconds.

All idle sources are dispatched before blocking. An idle source is destroyed when it is dispatched. After blocking, all other ready sources are dispatched. Then, idle sources are dispatched again, in case the dispatched events created idle sources. Finally, all sources marked with wl_event_source_check() are dispatched in a loop until their dispatch functions all return zero.

int wl_event_loop_get_fd(struct wl_event_loop *loop)¶

Get the event loop file descriptor.

This function returns the aggregate file descriptor, that represents all the event sources (idle sources excluded) associated with the given event loop context. When any event source makes an event available, it will be reflected in the aggregate file descriptor.

Return

The aggregate file descriptor.

Parameters

loop: The event loop context.

When the aggregate file descriptor delivers an event, one can call wl_event_loop_dispatch() on the event loop context to dispatch all the available events.

void wl_event_loop_add_destroy_listener(struct wl_event_loop *loop, struct wl_listener *listener)¶

Register a destroy listener for an event loop context.

See

wl_listener

Parameters

loop: The event loop context whose destruction to listen for.
listener: The listener with the callback to be called.

struct wl_listener *wl_event_loop_get_destroy_listener(struct wl_event_loop *loop, wl_notify_func_t notify)¶

Get the listener struct for the specified callback.

Return

The wl_listener registered to the event loop context with the given callback pointer.

Parameters

loop: The event loop context to inspect.
notify: The destroy callback to find.

struct wl_event_source¶

#include <wayland-server-core.h>

An abstract event source.

This is the generic type for fd, timer, signal, and idle sources. Functions that operate on specific source types must not be used with a different type, even if the function signature allows it.

Public Types

typedef int (*wl_event_loop_fd_func_t)(int fd, uint32_t mask, void *data)¶

File descriptor dispatch function type.

Functions of this type are used as callbacks for file descriptor events.

Return

If the event source is registered for re-check with wl_event_source_check(): 0 for all done, 1 for needing a re-check. If not registered, the return value is ignored and should be zero.

See

wl_event_loop_add_fd()

Parameters

fd: The file descriptor delivering the event.
mask: Describes the kind of the event as a bitwise-or of: WL_EVENT_READABLE, WL_EVENT_WRITABLE, WL_EVENT_HANGUP, WL_EVENT_ERROR.
data: The user data argument of the related wl_event_loop_add_fd() call.

typedef int (*wl_event_loop_timer_func_t)(void *data)¶

Timer dispatch function type.

Functions of this type are used as callbacks for timer expiry.

Return

If the event source is registered for re-check with wl_event_source_check(): 0 for all done, 1 for needing a re-check. If not registered, the return value is ignored and should be zero.

See

wl_event_loop_add_timer()

Parameters

data: The user data argument of the related wl_event_loop_add_timer() call.

typedef int (*wl_event_loop_signal_func_t)(int signal_number, void *data)¶

Signal dispatch function type.

Functions of this type are used as callbacks for (POSIX) signals.

Return

If the event source is registered for re-check with wl_event_source_check(): 0 for all done, 1 for needing a re-check. If not registered, the return value is ignored and should be zero.

See

wl_event_loop_add_signal()

Parameters

signal_number:
data: The user data argument of the related wl_event_loop_add_signal() call.

typedef void (*wl_event_loop_idle_func_t)(void *data)¶

Idle task function type.

Functions of this type are used as callbacks before blocking in wl_event_loop_dispatch().

See

wl_event_loop_add_idle() wl_event_loop_dispatch()

Parameters

data: The user data argument of the related wl_event_loop_add_idle() call.

Public Functions

struct wl_event_source *wl_event_loop_add_fd(struct wl_event_loop *loop, int fd, uint32_t mask, wl_event_loop_fd_func_t func, void *data)¶

Create a file descriptor event source.

The given file descriptor is initially watched for the events given in

mask. This can be changed as needed with wl_event_source_fd_update().

Return

A new file descriptor event source.

Parameters

loop: The event loop that will process the new source.
fd: The file descriptor to watch.
mask: A bitwise-or of which events to watch for: WL_EVENT_READABLE, WL_EVENT_WRITABLE.
func: The file descriptor dispatch function.
data: User data.

If it is possible that program execution causes the file descriptor to be read while leaving the data in a buffer without actually processing it, it may be necessary to register the file descriptor source to be re-checked, see wl_event_source_check(). This will ensure that the dispatch function gets called even if the file descriptor is not readable or writable anymore. This is especially useful with IPC libraries that automatically buffer incoming data, possibly as a side-effect of other operations.

See: wl_event_loop_fd_func_t

int wl_event_source_fd_update(struct wl_event_source *source, uint32_t mask)¶

Update a file descriptor source’s event mask.

This changes which events, readable and/or writable, cause the dispatch callback to be called on.

Return

0 on success, -1 on failure.

Parameters

source: The file descriptor event source to update.
mask: The new mask, a bitwise-or of: WL_EVENT_READABLE, WL_EVENT_WRITABLE.

File descriptors are usually writable to begin with, so they do not need to be polled for writable until a write actually fails. When a write fails, the event mask can be changed to poll for readable and writable, delivering a dispatch callback when it is possible to write more. Once all data has been written, the mask can be changed to poll only for readable to avoid busy-looping on dispatch.

See: wl_event_loop_add_fd()

struct wl_event_source *wl_event_loop_add_timer(struct wl_event_loop *loop, wl_event_loop_timer_func_t func, void *data)¶

Create a timer event source.

The timer is initially disarmed. It needs to be armed with a call to

wl_event_source_timer_update() before it can trigger a dispatch call.

Return

A new timer event source.

Parameters

loop: The event loop that will process the new source.
func: The timer dispatch function.
data: User data.

See: wl_event_loop_timer_func_t

int wl_event_source_timer_update(struct wl_event_source *source, int ms_delay)¶

Arm or disarm a timer.

If the timeout is zero, the timer is disarmed.

Return

0 on success, -1 on failure.

Parameters

source: The timer event source to modify.
ms_delay: The timeout in milliseconds.

If the timeout is non-zero, the timer is set to expire after the given timeout in milliseconds. When the timer expires, the dispatch function set with wl_event_loop_add_timer() is called once from wl_event_loop_dispatch(). If another dispatch is desired after another expiry, wl_event_source_timer_update() needs to be called again.

struct wl_event_source *wl_event_loop_add_signal(struct wl_event_loop *loop, int signal_number, wl_event_loop_signal_func_t func, void *data)¶

Create a POSIX signal event source.

This function blocks the normal delivery of the given signal in the calling thread, and creates a “watch” for it. Signal delivery no longer happens asynchronously, but by

wl_event_loop_dispatch() calling the dispatch callback function func.

Return

A new signal event source.

Parameters

loop: The event loop that will process the new source.
signal_number: Number of the signal to watch for.
func: The signal dispatch function.
data: User data.

It is the caller’s responsibility to ensure that all other threads have also blocked the signal.

See: wl_event_loop_signal_func_t

struct wl_event_source *wl_event_loop_add_idle(struct wl_event_loop *loop, wl_event_loop_idle_func_t func, void *data)¶

Create an idle task.

Idle tasks are dispatched before

wl_event_loop_dispatch() goes to sleep. See wl_event_loop_dispatch() for more details.

Return

A new idle task (an event source).

Parameters

loop: The event loop that will process the new task.
func: The idle task dispatch function.
data: User data.

Idle tasks fire once, and are automatically destroyed right after the callback function has been called.

An idle task can be cancelled before the callback has been called by wl_event_source_remove(). Calling wl_event_source_remove() after or from within the callback results in undefined behaviour.

See: wl_event_loop_idle_func_t

void wl_event_source_check(struct wl_event_source *source)¶

Mark event source to be re-checked.

This function permanently marks the event source to be re-checked after the normal dispatch of sources in

wl_event_loop_dispatch(). Re-checking will keep iterating over all such event sources until the dispatch function for them all returns zero.

Parameters

source: The event source to be re-checked.

Re-checking is used on sources that may become ready to dispatch as a side-effect of dispatching themselves or other event sources, including idle sources. Re-checking ensures all the incoming events have been fully drained before wl_event_loop_dispatch() returns.

int wl_event_source_remove(struct wl_event_source *source)¶

Remove an event source from its event loop.

The event source is removed from the event loop it was created for, and is effectively destroyed. This invalidates

source . The dispatch function of the source will no longer be called through this source.

Return

Zero.

Parameters

source: The event source to be removed.

struct wl_global¶

Public Members

struct wl_display *display¶

const struct wl_interface *interface¶

uint32_t name¶

uint32_t version¶

void *data¶

wl_global_bind_func_t bind¶

struct wl_list link¶

struct wl_interface

#include <wayland-util.h>

Protocol object interface.

A wl_interface describes the API of a protocol object defined in the Wayland protocol specification. The protocol implementation uses a wl_interface within its marshalling machinery for encoding client requests.

The name of a wl_interface is the name of the corresponding protocol interface, and version represents the version of the interface. The members method_count and event_count represent the number of methods (requests) and events in the respective wl_message members.

For example, consider a protocol interface foo, marked as version 1, with two requests and one event.

<interface name="foo" version="1">
  <request name="a"></request>
  <request name="b"></request>
  <event name="c"></event>
</interface>

Given two wl_message arrays foo_requests and foo_events, a wl_interface for foo might be:

struct wl_interface foo_interface = {
        "foo", 1,
        2, foo_requests,
        1, foo_events
};

Note: The server side of the protocol may define interface implementation types that incorporate the term interface in their name. Take care to not confuse these server-side structs with a wl_interface variable whose name also ends in interface. For example, while the server may define a type struct wl_foo_interface, the client may define a struct wl_interface wl_foo_interface.
See: wl_message
See: wl_proxy
See: Interfaces
See: Versioning

Public Members

const char *name: Interface name.

int version: Interface version.

int method_count: Number of methods (requests)

const struct wl_message *methods: Method (request) signatures.

int event_count: Number of events.

const struct wl_message *events: Event signatures.

class wl_list

#include <wayland-util.h>

Doubly-linked list.

On its own, an instance of struct wl_list represents the sentinel head of a doubly-linked list, and must be initialized using wl_list_init(). When empty, the list head’s next and prev members point to the list head itself, otherwise next references the first element in the list, and prev refers to the last element in the list.

Use the struct wl_list type to represent both the list head and the links between elements within the list. Use wl_list_empty() to determine if the list is empty in O(1).

All elements in the list must be of the same type. The element type must have a struct wl_list member, often named link by convention. Prior to insertion, there is no need to initialize an element’s link - invoking wl_list_init() on an individual list element’s struct wl_list member is unnecessary if the very next operation is wl_list_insert(). However, a common idiom is to initialize an element’s link prior to removal - ensure safety by invoking wl_list_init() before wl_list_remove().

Consider a list reference struct wl_list foo_list, an element type as struct element, and an element’s link member as struct wl_list link.

The following code initializes a list and adds three elements to it.

struct wl_list foo_list;

struct element {
        int foo;
        struct wl_list link;
};
struct element e1, e2, e3;

wl_list_init(&foo_list);
wl_list_insert(&foo_list, &e1.link);   // e1 is the first element
wl_list_insert(&foo_list, &e2.link);   // e2 is now the first element
wl_list_insert(&e2.link, &e3.link); // insert e3 after e2

The list now looks like [e2, e3, e1].

The wl_list API provides some iterator macros. For example, to iterate a list in ascending order:

struct element *e;
wl_list_for_each(e, foo_list, link) {
        do_something_with_element(e);
}

See the documentation of each iterator for details.

See: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/include/linux/list.h

Public Functions

void wl_list_init(struct wl_list *list)

Initializes the list.

Parameters

list: List to initialize

void wl_list_insert(struct wl_list *list, struct wl_list *elm)

Inserts an element into the list, after the element represented by list.

When list is a reference to the list itself (the head), set the containing struct of elm as the first element in the list.

Note

If elm is already part of a list, inserting it again will lead to list corruption.

Parameters

list: List element after which the new element is inserted
elm: Link of the containing struct to insert into the list

void wl_list_remove(struct wl_list *elm)

Removes an element from the list.

Note

This operation leaves elm in an invalid state.

Parameters

elm: Link of the containing struct to remove from the list

int wl_list_length(const struct wl_list *list)

Determines the length of the list.

Note

This is an O(n) operation.

Return

Number of elements in the list

Parameters

list: List whose length is to be determined

int wl_list_empty(const struct wl_list *list)

Determines if the list is empty.

Return

1 if empty, or 0 if not empty

Parameters

list: List whose emptiness is to be determined

void wl_list_insert_list(struct wl_list *list, struct wl_list *other)

Inserts all of the elements of one list into another, after the element represented by list.

Note

This leaves other in an invalid state.

Parameters

list: List element after which the other list elements will be inserted
other: List of elements to insert

Public Members

struct wl_list *prev: Previous list element.

struct wl_list *next: Next list element.

Iterates over a list.

This macro expresses a for-each iterator for wl_list. Given a list and wl_list link member name (often named link by convention), this macro assigns each element in the list to pos, which can then be referenced in a trailing code block. For example, given a wl_list of struct message elements:

struct message {
        char *contents;
        wl_list link;
};

struct wl_list *message_list;
// Assume message_list now "contains" many messages

struct message *m;
wl_list_for_each(m, message_list, link) {
        do_something_with_message(m);
}

Parameters

pos: Cursor that each list element will be assigned to
head: Head of the list to iterate over
member: Name of the link member within the element struct

wl_list_for_each_safe(pos, tmp, head, member)¶

Iterates over a list, safe against removal of the list element.

Note

Only removal of the current element, pos, is safe. Removing any other element during traversal may lead to a loop malfunction.

See

wl_list_for_each()

Parameters

pos: Cursor that each list element will be assigned to
tmp: Temporary pointer of the same type as pos
head: Head of the list to iterate over
member: Name of the link member within the element struct

wl_list_for_each_reverse(pos, head, member)¶

Iterates backwards over a list.

See

wl_list_for_each()

Parameters

pos: Cursor that each list element will be assigned to
head: Head of the list to iterate over
member: Name of the link member within the element struct

wl_list_for_each_reverse_safe(pos, tmp, head, member)¶

Iterates backwards over a list, safe against removal of the list element.

Note

Only removal of the current element, pos, is safe. Removing any other element during traversal may lead to a loop malfunction.

See

wl_list_for_each()

Parameters

pos: Cursor that each list element will be assigned to
tmp: Temporary pointer of the same type as pos
head: Head of the list to iterate over
member: Name of the link member within the element struct

class wl_listener¶

#include <wayland-server-core.h>

A single listener for Wayland signals.

wl_listener provides the means to listen for wl_signal notifications. Many Wayland objects use wl_listener for notification of significant events like object destruction.

Clients should create wl_listener objects manually and can register them as listeners to signals using wl_signal_add, assuming the signal is directly accessible. For opaque structs like wl_event_loop, adding a listener should be done through provided accessor methods. A listener can only listen to one signal at a time.

struct wl_listener your_listener;

your_listener.notify = your_callback_method;

// Direct access
wl_signal_add(&some_object->destroy_signal, &your_listener);

// Accessor access
wl_event_loop *loop = ...;
wl_event_loop_add_destroy_listener(loop, &your_listener);

If the listener is part of a larger struct, wl_container_of can be used to retrieve a pointer to it:

void your_listener(struct wl_listener *listener, void *data)
{
        struct your_data *data;

        your_data = wl_container_of(listener, data, your_member_name);
}

If you need to remove a listener from a signal, use wl_list_remove().

wl_list_remove(&your_listener.link);

See: wl_signal

Public Members

struct wl_list link¶

wl_notify_func_t notify¶

struct wl_message

#include <wayland-util.h>

Protocol message signature.

A wl_message describes the signature of an actual protocol message, such as a request or event, that adheres to the Wayland protocol wire format. The protocol implementation uses a wl_message within its demarshal machinery for decoding messages between a compositor and its clients. In a sense, a wl_message is to a protocol message like a class is to an object.

The name of a wl_message is the name of the corresponding protocol message.

The signature is an ordered list of symbols representing the data types of message arguments and, optionally, a protocol version and indicators for nullability. A leading integer in the signature indicates the since version of the protocol message. A ? preceding a data type symbol indicates that the following argument type is nullable. While it is a protocol violation to send messages with non-nullable arguments set to NULL, event handlers in clients might still get called with non-nullable object arguments set to NULL. This can happen when the client destroyed the object being used as argument on its side and an event referencing that object was sent before the server knew about its destruction. As this race cannot be prevented, clients should - as a general rule - program their event handlers such that they can handle object arguments declared non-nullable being NULL gracefully.

When no arguments accompany a message, signature is an empty string.

Symbols:

i: int
u: uint
f: fixed
s: string
o: object
n: new_id
a: array
h: fd
?: following argument is nullable

While demarshaling primitive arguments is straightforward, when demarshaling messages containing object or new_id arguments, the protocol implementation often must determine the type of the object. The types of a wl_message is an array of wl_interface references that correspond to o and n arguments in signature, with NULL placeholders for arguments with non-object types.

Consider the protocol event wl_display delete_id that has a single uint argument. The wl_message is:

{ "delete_id", "u", [NULL] }

Here, the message name is "delete_id", the signature is "u", and the argument types is [NULL], indicating that the uint argument has no corresponding wl_interface since it is a primitive argument.

In contrast, consider a wl_foo interface supporting protocol request bar that has existed since version 2, and has two arguments: a uint and an object of type wl_baz_interface that may be NULL. Such a wl_message might be:

{ "bar", "2u?o", [NULL, &wl_baz_interface] }

Here, the message name is "bar", and the signature is "2u?o". Notice how the 2 indicates the protocol version, the u indicates the first argument type is uint, and the ?o indicates that the second argument is an object that may be NULL. Lastly, the argument types array indicates that no wl_interface corresponds to the first argument, while the type wl_baz_interface corresponds to the second argument.

See: wl_argument
See: wl_interface
See: Wire Format

Public Members

const char *name: Message name.

const char *signature: Message signature.

const struct wl_interface **types: Object argument interfaces.

class wl_object

#include <wayland-server.h>

A protocol object.

A wl_object is an opaque struct identifying the protocol object underlying a wl_proxy or wl_resource.

Note: Functions accessing a wl_object are not normally used by client code. Clients should normally use the higher level interface generated by the scanner to interact with compositor objects.

Public Members

const struct wl_interface *interface¶

const void *implementation¶

uint32_t id¶

struct wl_protocol_logger¶

Public Functions

void wl_protocol_logger_destroy(struct wl_protocol_logger *logger)¶

Destroys a protocol logger.

This function destroys a protocol logger and removes it from the display it was added to with wl_display_add_protocol_logger. The logger object becomes invalid after calling this function.

See: wl_display_add_protocol_logger

Public Members

struct wl_list link¶

wl_protocol_logger_func_t func¶

void *user_data¶

struct wl_protocol_logger_message¶

#include <wayland-server-core.h>

Public Members

struct wl_resource *resource¶

int message_opcode¶

const struct wl_message *message¶

int arguments_count¶

const union wl_argument *arguments¶

struct wl_resource¶

#include <wayland-server.h>

Public Functions

const char *wl_resource_get_class(struct wl_resource *resource)¶

Retrieve the interface name (class) of a resource object.

Parameters

resource: The resource object

struct wl_resource *wl_resource_create(struct wl_client *client, const struct wl_interface *interface, int version, uint32_t id)¶

Create a new resource object.

Listeners added with

wl_client_add_resource_created_listener will be notified at the end of this function.

Parameters

client: The client owner of the new resource.
interface: The interface of the new resource.
version: The version of the new resource.
id: The id of the new resource. If 0, an available id will be used.

Public Members

struct wl_object object¶

wl_resource_destroy_func_t destroy¶

struct wl_list link¶

struct wl_signal deprecated_destroy_signal¶

struct wl_client *client¶

void *data¶

int version¶

wl_dispatcher_func_t dispatcher¶

struct wl_priv_signal destroy_signal¶

struct wl_signal destroy_signal

struct wl_resource_iterator_context¶

Public Members

void *user_data¶

wl_client_for_each_resource_iterator_func_t it¶

struct wl_shm_buffer¶

Public Functions

void *wl_shm_buffer_get_data(struct wl_shm_buffer *buffer)¶

Get a pointer to the memory for the SHM buffer.

Returns a pointer which can be used to read the data contained in the given SHM buffer.

Parameters

buffer: The buffer object

As this buffer is memory-mapped, reading from it may generate SIGBUS signals. This can happen if the client claims that the buffer is larger than it is or if something truncates the underlying file. To prevent this signal from causing the compositor to crash you should call wl_shm_buffer_begin_access and wl_shm_buffer_end_access around code that reads from the memory.

struct wl_shm_pool *wl_shm_buffer_ref_pool(struct wl_shm_buffer *buffer)¶

Get a reference to a shm_buffer’s shm_pool.

Returns a pointer to a buffer’s shm_pool and increases the shm_pool refcount.

Parameters

buffer: The buffer object

The compositor must remember to call wl_shm_pool_unref when it no longer needs the reference to ensure proper destruction of the pool.

See: wl_shm_pool_unref

void wl_shm_buffer_begin_access(struct wl_shm_buffer *buffer)¶

Mark that the given SHM buffer is about to be accessed.

An SHM buffer is a memory-mapped file given by the client. According to POSIX, reading from a memory-mapped region that extends off the end of the file will cause a SIGBUS signal to be generated. Normally this would cause the compositor to terminate. In order to make the compositor robust against clients that change the size of the underlying file or lie about its size, you should protect access to the buffer by calling this function before reading from the memory and call wl_shm_buffer_end_access afterwards. This will install a signal handler for SIGBUS which will prevent the compositor from crashing.

Parameters

buffer: The SHM buffer

After calling this function the signal handler will remain installed for the lifetime of the compositor process. Note that this function will not work properly if the compositor is also installing its own handler for SIGBUS.

If a SIGBUS signal is received for an address within the range of the SHM pool of the given buffer then the client will be sent an error event when wl_shm_buffer_end_access is called. If the signal is for an address outside that range then the signal handler will reraise the signal which would will likely cause the compositor to terminate.

It is safe to nest calls to these functions as long as the nested calls are all accessing the same buffer. The number of calls to wl_shm_buffer_end_access must match the number of calls to wl_shm_buffer_begin_access. These functions are thread-safe and it is allowed to simultaneously access different buffers or the same buffer from multiple threads.

void wl_shm_buffer_end_access(struct wl_shm_buffer *buffer)¶

Ends the access to a buffer started by wl_shm_buffer_begin_access.

This should be called after wl_shm_buffer_begin_access once the buffer is no longer being accessed. If a SIGBUS signal was generated in-between these two calls then the resource for the given buffer will be sent an error.

Parameters

buffer: The SHM buffer

Public Members

struct wl_resource *resource¶

int32_t width¶

int32_t height¶

int32_t stride¶

uint32_t format¶

int offset¶

struct wl_shm_pool *pool¶

struct wl_shm_pool¶

Public Functions

void wl_shm_pool_unref(struct wl_shm_pool *pool)¶

Unreference a shm_pool.

Drops a reference to a

wl_shm_pool object.

Parameters

pool: The pool object

This is only necessary if the compositor has explicitly taken a reference with wl_shm_buffer_ref_pool(), otherwise the pool will be automatically destroyed when appropriate.

See: wl_shm_buffer_ref_pool

Public Members

struct wl_resource *resource¶

int internal_refcount¶

int external_refcount¶

char *data¶

int32_t size¶

int32_t new_size¶

struct wl_shm_sigbus_data¶

Public Members

struct wl_shm_pool *current_pool¶

int access_count¶

int fallback_mapping_used¶

class wl_signal¶

#include <wayland-server-core.h>

A source of a type of observable event.

Signals are recognized points where significant events can be observed. Compositors as well as the server can provide signals. Observers are wl_listener’s that are added through wl_signal_add. Signals are emitted using wl_signal_emit, which will invoke all listeners until that listener is removed by wl_list_remove() (or whenever the signal is destroyed).

See: wl_listener for more information on using wl_signal

Public Functions

static void wl_signal_init(struct wl_signal *signal)¶

Initialize a new wl_signal for use.

Parameters

signal: The signal that will be initialized

static void wl_signal_add(struct wl_signal *signal, struct wl_listener *listener)¶

Add the specified listener to this signal.

Parameters

signal: The signal that will emit events to the listener
listener: The listener to add

static struct wl_listener *wl_signal_get(struct wl_signal *signal, wl_notify_func_t notify)¶

Gets the listener struct for the specified callback.

Return

the list item that corresponds to the specified listener, or NULL if none was found

Parameters

signal: The signal that contains the specified listener
notify: The listener that is the target of this search

static void wl_signal_emit(struct wl_signal *signal, void *data)¶

Emits this signal, notifying all registered listeners.

Parameters

signal: The signal object that will emit the signal
data: The data that will be emitted with the signal

Public Members

struct wl_list listener_list¶

struct wl_socket¶

Public Members

int fd¶

int fd_lock¶

struct sockaddr_un addr¶

char lock_addr[UNIX_PATH_MAX + LOCK_SUFFIXLEN]¶

struct wl_list link¶

struct wl_event_source *source¶

char *display_name¶

file event-loop.c

#include <stddef.h>#include <stdio.h>#include <errno.h>#include <signal.h>#include <stdlib.h>#include <stdint.h>#include <stdbool.h>#include <string.h>#include <fcntl.h>#include <sys/socket.h>#include <sys/un.h>#include <sys/epoll.h>#include <sys/signalfd.h>#include <sys/timerfd.h>#include <unistd.h>#include “wayland-util.h”#include “wayland-private.h”#include <stdarg.h>#include “/home/mvlad/src/wayland/src/wayland-server-core.h”#include “wayland-os.h”

Functions

static int wl_event_source_fd_dispatch(struct wl_event_source *source, struct epoll_event *ep)¶

static struct wl_event_source *add_source(struct wl_event_loop *loop, struct wl_event_source *source, uint32_t mask, void *data)¶

static int wl_event_source_timer_dispatch(struct wl_event_source *source, struct epoll_event *ep)¶

static int wl_event_source_signal_dispatch(struct wl_event_source *source, struct epoll_event *ep)¶

static void wl_event_loop_process_destroy_list(struct wl_event_loop *loop)¶

static bool post_dispatch_check(struct wl_event_loop *loop)¶

Variables

struct wl_event_source_interface fd_source_interface = {wl_event_source_fd_dispatch}¶

struct wl_event_source_interface timer_source_interface = {wl_event_source_timer_dispatch}¶

struct wl_event_source_interface signal_source_interface = {wl_event_source_signal_dispatch,}¶

struct wl_event_source_interface idle_source_interface = { NULL,}¶

file wayland-server-core.h

#include <sys/types.h>#include <stdint.h>#include <stdbool.h>#include “wayland-util.h”#include “wayland-version.h”

Defines

wl_client_for_each(client, list)¶: Iterate over a list of clients.

wl_resource_for_each(resource, list)¶

wl_resource_for_each_safe(resource, tmp, list)¶

Typedefs

typedef void (*wl_notify_func_t)(struct wl_listener *listener, void *data)¶

typedef void (*wl_global_bind_func_t)(struct wl_client *client, void *data, uint32_t version, uint32_t id)¶

typedef bool (*wl_display_global_filter_func_t)(const struct wl_client *client, const struct wl_global *global, void *data)¶

A filter function for wl_global objects.

A filter function enables the server to decide which globals to advertise to each client.

Parameters

client: The client object
global: The global object to show or hide
data: The user data pointer

When a wl_global filter is set, the given callback funtion will be called during wl_global advertisment and binding.

This function should return true if the global object should be made visible to the client or false otherwise.

typedef enum wl_iterator_result (*wl_client_for_each_resource_iterator_func_t)(struct wl_resource *resource, void *user_data)¶

typedef void (*wl_resource_destroy_func_t)(struct wl_resource *resource)¶

typedef void (*wl_protocol_logger_func_t)(void *user_data, enum wl_protocol_logger_type direction, const struct wl_protocol_logger_message *message)¶

Enums

enum [anonymous]¶

Values:

WL_EVENT_READABLE = 0x01¶

WL_EVENT_WRITABLE = 0x02¶

WL_EVENT_HANGUP = 0x04¶

enum wl_protocol_logger_type¶

Values:

WL_PROTOCOL_LOGGER_REQUEST¶

WL_PROTOCOL_LOGGER_EVENT¶

Functions

struct wl_event_loop *wl_event_loop_create(void)

void wl_event_loop_destroy(struct wl_event_loop *loop)

struct wl_event_source *wl_event_loop_add_fd(struct wl_event_loop *loop, int fd, uint32_t mask, wl_event_loop_fd_func_t func, void *data)

int wl_event_source_fd_update(struct wl_event_source *source, uint32_t mask)

struct wl_event_source *wl_event_loop_add_timer(struct wl_event_loop *loop, wl_event_loop_timer_func_t func, void *data)

struct wl_event_source *wl_event_loop_add_signal(struct wl_event_loop *loop, int signal_number, wl_event_loop_signal_func_t func, void *data)

int wl_event_source_timer_update(struct wl_event_source *source, int ms_delay)

int wl_event_source_remove(struct wl_event_source *source)

void wl_event_source_check(struct wl_event_source *source)

int wl_event_loop_dispatch(struct wl_event_loop *loop, int timeout)

void wl_event_loop_dispatch_idle(struct wl_event_loop *loop)

struct wl_event_source *wl_event_loop_add_idle(struct wl_event_loop *loop, wl_event_loop_idle_func_t func, void *data)

int wl_event_loop_get_fd(struct wl_event_loop *loop)

void wl_event_loop_add_destroy_listener(struct wl_event_loop *loop, struct wl_listener *listener)

struct wl_listener *wl_event_loop_get_destroy_listener(struct wl_event_loop *loop, wl_notify_func_t notify)

struct wl_display *wl_display_create(void)

void wl_display_destroy(struct wl_display *display)

struct wl_event_loop *wl_display_get_event_loop(struct wl_display *display)¶

int wl_display_add_socket(struct wl_display *display, const char *name)

const char *wl_display_add_socket_auto(struct wl_display *display)¶

int wl_display_add_socket_fd(struct wl_display *display, int sock_fd)

void wl_display_terminate(struct wl_display *display)¶

void wl_display_run(struct wl_display *display)¶

void wl_display_flush_clients(struct wl_display *display)¶

void wl_display_destroy_clients(struct wl_display *display)

uint32_t wl_display_get_serial(struct wl_display *display)

uint32_t wl_display_next_serial(struct wl_display *display)

void wl_display_add_destroy_listener(struct wl_display *display, struct wl_listener *listener)¶

void wl_display_add_client_created_listener(struct wl_display *display, struct wl_listener *listener)¶

Registers a listener for the client connection signal.

When a new client object is created, listener will be notified, carrying a pointer to the new wl_client object.

wl_client_create wl_display wl_listener

Parameters

display: The display object
listener: Signal handler object

struct wl_listener *wl_display_get_destroy_listener(struct wl_display *display, wl_notify_func_t notify)¶

struct wl_global *wl_global_create(struct wl_display *display, const struct wl_interface *interface, int version, void *data, wl_global_bind_func_t bind)¶

void wl_global_destroy(struct wl_global *global)¶

void wl_display_set_global_filter(struct wl_display *display, wl_display_global_filter_func_t filter, void *data)

const struct wl_interface *wl_global_get_interface(const struct wl_global *global)¶

void *wl_global_get_user_data(const struct wl_global *global)¶

struct wl_client *wl_client_create(struct wl_display *display, int fd)

struct wl_list *wl_display_get_client_list(struct wl_display *display)

struct wl_list *wl_client_get_link(struct wl_client *client)

struct wl_client *wl_client_from_link(struct wl_list *link)

void wl_client_destroy(struct wl_client *client)¶

void wl_client_flush(struct wl_client *client)

void wl_client_get_credentials(struct wl_client *client, pid_t *pid, uid_t *uid, gid_t *gid)

int wl_client_get_fd(struct wl_client *client)

void wl_client_add_destroy_listener(struct wl_client *client, struct wl_listener *listener)¶

struct wl_listener *wl_client_get_destroy_listener(struct wl_client *client, wl_notify_func_t notify)¶

struct wl_resource *wl_client_get_object(struct wl_client *client, uint32_t id)

void wl_client_post_no_memory(struct wl_client *client)¶

void wl_client_post_implementation_error(struct wl_client *client, const char *msg, ...)

void wl_client_add_resource_created_listener(struct wl_client *client, struct wl_listener *listener)

void wl_client_for_each_resource(struct wl_client *client, wl_client_for_each_resource_iterator_func_t iterator, void *user_data)

void wl_resource_post_event(struct wl_resource *resource, uint32_t opcode, ...)¶

void wl_resource_post_event_array(struct wl_resource *resource, uint32_t opcode, union wl_argument *args)¶

void wl_resource_queue_event(struct wl_resource *resource, uint32_t opcode, ...)¶

void wl_resource_queue_event_array(struct wl_resource *resource, uint32_t opcode, union wl_argument *args)¶

void wl_resource_post_error(struct wl_resource *resource, uint32_t code, const char *msg, ...)¶

void wl_resource_post_no_memory(struct wl_resource *resource)¶

struct wl_display *wl_client_get_display(struct wl_client *client)

struct wl_resource *wl_resource_create(struct wl_client *client, const struct wl_interface *interface, int version, uint32_t id)

void wl_resource_set_implementation(struct wl_resource *resource, const void *implementation, void *data, wl_resource_destroy_func_t destroy)¶

void wl_resource_set_dispatcher(struct wl_resource *resource, wl_dispatcher_func_t dispatcher, const void *implementation, void *data, wl_resource_destroy_func_t destroy)¶

void wl_resource_destroy(struct wl_resource *resource)¶

uint32_t wl_resource_get_id(struct wl_resource *resource)¶

struct wl_list *wl_resource_get_link(struct wl_resource *resource)¶

struct wl_resource *wl_resource_from_link(struct wl_list *resource)¶

struct wl_resource *wl_resource_find_for_client(struct wl_list *list, struct wl_client *client)¶

struct wl_client *wl_resource_get_client(struct wl_resource *resource)¶

void wl_resource_set_user_data(struct wl_resource *resource, void *data)¶

void *wl_resource_get_user_data(struct wl_resource *resource)¶

int wl_resource_get_version(struct wl_resource *resource)¶

void wl_resource_set_destructor(struct wl_resource *resource, wl_resource_destroy_func_t destroy)¶

int wl_resource_instance_of(struct wl_resource *resource, const struct wl_interface *interface, const void *implementation)¶

const char *wl_resource_get_class(struct wl_resource *resource)

void wl_resource_add_destroy_listener(struct wl_resource *resource, struct wl_listener *listener)¶

struct wl_listener *wl_resource_get_destroy_listener(struct wl_resource *resource, wl_notify_func_t notify)¶

struct wl_shm_buffer *wl_shm_buffer_get(struct wl_resource *resource)¶

void wl_shm_buffer_begin_access(struct wl_shm_buffer *buffer)

void wl_shm_buffer_end_access(struct wl_shm_buffer *buffer)

void *wl_shm_buffer_get_data(struct wl_shm_buffer *buffer)

int32_t wl_shm_buffer_get_stride(struct wl_shm_buffer *buffer)¶

uint32_t wl_shm_buffer_get_format(struct wl_shm_buffer *buffer)¶

int32_t wl_shm_buffer_get_width(struct wl_shm_buffer *buffer)¶

int32_t wl_shm_buffer_get_height(struct wl_shm_buffer *buffer)¶

struct wl_shm_pool *wl_shm_buffer_ref_pool(struct wl_shm_buffer *buffer)

void wl_shm_pool_unref(struct wl_shm_pool *pool)

int wl_display_init_shm(struct wl_display *display)¶

uint32_t *wl_display_add_shm_format(struct wl_display *display, uint32_t format)

struct wl_shm_buffer *wl_shm_buffer_create(struct wl_client *client, uint32_t id, int32_t width, int32_t height, int32_t stride, uint32_t format)¶

void wl_log_set_handler_server(wl_log_func_t handler)¶

struct wl_protocol_logger *wl_display_add_protocol_logger(struct wl_display *display, wl_protocol_logger_func_t, void *user_data)

void wl_protocol_logger_destroy(struct wl_protocol_logger *logger)

file wayland-server.c

#include <stdlib.h>#include <stdint.h>#include <stddef.h>#include <stdio.h>#include <stdarg.h>#include <stdbool.h>#include <errno.h>#include <string.h>#include <unistd.h>#include <sys/socket.h>#include <sys/un.h>#include <dlfcn.h>#include <assert.h>#include <sys/time.h>#include <fcntl.h>#include <sys/file.h>#include <sys/stat.h>#include “wayland-util.h”#include “wayland-private.h”#include “wayland-server.h”#include “wayland-os.h”

Defines

_GNU_SOURCE¶

UNIX_PATH_MAX¶

LOCK_SUFFIX¶

LOCK_SUFFIXLEN¶

Functions

static void log_closure(struct wl_resource *resource, struct wl_closure *closure, int send)¶

static bool verify_objects(struct wl_resource *resource, uint32_t opcode, union wl_argument *args)¶

static void handle_array(struct wl_resource *resource, uint32_t opcode, union wl_argument *args, int (*send_func)(struct wl_closure *, struct wl_connection *))¶

void wl_resource_post_event_array(struct wl_resource *resource, uint32_t opcode, union wl_argument *args)

void wl_resource_post_event(struct wl_resource *resource, uint32_t opcode, ...)

void wl_resource_queue_event_array(struct wl_resource *resource, uint32_t opcode, union wl_argument *args)

void wl_resource_queue_event(struct wl_resource *resource, uint32_t opcode, ...)

static void wl_resource_post_error_vargs(struct wl_resource *resource, uint32_t code, const char *msg, va_list argp)¶

void wl_resource_post_error(struct wl_resource *resource, uint32_t code, const char *msg, ...)

static void destroy_client_with_error(struct wl_client *client, const char *reason)¶

static int wl_client_connection_data(int fd, uint32_t mask, void *data)¶

static int bind_display(struct wl_client *client, struct wl_display *display)¶

void wl_client_post_no_memory(struct wl_client *client)

void wl_resource_post_no_memory(struct wl_resource *resource)

static bool resource_is_deprecated(struct wl_resource *resource)¶

Detect if a wl_resource uses the deprecated public definition.

Before Wayland 1.2.0, the definition of struct wl_resource was public. It was made opaque just before 1.2.0, and later new fields were added. The new fields cannot be accessed if a program is using the deprecated defition, as there would not be memory allocated for them.

The creation pattern for the deprecated definition was wl_resource_init() followed by wl_client_add_resource(). wl_resource_init() was an inline function and no longer exists, but binaries might still carry it. wl_client_add_resource() still exists for ABI compatiblity.

static enum wl_iterator_result destroy_resource(void *element, void *data, uint32_t flags)¶

void wl_resource_destroy(struct wl_resource *resource)

uint32_t wl_resource_get_id(struct wl_resource *resource)

struct wl_list *wl_resource_get_link(struct wl_resource *resource)

struct wl_resource *wl_resource_from_link(struct wl_list *link)

struct wl_resource *wl_resource_find_for_client(struct wl_list *list, struct wl_client *client)

struct wl_client *wl_resource_get_client(struct wl_resource *resource)

void wl_resource_set_user_data(struct wl_resource *resource, void *data)

void *wl_resource_get_user_data(struct wl_resource *resource)

int wl_resource_get_version(struct wl_resource *resource)

void wl_resource_set_destructor(struct wl_resource *resource, wl_resource_destroy_func_t destroy)

int wl_resource_instance_of(struct wl_resource *resource, const struct wl_interface *interface, const void *implementation)

void wl_resource_add_destroy_listener(struct wl_resource *resource, struct wl_listener *listener)

struct wl_listener *wl_resource_get_destroy_listener(struct wl_resource *resource, wl_notify_func_t notify)

void wl_client_add_destroy_listener(struct wl_client *client, struct wl_listener *listener)

struct wl_listener *wl_client_get_destroy_listener(struct wl_client *client, wl_notify_func_t notify)

void wl_client_destroy(struct wl_client *client)

static bool wl_global_is_visible(const struct wl_client *client, const struct wl_global *global)¶

static void registry_bind(struct wl_client *client, struct wl_resource *resource, uint32_t name, const char *interface, uint32_t version, uint32_t id)¶

static void display_sync(struct wl_client *client, struct wl_resource *resource, uint32_t id)¶

static void unbind_resource(struct wl_resource *resource)¶

static void display_get_registry(struct wl_client *client, struct wl_resource *resource, uint32_t id)¶

static void destroy_client_display_resource(struct wl_resource *resource)¶

static void wl_socket_destroy(struct wl_socket *s)¶

static struct wl_socket *wl_socket_alloc(void)¶

struct wl_global *wl_global_create(struct wl_display *display, const struct wl_interface *interface, int version, void *data, wl_global_bind_func_t bind)

void wl_global_destroy(struct wl_global *global)

const struct wl_interface *wl_global_get_interface(const struct wl_global *global)

void *wl_global_get_user_data(const struct wl_global *global)

struct wl_event_loop *wl_display_get_event_loop(struct wl_display *display)

void wl_display_terminate(struct wl_display *display)

void wl_display_run(struct wl_display *display)

void wl_display_flush_clients(struct wl_display *display)

static int socket_data(int fd, uint32_t mask, void *data)¶

static int wl_socket_lock(struct wl_socket *socket)¶

static int wl_socket_init_for_display_name(struct wl_socket *s, const char *name)¶

static int _wl_display_add_socket(struct wl_display *display, struct wl_socket *s)¶

const char *wl_display_add_socket_auto(struct wl_display *display)

void wl_display_add_destroy_listener(struct wl_display *display, struct wl_listener *listener)

void wl_display_add_client_created_listener(struct wl_display *display, struct wl_listener *listener)

Registers a listener for the client connection signal.

When a new client object is created, listener will be notified, carrying a pointer to the new wl_client object.

wl_client_create wl_display wl_listener

Parameters

display: The display object
listener: Signal handler object

struct wl_listener *wl_display_get_destroy_listener(struct wl_display *display, wl_notify_func_t notify)

void wl_resource_set_implementation(struct wl_resource *resource, const void *implementation, void *data, wl_resource_destroy_func_t destroy)

void wl_resource_set_dispatcher(struct wl_resource *resource, wl_dispatcher_func_t dispatcher, const void *implementation, void *data, wl_resource_destroy_func_t destroy)

void wl_log_set_handler_server(wl_log_func_t handler)

static enum wl_iterator_result resource_iterator_helper(void *res, void *user_data, uint32_t flags)¶

Variables

int debug_server = 0¶

const struct wl_registry_interface registry_interface = {registry_bind}¶

const struct wl_display_interface display_interface = {display_sync,display_get_registry}¶

file wayland-server.h

#include <stdint.h>#include “wayland-server-core.h”#include “wayland-server-protocol.h”

Include the server API, deprecations and protocol C API.

Warning: Use of this header file is discouraged. Prefer including wayland-server-core.h instead, which does not include the server protocol header and as such only defines the library API, excluding the deprecated API below.

Functions

uint32_t wl_client_add_resource(struct wl_client *client, struct wl_resource *resource)¶

struct wl_resource *wl_client_add_object(struct wl_client *client, const struct wl_interface *interface, const void *implementation, uint32_t id, void *data)¶

struct wl_resource *wl_client_new_object(struct wl_client *client, const struct wl_interface *interface, const void *implementation, void *data)¶

struct wl_global *wl_display_add_global(struct wl_display *display, const struct wl_interface *interface, void *data, wl_global_bind_func_t bind)¶

void wl_display_remove_global(struct wl_display *display, struct wl_global *global)¶

file wayland-shm.c

#include <stdbool.h>#include <stdio.h>#include <stdlib.h>#include <stdint.h>#include <string.h>#include <sys/mman.h>#include <unistd.h>#include <assert.h>#include <signal.h>#include <pthread.h>#include <errno.h>#include “wayland-util.h”#include “wayland-private.h”#include “wayland-server.h”

Defines

_GNU_SOURCE

Functions

static void shm_pool_finish_resize(struct wl_shm_pool *pool)¶

static void shm_pool_unref(struct wl_shm_pool *pool, bool external)¶

static void destroy_buffer(struct wl_resource *resource)¶

static void shm_buffer_destroy(struct wl_client *client, struct wl_resource *resource)¶

static bool format_is_supported(struct wl_client *client, uint32_t format)¶

static void shm_pool_create_buffer(struct wl_client *client, struct wl_resource *resource, uint32_t id, int32_t offset, int32_t width, int32_t height, int32_t stride, uint32_t format)¶

static void destroy_pool(struct wl_resource *resource)¶

static void shm_pool_destroy(struct wl_client *client, struct wl_resource *resource)¶

static void shm_pool_resize(struct wl_client *client, struct wl_resource *resource, int32_t size)¶

static void shm_create_pool(struct wl_client *client, struct wl_resource *resource, uint32_t id, int fd, int32_t size)¶

static void bind_shm(struct wl_client *client, void *data, uint32_t version, uint32_t id)¶

int wl_display_init_shm(struct wl_display *display)

struct wl_shm_buffer *wl_shm_buffer_get(struct wl_resource *resource)

int32_t wl_shm_buffer_get_stride(struct wl_shm_buffer *buffer)

uint32_t wl_shm_buffer_get_format(struct wl_shm_buffer *buffer)

int32_t wl_shm_buffer_get_width(struct wl_shm_buffer *buffer)

int32_t wl_shm_buffer_get_height(struct wl_shm_buffer *buffer)

static void reraise_sigbus(void)¶

static void sigbus_handler(int signum, siginfo_t *info, void *context)¶

static void destroy_sigbus_data(void *data)¶

static void init_sigbus_data_key(void)¶

Variables

pthread_once_t wl_shm_sigbus_once = PTHREAD_ONCE_INIT¶

pthread_key_t wl_shm_sigbus_data_key¶

struct sigaction wl_shm_old_sigbus_action¶

const struct wl_buffer_interface shm_buffer_interface = {shm_buffer_destroy}¶

const struct wl_shm_pool_interface shm_pool_interface = {shm_pool_create_buffer,shm_pool_destroy,shm_pool_resize}¶

const struct wl_shm_interface shm_interface = {shm_create_pool}¶

file wayland-util.h

#include <math.h>#include <stddef.h>#include <inttypes.h>#include <stdarg.h>

Utility classes, functions, and macros.

Defines

WL_EXPORT¶: Visibility attribute.

WL_DEPRECATED¶: Deprecated attribute.

WL_PRINTF(x, y)¶

Printf-style argument attribute.

See

https://gcc.gnu.org/onlinedocs/gcc-3.2.1/gcc/Function-Attributes.html

Parameters

x: Ordinality of the format string argument
y: Ordinality of the argument to check against the format string

wl_container_of(ptr, sample, member)¶

Retrieves a pointer to a containing struct, given a member name.

This macro allows “conversion” from a pointer to a member to its containing struct. This is useful if you have a contained item like a wl_list, wl_listener, or wl_signal, provided via a callback or other means, and would like to retrieve the struct that contains it.

To demonstrate, the following example retrieves a pointer to example_container given only its destroy_listener member:

struct example_container {
        struct wl_listener destroy_listener;
        // other members...
};

void example_container_destroy(struct wl_listener *listener, void *data)
{
        struct example_container *ctr;

        ctr = wl_container_of(listener, ctr, destroy_listener);
        // destroy ctr...
}

Note

sample need not be a valid pointer. A null or uninitialised pointer is sufficient.

Return

The container for the specified pointer

Parameters

ptr: Valid pointer to the contained member
sample: Pointer to a struct whose type contains ptr
member: Named location of ptr within the sample type

Typedefs

typedef int32_t wl_fixed_t

Fixed-point number.

A wl_fixed_t is a 24.8 signed fixed-point number with a sign bit, 23 bits of integer precision and 8 bits of decimal precision. Consider wl_fixed_t as an opaque struct with methods that facilitate conversion to and from double and int types.

typedef int (*wl_dispatcher_func_t)(const void *, void *, uint32_t, const struct wl_message *, union wl_argument *)

Dispatcher function type alias.

A dispatcher is a function that handles the emitting of callbacks in client code. For programs directly using the C library, this is done by using libffi to call function pointers. When binding to languages other than C, dispatchers provide a way to abstract the function calling process to be friendlier to other function calling systems.

A dispatcher takes five arguments: The first is the dispatcher-specific implementation associated with the target object. The second is the object upon which the callback is being invoked (either wl_proxy or wl_resource). The third and fourth arguments are the opcode and the wl_message corresponding to the callback. The final argument is an array of arguments received from the other process via the wire protocol.

Return

0 on success, or -1 on failure

Parameters

const void *: Dispatcher-specific implementation data
void *: Callback invocation target (wl_proxy or wl_resource)
uint32_t: Callback opcode
const struct wl_message *: Callback message signature
union wl_argument *: Array of received arguments

typedef void (*wl_log_func_t)(const char *, va_list)

Log function type alias.

The C implementation of the Wayland protocol abstracts the details of logging. Users may customize the logging behavior, with a function conforming to the wl_log_func_t type, via wl_log_set_handler_client and wl_log_set_handler_server.

A wl_log_func_t must conform to the expectations of vprintf, and expects two arguments: a string to write and a corresponding variable argument list. While the string to write may contain format specifiers and use values in the variable argument list, the behavior of any wl_log_func_t depends on the implementation.

Note

Take care to not confuse this with wl_protocol_logger_func_t, which is a specific server-side logger for requests and events.

See

wl_log_set_handler_client

See

wl_log_set_handler_server

Parameters

const char *: String to write to the log, containing optional format specifiers
va_list: Variable argument list

Enums

enum wl_iterator_result

Return value of an iterator function.

See: wl_client_for_each_resource_iterator_func_t
See: wl_client_for_each_resource

Values:

WL_ITERATOR_STOP: Stop the iteration.

WL_ITERATOR_CONTINUE: Continue the iteration.

Functions

static double wl_fixed_to_double(wl_fixed_t f)

Converts a fixed-point number to a floating-point number.

Return

Floating-point representation of the fixed-point argument

Parameters

f: Fixed-point number to convert

static wl_fixed_t wl_fixed_from_double(double d)

Converts a floating-point number to a fixed-point number.

Return

Fixed-point representation of the floating-point argument

Parameters

d: Floating-point number to convert

static int wl_fixed_to_int(wl_fixed_t f)

Converts a fixed-point number to an integer.

Return

Integer component of the fixed-point argument

Parameters

f: Fixed-point number to convert

static wl_fixed_t wl_fixed_from_int(int i)

Converts an integer to a fixed-point number.

Return

Fixed-point representation of the integer argument

Parameters

i: Integer to convert

dir /home/mvlad/src/wayland/src