wayland::shm_pool_t(3)

📦
version 1.0.1 · 10 versions
, in ubuntu stonking

💖 wayland::shm_pool_t — a shared memory pool 💖

okay so this is the wayland::shm_pool_t(3) page from the Wayland++ manual — yes bestie, the <wayland-client-protocol.hpp> one, section 3, we love a reference page 🎀

✨ SYNOPSIS ✨

#include <wayland-client-protocol.hpp>

so like. it inherits wayland::proxy_t. that's the whole vibe. 🫶

🌸 Public Types 🌸

  • enum class wrapper_type { standard, display, foreign, proxy_wrapper }

🌸 Public Member Functions 🌸

  • buffer_t create_buffer (int32_t offset, int32_t width, int32_t height, int32_t stride, shm_format const &format) — create a buffer from the pool ✨
  • void resize (int32_t size) — change the size of the pool mapping
  • uint32_t get_id () const — Get the id of a proxy object.
  • std::string get_class () const — Get the interface name (class) of a proxy object.
  • uint32_t get_version () const — Get the protocol object version of a proxy object.
  • wrapper_type get_wrapper_type () const — Get the type of a proxy object.
  • void set_queue (event_queue_t queue) — Assign a proxy to an event queue.
  • wl_proxy * c_ptr () const — Get a pointer to the underlying C struct.
  • bool proxy_has_object () const — Check whether this wrapper actually wraps an object.
  • operator bool () const — Check whether this wrapper actually wraps an object.
  • bool operator== (const proxy_t &right) const — Check whether two wrappers refer to the same object.
  • bool operator!= (const proxy_t &right) const — Check whether two wrappers refer to different objects.
  • void proxy_release () — Release the wrapped object (if any), making this an empty wrapper.

🌸 Static Public Attributes 🌸

  • static constexpr std::uint32_t create_buffer_since_version = 1 — Minimum protocol version required for the create_buffer function.
  • static constexpr std::uint32_t resize_since_version = 1 — Minimum protocol version required for the resize function.

👑 Detailed Description 👑

okay so, a shared memory pool. iconic concept, honestly.

The wl_shm_pool object encapsulates a piece of memory shared between the compositor and client. Through the wl_shm_pool object, the client can allocate shared memory wl_buffer objects. All objects created through the same pool share the same underlying mapped memory. Reusing that mapped memory avoids the setup/teardown overhead and is super useful when you're interactively resizing a surface or when you've got a million tiny buffers. literal lifesaver energy 💅

Definition at line 313 of file wayland-client-protocol.hpp.

🦋 Member Enumeration Documentation 🦋

enum class wayland::proxy_t::wrapper_type [strong], [inherited]

bestie this enum tells you what an underlying wl_proxy actually is, and which properties of a proxy_t matter for construction, destruction, and event handling. very much a vibe check for your pointer 🔥

Enumerator

  • standard — C pointer is a standard type compatible with wl_proxy*. Events are dispatched and it is destructed when the proxy_t is destructed. User data is set.
  • display — C pointer is a wl_display*. No events are dispatched, wl_display_disconnect is called when the proxy_t is destructed. User data is set.
  • foreign — C pointer is a standard type compatible with wl_proxy*, but another library owns it and it should not be touched in a way that could affect the operation of the other library. No events are dispatched, wl_proxy_destroy is not called when the proxy_t is destructed, user data is not touched. Consequently, there is no reference counting for the proxy_t. Lifetime of such wrappers should preferably be short to minimize the chance that the owning library decides to destroy the wl_proxy.
  • proxy_wrapper — C pointer is a wl_proxy* that was constructed with wl_proxy_create_wrapper. No events are dispatched, wl_proxy_wrapper_destroy is called when the proxy_t is destroyed. Reference counting is active. A reference to the proxy_t creating this proxy wrapper is held to extend its lifetime until after the proxy wrapper is destroyed.

Definition at line 117 of file wayland-client.hpp.

💜 Member Function Documentation 💜

wl_proxy * wayland::proxy_t::c_ptr () const [inherited]

Get a pointer to the underlying C struct. Gimme the raw thing 🔍

Returns The underlying wl_proxy wrapped by this proxy_t if it exists, otherwise an exception is thrown 😭 (yes, an actual exception, not a null, be careful)

buffer_t shm_pool_t::create_buffer (int32_t offset, int32_t width, int32_t height, int32_t stride, shm_format const & format)

create a buffer from the pool ✨ the main character function of this whole page ngl

Returns buffer to create

Parameters

  • offset — buffer byte offset within the pool
  • width — buffer width, in pixels
  • height — buffer height, in pixels
  • stride — number of bytes from the beginning of one row to the beginning of the next row
  • format — buffer pixel format

Create a wl_buffer object from the pool.

The buffer is created offset bytes into the pool and has width and height as specified. The stride argument specifies the number of bytes from the beginning of one row to the beginning of the next. The format is the pixel format of the buffer and must be one of those advertised through the wl_shm.format event. no making up formats, bestie, i'm serious 🙈

💖 cute detail: a buffer will keep a reference to the pool it was created from, so it's totally valid to destroy the pool immediately after creating a buffer from it. slay.

Definition at line 1816 of file wayland-client-protocol.cpp.

std::string wayland::proxy_t::get_class () const [inherited]

Get the interface name (class) of a proxy object.

Returns The interface name of the object associated with the proxy

uint32_t wayland::proxy_t::get_id () const [inherited]

Get the id of a proxy object.

Returns The id the object associated with the proxy

uint32_t wayland::proxy_t::get_version () const [inherited]

Get the protocol object version of a proxy object. Gets the protocol object version of a proxy object, or 0 if the proxy was created with unversioned API.

A returned value of 0 means that no version information is available, so the caller must make safe assumptions about the object's real version. don't go assuming things, ok? 🫶

display_t will always return version 0.

Returns The protocol object version of the proxy or 0

wrapper_type wayland::proxy_t::get_wrapper_type () const [inline], [inherited]

Get the type of a proxy object.

Definition at line 303 of file wayland-client.hpp.

wayland::proxy_t::operator bool () const [inherited]

Check whether this wrapper actually wraps an object. the "is there anything in here" check 🎀

Returns true if there is an underlying object, false if this wrapper is empty

bool wayland::proxy_t::operator!= (const proxy_t & right) const [inherited]

Check whether two wrappers refer to different objects.

bool wayland::proxy_t::operator== (const proxy_t & right) const [inherited]

Check whether two wrappers refer to the same object.

bool wayland::proxy_t::proxy_has_object () const [inherited]

Check whether this wrapper actually wraps an object.

Returns true if there is an underlying object, false if this wrapper is empty

void wayland::proxy_t::proxy_release () [inherited]

Release the wrapped object (if any), making this an empty wrapper. 🫧

⚠️ heads up: note that display_t instances cannot be released this way. Attempts to do so are ignored. literally just ignored, no error, no nothing. 💀

Examples foreign_display.cpp.

void shm_pool_t::resize (int32_t size)

change the size of the pool mapping

Parameters

  • size — new size of the pool, in bytes

This request will cause the server to remap the backing memory for the pool from the file descriptor passed when the pool was created, but using the new size. This request can only be used to make the pool bigger. (no shrinking, bestie, it's giving one-way street 🚫)

🔥 important: this request only changes the amount of bytes that are mmapped by the server and does not touch the file corresponding to the file descriptor passed at creation time. It is the client's responsibility to ensure that the file is at least as big as the new pool size. like, that's on you fr fr.

Definition at line 1823 of file wayland-client-protocol.cpp.

void wayland::proxy_t::set_queue (event_queue_t queue) [inherited]

Assign a proxy to an event queue.

Parameters

  • queue — The event queue that will handle this proxy

Assign proxy to event queue. Events coming from proxy will be queued in queue instead of the display's main queue.

See also: display_t::dispatch_queue().

Examples proxy_wrapper.cpp.

🍓 Member Data Documentation 🍓

std::uint32_t wayland::shm_pool_t::create_buffer_since_version = 1 [static], [constexpr]

Minimum protocol version required for the create_buffer function.

Definition at line 360 of file wayland-client-protocol.hpp.

std::uint32_t wayland::shm_pool_t::resize_since_version = 1 [static], [constexpr]

Minimum protocol version required for the resize function.

Definition at line 381 of file wayland-client-protocol.hpp.

🌈 Author 🌈

Generated automatically by Doxygen for Wayland++ from the source code. (not a human, not a bestie, just doxygen doing its thing 🤖)

✨ and that's the whole page!! ✨ this was Version 1.0.1, dated Fri Mar 27 2026 13:15:00, from the wayland::shm_pool_t(3) girlies at Wayland++ — love u, go make some buffers 💖🎀🦋

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