---
name: "wayland_zwp_linux_surface_synchronization_v1_t"
section: "3"
platform: "linux"
package: "waylandpp-dev"
version: "1.0.0-6+b2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/wayland_zwp_linux_surface_synchronization_v1_t"
---

# wayland\_zwp\_linux\_surface\_synchronization\_v1\_t(3)

per-surface explicit synchronization support

## NAME

wayland::zwp\_linux\_surface\_synchronization\_v1\_t - per-surface explicit synchronization support

## SYNOPSIS

`#include <wayland-client-protocol-unstable.hpp>`

Inherits **wayland::proxy\_t**.

### Public Types

enum class **wrapper\_type** { **standard**, **display**, **foreign**, **proxy\_wrapper** }\

### Public Member Functions

void **set\_acquire\_fence** (int fd)\
 set the acquire fence  **zwp\_linux\_buffer\_release\_v1\_t** **get\_release** ()\
 release fence for last-attached buffer  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 **set\_acquire\_fence\_since\_version** = 1\
 Minimum protocol version required for the **set\_acquire\_fence** function.  static constexpr std::uint32\_t **get\_release\_since\_version** = 1\
 Minimum protocol version required for the **get\_release** function.

## Detailed Description

per-surface explicit synchronization support

This object implements per-surface explicit synchronization.

Synchronization refers to co-ordination of pipelined operations performed on buffers. Most GPU clients will schedule an asynchronous operation to render to the buffer, then immediately send the buffer to the compositor to be attached to a surface.

In implicit synchronization, ensuring that the rendering operation is complete before the compositor displays the buffer is an implementation detail handled by either the kernel or userspace graphics driver.

By contrast, in explicit synchronization, dma\_fence objects mark when the asynchronous operations are complete. When submitting a buffer, the client provides an acquire fence which will be waited on before the compositor accesses the buffer. The Wayland server, through a zwp\_linux\_buffer\_release\_v1 object, will inform the client with an event which may be accompanied by a release fence, when the compositor will no longer access the buffer contents due to the specific commit that requested the release event.

Each surface can be associated with only one object of this interface at any time.

In version 1 of this interface, explicit synchronization is only guaranteed to be supported for buffers created with any version of the wp\_linux\_dmabuf buffer factory. Version 2 additionally guarantees explicit synchronization support for opaque EGL buffers, which is a type of platform specific buffers described in the EGL\_WL\_bind\_wayland\_display extension. Compositors are free to support explicit synchronization for additional buffer types.

Definition at line **2246** of file **wayland-client-protocol-unstable.hpp**.

## Member Enumeration Documentation

### enum class wayland::proxy\_t::wrapper\_type` [strong]`, ` [inherited]`

Underlying wl\_proxy type and properties of a **proxy\_t** that affect construction, destruction, and event handling

**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* **116** *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.*

**Returns**

*The underlying wl\_proxy wrapped by this* **proxy\_t** *if it exists, otherwise an exception is thrown*

### 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*

### zwp\_linux\_buffer\_release\_v1\_t zwp\_linux\_surface\_synchronization\_v1\_t::get\_release ()

*release fence for last-attached buffer*

**Returns**

*new zwp\_linux\_buffer\_release\_v1 object*

*Create a listener for the release of the buffer attached by the client with wl\_surface.attach. See zwp\_linux\_buffer\_release\_v1 documentation for more information.*

*The release object is double-buffered state, and will be associated with the buffer that is attached to the surface at wl\_surface.commit time.*

*If a zwp\_linux\_buffer\_release\_v1 object has already been requested for the surface in the same commit cycle, a DUPLICATE\_RELEASE error is raised.*

*If the associated wl\_surface was destroyed, a NO\_SURFACE error is raised.*

*If at surface commit time there is no buffer attached, a NO\_BUFFER error is raised.*

*Definition at line* **5617** *of file* **wayland-client-protocol-unstable.cpp***.*

### 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.*

**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* **302** *of file* **wayland-client.hpp***.*

### wayland::proxy\_t::operator bool () const` [inherited]`

*Check whether this wrapper actually wraps an object.*

**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. Note that* **display\_t** *instances cannot be released this way. Attempts to do so are ignored.*

**Examples** **foreign\_display.cpp***.*

### void zwp\_linux\_surface\_synchronization\_v1\_t::set\_acquire\_fence (int fd)

*set the acquire fence*

**Parameters**

*fd acquire fence fd*

*Set the acquire fence that must be signaled before the compositor may sample from the buffer attached with wl\_surface.attach. The fence is a dma\_fence kernel object.*

*The acquire fence is double-buffered state, and will be applied on the next wl\_surface.commit request for the associated surface. Thus, it applies only to the buffer that is attached to the surface at commit time.*

*If the provided fd is not a valid dma\_fence fd, then an INVALID\_FENCE error is raised.*

*If a fence has already been attached during the same commit cycle, a DUPLICATE\_FENCE error is raised.*

*If the associated wl\_surface was destroyed, a NO\_SURFACE error is raised.*

*If at surface commit time the attached buffer does not support explicit synchronization, an UNSUPPORTED\_BUFFER error is raised.*

*If at surface commit time there is no buffer attached, a NO\_BUFFER error is raised.*

*Definition at line* **5611** *of file* **wayland-client-protocol-unstable.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

### constexpr std::uint32\_t wayland::zwp\_linux\_surface\_synchronization\_v1\_t::get\_release\_since\_version = 1` [static]`, ` [constexpr]`

*Minimum protocol version required for the* **get\_release** *function.*

*Definition at line* **2328** *of file* **wayland-client-protocol-unstable.hpp***.*

### constexpr std::uint32\_t wayland::zwp\_linux\_surface\_synchronization\_v1\_t::set\_acquire\_fence\_since\_version = 1` [static]`, ` [constexpr]`

*Minimum protocol version required for the* **set\_acquire\_fence** *function.*

*Definition at line* **2300** *of file* **wayland-client-protocol-unstable.hpp***.*

## Author

*Generated automatically by Doxygen for Wayland++ from the source code.*