vkGetPastPresentationTimingGOOGLE(3)

# vkGetPastPresentationTimingGOOGLE(3) Manual Page

## Name

vkGetPastPresentationTimingGOOGLE - Obtain timing of a previously-presented image

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## C Specification

The implementation will maintain a limited amount of history of timing information about previous presents. Because of the asynchronous nature of the presentation engine, the timing information for a given vkQueuePresentKHR command will become available some time later. These time values can be asynchronously queried, and will be returned if available. All time values are in nanoseconds, relative to a monotonically-increasing clock (e.g. `CLOCK_MONOTONIC` (see clock_gettime(2)) on Android and Linux).

To asynchronously query the presentation engine, for newly-available timing information about one or more previous presents to a given swapchain, call:

    // Provided by VK_GOOGLE_display_timing
    VkResult vkGetPastPresentationTimingGOOGLE(
        VkDevice                                    device,
        VkSwapchainKHR                              swapchain,
        uint32_t*                                   pPresentationTimingCount,
        VkPastPresentationTimingGOOGLE*             pPresentationTimings);

## Parameters

- `device` is the device associated with `swapchain`.

- `swapchain` is the swapchain to obtain presentation timing information duration for.

- `pPresentationTimingCount` is a pointer to an integer related to the number of `VkPastPresentationTimingGOOGLE` structures to query, as described below.

- `pPresentationTimings` is either `NULL` or a pointer to an array of `VkPastPresentationTimingGOOGLE` structures.

## Description

If `pPresentationTimings` is `NULL`, then the number of newly-available timing records for the given `swapchain` is returned in `pPresentationTimingCount`. Otherwise, `pPresentationTimingCount` must point to a variable set by the user to the number of elements in the `pPresentationTimings` array, and on return the variable is overwritten with the number of structures actually written to `pPresentationTimings`. If the value of `pPresentationTimingCount` is less than the number of newly-available timing records, at most `pPresentationTimingCount` structures will be written, and `VK_INCOMPLETE` will be returned instead of `VK_SUCCESS`, to indicate that not all the available timing records were returned.

Valid Usage (Implicit)

- VUID-vkGetPastPresentationTimingGOOGLE-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetPastPresentationTimingGOOGLE-swapchain-parameter
  `swapchain` must be a valid VkSwapchainKHR handle

- VUID-vkGetPastPresentationTimingGOOGLE-pPresentationTimingCount-parameter
  `pPresentationTimingCount` must be a valid pointer to a `uint32_t` value

- VUID-vkGetPastPresentationTimingGOOGLE-pPresentationTimings-parameter
  If the value referenced by `pPresentationTimingCount` is not `0`, and `pPresentationTimings` is not `NULL`, `pPresentationTimings` must be a valid pointer to an array of `pPresentationTimingCount` VkPastPresentationTimingGOOGLE structures

- VUID-vkGetPastPresentationTimingGOOGLE-swapchain-parent
  `swapchain` must have been created, allocated, or retrieved from `device`

Host Synchronization

- Host access to `swapchain` must be externally synchronized

Return Codes

On success, this command returns

  - `VK_SUCCESS`

  - `VK_INCOMPLETE`

On failure, this command returns

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

  - `VK_ERROR_DEVICE_LOST`

  - `VK_ERROR_OUT_OF_DATE_KHR`

  - `VK_ERROR_SURFACE_LOST_KHR`

## See Also

VK_GOOGLE_display_timing, VkDevice, VkPastPresentationTimingGOOGLE, VkSwapchainKHR

## Document Notes

For more information, see the Vulkan Specification

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.

## Copyright

Copyright 2014-2024 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0