vkWaitForPresentKHR

When the presentWait feature is enabled, an application can wait for an image to be presented to the user by first specifying a presentId for the target presentation by adding a VkPresentIdKHR structure to the pNext chain of the VkPresentInfoKHR structure and then waiting for that presentation to complete by calling:

VkResult vkWaitForPresentKHR(
    VkDevice device,
    VkSwapchainKHR swapchain,
    uint64_t presentId,
    uint64_t timeout);

• device is the device associated with swapchain.
• swapchain is the non-retired swapchain on which an image was queued for presentation.
• presentId is the presentation presentId to wait for.
• timeout is the timeout period in units of nanoseconds. timeout is adjusted to the closest value allowed by the implementation-dependent timeout accuracy, which may be substantially longer than one nanosecond, and may be longer than the requested period.

vkWaitForPresentKHR waits for the presentId associated with swapchain to be increased in value so that it is at least equal to presentId.

For VK_PRESENT_MODE_MAILBOX_KHR (or other present mode where images may be replaced in the presentation queue) any wait of this type associated with such an image must be signaled no later than a wait associated with the replacing image would be signaled.

When the presentation has completed, the presentId associated with the related pSwapchains entry will be increased in value so that it is at least equal to the value provided in the VkPresentIdKHR structure.

There is no requirement for any precise timing relationship between the presentation of the image to the user and the update of the presentId value, but implementations should make this as close as possible to the presentation of the first pixel in the next image being presented to the user.

The call to vkWaitForPresentKHR will block until either the presentId associated with swapchain is greater than or equal to presentId, or timeout nanoseconds passes. When the swapchain becomes OUT_OF_DATE, the call will either return VK_SUCCESS (if the image was delivered to the presentation engine and may have been presented to the user) or will return early with status VK_ERROR_OUT_OF_DATE_KHR (if the image was not presented to the user).

As an exception to the normal rules for objects which are externally synchronized, the swapchain passed to vkWaitForPresentKHR may be simultaneously used by other threads in calls to functions other than vkDestroySwapchainKHR. Access to the swapchain data associated with this extension must be atomic within the implementation.