1// Copyright (c) 2016-2020 NVIDIA Corporation 2// 3// SPDX-License-Identifier: CC-BY-4.0 4 5include::{generated}/meta/{refprefix}VK_NV_external_memory.txt[] 6 7=== Other Extension Metadata 8 9*Last Modified Date*:: 10 2016-08-19 11*IP Status*:: 12 No known IP claims. 13*Contributors*:: 14 - James Jones, NVIDIA 15 - Carsten Rohde, NVIDIA 16 17=== Description 18 19Applications may wish to export memory to other Vulkan instances or other 20APIs, or import memory from other Vulkan instances or other APIs to enable 21Vulkan workloads to be split up across application module, process, or API 22boundaries. 23This extension enables applications to create exportable Vulkan memory 24objects such that the underlying resources can be referenced outside the 25Vulkan instance that created them. 26 27include::{generated}/interfaces/VK_NV_external_memory.txt[] 28 29=== Issues 30 311) If memory objects are shared between processes and APIs, is this 32considered aliasing according to the rules outlined in the 33<<resources-memory-aliasing,Memory Aliasing>> section? 34 35*RESOLVED*: Yes, but strict exceptions to the rules are added to allow some 36forms of aliasing in these cases. 37Further, other extensions may build upon these new aliasing rules to define 38specific support usage within Vulkan for imported native memory objects, or 39memory objects from other APIs. 40 412) Are new image layouts or metadata required to specify image layouts and 42layout transitions compatible with non-Vulkan APIs, or with other instances 43of the same Vulkan driver? 44 45*RESOLVED*: No. 46Separate instances of the same Vulkan driver running on the same GPU should 47have identical internal layout semantics, so applictions have the tools they 48need to ensure views of images are consistent between the two instances. 49Other APIs will fall into two categories: Those that are Vulkan compatible 50(a term to be defined by subsequent interopability extensions), or Vulkan 51incompatible. 52When sharing images with Vulkan incompatible APIs, the Vulkan image must be 53transitioned to the ename:VK_IMAGE_LAYOUT_GENERAL layout before handing it 54off to the external API. 55 56Note this does not attempt to address cross-device transitions, nor 57transitions to engines on the same device which are not visible within the 58Vulkan API. 59Both of these are beyond the scope of this extension. 60 61=== Examples 62 63[source,c++] 64---------------------------------------- 65 66 // TODO: Write some sample code here. 67 68---------------------------------------- 69 70=== Version History 71 72 * Revision 1, 2016-08-19 (James Jones) 73 - Initial draft 74