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.adoc[] 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.adoc[] 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 applications have the tools 48they need to ensure views of images are consistent between the two 49instances. 50Other APIs will fall into two categories: Those that are Vulkan compatible 51(a term to be defined by subsequent interopability extensions), or Vulkan 52incompatible. 53When sharing images with Vulkan incompatible APIs, the Vulkan image must be 54transitioned to the ename:VK_IMAGE_LAYOUT_GENERAL layout before handing it 55off to the external API. 56 57Note this does not attempt to address cross-device transitions, nor 58transitions to engines on the same device which are not visible within the 59Vulkan API. 60Both of these are beyond the scope of this extension. 61 62=== Examples 63 64[source,c++] 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