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+<!--
+Copyright 2018-2021 The Khronos Group Inc.
+
+SPDX-License-Identifier: CC-BY-4.0
+-->
+
+# What Happened To The Vulkan Extension Loader?
+
+If you're looking for the files vulkan_ext.[ch] in this directory, they have
+been removed. There were two significant problems with these simple
+wrappers.
+
+First, vulkan_ext exported all extension entrypoints. However, the Vulkan
+loader also exports entrypoints for the window system integration
+extensions. If someone tried to compile a project and link it to both the
+loader and vulkan_ext, they would get a bunch of redefined symbols. This
+linking error is difficult to work around, because vulkan_ext does not have
+an easy method of disabling the entrypoints at compile time. It is possible
+to remove these entrypoints when generating vulkan_ext, but even then you
+have to manually compile a list of every single extension to be disabled.
+
+Second, each entrypoint is only stored once, regardless of how many
+instances or devices are created. This means that attempting to use multiple
+instances or devices in parallel can result in one device calling function
+pointers that are only valid on the other device, which will crash. You may
+be able to work around this by never initializing the device dispatch
+(vkExtInitDevice), but we haven't tried this.
+
+It is still possible to retrieve the last versions of these files in the
+Github KhronosGroup/Vulkan-Docs repository from the 'v1.1.75' release tag.
+It is also possible to regenerate them from ../../xml/vk.xml, although we
+are no longer maintaining the generator code and it may eventually stop
+working correctly. See README.adoc and the `extloader` Makefile target in
+that directory.