dawn-cmake/src/dawn_native/vulkan/BindGroupLayoutVk.h
Austin Eng 642009261e Reland "Slab-allocate VkDescriptorSets"
This is a reland of 96c4019214e0b2d7c0843eacf96398a6a1198d1f

It includes a fix to add a dummy descriptor count if the
VkDescriptorPool would be empty, and adds a test that a bind group
with an empty bind group layout may be created and used.

Original change's description:
> Slab-allocate VkDescriptorSets
>
> This introduces a slab allocator for VkDescriptorSets which creates
> a VkDescriptorPool pre-allocated with multiple VkDescriptorSets per
> BindGroupLayout. In the future, we can deduplicate pools that have
> the same, or roughly the same, descriptor counts.
>
> This CL also removes the old DescriptorSetService and moves most of
> the functionality onto the DescriptorSetAllocator itself to keep
> the tracking logic in one place.
>
> Bug: dawn:340
> Change-Id: I785b17f4353fb3d40c9ccc33746600d6794efe7c
> Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/19320
> Reviewed-by: Austin Eng <enga@chromium.org>
> Commit-Queue: Austin Eng <enga@chromium.org>

Bug: dawn:340
Change-Id: Iabb744f110d0cab442bb857b31c87ba46bf0ad7a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/20321
Commit-Queue: Austin Eng <enga@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
2020-04-23 19:56:32 +00:00

75 lines
2.9 KiB
C++

// Copyright 2018 The Dawn Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef DAWNNATIVE_VULKAN_BINDGROUPLAYOUTVK_H_
#define DAWNNATIVE_VULKAN_BINDGROUPLAYOUTVK_H_
#include "dawn_native/BindGroupLayout.h"
#include "common/Serial.h"
#include "common/SlabAllocator.h"
#include "common/vulkan_platform.h"
#include <vector>
namespace dawn_native { namespace vulkan {
class BindGroup;
struct DescriptorSetAllocation;
class DescriptorSetAllocator;
class Device;
VkDescriptorType VulkanDescriptorType(wgpu::BindingType type, bool isDynamic);
// In Vulkan descriptor pools have to be sized to an exact number of descriptors. This means
// it's hard to have something where we can mix different types of descriptor sets because
// we don't know if their vector of number of descriptors will be similar.
//
// That's why that in addition to containing the VkDescriptorSetLayout to create
// VkDescriptorSets for its bindgroups, the layout also acts as an allocator for the descriptor
// sets.
//
// The allocations is done with one pool per descriptor set, which is inefficient, but at least
// the pools are reused when no longer used. Minimizing the number of descriptor pool allocation
// is important because creating them can incur GPU memory allocation which is usually an
// expensive syscall.
class BindGroupLayout final : public BindGroupLayoutBase {
public:
static ResultOrError<BindGroupLayout*> Create(Device* device,
const BindGroupLayoutDescriptor* descriptor);
BindGroupLayout(DeviceBase* device, const BindGroupLayoutDescriptor* descriptor);
VkDescriptorSetLayout GetHandle() const;
ResultOrError<BindGroup*> AllocateBindGroup(Device* device,
const BindGroupDescriptor* descriptor);
void DeallocateBindGroup(BindGroup* bindGroup,
DescriptorSetAllocation* descriptorSetAllocation);
void FinishDeallocation(Serial completedSerial);
private:
~BindGroupLayout() override;
MaybeError Initialize();
VkDescriptorSetLayout mHandle = VK_NULL_HANDLE;
SlabAllocator<BindGroup> mBindGroupAllocator;
std::unique_ptr<DescriptorSetAllocator> mDescriptorSetAllocator;
};
}} // namespace dawn_native::vulkan
#endif // DAWNNATIVE_VULKAN_BINDGROUPLAYOUTVK_H_