Branch
-
Show log
Commit
-
Hash : 0b9caaf7
Author :
Date : 2025-10-16T09:28:43
Vulkan: Limit atomic counters to 32 Technically, the limit for atomic counters can be very large; we use an SSBO to emulate them, which can commonly be gigabytes. However, some tests create as many atomic counters as possible, which with the added logic to use those atomic counters result in huge shaders, risking exhausting SPIR-V's 16-bit ids. Given most GLES drivers expose a limit of 8, there's no reason for ANGLE to expose 4096 of them. This limit is lowered to 32 in this change. Bug: angleproject:42262227 Change-Id: I9f1db94bb688050cbd9b4eaa7af65317ab806322 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/7042357 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Charlie Lao <cclao@google.com>
-
Files
- AllocatorHelperPool.cpp
- AllocatorHelperPool.h
- BUILD.gn
- BufferVk.cpp
- BufferVk.h
- CLCommandQueueVk.cpp
- CLCommandQueueVk.h
- CLContextVk.cpp
- CLContextVk.h
- CLDeviceVk.cpp
- CLDeviceVk.h
- CLEventVk.cpp
- CLEventVk.h
- CLKernelVk.cpp
- CLKernelVk.h
- CLMemoryVk.cpp
- CLMemoryVk.h
- CLPlatformVk.cpp
- CLPlatformVk.h
- CLProgramVk.cpp
- CLProgramVk.h
- CLSamplerVk.cpp
- CLSamplerVk.h
- CommandQueue.cpp
- CommandQueue.h
- CompilerVk.cpp
- CompilerVk.h
- ContextVk.cpp
- ContextVk.h
- DebugAnnotatorVk.cpp
- DebugAnnotatorVk.h
- DeviceVk.cpp
- DeviceVk.h
- DisplayVk.cpp
- DisplayVk.h
- DisplayVk_api.h
- FenceNVVk.cpp
- FenceNVVk.h
- FramebufferVk.cpp
- FramebufferVk.h
- ImageVk.cpp
- ImageVk.h
- MemoryObjectVk.cpp
- MemoryObjectVk.h
- MemoryTracking.cpp
- MemoryTracking.h
- OWNERS
- OverlayVk.cpp
- OverlayVk.h
- PersistentCommandPool.cpp
- PersistentCommandPool.h
- ProgramExecutableVk.cpp
- ProgramExecutableVk.h
- ProgramPipelineVk.cpp
- ProgramPipelineVk.h
- ProgramVk.cpp
- ProgramVk.h
- QueryVk.cpp
- QueryVk.h
- README.md
- RenderTargetVk.cpp
- RenderTargetVk.h
- RenderbufferVk.cpp
- RenderbufferVk.h
- SamplerVk.cpp
- SamplerVk.h
- SecondaryCommandBuffer.cpp
- SecondaryCommandBuffer.h
- SecondaryCommandPool.cpp
- SecondaryCommandPool.h
- SemaphoreVk.cpp
- SemaphoreVk.h
- ShaderInterfaceVariableInfoMap.cpp
- ShaderInterfaceVariableInfoMap.h
- ShaderVk.cpp
- ShaderVk.h
- ShareGroupVk.cpp
- ShareGroupVk.h
- Suballocation.cpp
- Suballocation.h
- SurfaceVk.cpp
- SurfaceVk.h
- SyncVk.cpp
- SyncVk.h
- TextureVk.cpp
- TextureVk.h
- TransformFeedbackVk.cpp
- TransformFeedbackVk.h
- UtilsVk.cpp
- UtilsVk.h
- VertexArrayVk.cpp
- VertexArrayVk.h
- VkImageImageSiblingVk.cpp
- VkImageImageSiblingVk.h
- VulkanSecondaryCommandBuffer.cpp
- VulkanSecondaryCommandBuffer.h
- android/
- cl_types.h
- clspv_utils.cpp
- clspv_utils.h
- doc/
- fuchsia/
- gen_vk_format_table.py
- gen_vk_internal_shaders.py
- gen_vk_mandatory_format_support_table.py
- linux/
- mac/
- null/
- shaders/
- spv_utils.cpp
- spv_utils.h
- vk_barrier_data.cpp
- vk_barrier_data.h
- vk_cache_utils.cpp
- vk_cache_utils.h
- vk_caps_utils.cpp
- vk_caps_utils.h
- vk_cl_utils.cpp
- vk_cl_utils.h
- vk_command_buffer_utils.h
- vk_format_map.json
- vk_format_table_autogen.cpp
- vk_format_utils.cpp
- vk_format_utils.h
- vk_helpers.cpp
- vk_helpers.h
- vk_internal_shaders_autogen.cpp
- vk_internal_shaders_autogen.gni
- vk_internal_shaders_autogen.h
- vk_mandatory_format_support_data.json
- vk_mandatory_format_support_table_autogen.cpp
- vk_mem_alloc_wrapper.cpp
- vk_mem_alloc_wrapper.h
- vk_ref_counted_event.cpp
- vk_ref_counted_event.h
- vk_renderer.cpp
- vk_renderer.h
- vk_resource.cpp
- vk_resource.h
- vk_utils.cpp
- vk_utils.h
- vk_wrapper.h
- vulkan_backend.gni
- win32/
-
README.md
-
ANGLE: Vulkan Back-end
ANGLE’s Vulkan back-end implementation lives in this folder.
Vulkan is an explicit graphics API. Compared to APIs like OpenGL or D3D11 explicit APIs can offer a number of significant benefits:
- Lower API call CPU overhead.
- A smaller API surface with more direct hardware control.
- Better support for multi-core programming.
- Vulkan in particular has open-source tooling and tests.
Back-end Design
The
vk::Rendererclass represents anEGLDisplay.vk::Rendererowns shared global resources like the VkDevice, VkQueue, the Vulkan format tables and internal Vulkan shaders. The ContextVk class implements the back-end of a front-end OpenGL Context. ContextVk processes state changes and handles action commands likeglDrawArraysandglDrawElements.Command recording
A render pass has three states:
unstarted, started and active (we call itactivein short), started but inactive (we call itinactivein short). The back-end records commands into command buffers via the followingContextVkAPIs:-
beginNewRenderPass: Writes out (aka flushes) prior pending commands into a primary command buffer, then starts a new render pass. Returns a secondary command buffer inside a render pass instance. -
getOutsideRenderPassCommandBuffer: May flush prior command buffers and close the render pass if necessary, in addition to issuing the appropriate barriers. Returns a secondary command buffer outside a render pass instance. -
getStartedRenderPassCommands: Returns a reference to the currently open render pass’ commands buffer. -
onRenderPassFinished: Puts render pass into inactive state where you can not record more commands into secondary command buffer, except in some special cases where ANGLE does some optimization internally. -
flushCommandsAndEndRenderPassWithoutSubmit: Marks the end of render pass. It flushes secondary command buffer into vulkan’s primary command buffer, puts secondary command buffer back to unstarted state and then goes into recycler for reuse.
The back-end (mostly) records Image and Buffer barriers through additional
CommandResourcesAPIs, the result of which is passed togetOutsideRenderPassCommandBuffer. Note that the barriers are not actually recorded untilgetOutsideRenderPassCommandBufferis called:-
onBufferTransferReadandonBufferComputeShaderReadaccumulateVkBufferread barriers. -
onBufferTransferWriteandonBufferComputeShaderWriteaccumulateVkBufferwrite barriers. -
onBuffferSelfCopyis a special case forVkBufferself copies. It behaves the same as write. -
onImageTransferReadandonImageComputerShadeReadaccumulateVkImageread barriers. -
onImageTransferWriteandonImageComputerShadeWriteaccumulateVkImagewrite barriers. -
onImageRenderPassReadandonImageRenderPassWriteaccumulateVkImagebarriers inside a started RenderPass.
After the back-end records commands to the primary buffer and we flush (e.g. on swap) or when we call
vk::Renderer::finishQueueSerial, ANGLE submits the primary command buffer to aVkQueue.See the code for more details.
Simple command recording example
In this example we’ll be recording a buffer copy command:
// Ensure that ANGLE sets proper read and write barriers for the Buffers. vk::CommandResources resources; resources.onBufferTransferWrite(dstBuffer); resources.onBufferTransferRead(srcBuffer); // Get a pointer to a secondary command buffer for command recording. vk::OutsideRenderPassCommandBuffer *commandBuffer; ANGLE_TRY(contextVk->getOutsideRenderPassCommandBuffer(resources, &commandBuffer)); // Record the copy command into the secondary buffer. We're done! commandBuffer->copyBuffer(srcBuffer->getBuffer(), dstBuffer->getBuffer(), copyCount, copies);Additional Reading
More implementation details can be found in the
docdirectory: