Implement pipeline barrier as noop
Because of existing synchronization mechanisms in SwiftShader,
pipeline barriers can be noop for now. If we do remove those
synchronization mechanisms, there's also a simple way of
implementing pipeline barriers, which is commented on here.
Bug b/118619338
Change-Id: If82d275c46f234e5549018115c9f19f21e2c09b2
Reviewed-on: https://swiftshader-review.googlesource.com/c/22708
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>
diff --git a/src/Vulkan/VkCommandBuffer.cpp b/src/Vulkan/VkCommandBuffer.cpp
index dbcb386..0cd512d 100644
--- a/src/Vulkan/VkCommandBuffer.cpp
+++ b/src/Vulkan/VkCommandBuffer.cpp
@@ -143,6 +143,27 @@
const VkBufferImageCopy region;
};
+struct PipelineBarrier : public CommandBuffer::Command
+{
+ PipelineBarrier()
+ {
+ }
+
+ void play(CommandBuffer* commandBuffer)
+ {
+ // This can currently be a noop. The sw::Surface locking/unlocking mechanism used by the renderer already takes care of
+ // making sure the read/writes always happen in order. Eventually, if we remove this synchronization mechanism, we can
+ // have a very simple implementation that simply calls sw::Renderer::sync(), since the driver is free to move the source
+ // stage towards the bottom of the pipe and the target stage towards the top, so a full pipeline sync is spec compliant.
+
+ // Right now all buffers are read-only in drawcalls but a similar mechanism will be required once we support SSBOs.
+
+ // Also note that this would be a good moment to update cube map borders or decompress compressed textures, if necessary.
+ }
+
+private:
+};
+
CommandBuffer::CommandBuffer(VkCommandBufferLevel pLevel) : level(pLevel)
{
// FIXME (b/119409619): replace this vector by an allocator so we can control all memory allocations
@@ -242,7 +263,7 @@
uint32_t bufferMemoryBarrierCount, const VkBufferMemoryBarrier* pBufferMemoryBarriers,
uint32_t imageMemoryBarrierCount, const VkImageMemoryBarrier* pImageMemoryBarriers)
{
- UNIMPLEMENTED();
+ commands->push_back(std::make_unique<PipelineBarrier>());
}
void CommandBuffer::bindPipeline(VkPipelineBindPoint pipelineBindPoint, VkPipeline pipeline)
