Bug 1617086 - Keep WebGPU pass dependencies alive while recording r=jgilbert

Since we switched to "software" pass recording,
`wgpu` no longer keeps references to the objects used when recording a pass.
This means Gecko needs to keep them alive up until the encoding is done.

Differential Revision: https://phabricator.services.mozilla.com/D65319

--HG--
extra : moz-landing-system : lando

dom/webgpu/ComputePassEncoder.cpp

@@ -38,6 +38,7 @@ void ComputePassEncoder::SetBindGroup(
     uint32_t aSlot, const BindGroup& aBindGroup,
     const dom::Sequence<uint32_t>& aDynamicOffsets) {
   if (mValid) {
+    mUsedBindGroups.push_back(&aBindGroup);
     ffi::wgpu_compute_pass_set_bind_group(&mRaw, aSlot, aBindGroup.mId,
                                           aDynamicOffsets.Elements(),
                                           aDynamicOffsets.Length());
@@ -46,6 +47,7 @@ void ComputePassEncoder::SetBindGroup(
 
 void ComputePassEncoder::SetPipeline(const ComputePipeline& aPipeline) {
   if (mValid) {
+    mUsedPipelines.push_back(&aPipeline);
     ffi::wgpu_compute_pass_set_pipeline(&mRaw, aPipeline.mId);
   }
 }

dom/webgpu/ComputePassEncoder.h

@@ -14,6 +14,7 @@
 namespace mozilla {
 namespace webgpu {
 
+class BindGroup;
 class Buffer;
 class CommandEncoder;
 class ComputePipeline;
@@ -32,6 +33,9 @@ class ComputePassEncoder final : public ObjectBase,
   void Cleanup() {}
 
   ffi::WGPURawPass mRaw;
+  // keep all the used objects alive while the pass is recorded
+  std::vector<RefPtr<const BindGroup>> mUsedBindGroups;
+  std::vector<RefPtr<const ComputePipeline>> mUsedPipelines;
 
  public:
   void SetBindGroup(uint32_t aSlot, const BindGroup& aBindGroup,

dom/webgpu/RenderPassEncoder.cpp

@@ -117,7 +117,15 @@ ffi::WGPURawPass BeginRenderPass(RawId aEncoderId,
 
 RenderPassEncoder::RenderPassEncoder(CommandEncoder* const aParent,
                                      const dom::GPURenderPassDescriptor& aDesc)
-    : ChildOf(aParent), mRaw(BeginRenderPass(aParent->mId, aDesc)) {}
+    : ChildOf(aParent), mRaw(BeginRenderPass(aParent->mId, aDesc)) {
+  for (const auto& at : aDesc.mColorAttachments) {
+    mUsedTextureViews.push_back(at.mAttachment);
+  }
+  if (aDesc.mDepthStencilAttachment.WasPassed()) {
+    mUsedTextureViews.push_back(
+        aDesc.mDepthStencilAttachment.Value().mAttachment);
+  }
+}
 
 RenderPassEncoder::~RenderPassEncoder() {
   if (mValid) {
@@ -130,6 +138,7 @@ void RenderPassEncoder::SetBindGroup(
     uint32_t aSlot, const BindGroup& aBindGroup,
     const dom::Sequence<uint32_t>& aDynamicOffsets) {
   if (mValid) {
+    mUsedBindGroups.push_back(&aBindGroup);
     ffi::wgpu_render_pass_set_bind_group(&mRaw, aSlot, aBindGroup.mId,
                                          aDynamicOffsets.Elements(),
                                          aDynamicOffsets.Length());
@@ -138,6 +147,7 @@ void RenderPassEncoder::SetBindGroup(
 
 void RenderPassEncoder::SetPipeline(const RenderPipeline& aPipeline) {
   if (mValid) {
+    mUsedPipelines.push_back(&aPipeline);
     ffi::wgpu_render_pass_set_pipeline(&mRaw, aPipeline.mId);
   }
 }
@@ -145,6 +155,7 @@ void RenderPassEncoder::SetPipeline(const RenderPipeline& aPipeline) {
 void RenderPassEncoder::SetIndexBuffer(const Buffer& aBuffer,
                                        uint64_t aOffset) {
   if (mValid) {
+    mUsedBuffers.push_back(&aBuffer);
     ffi::wgpu_render_pass_set_index_buffer(&mRaw, aBuffer.mId, aOffset);
   }
 }
@@ -152,6 +163,7 @@ void RenderPassEncoder::SetIndexBuffer(const Buffer& aBuffer,
 void RenderPassEncoder::SetVertexBuffer(uint32_t aSlot, const Buffer& aBuffer,
                                         uint64_t aOffset) {
   if (mValid) {
+    mUsedBuffers.push_back(&aBuffer);
     // TODO: change the Rust API to use a single vertex buffer?
     ffi::wgpu_render_pass_set_vertex_buffers(&mRaw, aSlot, &aBuffer.mId,
                                              &aOffset, 1);

dom/webgpu/RenderPassEncoder.h

@@ -38,6 +38,11 @@ class RenderPassEncoder final : public ObjectBase,
   void Cleanup() {}
 
   ffi::WGPURawPass mRaw;
+  // keep all the used objects alive while the pass is recorded
+  std::vector<RefPtr<const BindGroup>> mUsedBindGroups;
+  std::vector<RefPtr<const Buffer>> mUsedBuffers;
+  std::vector<RefPtr<const RenderPipeline>> mUsedPipelines;
+  std::vector<RefPtr<const TextureView>> mUsedTextureViews;
 
  public:
   void SetBindGroup(uint32_t aSlot, const BindGroup& aBindGroup,