Let DeviceBase know about Completed and LastSubmitted command Serials

This is needed to implement the timeline fence signal tracker in the frontend

Bug: dawn:26
Change-Id: Id6eb2afb81385de5093b57c5cb23ace93c8aab1b
Reviewed-on: https://dawn-review.googlesource.com/c/2741
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Austin Eng <enga@chromium.org>

src/dawn_native/opengl/DeviceGL.cpp

@@ -50,6 +50,17 @@ namespace dawn_native { namespace opengl {
         CollectPCIInfo();
     }
 
+    Device::~Device() {
+        CheckPassedFences();
+        ASSERT(mFencesInFlight.empty());
+
+        // Some operations might have been started since the last submit and waiting
+        // on a serial that doesn't have a corresponding fence enqueued. Force all
+        // operations to look as if they were completed (because they were).
+        mCompletedSerial = mLastSubmittedSerial + 1;
+        Tick();
+    }
+
     BindGroupBase* Device::CreateBindGroup(BindGroupBuilder* builder) {
         return new BindGroup(builder);
     }
@@ -112,7 +123,47 @@ namespace dawn_native { namespace opengl {
         return new TextureView(texture, descriptor);
     }
 
+    void Device::SubmitFenceSync() {
+        GLsync sync = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
+        mLastSubmittedSerial++;
+        mFencesInFlight.emplace(sync, mLastSubmittedSerial);
+    }
+
+    Serial Device::GetCompletedCommandSerial() const {
+        return mCompletedSerial;
+    }
+
+    Serial Device::GetLastSubmittedCommandSerial() const {
+        return mLastSubmittedSerial;
+    }
+
     void Device::TickImpl() {
+        CheckPassedFences();
+    }
+
+    void Device::CheckPassedFences() {
+        while (!mFencesInFlight.empty()) {
+            GLsync sync = mFencesInFlight.front().first;
+            Serial fenceSerial = mFencesInFlight.front().second;
+
+            GLint status = 0;
+            GLsizei length;
+            glGetSynciv(sync, GL_SYNC_CONDITION, sizeof(GLint), &length, &status);
+            ASSERT(length == 1);
+
+            // Fence are added in order, so we can stop searching as soon
+            // as we see one that's not ready.
+            if (!status) {
+                return;
+            }
+
+            glDeleteSync(sync);
+
+            mFencesInFlight.pop();
+
+            ASSERT(fenceSerial > mCompletedSerial);
+            mCompletedSerial = fenceSerial;
+        }
     }
 
     const dawn_native::PCIInfo& Device::GetPCIInfo() const {

src/dawn_native/opengl/DeviceGL.h

@@ -23,6 +23,8 @@
 
 #include "glad/glad.h"
 
+#include <queue>
+
 // Remove windows.h macros after glad's include of windows.h
 #if defined(DAWN_PLATFORM_WINDOWS)
 #    include "common/windows_with_undefs.h"
@@ -33,6 +35,11 @@ namespace dawn_native { namespace opengl {
     class Device : public DeviceBase {
       public:
         Device();
+        ~Device();
+
+        void SubmitFenceSync();
+
+        // Dawn API
         BindGroupBase* CreateBindGroup(BindGroupBuilder* builder) override;
         BlendStateBase* CreateBlendState(BlendStateBuilder* builder) override;
         BufferViewBase* CreateBufferView(BufferViewBuilder* builder) override;
@@ -44,6 +51,8 @@ namespace dawn_native { namespace opengl {
         RenderPipelineBase* CreateRenderPipeline(RenderPipelineBuilder* builder) override;
         SwapChainBase* CreateSwapChain(SwapChainBuilder* builder) override;
 
+        Serial GetCompletedCommandSerial() const final override;
+        Serial GetLastSubmittedCommandSerial() const final override;
         void TickImpl() override;
 
         const dawn_native::PCIInfo& GetPCIInfo() const override;
@@ -66,6 +75,12 @@ namespace dawn_native { namespace opengl {
             const TextureViewDescriptor* descriptor) override;
         void CollectPCIInfo();
 
+        void CheckPassedFences();
+
+        Serial mCompletedSerial = 0;
+        Serial mLastSubmittedSerial = 0;
+        std::queue<std::pair<GLsync, Serial>> mFencesInFlight;
+
         dawn_native::PCIInfo mPCIInfo;
     };
 

src/dawn_native/opengl/QueueGL.cpp

@@ -23,9 +23,13 @@ namespace dawn_native { namespace opengl {
     }
 
     void Queue::SubmitImpl(uint32_t numCommands, CommandBufferBase* const* commands) {
+        Device* device = ToBackend(GetDevice());
+
         for (uint32_t i = 0; i < numCommands; ++i) {
             ToBackend(commands[i])->Execute();
         }
+
+        device->SubmitFenceSync();
     }
 
 }}  // namespace dawn_native::opengl