Add ability to pre-initialize vulkan semaphores when flushing surfaces

Bug: skia:
Change-Id: I2d3eb68d2ac6045fe3e30350fdd21140e22861d7
Reviewed-on: https://skia-review.googlesource.com/24645
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>

include/core/SkSurface.h

@@ -320,15 +320,21 @@ public:
     void flush();
 
     /**
-     * Issue any pending surface IO to the current backend 3D API. After issuing all commands, we
-     * will issue numSemaphore semaphores for the gpu to signal. We will then fill in the array
-     * signalSemaphores with the info on the semaphores we submitted. The client is reposonsible for
-     * allocating enough space in signalSemaphores to handle numSemaphores of GrBackendSemaphores.
-     * The client will also take ownership of the returned underlying backend semaphores.
+     * Issue any pending surface IO to the current backend 3D API. After issuing all commands,
+     * numSemaphore semaphores will be signaled by the gpu. The client passes in an array of
+     * numSemaphores GrBackendSemaphores. In general these GrBackendSemaphore's can be either
+     * initialized or not. If they are initialized, the backend uses the passed in semaphore.
+     * If it is not initialized, a new semaphore is created and the GrBackendSemaphore object
+     * is initialized with that semaphore.
+     *
+     * If the backend API is OpenGL only uninitialized GrBackendSemaphores are supported.
+     * If the backend API is Vulkan either initialized or unitialized semaphores are supported.
+     * If unitialized, the semaphores which are created will be valid for use only with the VkDevice
+     * with which they were created.
      *
      * If this call returns false, the GPU backend will not have created or added any semaphores to
-     * signal. Thus the array of semaphores will remain uninitialized. However, we will still flush
-     * any pending surface IO.
+     * signal. Thus the array of semaphores will remain uninitialized. However, any pending surface
+     * IO will still be flush.
      */
     bool flushAndSignalSemaphores(int numSemaphores, GrBackendSemaphore* signalSemaphores);
 

include/gpu/GrBackendSemaphore.h

@@ -39,6 +39,8 @@ public:
     }
 #endif
 
+    bool isInitialized() const { return fIsInitialized; }
+
     GrGLsync glSync() const {
         if (!fIsInitialized || kOpenGL_GrBackend != fBackend) {
             return 0;

src/gpu/GrRenderTargetContext.cpp

@@ -1426,7 +1426,12 @@ bool GrRenderTargetContext::prepareForExternalIO(int numSemaphores,
 
     SkTArray<sk_sp<GrSemaphore>> semaphores(numSemaphores);
     for (int i = 0; i < numSemaphores; ++i) {
+        if (backendSemaphores[i].isInitialized()) {
+            semaphores.push_back(fContext->resourceProvider()->wrapBackendSemaphore(
+                    backendSemaphores[i], kBorrow_GrWrapOwnership));
+        } else {
             semaphores.push_back(fContext->resourceProvider()->makeSemaphore(false));
+        }
         // Create signal semaphore ops and force the final one to call flush.
         bool forceFlush = (i == (numSemaphores - 1));
         std::unique_ptr<GrOp> signalOp(GrSemaphoreOp::MakeSignal(semaphores.back(),
@@ -1438,8 +1443,10 @@ bool GrRenderTargetContext::prepareForExternalIO(int numSemaphores,
     this->drawingManager()->prepareSurfaceForExternalIO(fRenderTargetProxy.get());
 
     for (int i = 0; i < numSemaphores; ++i) {
+        if (!backendSemaphores[i].isInitialized()) {
             semaphores[i]->setBackendSemaphore(&backendSemaphores[i]);
         }
+    }
     return true;
 }
 

src/gpu/vk/GrVkSemaphore.cpp

@@ -18,7 +18,7 @@
 
 sk_sp<GrVkSemaphore> GrVkSemaphore::Make(const GrVkGpu* gpu, bool isOwned) {
     VkSemaphoreCreateInfo createInfo;
-    memset(&createInfo, 0, sizeof(VkFenceCreateInfo));
+    memset(&createInfo, 0, sizeof(VkSemaphoreCreateInfo));
     createInfo.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
     createInfo.pNext = nullptr;
     createInfo.flags = 0;

tests/SurfaceSemaphoreTest.cpp

@@ -124,6 +124,24 @@ void surface_semaphore_test(skiatest::Reporter* reporter,
     mainCanvas->clear(SK_ColorBLUE);
 
     SkAutoTArray<GrBackendSemaphore> semaphores(2);
+#ifdef SK_VULKAN
+    if (kVulkan_GrBackend == mainInfo.backend()) {
+        // Initialize the secondary semaphore instead of having Ganesh create one internally
+        GrVkGpu* gpu = static_cast<GrVkGpu*>(mainCtx->getGpu());
+        const GrVkInterface* interface = gpu->vkInterface();
+        VkDevice device = gpu->device();
+
+        VkSemaphore vkSem;
+
+        VkSemaphoreCreateInfo createInfo;
+        createInfo.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
+        createInfo.pNext = nullptr;
+        createInfo.flags = 0;
+        GR_VK_CALL_ERRCHECK(interface, CreateSemaphore(device, &createInfo, nullptr, &vkSem));
+
+        semaphores[1].initVulkan(vkSem);
+    }
+#endif
 
     mainSurface->flushAndSignalSemaphores(2, semaphores.get());