[Fuchsia] Don't reuse Vulkan semaphores in VulkanSwapChain

VulkanSwapChain reuses semaphores used in Swapchain. That logic depends
on fences support in Swapchain, but Fuchsia's swapchain implementation
doesn't support fences. This CL disables semaphores re-use on Fuchsia.

Bug: 1117070
Change-Id: I8d57a527b572f7da1fd27821b36fae332307b725
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2365357Reviewed-by: Peng Huang <penghuang@chromium.org>
Commit-Queue: Peng Huang <penghuang@chromium.org>
Auto-Submit: Sergey Ulanov <sergeyu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799998}

gpu/vulkan/vulkan_swap_chain.cc

@@ -12,6 +12,7 @@
 #include "base/threading/scoped_blocking_call.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
+#include "build/build_config.h"
 #include "gpu/vulkan/vulkan_device_queue.h"
 #include "gpu/vulkan/vulkan_fence_helper.h"
 #include "gpu/vulkan/vulkan_function_pointers.h"
@@ -86,6 +87,7 @@ void VulkanSwapChain::Destroy() {
 
   WaitUntilPostSubBufferAsyncFinished();
 
+#if !defined(OS_FUCHSIA)
   if (UNLIKELY(!fence_and_semaphores_queue_.empty())) {
     VkDevice device = device_queue_->GetVulkanDevice();
     {
@@ -106,6 +108,7 @@ void VulkanSwapChain::Destroy() {
     }
     fence_and_semaphores_queue_.clear();
   }
+#endif  // !defined(OS_FUCHSIA)
 
   DCHECK(!is_writing_);
   DestroySwapImages();
@@ -199,9 +202,11 @@ bool VulkanSwapChain::InitializeSwapChain(
     // Reuse |post_sub_buffer_task_runner_| and |fence_and_semaphores_queue_|
     // from the |old_swap_chain|.
     post_sub_buffer_task_runner_ = old_swap_chain->post_sub_buffer_task_runner_;
+#if !defined(OS_FUCHSIA)
     fence_and_semaphores_queue_ =
         std::move(old_swap_chain->fence_and_semaphores_queue_);
     old_swap_chain->fence_and_semaphores_queue_.clear();
+#endif  // !defined(OS_FUCHSIA)
   }
 
   VkSwapchainKHR new_swap_chain = VK_NULL_HANDLE;
@@ -418,8 +423,10 @@ bool VulkanSwapChain::AcquireNextImage() {
   // TODO(penghuang): make VulkanDeviceQueue threadsafe.
   VkDevice device = device_queue_->GetVulkanDevice();
   auto fence_and_semaphores = GetOrCreateFenceAndSemaphores();
-  if (UNLIKELY(fence_and_semaphores.fence == VK_NULL_HANDLE)) {
-    DCHECK(fence_and_semaphores.semaphores[0] == VK_NULL_HANDLE);
+  if (UNLIKELY(fence_and_semaphores.semaphores[0] == VK_NULL_HANDLE)) {
+#if !defined(OS_FUCHSIA)
+    DCHECK(fence_and_semaphores.fence == VK_NULL_HANDLE);
+#endif  // !defined(OS_FUCHSIA)
     DCHECK(fence_and_semaphores.semaphores[1] == VK_NULL_HANDLE);
     return false;
   }
@@ -490,6 +497,7 @@ VulkanSwapChain::GetOrCreateFenceAndSemaphores() {
   VkDevice device = device_queue_->GetVulkanDevice();
   FenceAndSemaphores fence_and_semaphores;
   do {
+#if !defined(OS_FUCHSIA)
     if (LIKELY(!fence_and_semaphores_queue_.empty())) {
       fence_and_semaphores = fence_and_semaphores_queue_.front();
       auto result = vkGetFenceStatus(device, fence_and_semaphores.fence);
@@ -518,6 +526,7 @@ VulkanSwapChain::GetOrCreateFenceAndSemaphores() {
         break;
       }
     }
+#endif  // !defined(OS_FUCHSIA)
 
     if (UNLIKELY(fence_and_semaphores.semaphores[0] == VK_NULL_HANDLE))
       fence_and_semaphores.semaphores[0] = CreateSemaphore(device);
@@ -543,8 +552,17 @@ VulkanSwapChain::GetOrCreateFenceAndSemaphores() {
 
 void VulkanSwapChain::ReturnFenceAndSemaphores(
     const FenceAndSemaphores& fence_and_semaphores) {
+#if defined(OS_FUCHSIA)
+  VkDevice device = device_queue_->GetVulkanDevice();
+  DCHECK(fence_and_semaphores.fence == VK_NULL_HANDLE);
+  vkDestroySemaphore(device, fence_and_semaphores.semaphores[0],
+                     nullptr /* pAllocator */);
+  vkDestroySemaphore(device, fence_and_semaphores.semaphores[1],
+                     nullptr /* pAllocator */);
+#else
   DCHECK(fence_and_semaphores.fence != VK_NULL_HANDLE);
   fence_and_semaphores_queue_.push_back(fence_and_semaphores);
+#endif
 }
 
 VulkanSwapChain::ScopedWrite::ScopedWrite(VulkanSwapChain* swap_chain)

gpu/vulkan/vulkan_swap_chain.h

@@ -18,6 +18,7 @@
 #include "base/synchronization/condition_variable.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_checker.h"
+#include "build/build_config.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/swap_result.h"
@@ -188,9 +189,13 @@ class COMPONENT_EXPORT(VULKAN) VulkanSwapChain {
   // For executing PosSubBufferAsync tasks off the GPU main thread.
   scoped_refptr<base::SequencedTaskRunner> post_sub_buffer_task_runner_;
 
+#if !defined(OS_FUCHSIA)
   // Available fence and semaphores can be reused when fence is passed.
+  // Not used on Fuchsia because Fuchsia's swapchain implementation doesn't
+  // support fences.
   base::circular_deque<FenceAndSemaphores> fence_and_semaphores_queue_
       GUARDED_BY(lock_);
+#endif
 
   THREAD_CHECKER(thread_checker_);