vulkan: Don't dequeue in AcquireNextImageKHR if in shared mode

We've already got the shared buffer dequeued. All we need to do here
is make the semaphore and fence work.

Test: build
Change-Id: I77a49c312e91b5e0657b87ac2748428c631bdbc0

1 files changed, 10 insertions, 0 deletions

diff --git a/vulkan/libvulkan/swapchain.cpp b/vulkan/libvulkan/swapchain.cpp
index e2e733e0a3..a4f968a7b2 100644
--- a/vulkan/libvulkan/swapchain.cpp
+++ b/vulkan/libvulkan/swapchain.cpp
@@ -1210,6 +1210,16 @@ VkResult AcquireNextImageKHR(VkDevice device,
         timeout != UINT64_MAX,
         "vkAcquireNextImageKHR: non-infinite timeouts not yet implemented");
 
+    if (swapchain.shared) {
+        // In shared mode, we keep the buffer dequeued all the time, so we don't
+        // want to dequeue a buffer here. Instead, just ask the driver to ensure
+        // the semaphore and fence passed to us will be signalled.
+        *image_index = 0;
+        result = GetData(device).driver.AcquireImageANDROID(
+                device, swapchain.images[*image_index].image, -1, semaphore, vk_fence);
+        return result;
+    }
+
     ANativeWindowBuffer* buffer;
     int fence_fd;
     err = window->dequeueBuffer(window, &buffer, &fence_fd);