commit 4cabdd0dd2b0f4040845e007095dc1cf0ae2df4b
author Sally Qi <sallyqi@google.com> Thu Aug 05 16:45:57 2021 -0700
committer Sally Qi <sallyqi@google.com> Thu Aug 19 10:19:58 2021 -0700
tree 12d1ddee04dcba9ee7801064513d8929a2fc7da1
parent 8d7957078701de11d045a8c8d10f0c35a32c5074

First patch for async renderengine.

1. return a std::future object from DrawLayers() instead to make it
asynchronously
2. retire drawFence value from drawLayers() parameter list.

Bug: 180657548
Test: android.hardware.graphics.composer@2.2-vts, libcompositionengine_test, libsurfaceflinger_unittest and
librenderengine_test pass

Change-Id: If63c11762d1cce7b053cc72aaeaed6dd7904877f

libs/renderengine/threaded/RenderEngineThreaded.cpp

diff --git a/libs/renderengine/threaded/RenderEngineThreaded.cpp b/libs/renderengine/threaded/RenderEngineThreaded.cpp
index 8e666d5..9a8201f 100644
--- a/libs/renderengine/threaded/RenderEngineThreaded.cpp
+++ b/libs/renderengine/threaded/RenderEngineThreaded.cpp
@@ -304,27 +304,33 @@
     return mRenderEngine->canSkipPostRenderCleanup();
 }
 
-status_t RenderEngineThreaded::drawLayers(const DisplaySettings& display,
-                                          const std::vector<const LayerSettings*>& layers,
-                                          const std::shared_ptr<ExternalTexture>& buffer,
-                                          const bool useFramebufferCache,
-                                          base::unique_fd&& bufferFence,
-                                          base::unique_fd* drawFence) {
+void RenderEngineThreaded::drawLayersInternal(
+        const std::shared_ptr<std::promise<RenderEngineResult>>&& resultPromise,
+        const DisplaySettings& display, const std::vector<const LayerSettings*>& layers,
+        const std::shared_ptr<ExternalTexture>& buffer, const bool useFramebufferCache,
+        base::unique_fd&& bufferFence) {
+    resultPromise->set_value({NO_ERROR, base::unique_fd()});
+    return;
+}
+
+std::future<RenderEngineResult> RenderEngineThreaded::drawLayers(
+        const DisplaySettings& display, const std::vector<const LayerSettings*>& layers,
+        const std::shared_ptr<ExternalTexture>& buffer, const bool useFramebufferCache,
+        base::unique_fd&& bufferFence) {
     ATRACE_CALL();
-    std::promise<status_t> resultPromise;
-    std::future<status_t> resultFuture = resultPromise.get_future();
+    const auto resultPromise = std::make_shared<std::promise<RenderEngineResult>>();
+    std::future<RenderEngineResult> resultFuture = resultPromise->get_future();
     {
         std::lock_guard lock(mThreadMutex);
-        mFunctionCalls.push([&resultPromise, &display, &layers, &buffer, useFramebufferCache,
-                             &bufferFence, &drawFence](renderengine::RenderEngine& instance) {
+        mFunctionCalls.push([resultPromise, &display, &layers, &buffer, useFramebufferCache,
+                             &bufferFence](renderengine::RenderEngine& instance) {
             ATRACE_NAME("REThreaded::drawLayers");
-            status_t status = instance.drawLayers(display, layers, buffer, useFramebufferCache,
-                                                  std::move(bufferFence), drawFence);
-            resultPromise.set_value(status);
+            instance.drawLayersInternal(std::move(resultPromise), display, layers, buffer,
+                                        useFramebufferCache, std::move(bufferFence));
         });
     }
     mCondition.notify_one();
-    return resultFuture.get();
+    return resultFuture;
 }
 
 void RenderEngineThreaded::cleanFramebufferCache() {