From 5fc80e7b32a00b4e43b4ce13d60bd82796130182 Mon Sep 17 00:00:00 2001
From: chaviw <chaviw@google.com>
Date: Thu, 30 Apr 2020 12:14:35 -0700
Subject: [PATCH] Send drawFinish callback even if did not draw

There are cases where ViewRootImpl requests to draw, but there was
nothing new to draw. In that case, the callback will never be invoked
and ViewRootImpl will wait forever.

This change will invoke the callback even if there is nothing to draw.
It will use the last frameNumber since nothing new has drawn

Test: Request draw with nothing new. Callback is invoked
Fixes: 155429223
Change-Id: I7c9ed7fd63a451b17133a11ffbcf8fb64be558e5
---
 libs/hwui/renderthread/CanvasContext.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libs/hwui/renderthread/CanvasContext.cpp b/libs/hwui/renderthread/CanvasContext.cpp
index c19b1878ad45b..335bcdcfc1fb1 100644
--- a/libs/hwui/renderthread/CanvasContext.cpp
+++ b/libs/hwui/renderthread/CanvasContext.cpp
@@ -440,6 +440,12 @@ void CanvasContext::draw() {
 
     if (dirty.isEmpty() && Properties::skipEmptyFrames && !surfaceRequiresRedraw()) {
         mCurrentFrameInfo->addFlag(FrameInfoFlags::SkippedFrame);
+        // Notify the callbacks, even if there's nothing to draw so they aren't waiting
+        // indefinitely
+        for (auto& func : mFrameCompleteCallbacks) {
+            std::invoke(func, mFrameNumber);
+        }
+        mFrameCompleteCallbacks.clear();
         return;
     }