hwui: add reason for skipped frames

.. so we could report the unintentional skipped frames to Perfetto,
rather than report undrawn frames as well.

Test: manual
Bug: 294884928
Change-Id: Ic49f4050cb3028d7adb5c930947ff6b72655d832

1 files changed, 26 insertions, 0 deletions

diff --git a/libs/hwui/FrameInfo.cpp b/libs/hwui/FrameInfo.cpp
index 8191f5e6a83a..a958a091a830 100644
--- a/libs/hwui/FrameInfo.cpp
+++ b/libs/hwui/FrameInfo.cpp
@@ -15,6 +15,8 @@
  */
 #include "FrameInfo.h"
 
+#include <gui/TraceUtils.h>
+
 #include <cstring>
 
 namespace android {
@@ -51,6 +53,30 @@ static_assert(static_cast<int>(FrameInfoIndex::NumIndexes) == 23,
 
 void FrameInfo::importUiThreadInfo(int64_t* info) {
     memcpy(mFrameInfo, info, UI_THREAD_FRAME_INFO_SIZE * sizeof(int64_t));
+    mSkippedFrameReason.reset();
+}
+
+const char* toString(SkippedFrameReason reason) {
+    switch (reason) {
+        case SkippedFrameReason::DrawingOff:
+            return "DrawingOff";
+        case SkippedFrameReason::ContextIsStopped:
+            return "ContextIsStopped";
+        case SkippedFrameReason::NothingToDraw:
+            return "NothingToDraw";
+        case SkippedFrameReason::NoOutputTarget:
+            return "NoOutputTarget";
+        case SkippedFrameReason::NoBuffer:
+            return "NoBuffer";
+        case SkippedFrameReason::AlreadyDrawn:
+            return "AlreadyDrawn";
+    }
+}
+
+void FrameInfo::setSkippedFrameReason(android::uirenderer::SkippedFrameReason reason) {
+    ATRACE_FORMAT_INSTANT("Frame skipped: %s", toString(reason));
+    addFlag(FrameInfoFlags::SkippedFrame);
+    mSkippedFrameReason = reason;
 }
 
 } /* namespace uirenderer */