Skip sending HWUI hints when frame does not draw

Sending HWUI ADPF CPU hints when the frame is not drawn can undercount
the actual workload duration and lead to inadequate boosting. This
patch prevents this by not sending hints when the frame is not drawn.

Bug: b/239677101
Test: manual
Change-Id: Ia308f59740c83977df02dff6d9f9289f2b8d439e

libs/hwui/renderthread/CanvasContext.cpp

@@ -472,11 +472,11 @@ void CanvasContext::notifyFramePending() {
     mRenderThread.pushBackFrameCallback(this);
 }
 
-nsecs_t CanvasContext::draw() {
+std::optional<nsecs_t> CanvasContext::draw() {
     if (auto grContext = getGrContext()) {
         if (grContext->abandoned()) {
             LOG_ALWAYS_FATAL("GrContext is abandoned/device lost at start of CanvasContext::draw");
-            return 0;
+            return std::nullopt;
         }
     }
     SkRect dirty;
@@ -498,7 +498,7 @@ nsecs_t CanvasContext::draw() {
             std::invoke(func, false /* didProduceBuffer */);
         }
         mFrameCommitCallbacks.clear();
-        return 0;
+        return std::nullopt;
     }
 
     ScopedActiveContext activeContext(this);
@@ -543,6 +543,8 @@ nsecs_t CanvasContext::draw() {
     }
 
     bool requireSwap = false;
+    bool didDraw = false;
+
     int error = OK;
     bool didSwap = mRenderPipeline->swapBuffers(frame, drawResult.success, windowDirty,
                                                 mCurrentFrameInfo, &requireSwap);
@@ -553,7 +555,7 @@ nsecs_t CanvasContext::draw() {
     mIsDirty = false;
 
     if (requireSwap) {
-        bool didDraw = true;
+        didDraw = true;
         // Handle any swapchain errors
         error = mNativeSurface->getAndClearError();
         if (error == TIMED_OUT) {
@@ -649,7 +651,9 @@ nsecs_t CanvasContext::draw() {
     }
 
     mRenderThread.cacheManager().onFrameCompleted();
-    return mCurrentFrameInfo->get(FrameInfoIndex::DequeueBufferDuration);
+    return didDraw ? std::make_optional(
+                             mCurrentFrameInfo->get(FrameInfoIndex::DequeueBufferDuration))
+                   : std::nullopt;
 }
 
 void CanvasContext::reportMetricsWithPresentTime() {

libs/hwui/renderthread/CanvasContext.h

@@ -138,7 +138,7 @@ public:
     bool makeCurrent();
     void prepareTree(TreeInfo& info, int64_t* uiFrameInfo, int64_t syncQueued, RenderNode* target);
     // Returns the DequeueBufferDuration.
-    nsecs_t draw();
+    std::optional<nsecs_t> draw();
     void destroy();
 
     // IFrameCallback, Choreographer-driven frame callback entry point

libs/hwui/renderthread/DrawFrameTask.cpp

@@ -19,6 +19,7 @@
 #include <dlfcn.h>
 #include <gui/TraceUtils.h>
 #include <utils/Log.h>
+
 #include <algorithm>
 
 #include "../DeferredLayerUpdater.h"
@@ -28,6 +29,7 @@
 #include "CanvasContext.h"
 #include "RenderThread.h"
 #include "thread/CommonPool.h"
+#include "utils/TimeUtils.h"
 
 namespace android {
 namespace uirenderer {
@@ -146,6 +148,7 @@ void DrawFrameTask::run() {
 
     bool canUnblockUiThread;
     bool canDrawThisFrame;
+    bool didDraw = false;
     {
         TreeInfo info(TreeInfo::MODE_FULL, *mContext);
         info.forceDrawFrame = mForceDrawFrame;
@@ -188,7 +191,9 @@ void DrawFrameTask::run() {
 
     nsecs_t dequeueBufferDuration = 0;
     if (CC_LIKELY(canDrawThisFrame)) {
-        dequeueBufferDuration = context->draw();
+        std::optional<nsecs_t> drawResult = context->draw();
+        didDraw = drawResult.has_value();
+        dequeueBufferDuration = drawResult.value_or(0);
     } else {
         // Do a flush in case syncFrameState performed any texture uploads. Since we skipped
         // the draw() call, those uploads (or deletes) will end up sitting in the queue.
@@ -209,8 +214,9 @@ void DrawFrameTask::run() {
     }
 
     if (!mHintSessionWrapper) mHintSessionWrapper.emplace(mUiThreadId, mRenderThreadId);
-    constexpr int64_t kSanityCheckLowerBound = 100000;       // 0.1ms
-    constexpr int64_t kSanityCheckUpperBound = 10000000000;  // 10s
+
+    constexpr int64_t kSanityCheckLowerBound = 100_us;
+    constexpr int64_t kSanityCheckUpperBound = 10_s;
     int64_t targetWorkDuration = frameDeadline - intendedVsync;
     targetWorkDuration = targetWorkDuration * Properties::targetCpuTimePercentage / 100;
     if (targetWorkDuration > kSanityCheckLowerBound &&
@@ -219,12 +225,15 @@ void DrawFrameTask::run() {
         mLastTargetWorkDuration = targetWorkDuration;
         mHintSessionWrapper->updateTargetWorkDuration(targetWorkDuration);
     }
-    int64_t frameDuration = systemTime(SYSTEM_TIME_MONOTONIC) - frameStartTime;
-    int64_t actualDuration = frameDuration -
-                             (std::min(syncDelayDuration, mLastDequeueBufferDuration)) -
-                             dequeueBufferDuration;
-    if (actualDuration > kSanityCheckLowerBound && actualDuration < kSanityCheckUpperBound) {
-        mHintSessionWrapper->reportActualWorkDuration(actualDuration);
+
+    if (didDraw) {
+        int64_t frameDuration = systemTime(SYSTEM_TIME_MONOTONIC) - frameStartTime;
+        int64_t actualDuration = frameDuration -
+                                 (std::min(syncDelayDuration, mLastDequeueBufferDuration)) -
+                                 dequeueBufferDuration;
+        if (actualDuration > kSanityCheckLowerBound && actualDuration < kSanityCheckUpperBound) {
+            mHintSessionWrapper->reportActualWorkDuration(actualDuration);
+        }
     }
 
     mLastDequeueBufferDuration = dequeueBufferDuration;