commit 42ccc9346c6036feec6b658405a3905613cf199f
author Dominik Laskowski <domlaskowski@google.com> Thu Apr 20 10:08:04 2023 -0400
committer Dominik Laskowski <domlaskowski@google.com> Fri Apr 21 13:30:23 2023 -0400
tree b5c4b33f1bfa6e8e1b54fd426eeb75acbd564104
parent 84a221ab1ffe75608573ea8d1772e4a3a447c1a6

SF: Extract SurfaceFlinger::wouldPresentEarly

Short-circuit a few fetches and arithmetic operations.

Bug: 241285475
Test: libscheduler_test after Idf9f43b37f3479c94a478d154eaa46f43e0c6c9d
Change-Id: Ib40794cca0c44f8151ca9f37ba58ac4d892c66ee

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 38f8db0..7171adc 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -2146,7 +2146,13 @@
     }));
 }
 
-auto SurfaceFlinger::getPreviousPresentFence(TimePoint frameTime, Period vsyncPeriod)
+bool SurfaceFlinger::wouldPresentEarly(TimePoint frameTime, Period vsyncPeriod) const {
+    const bool isThreeVsyncsAhead = mExpectedPresentTime - frameTime > 2 * vsyncPeriod;
+    return isThreeVsyncsAhead ||
+            mPreviousPresentFences[0].fenceTime->getSignalTime() != Fence::SIGNAL_TIME_PENDING;
+}
+
+auto SurfaceFlinger::getPreviousPresentFence(TimePoint frameTime, Period vsyncPeriod) const
         -> const FenceTimePtr& {
     const bool isTwoVsyncsAhead = mExpectedPresentTime - frameTime > vsyncPeriod;
     const size_t i = static_cast<size_t>(isTwoVsyncsAhead);
@@ -2610,21 +2616,14 @@
         refreshArgs.devOptFlashDirtyRegionsDelay = std::chrono::milliseconds(mDebugFlashDelay);
     }
 
-    const auto prevVsyncTime = mExpectedPresentTime - mScheduler->getVsyncSchedule()->period();
-    const auto hwcMinWorkDuration = mVsyncConfiguration->getCurrentConfigs().hwcMinWorkDuration;
-
     const Period vsyncPeriod = mScheduler->getVsyncSchedule()->period();
-    const bool threeVsyncsAhead = mExpectedPresentTime - frameTime > 2 * vsyncPeriod;
 
-    // We should wait for the earliest present time if HWC doesn't support ExpectedPresentTime,
-    // and the next vsync is not already taken by the previous frame.
-    const bool waitForEarliestPresent =
-            !getHwComposer().getComposer()->isSupported(
-                    Hwc2::Composer::OptionalFeature::ExpectedPresentTime) &&
-            (threeVsyncsAhead ||
-             mPreviousPresentFences[0].fenceTime->getSignalTime() != Fence::SIGNAL_TIME_PENDING);
+    if (!getHwComposer().getComposer()->isSupported(
+                Hwc2::Composer::OptionalFeature::ExpectedPresentTime) &&
+        wouldPresentEarly(frameTime, vsyncPeriod)) {
+        const auto prevVsyncTime = mExpectedPresentTime - vsyncPeriod;
+        const auto hwcMinWorkDuration = mVsyncConfiguration->getCurrentConfigs().hwcMinWorkDuration;
 
-    if (waitForEarliestPresent) {
         refreshArgs.earliestPresentTime = prevVsyncTime - hwcMinWorkDuration;
     }