commit ec7aa8a7287629522b4fab712bad465f0d132be4
author Ady Abraham <adyabr@google.com> Mon Jun 28 12:37:09 2021 -0700
committer Ady Abraham <adyabr@google.com> Mon Jun 28 12:38:41 2021 -0700
tree 059c8517ad2df5d50cdb58222606c0674f49b145
parent b3c68852626da31ae79870defbd54bfd9df7ffdf

SF: check previous present fence to avoid early presentation

If SurfaceFlinger finishes composition a vsyncPeriod or more before it
planned to, it sleeps before calling composer to present the frame to
avoid early presentation. In this CL we are removing the sleep if the
previous present fence is still pending, as early presentation is not
possible (composer has already a frame queued).

Bug: 190842189
Test: Bouncy ball while forcing client composition
Change-Id: Id913a21b3489973d82498c6154843656972b6e1a

services/surfaceflinger/DisplayHardware/HWComposer.h

diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index cd6f9f5..b1849e8 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -27,7 +27,7 @@
 #include <vector>
 
 #include <android-base/thread_annotations.h>
-#include <ui/Fence.h>
+#include <ui/FenceTime.h>
 
 // TODO(b/129481165): remove the #pragma below and fix conversion issues
 #pragma clang diagnostic push
@@ -134,6 +134,7 @@
     virtual status_t getDeviceCompositionChanges(
             HalDisplayId, bool frameUsesClientComposition,
             std::chrono::steady_clock::time_point earliestPresentTime,
+            const std::shared_ptr<FenceTime>& previousPresentFence,
             std::optional<DeviceRequestedChanges>* outChanges) = 0;
 
     virtual status_t setClientTarget(HalDisplayId, uint32_t slot, const sp<Fence>& acquireFence,
@@ -141,7 +142,8 @@
 
     // Present layers to the display and read releaseFences.
     virtual status_t presentAndGetReleaseFences(
-            HalDisplayId, std::chrono::steady_clock::time_point earliestPresentTime) = 0;
+            HalDisplayId, std::chrono::steady_clock::time_point earliestPresentTime,
+            const std::shared_ptr<FenceTime>& previousPresentFence) = 0;
 
     // set power mode
     virtual status_t setPowerMode(PhysicalDisplayId, hal::PowerMode) = 0;
@@ -275,6 +277,7 @@
     status_t getDeviceCompositionChanges(
             HalDisplayId, bool frameUsesClientComposition,
             std::chrono::steady_clock::time_point earliestPresentTime,
+            const std::shared_ptr<FenceTime>& previousPresentFence,
             std::optional<DeviceRequestedChanges>* outChanges) override;
 
     status_t setClientTarget(HalDisplayId, uint32_t slot, const sp<Fence>& acquireFence,
@@ -282,7 +285,8 @@
 
     // Present layers to the display and read releaseFences.
     status_t presentAndGetReleaseFences(
-            HalDisplayId, std::chrono::steady_clock::time_point earliestPresentTime) override;
+            HalDisplayId, std::chrono::steady_clock::time_point earliestPresentTime,
+            const std::shared_ptr<FenceTime>& previousPresentFence) override;
 
     // set power mode
     status_t setPowerMode(PhysicalDisplayId, hal::PowerMode mode) override;