commit 2713c30843816d3511b39b85a2c268a2b7682047
author Dan Stoza <stoza@google.com> Wed Mar 28 17:07:36 2018 -0700
committer Jorim Jaggi <jjaggi@google.com> Fri Apr 06 12:16:58 2018 +0000
tree 29ad7dff46cb10aca4c03652c012637dfa0d843f
parent c650f6215df216542f16918c8477ea2f73e9214d

Early wake-up for transitions (1/2)

On some devices it's very likely that we fall into GL comp during
app transitions. However, SF offsets are chosen in a way such that
the time to finish a frame is just too tight to be completely jank
free when hitting GL composition in SurfaceFlinger. Thus, we
introduce the concept of a separate early offset, and wakeup
SurfaceFlinger at that time if we think that hitting GL comp is
likely, or we already hit GL comp in the last frame.

Test: Open app, check vsync offsets in systrace
Test: Open many dialogs/apps to fall into GPU comp.
Bug: 75985430
Change-Id: Ie17e30c4575359fa11bb8912f68dcafe3e569ddb
Merged-In: Ie17e30c4575359fa11bb8912f68dcafe3e569ddb

libs/gui/SurfaceComposerClient.cpp

diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index bbf681e..63560c4 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -101,7 +101,8 @@
 SurfaceComposerClient::Transaction::Transaction(const Transaction& other) :
     mForceSynchronous(other.mForceSynchronous),
     mTransactionNestCount(other.mTransactionNestCount),
-    mAnimation(other.mAnimation) {
+    mAnimation(other.mAnimation),
+    mEarlyWakeup(other.mEarlyWakeup) {
     mDisplayStates = other.mDisplayStates;
     mComposerStates = other.mComposerStates;
 }
@@ -157,9 +158,13 @@
     if (mAnimation) {
         flags |= ISurfaceComposer::eAnimation;
     }
+    if (mEarlyWakeup) {
+        flags |= ISurfaceComposer::eEarlyWakeup;
+    }
 
     mForceSynchronous = false;
     mAnimation = false;
+    mEarlyWakeup = false;
 
     sf->setTransactionState(composerStates, displayStates, flags);
     mStatus = NO_ERROR;
@@ -185,6 +190,10 @@
     mAnimation = true;
 }
 
+void SurfaceComposerClient::Transaction::setEarlyWakeup() {
+    mEarlyWakeup = true;
+}
+
 layer_state_t* SurfaceComposerClient::Transaction::getLayerState(const sp<SurfaceControl>& sc) {
     if (mComposerStates.count(sc) == 0) {
         // we don't have it, add an initialized layer_state to our list

libs/gui/include/gui/ISurfaceComposer.h

diff --git a/libs/gui/include/gui/ISurfaceComposer.h b/libs/gui/include/gui/ISurfaceComposer.h
index 3591090..e401572 100644
--- a/libs/gui/include/gui/ISurfaceComposer.h
+++ b/libs/gui/include/gui/ISurfaceComposer.h
@@ -61,6 +61,11 @@
     enum {
         eSynchronous = 0x01,
         eAnimation   = 0x02,
+
+        // Indicates that this transaction will likely result in a lot of layers being composed, and
+        // thus, SurfaceFlinger should wake-up earlier to avoid missing frame deadlines. In this
+        // case SurfaceFlinger will wake up at (sf vsync offset - debug.sf.early_phase_offset_ns)
+        eEarlyWakeup = 0x04
     };
 
     enum {

libs/gui/include/gui/SurfaceComposerClient.h

diff --git a/libs/gui/include/gui/SurfaceComposerClient.h b/libs/gui/include/gui/SurfaceComposerClient.h
index ffc22f6..377fe68 100644
--- a/libs/gui/include/gui/SurfaceComposerClient.h
+++ b/libs/gui/include/gui/SurfaceComposerClient.h
@@ -154,6 +154,7 @@
         uint32_t                    mForceSynchronous = 0;
         uint32_t                    mTransactionNestCount = 0;
         bool                        mAnimation = false;
+        bool                        mEarlyWakeup = false;
 
         int mStatus = NO_ERROR;
 
@@ -273,6 +274,7 @@
                 const Rect& displayRect);
         void setDisplaySize(const sp<IBinder>& token, uint32_t width, uint32_t height);
         void setAnimationTransaction();
+        void setEarlyWakeup();
     };
 
     status_t    destroySurface(const sp<IBinder>& id);