From 124d0c675a3c0d4fcd48e5af8463b8b938b09080 Mon Sep 17 00:00:00 2001
From: Matt Buckley <mattbuckley@google.com>
Date: Thu, 19 Jan 2023 03:04:19 +0000
Subject: [PATCH] Move hint session initialization to setSurface

Hint session initialization was previously during draw() which can be
problematic as it's not guaranteed to have unblocked choreographer yet.
This moves it somewhere less problematic, and reports actual work
durations in a separate renderthread callback to ensure these binders
don't block the critical path more than necessary.

Bug: 263755904
Test: manual
Change-Id: Icd7e1fcd84cd3f493bea34d1b48d14444d2f5b68
---
 libs/hwui/renderthread/CanvasContext.cpp      |  2 ++
 libs/hwui/renderthread/HintSessionWrapper.cpp | 24 ++++++++-----------
 libs/hwui/renderthread/HintSessionWrapper.h   |  3 +--
 3 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/libs/hwui/renderthread/CanvasContext.cpp b/libs/hwui/renderthread/CanvasContext.cpp
index f223137241d15..6f549dcb5a976 100644
--- a/libs/hwui/renderthread/CanvasContext.cpp
+++ b/libs/hwui/renderthread/CanvasContext.cpp
@@ -194,6 +194,8 @@ void CanvasContext::setSurface(ANativeWindow* window, bool enableTimeout) {
     ATRACE_CALL();
 
     if (window) {
+        // Ensure the hint session is running here, away from any critical paths
+        mHintSessionWrapper.init();
         mNativeSurface = std::make_unique<ReliableSurface>(window);
         mNativeSurface->init();
         if (enableTimeout) {
diff --git a/libs/hwui/renderthread/HintSessionWrapper.cpp b/libs/hwui/renderthread/HintSessionWrapper.cpp
index dece548e9dc19..8c9f65fac10c4 100644
--- a/libs/hwui/renderthread/HintSessionWrapper.cpp
+++ b/libs/hwui/renderthread/HintSessionWrapper.cpp
@@ -95,17 +95,13 @@ HintSessionWrapper::~HintSessionWrapper() {
     }
 }
 
-bool HintSessionWrapper::useHintSession() {
-    if (!Properties::useHintManager || !Properties::isDrawingEnabled()) return false;
-    if (mHintSession) return true;
-    // If session does not exist, create it;
-    // this defers session creation until we try to actually use it.
-    if (!mSessionValid) return false;
-    return init();
-}
-
 bool HintSessionWrapper::init() {
-    if (mUiThreadId < 0 || mRenderThreadId < 0) return false;
+    // If it already exists, broke last time we tried this, shouldn't be running, or
+    // has bad argument values, don't even bother
+    if (mHintSession != nullptr || !mSessionValid || !Properties::useHintManager ||
+        !Properties::isDrawingEnabled() || mUiThreadId < 0 || mRenderThreadId < 0) {
+        return false;
+    }
 
     // Assume that if we return before the end, it broke
     mSessionValid = false;
@@ -130,7 +126,7 @@ bool HintSessionWrapper::init() {
 }
 
 void HintSessionWrapper::updateTargetWorkDuration(long targetWorkDurationNanos) {
-    if (!useHintSession()) return;
+    if (mHintSession == nullptr) return;
     targetWorkDurationNanos = targetWorkDurationNanos * Properties::targetCpuTimePercentage / 100;
     if (targetWorkDurationNanos != mLastTargetWorkDuration &&
         targetWorkDurationNanos > kSanityCheckLowerBound &&
@@ -142,7 +138,7 @@ void HintSessionWrapper::updateTargetWorkDuration(long targetWorkDurationNanos)
 }
 
 void HintSessionWrapper::reportActualWorkDuration(long actualDurationNanos) {
-    if (!useHintSession()) return;
+    if (mHintSession == nullptr) return;
     if (actualDurationNanos > kSanityCheckLowerBound &&
         actualDurationNanos < kSanityCheckUpperBound) {
         gAPH_reportActualWorkDurationFn(mHintSession, actualDurationNanos);
@@ -150,7 +146,7 @@ void HintSessionWrapper::reportActualWorkDuration(long actualDurationNanos) {
 }
 
 void HintSessionWrapper::sendLoadResetHint() {
-    if (!useHintSession()) return;
+    if (mHintSession == nullptr) return;
     nsecs_t now = systemTime();
     if (now - mLastFrameNotification > kResetHintTimeout) {
         gAPH_sendHintFn(mHintSession, static_cast<int>(SessionHint::CPU_LOAD_RESET));
@@ -159,7 +155,7 @@ void HintSessionWrapper::sendLoadResetHint() {
 }
 
 void HintSessionWrapper::sendLoadIncreaseHint() {
-    if (!useHintSession()) return;
+    if (mHintSession == nullptr) return;
     gAPH_sendHintFn(mHintSession, static_cast<int>(SessionHint::CPU_LOAD_UP));
 }
 
diff --git a/libs/hwui/renderthread/HintSessionWrapper.h b/libs/hwui/renderthread/HintSessionWrapper.h
index c0f7a57bed754..f2f1298c1eec7 100644
--- a/libs/hwui/renderthread/HintSessionWrapper.h
+++ b/libs/hwui/renderthread/HintSessionWrapper.h
@@ -34,10 +34,9 @@ public:
     void reportActualWorkDuration(long actualDurationNanos);
     void sendLoadResetHint();
     void sendLoadIncreaseHint();
+    bool init();
 
 private:
-    bool useHintSession();
-    bool init();
     APerformanceHintSession* mHintSession = nullptr;
 
     nsecs_t mLastFrameNotification = 0;