From 4b60d29375d3422e4d08382c44b0faa5343f6eda Mon Sep 17 00:00:00 2001
From: Yurii Zubrytskyi <zyy@google.com>
Date: Thu, 1 Dec 2022 00:34:09 -0800
Subject: [PATCH] Move IO from under the ResourcesManager lock

ApkAssets.isUpToDate() performs IO for many types of assets,
and doing it under a highly contended lock may cause visible
jank.

Given that we don't have to remove the key right at the time of
the lookup, it's fine to move the up-to-date check out of the
lock - if it's not, the function would replace the outdated
asset anyway

Bug: 259941466
Test: build + boot
Change-Id: I8828deadc82180e93bbd9fc34f80a7bd9411d4ad
---
 core/java/android/app/ResourcesManager.java | 26 +++++++++++----------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/core/java/android/app/ResourcesManager.java b/core/java/android/app/ResourcesManager.java
index d275c8336251d..322176100e926 100644
--- a/core/java/android/app/ResourcesManager.java
+++ b/core/java/android/app/ResourcesManager.java
@@ -305,9 +305,13 @@ public class ResourcesManager {
             for (int i = mCachedApkAssets.size() - 1; i >= 0; i--) {
                 final ApkKey key = mCachedApkAssets.keyAt(i);
                 if (key.path.equals(path)) {
-                    WeakReference<ApkAssets> apkAssetsRef = mCachedApkAssets.removeAt(i);
-                    if (apkAssetsRef != null && apkAssetsRef.get() != null) {
-                        apkAssetsRef.get().close();
+                    final WeakReference<ApkAssets> apkAssetsRef = mCachedApkAssets.removeAt(i);
+                    if (apkAssetsRef == null) {
+                        continue;
+                    }
+                    final ApkAssets apkAssets = apkAssetsRef.get();
+                    if (apkAssets != null) {
+                        apkAssets.close();
                     }
                 }
             }
@@ -446,16 +450,14 @@ public class ResourcesManager {
         ApkAssets apkAssets;
 
         // Optimistically check if this ApkAssets exists somewhere else.
+        final WeakReference<ApkAssets> apkAssetsRef;
         synchronized (mLock) {
-            final WeakReference<ApkAssets> apkAssetsRef = mCachedApkAssets.get(key);
-            if (apkAssetsRef != null) {
-                apkAssets = apkAssetsRef.get();
-                if (apkAssets != null && apkAssets.isUpToDate()) {
-                    return apkAssets;
-                } else {
-                    // Clean up the reference.
-                    mCachedApkAssets.remove(key);
-                }
+            apkAssetsRef = mCachedApkAssets.get(key);
+        }
+        if (apkAssetsRef != null) {
+            apkAssets = apkAssetsRef.get();
+            if (apkAssets != null && apkAssets.isUpToDate()) {
+                return apkAssets;
             }
         }