ThemedResourceCache: Replace ArrayMap with HashMap for performance

kdrag0n · kdrag0n · commit a5e881cab16e · 2021-10-16T05:58:26.000-07:00
When opening and closing activities in Settings, a significant amount of CPU time is spent looking up ArrayMap entries, as reported by simpleperf: 0.12% /system/framework/arm64/boot-framework.oat android.util.ArrayMap.binarySearchHashes ThemedResourceCache is responsible for a significant portion of the time spent in ArrayMap lookups: 0.08% 0.08% /system/framework/arm64/boot-framework.oat android.util.ArrayMap.binarySearchHashes | -- android.util.ArrayMap.binarySearchHashes | --50.00%-- android.util.ArrayMap.indexOf | |--36.71%-- android.util.ArrayMap.get | |--0.87%-- [hit in function] | | | |--9.64%-- android.content.res.ThemedResourceCache.getThemedLocked | | android.content.res.ThemedResourceCache.get | | | | | |--77.92%-- android.content.res.DrawableCache.getInstance | | | android.content.res.ResourcesImpl.loadDrawable | | | android.content.res.Resources.loadDrawable | | | android.content.res.TypedArray.getDrawableForDensity | | | android.content.res.Resources.getColor [DEDUPED] | | | | | | | |--62.94%-- android.view.View.<init> | | | | | | | | | |--64.58%-- android.view.ViewGroup.<init> | | | | | android.widget.LinearLayout.<init> | | | | | android.widget.LinearLayout.<init> | | | | | art_quick_invoke_stub | | | | | art::ArtMethod::Invoke(art::Thread*, unsigned int*, unsigned int, art::JValue*, char const*) | | | | | art::InvokeConstructor(art::ScopedObjectAccessAlreadyRunnable const&, art::ArtMethod*, art::ObjPtr<art::mirror::Object>, _jobject*) | | | | | art::Constructor_newInstance0(_JNIEnv*, _jobject*, _jobjectArray*) | | | | | art_jni_trampoline | | | | | java.lang.reflect.Constructor.newInstance | | | | | android.view.LayoutInflater.createView | | | | | com.android.internal.policy.PhoneLayoutInflater.onCreateView | | | | | android.view.LayoutInflater.onCreateView | | | | | android.view.LayoutInflater.onCreateView | | | | | android.view.LayoutInflater.createViewFromTag | | | | | android.view.LayoutInflater.inflate | | | | | android.view.LayoutInflater.inflate | | | | | | | | | --35.42%-- android.widget.TextView.<init> | | | | android.widget.Button.<init> | | | | art_quick_invoke_stub | | | | art::ArtMethod::Invoke(art::Thread*, unsigned int*, unsigned int, art::JValue*, char const*) | | | | art::InvokeConstructor(art::ScopedObjectAccessAlreadyRunnable const&, art::ArtMethod*, art::ObjPtr<art::mirror::Object>, _jobject*) | | | | art::Constructor_newInstance0(_JNIEnv*, _jobject*, _jobjectArray*) | | | | art_jni_trampoline | | | | java.lang.reflect.Constructor.newInstance | | | | android.view.LayoutInflater.createView | | | | com.android.internal.policy.PhoneLayoutInflater.onCreateView | | | | android.view.LayoutInflater.onCreateView | | | | android.view.LayoutInflater.onCreateView | | | | android.view.LayoutInflater.createViewFromTag | | | | android.view.LayoutInflater.rInflate | | | | android.view.LayoutInflater.rInflate | | | | android.view.LayoutInflater.rInflate | | | | android.view.LayoutInflater.inflate | | | | android.view.LayoutInflater.inflate | | | | android.view.LayoutInflater.inflate | | | | | | | --37.06%-- com.android.internal.widget.ToolbarWidgetWrapper.<init> | | | | | --22.08%-- android.content.res.ConfigurationBoundResourceCache.get | | android.content.res.ConfigurationBoundResourceCache.getInstance | | android.content.res.ResourcesImpl.loadComplexColorFromName | | android.content.res.ResourcesImpl.loadColorStateList | | android.content.res.Resources.loadColorStateList | | android.content.res.TypedArray.getColorStateList | | android.widget.TextView.readTextAppearance | | android.widget.TextView.setTextAppearance | | android.widget.TextView.setTextAppearance | | android.widget.Toolbar.setTitle | | com.android.wifi.x.com.android.internal.util.StateMachine$SmHandler.handleMessage | | android.view.SurfaceControl.copyFrom Empirical testing reveals that mThemedEntries usually contains around 14 entries, at which HashMap is 35% faster than ArrayMap for lookups and 54% faster [1] for insertions. The increased memory usage should be negligible at this size, so we can safely convert the map to a HashMap in order to improve performance in this hotpath. [1] https://docs.google.com/spreadsheets/d/136UJS2yVlZyPx30KDNgj4AWldkp9xbzIcWkLFj9RGgk/edit Test: simpleperf record -a; verify that ThemedResourceCache no longer appears under ArrayMap.binarySearchHashes Change-Id: I39e1c4b03fe0e60f933f02e253d2d3c4a483146f
diff --git a/core/java/android/content/res/ThemedResourceCache.java b/core/java/android/content/res/ThemedResourceCache.java
@@ -22,10 +22,10 @@
 import android.content.pm.ActivityInfo.Config;
 import android.content.res.Resources.Theme;
 import android.content.res.Resources.ThemeKey;
-import android.util.ArrayMap;
 import android.util.LongSparseArray;
 
 import java.lang.ref.WeakReference;
+import java.util.HashMap;
 
 /**
  * Data structure used for caching data against themes.
@@ -34,7 +34,7 @@
  */
 abstract class ThemedResourceCache<T> {
     @UnsupportedAppUsage
-    private ArrayMap<ThemeKey, LongSparseArray<WeakReference<T>>> mThemedEntries;
+    private HashMap<ThemeKey, LongSparseArray<WeakReference<T>>> mThemedEntries;
     private LongSparseArray<WeakReference<T>> mUnthemedEntries;
     private LongSparseArray<WeakReference<T>> mNullThemedEntries;
 
@@ -154,7 +154,7 @@ private LongSparseArray<WeakReference<T>> getThemedLocked(@Nullable Theme t, boo
 
         if (mThemedEntries == null) {
             if (create) {
-                mThemedEntries = new ArrayMap<>(1);
+                mThemedEntries = new HashMap<>(1);
             } else {
                 return null;
             }
@@ -199,11 +199,8 @@ private LongSparseArray<WeakReference<T>> getUnthemedLocked(boolean create) {
     private boolean prune(@Config int configChanges) {
         synchronized (this) {
             if (mThemedEntries != null) {
-                for (int i = mThemedEntries.size() - 1; i >= 0; i--) {
-                    if (pruneEntriesLocked(mThemedEntries.valueAt(i), configChanges)) {
-                        mThemedEntries.removeAt(i);
-                    }
-                }
+                mThemedEntries.entrySet()
+                    .removeIf(entry -> pruneEntriesLocked(entry.getValue(), configChanges));
             }
 
             pruneEntriesLocked(mNullThemedEntries, configChanges);
