SystemServiceRegistry: Replace ArrayMap with HashMap for performance

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

PackageManagerService 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]
               |    |
               |    |--5.42%-- android.app.SystemServiceRegistry.getSystemService
               |    |          android.app.ContextImpl.getSystemService
               |    |          android.view.ContextThemeWrapper.getSystemService
               |    |          android.app.Activity.getSystemService
               |    |    |
               |    |    |--52.18%-- TemporaryFile-kEdnnv[+9b97baa8]
               |    |    |           TemporaryFile-FwF2he[+9b96d048]
               |    |    |           art_quick_invoke_stub
               |    |    |           art::ArtMethod::Invoke(art::Thread*, unsigned int*, unsigned int, art::JValue*, char const*)
               |    |    |           art::interpreter::ArtInterpreterToCompiledCodeBridge(art::Thread*, art::ArtMethod*, art::ShadowFrame*, unsigned short, art::JValue*)
               |    |    |           bool art::interpreter::DoCall<false, false>(art::ArtMethod*, art::Thread*, art::ShadowFrame&, art::Instruction const*, unsigned short, art::JValue*)
               |    |    |           MterpInvokeVirtual
               |    |    |           mterp_op_invoke_virtual
               |    |    |           libcrypto.so[+3fac6]
               |    |    |           MterpInvokeDirect
               |    |    |           mterp_op_invoke_direct
               |    |    |           libcrypto.so[+3faa8]
               |    |    |           MterpInvokeVirtual
               |    |    |           mterp_op_invoke_virtual
               |    |    |           libcrypto.so[+3730c]
               |    |    |           art::interpreter::Execute(art::Thread*, art::CodeItemDataAccessor const&, art::ShadowFrame&, art::JValue, bool, bool) (.llvm.13341777805210357670)
               |    |    |           artQuickToInterpreterBridge
               |    |    |           art_quick_to_interpreter_bridge
               |    |    |           java.util.concurrent.Executors$RunnableAdapter.call
               |    |    |           java.util.concurrent.FutureTask.run
               |    |    |           java.util.concurrent.ThreadPoolExecutor.runWorker
               |    |    |           java.util.concurrent.ThreadPoolExecutor$Worker.run
               |    |    |           java.lang.Thread.run
               |    |    |           art_quick_invoke_stub
               |    |    |           art::ArtMethod::Invoke(art::Thread*, unsigned int*, unsigned int, art::JValue*, char const*)
               |    |    |           art::JValue art::InvokeVirtualOrInterfaceWithJValues<art::ArtMethod*>(art::ScopedObjectAccessAlreadyRunnable const&, _jobject*, art::ArtMethod*, jvalue const*)
               |    |    |           art::Thread::CreateCallback(void*)
               |    |    |           __pthread_start(void*)
               |    |    |           __start_thread
               |    |    |
               |    |     --47.82%-- android.view.ContextThemeWrapper.getSystemService
               |    |                android.view.ContextThemeWrapper.getSystemService
               |    |                android.content.Context.getSystemService
               |    |                android.view.View.onVisibilityAggregated
               |    |                android.view.View.dispatchAttachedToWindow
               |    |                android.view.ViewGroup.dispatchAttachedToWindow
               |    |                android.view.ViewGroup.dispatchAttachedToWindow
               |    |                android.view.ViewGroup.dispatchAttachedToWindow
               |    |                android.view.ViewGroup.dispatchAttachedToWindow
               |    |                android.view.ViewGroup.dispatchAttachedToWindow
               |    |                android.view.ViewGroup.dispatchAttachedToWindow
               |    |                android.view.ViewGroup.dispatchAttachedToWindow
               |    |                android.view.ViewRootImpl.performTraversals
               |    |                android.view.ViewRootImpl.doTraversal
               |    |                android.content.ContextWrapper.getAssets [DEDUPED]
               |    |                android.view.Choreographer.doCallbacks
               |    |                android.view.Choreographer.doFrame
               |    |                android.view.Choreographer$FrameDisplayEventReceiver.run
               |    |                android.os.Handler.dispatchMessage
               |    |                android.os.Looper.loop
               |    |                android.app.ActivityThread.main
               |    |                art_quick_invoke_static_stub
               |    |                art::ArtMethod::Invoke(art::Thread*, unsigned int*, unsigned int, art::JValue*, char const*)
               |    |                art::InvokeMethod(art::ScopedObjectAccessAlreadyRunnable const&, _jobject*, _jobject*, _jobject*, unsigned long)
               |    |                art::Method_invoke(_JNIEnv*, _jobject*, _jobject*, _jobjectArray*)
               |    |                art_jni_trampoline
               |    |                com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run
               |    |                com.android.internal.os.ZygoteInit.main
               |    |                art_quick_invoke_static_stub
               |    |                art::ArtMethod::Invoke(art::Thread*, unsigned int*, unsigned int, art::JValue*, char const*)
               |    |                art::JValue art::InvokeWithVarArgs<art::ArtMethod*>(art::ScopedObjectAccessAlreadyRunnable const&, _jobject*, art::ArtMethod*, std::__va_list)
               |    |                art::JValue art::InvokeWithVarArgs<_jmethodID*>(art::ScopedObjectAccessAlreadyRunnable const&, _jobject*, _jmethodID*, std::__va_list)
               |    |                art::JNI<true>::CallStaticVoidMethodV(_JNIEnv*, _jclass*, _jmethodID*, std::__va_list)
               |    |                _JNIEnv::CallStaticVoidMethod(_jclass*, _jmethodID*, ...)
               |    |                android::AndroidRuntime::start(char const*, android::Vector<android::String8> const&, bool)
               |    |                main
               |    |                __libc_init
               |    |

Empirical testing reveals that SYSTEM_SERVICE_FETCHERS contains 134
entries, at which HashMap is 54% faster than ArrayMap for lookups and
74% faster [1] for insertions. The increased memory usage should be
a worthwhile trade-off at this size, so we can safely convert the map
to a HashMap in order to improve performance in this hotpath.

Because SYSTEM_SERVICE_NAMES, SYSTEM_SERVICE_FETCHERS, and
SYSTEM_SERVICE_CLASS_NAMES have the same names and similar uses, all of
them have been converted to HashMaps for consistency and performance.

[1] https://docs.google.com/spreadsheets/d/136UJS2yVlZyPx30KDNgj4AWldkp9xbzIcWkLFj9RGgk/edit

Test: simpleperf record -a; verify that SystemServiceRegistry no longer
      appears under ArrayMap.binarySearchHashes
Change-Id: I2a5b23793a4fc8aa720eead3ecc7ca4589cb67da

1 files changed, 4 insertions, 4 deletions

diff --git a/core/java/android/app/SystemServiceRegistry.java b/core/java/android/app/SystemServiceRegistry.java
index 32ea41b2c75f..e727b78e8add 100644
--- a/core/java/android/app/SystemServiceRegistry.java
+++ b/core/java/android/app/SystemServiceRegistry.java
@@ -202,7 +202,6 @@ import android.telecom.TelecomManager;
 import android.telephony.MmsManager;
 import android.telephony.TelephonyFrameworkInitializer;
 import android.telephony.TelephonyRegistryManager;
-import android.util.ArrayMap;
 import android.util.Log;
 import android.util.Slog;
 import android.uwb.UwbManager;
@@ -234,6 +233,7 @@ import com.android.internal.os.IDropBoxManagerService;
 import com.android.internal.policy.PhoneLayoutInflater;
 import com.android.internal.util.Preconditions;
 
+import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
 
@@ -253,10 +253,10 @@ public final class SystemServiceRegistry {
     // Service registry information.
     // This information is never changed once static initialization has completed.
     private static final Map<Class<?>, String> SYSTEM_SERVICE_NAMES =
-            new ArrayMap<Class<?>, String>();
+            new HashMap<Class<?>, String>();
     private static final Map<String, ServiceFetcher<?>> SYSTEM_SERVICE_FETCHERS =
-            new ArrayMap<String, ServiceFetcher<?>>();
-    private static final Map<String, String> SYSTEM_SERVICE_CLASS_NAMES = new ArrayMap<>();
+            new HashMap<String, ServiceFetcher<?>>();
+    private static final Map<String, String> SYSTEM_SERVICE_CLASS_NAMES = new HashMap<>();
 
     private static int sServiceCacheSize;