Merge "Introduce a LazyJniRegistrar helper class for system server" into main

8 files changed, 118 insertions, 4 deletions

diff --git a/services/core/java/com/android/server/ConsumerIrService.java b/services/core/java/com/android/server/ConsumerIrService.java
index ee6d808aa549..8362079b9009 100644
--- a/services/core/java/com/android/server/ConsumerIrService.java
+++ b/services/core/java/com/android/server/ConsumerIrService.java
@@ -30,6 +30,8 @@ import android.os.RemoteException;
 import android.os.ServiceManager;
 import android.util.Slog;
 
+import com.android.server.utils.LazyJniRegistrar;
+
 public class ConsumerIrService extends IConsumerIrService.Stub {
     private static final String TAG = "ConsumerIrService";
 
@@ -39,6 +41,10 @@ public class ConsumerIrService extends IConsumerIrService.Stub {
     private static native int halTransmit(int carrierFrequency, int[] pattern);
     private static native int[] halGetCarrierFrequencies();
 
+    static {
+        LazyJniRegistrar.registerConsumerIrService();
+    }
+
     private final Context mContext;
     private final PowerManager.WakeLock mWakeLock;
     private final boolean mHasNativeHal;
diff --git a/services/core/java/com/android/server/utils/LazyJniRegistrar.java b/services/core/java/com/android/server/utils/LazyJniRegistrar.java
new file mode 100644
index 000000000000..ac4a92e12909
--- /dev/null
+++ b/services/core/java/com/android/server/utils/LazyJniRegistrar.java
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.utils;
+
+import com.android.tools.r8.keepanno.annotations.KeepItemKind;
+import com.android.tools.r8.keepanno.annotations.MethodAccessFlags;
+import com.android.tools.r8.keepanno.annotations.UsedByNative;
+
+/**
+ * Utility class for lazily registering native methods for a given class.
+ *
+ * <p><strong>Note: </strong>Most native methods are registered eagerly via the
+ * native {@code JNI_OnLoad} hook when system server loads its primary native
+ * lib. However, some classes within system server may be stripped if unused.
+ * This class offers a way to selectively register their native methods. Such
+ * register calls should typically be done from that class's {@code static {}}
+ * init block.
+ */
+@UsedByNative(
+        description = "Referenced from JNI in jni/com_android_server_utils_LazyJniRegistrar.cpp",
+        kind = KeepItemKind.CLASS_AND_MEMBERS,
+        methodAccess = {MethodAccessFlags.NATIVE})
+public final class LazyJniRegistrar {
+
+    // Note: {@link SystemServer#run} loads the native "android_servers" lib, so no need to do so
+    // explicitly here. Classes that use this registration must not be initialized before this.
+
+    /** Registers native methods for ConsumerIrService. */
+    public static native void registerConsumerIrService();
+
+    /** Registers native methods for VrManagerService. */
+    public static native void registerVrManagerService();
+}
diff --git a/services/core/java/com/android/server/utils/OWNERS b/services/core/java/com/android/server/utils/OWNERS
index fbc0b56c2eb7..9f1cc8196736 100644
--- a/services/core/java/com/android/server/utils/OWNERS
+++ b/services/core/java/com/android/server/utils/OWNERS
@@ -10,6 +10,7 @@ per-file Watcher.java = file:/services/core/java/com/android/server/pm/OWNERS
 per-file Watcher.java = shombert@google.com
 per-file EventLogger.java = file:/platform/frameworks/av:/media/janitors/media_solutions_OWNERS
 per-file EventLogger.java = jmtrivi@google.com
+per-file LazyJniRegistrar.java = file:/PERFORMANCE_OWNERS
 
 # Bug component : 158088 = per-file AnrTimer*.java
 per-file AnrTimer*.java = file:/PERFORMANCE_OWNERS
diff --git a/services/core/java/com/android/server/vr/VrManagerService.java b/services/core/java/com/android/server/vr/VrManagerService.java
index 1ff01a6c70bf..9cfe3bab6e0b 100644
--- a/services/core/java/com/android/server/vr/VrManagerService.java
+++ b/services/core/java/com/android/server/vr/VrManagerService.java
@@ -67,6 +67,7 @@ import com.android.server.FgThread;
 import com.android.server.LocalServices;
 import com.android.server.SystemConfig;
 import com.android.server.SystemService;
+import com.android.server.utils.LazyJniRegistrar;
 import com.android.server.utils.ManagedApplicationService;
 import com.android.server.utils.ManagedApplicationService.BinderChecker;
 import com.android.server.utils.ManagedApplicationService.LogEvent;
@@ -131,6 +132,10 @@ public class VrManagerService extends SystemService
     private static native void initializeNative();
     private static native void setVrModeNative(boolean enabled);
 
+    static {
+        LazyJniRegistrar.registerVrManagerService();
+    }
+
     private final Object mLock = new Object();
 
     private final IBinder mOverlayToken = new Binder();
diff --git a/services/core/jni/Android.bp b/services/core/jni/Android.bp
index 662f916d8a69..a60769c91eda 100644
--- a/services/core/jni/Android.bp
+++ b/services/core/jni/Android.bp
@@ -75,6 +75,7 @@ cc_library_static {
         "com_android_server_am_LowMemDetector.cpp",
         "com_android_server_pm_PackageManagerShellCommandDataLoader.cpp",
         "com_android_server_sensor_SensorService.cpp",
+        "com_android_server_utils_LazyJniRegistrar.cpp",
         "com_android_server_wm_TaskFpsCallbackController.cpp",
         "onload.cpp",
         ":lib_cachedAppOptimizer_native",
diff --git a/services/core/jni/OWNERS b/services/core/jni/OWNERS
index b622751fc3e8..8052b092a1e1 100644
--- a/services/core/jni/OWNERS
+++ b/services/core/jni/OWNERS
@@ -30,6 +30,7 @@ per-file com_android_server_vibrator_* = file:/services/core/java/com/android/se
 per-file com_android_server_am_CachedAppOptimizer.cpp = file:/PERFORMANCE_OWNERS
 per-file com_android_server_am_Freezer.cpp = file:/PERFORMANCE_OWNERS
 per-file com_android_server_companion_virtual_InputController.cpp = file:/services/companion/java/com/android/server/companion/virtual/OWNERS
+per-file com_android_server_utils_LazyJniRegistrar.cpp = file:/PERFORMANCE_OWNERS
 
 # Memory
 per-file com_android_server_am_OomConnection.cpp = file:/MEMORY_OWNERS
diff --git a/services/core/jni/com_android_server_utils_LazyJniRegistrar.cpp b/services/core/jni/com_android_server_utils_LazyJniRegistrar.cpp
new file mode 100644
index 000000000000..ad7781e3b8b5
--- /dev/null
+++ b/services/core/jni/com_android_server_utils_LazyJniRegistrar.cpp
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <nativehelper/JNIHelp.h>
+
+#include "jni.h"
+
+namespace android {
+
+// Forward declared per-class registration methods.
+int register_android_server_ConsumerIrService(JNIEnv* env);
+int register_android_server_vr_VrManagerService(JNIEnv* env);
+
+namespace {
+
+// TODO(b/)375264322: Remove these trampoline methods after finalizing the
+// registrar implementation. Instead, just update the called methods to take a
+// class arg, and hand those methods to jniRegisterNativeMethods directly.
+void registerConsumerIrService(JNIEnv* env, jclass) {
+    register_android_server_ConsumerIrService(env);
+}
+
+void registerVrManagerService(JNIEnv* env, jclass) {
+    register_android_server_vr_VrManagerService(env);
+}
+
+static const JNINativeMethod sJniRegistrarMethods[] = {
+        {"registerConsumerIrService", "()V", (void*)registerConsumerIrService},
+        {"registerVrManagerService", "()V", (void*)registerVrManagerService},
+};
+
+} // namespace
+
+int register_android_server_utils_LazyJniRegistrar(JNIEnv* env) {
+    return jniRegisterNativeMethods(env, "com/android/server/utils/LazyJniRegistrar",
+                                    sJniRegistrarMethods, NELEM(sJniRegistrarMethods));
+}
+
+} // namespace android
diff --git a/services/core/jni/onload.cpp b/services/core/jni/onload.cpp
index f9633e2e0b23..e56688b59f3f 100644
--- a/services/core/jni/onload.cpp
+++ b/services/core/jni/onload.cpp
@@ -25,7 +25,6 @@
 
 namespace android {
 int register_android_server_BatteryStatsService(JNIEnv* env);
-int register_android_server_ConsumerIrService(JNIEnv *env);
 int register_android_server_InputManager(JNIEnv* env);
 int register_android_server_LightsService(JNIEnv* env);
 int register_android_server_PowerManagerService(JNIEnv* env);
@@ -38,7 +37,6 @@ int register_android_server_UsbAlsaJackDetector(JNIEnv* env);
 int register_android_server_UsbAlsaMidiDevice(JNIEnv* env);
 int register_android_server_UsbDeviceManager(JNIEnv* env);
 int register_android_server_UsbHostManager(JNIEnv* env);
-int register_android_server_vr_VrManagerService(JNIEnv* env);
 int register_android_server_vibrator_VibratorController(JavaVM* vm, JNIEnv* env);
 int register_android_server_vibrator_VibratorManagerService(JavaVM* vm, JNIEnv* env);
 int register_android_server_location_GnssLocationProvider(JNIEnv* env);
@@ -55,6 +53,7 @@ int register_android_server_am_OomConnection(JNIEnv* env);
 int register_android_server_am_CachedAppOptimizer(JNIEnv* env);
 int register_android_server_am_LowMemDetector(JNIEnv* env);
 int register_android_server_utils_AnrTimer(JNIEnv *env);
+int register_android_server_utils_LazyJniRegistrar(JNIEnv* env);
 int register_com_android_server_soundtrigger_middleware_AudioSessionProviderImpl(JNIEnv* env);
 int register_com_android_server_soundtrigger_middleware_ExternalCaptureStateTracker(JNIEnv* env);
 int register_android_server_com_android_server_pm_PackageManagerShellCommandDataLoader(JNIEnv* env);
@@ -71,6 +70,9 @@ int register_com_android_server_display_DisplayControl(JNIEnv* env);
 int register_com_android_server_SystemClockTime(JNIEnv* env);
 int register_android_server_display_smallAreaDetectionController(JNIEnv* env);
 int register_com_android_server_accessibility_BrailleDisplayConnection(JNIEnv* env);
+
+// Note: Consider adding new JNI entrypoints for optional services to
+// LazyJniRegistrar instead, and relying on lazy registration.
 };
 
 using namespace android;
@@ -98,14 +100,12 @@ extern "C" jint JNI_OnLoad(JavaVM* vm, void* /* reserved */)
     register_android_server_UsbAlsaJackDetector(env);
     register_android_server_UsbAlsaMidiDevice(env);
     register_android_server_UsbHostManager(env);
-    register_android_server_vr_VrManagerService(env);
     register_android_server_vibrator_VibratorController(vm, env);
     register_android_server_vibrator_VibratorManagerService(vm, env);
     register_android_server_SystemServer(env);
     register_android_server_location_GnssLocationProvider(env);
     register_android_server_connectivity_Vpn(env);
     register_android_server_devicepolicy_CryptoTestHelper(env);
-    register_android_server_ConsumerIrService(env);
     register_android_server_BatteryStatsService(env);
     register_android_server_tv_TvUinputBridge(env);
     register_android_server_tv_TvInputHal(env);
@@ -118,6 +118,7 @@ extern "C" jint JNI_OnLoad(JavaVM* vm, void* /* reserved */)
     register_android_server_am_CachedAppOptimizer(env);
     register_android_server_am_LowMemDetector(env);
     register_android_server_utils_AnrTimer(env);
+    register_android_server_utils_LazyJniRegistrar(env);
     register_com_android_server_soundtrigger_middleware_AudioSessionProviderImpl(env);
     register_com_android_server_soundtrigger_middleware_ExternalCaptureStateTracker(env);
     register_android_server_com_android_server_pm_PackageManagerShellCommandDataLoader(env);