Merge "Introduce JniStringCache to cache jstring instances." into main (7f3309cd) · Commits · e / os / android_frameworks_base

core/java/android/app/ActivityThread.java

+8 −0

Original line number	Diff line number	Diff line
		@@ -246,6 +246,7 @@ import com.android.internal.os.BackgroundThread;
		import com.android.internal.os.BinderCallsStats;
		import com.android.internal.os.BinderInternal;
		import com.android.internal.os.DebugStore;
		import com.android.internal.os.JniStringCache;
		import com.android.internal.os.RuntimeInit;
		import com.android.internal.os.SafeZipPathValidatorCallback;
		import com.android.internal.os.SomeArgs;
		@@ -1948,6 +1949,9 @@ public final class ActivityThread extends ClientTransactionHandler
		if (dumpAllocatorStats) {
		Debug.logAllocatorStats();
		}

		pw.println(" ");
		JniStringCache.dump(pw);
		}

		@NeverCompile
		@@ -7686,6 +7690,10 @@ public final class ActivityThread extends ClientTransactionHandler
		}
		if (DEBUG_MEMORY_TRIM) Slog.v(TAG, "Trimming memory to level: " + level);

		if (level >= ComponentCallbacks2.TRIM_MEMORY_BACKGROUND) {
		JniStringCache.clear();
		}

		try {
		if (skipBgMemTrimOnFgApp()
		&& mLastProcessState <= ActivityManager.PROCESS_STATE_IMPORTANT_FOREGROUND

core/java/android/os/flags.aconfig

+7 −0

Original line number	Diff line number	Diff line
		@@ -370,6 +370,13 @@ flag {
		bug: "345802719"
		}

		flag {
		name: "parcel_string_cache_enabled"
		namespace: "system_performance"
		description: "Enable JNIStringCache in Parcel"
		bug: "442140362"
		}

		flag {
		name: "remove_app_profiler_pss_collection"
		is_exported: true

core/java/com/android/internal/os/JniStringCache.java

0 → 100644

+67 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2025 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.internal.os;

		import dalvik.annotation.optimization.CriticalNative;
		import dalvik.annotation.optimization.NeverCompile;
		import java.io.PrintWriter;

		/** Java companion to native JNIStringCache class. */
		public final class JniStringCache {

		/** Dumps cache statistics to the given writer. */
		@NeverCompile
		public static void dump(PrintWriter pw) {
		if (!android.os.Flags.parcelStringCacheEnabled()) {
		return;
		}

		pw.println("JniStringCache");
		pw.format(
		" Hits: %,10d Misses: %,10d\n",
		nativeHits(), nativeMisses());
		pw.format(
		" Evictions: %,10d Skips: %,10d\n",
		nativeEvictions(), nativeSkips());
		pw.flush();
		pw.println(" ");
		}

		/** Clears the cache. */
		public static void clear() {
		if (!android.os.Flags.parcelStringCacheEnabled()) {
		return;
		}

		nativeClear();
		}

		@CriticalNative
		private static native long nativeHits();

		@CriticalNative
		private static native long nativeMisses();

		@CriticalNative
		private static native long nativeEvictions();

		@CriticalNative
		private static native long nativeSkips();

		@CriticalNative
		private static native void nativeClear();
		}

core/java/com/android/internal/os/OWNERS

+3 −0

Original line number	Diff line number	Diff line
		@@ -22,3 +22,6 @@ per-file ApplicationSharedMemory = file:/PERFORMANCE_OWNERS

		# Memcg memory accounting
		per-file MemcgProcMemoryUtil.java = file:/PERFORMANCE_OWNERS

		# JniStringCache
		per-file JniStringCache = file:/PERFORMANCE_OWNERS

core/jni/Android.bp

+1 −0

Original line number	Diff line number	Diff line
		@@ -258,6 +258,7 @@ cc_library_shared_for_libandroid_runtime {
		"com_android_internal_os_ClassLoaderFactory.cpp",
		"com_android_internal_os_DebugStore.cpp",
		"com_android_internal_os_FuseAppLoop.cpp",
		"com_android_internal_os_JniStringCache.cpp",
		"com_android_internal_os_KernelAllocationStats.cpp",
		"com_android_internal_os_KernelCpuBpfTracking.cpp",
		"com_android_internal_os_KernelCpuTotalBpfMapReader.cpp",