Modify PropertyInvalidatedCache (659dcc86) · Commits · e / os / android_frameworks_base

core/java/android/app/PropertyInvalidatedCache.java

+57 −5

Original line number	Diff line number	Diff line
		@@ -34,6 +34,7 @@ import java.io.IOException;
		import java.io.PrintWriter;
		import java.util.ArrayList;
		import java.util.HashMap;
		import java.util.HashSet;
		import java.util.LinkedHashMap;
		import java.util.Map;
		import java.util.Objects;
		@@ -259,13 +260,20 @@ public abstract class PropertyInvalidatedCache<Query, Result> {
		@GuardedBy("sCorkLock")
		private static final HashMap<String, Integer> sCorks = new HashMap<>();

		/**
		* A map of cache keys that have been disabled in the local process. When a key is
		* disabled locally, existing caches are disabled and the key is saved in this map.
		* Future cache instances that use the same key will be disabled in their constructor.
		*/
		@GuardedBy("sCorkLock")
		private static final HashSet<String> sDisabledKeys = new HashSet<>();

		/**
		* Weakly references all cache objects in the current process, allowing us to iterate over
		* them all for purposes like issuing debug dumps and reacting to memory pressure.
		*/
		@GuardedBy("sCorkLock")
		private static final WeakHashMap<PropertyInvalidatedCache, Void> sCaches =
		new WeakHashMap<>();
		private static final WeakHashMap<PropertyInvalidatedCache, Void> sCaches = new WeakHashMap<>();

		private final Object mLock = new Object();

		@@ -348,6 +356,9 @@ public abstract class PropertyInvalidatedCache<Query, Result> {
		};
		synchronized (sCorkLock) {
		sCaches.put(this, null);
		if (sDisabledKeys.contains(mCacheName)) {
		disableInstance();
		}
		}
		}

		@@ -371,6 +382,14 @@ public abstract class PropertyInvalidatedCache<Query, Result> {
		*/
		protected abstract Result recompute(Query query);

		/**
		* Return true if the query should bypass the cache. The default behavior is to
		* always use the cache but the method can be overridden for a specific class.
		*/
		protected boolean bypass(Query query) {
		return false;
		}

		/**
		* Determines if a pair of responses are considered equal. Used to determine whether
		* a cache is inadvertently returning stale results when VERIFY is set to true.
		@@ -414,13 +433,37 @@ public abstract class PropertyInvalidatedCache<Query, Result> {
		/**
		* Disable the use of this cache in this process.
		*/
		public final void disableLocal() {
		public final void disableInstance() {
		synchronized (mLock) {
		mDisabled = true;
		clear();
		}
		}

		/**
		* Disable the local use of all caches with the same name. All currently registered caches
		* using the key will be disabled now, and all future cache instances that use the key will be
		* disabled in their constructor.
		*/
		public static final void disableLocal(@NonNull String name) {
		synchronized (sCorkLock) {
		sDisabledKeys.add(name);
		for (PropertyInvalidatedCache cache : sCaches.keySet()) {
		if (name.equals(cache.mCacheName)) {
		cache.disableInstance();
		}
		}
		}
		}

		/**
		* Disable this cache in the current process, and all other caches that use the same
		* property.
		*/
		public final void disableLocal() {
		disableLocal(mCacheName);
		}

		/**
		* Return whether the cache is disabled in this process.
		*/
		@@ -435,8 +478,8 @@ public abstract class PropertyInvalidatedCache<Query, Result> {
		// Let access to mDisabled race: it's atomic anyway.
		long currentNonce = (!isDisabledLocal()) ? getCurrentNonce() : NONCE_DISABLED;
		for (;;) {
		if (currentNonce == NONCE_DISABLED \|\| currentNonce == NONCE_UNSET \|\|
		currentNonce == NONCE_CORKED) {
		if (currentNonce == NONCE_DISABLED \|\| currentNonce == NONCE_UNSET
		\|\| currentNonce == NONCE_CORKED \|\| bypass(query)) {
		if (!mDisabled) {
		// Do not bother collecting statistics if the cache is
		// locally disabled.
		@@ -874,6 +917,15 @@ public abstract class PropertyInvalidatedCache<Query, Result> {
		sEnabled = false;
		}

		/**
		* Report the disabled status of this cache instance. The return value does not
		* reflect status of the property key.
		*/
		@VisibleForTesting(visibility = VisibleForTesting.Visibility.PACKAGE)
		public boolean getDisabledState() {
		return isDisabledLocal();
		}

		/**
		* Returns a list of caches alive at the current time.
		*/

core/tests/coretests/src/android/app/PropertyInvalidatedCacheTests.java

0 → 100644

+117 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2021 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 android.app;

		import static org.junit.Assert.assertEquals;

		import androidx.test.filters.SmallTest;

		import org.junit.Test;

		/**
		* Test for verifying the behavior of {@link PropertyInvalidatedCache}. This test does
		* not use any actual binder calls - it is entirely self-contained.
		* <p>
		* Build/Install/Run:
		* atest FrameworksCoreTests:PropertyInvalidatedCacheTests
		*/
		@SmallTest
		public class PropertyInvalidatedCacheTests {

		static final String CACHE_PROPERTY = "cache_key.cache_test_a";

		// This class is a proxy for binder calls. It contains a counter that increments
		// every time the class is queried.
		private static class ServerProxy {
		// The number of times this class was queried.
		private int mCount = 0;

		// A single query. The key behavior is that the query count is incremented.
		boolean query(int x) {
		mCount++;
		return value(x);
		}

		// Return the expected value of an input, without incrementing the query count.
		boolean value(int x) {
		return x % 3 == 0;
		}

		// Verify the count.
		void verify(int x) {
		assertEquals(x, mCount);
		}
		}

		@Test
		public void testDisableCache1() {

		// A stand-in for the binder. The test verifies that calls are passed through to
		// this class properly.
		ServerProxy tester = new ServerProxy();

		// Three caches, all using the same system property but one uses a different name.
		PropertyInvalidatedCache<Integer, Boolean> cache1 =
		new PropertyInvalidatedCache<>(4, CACHE_PROPERTY) {
		@Override
		protected Boolean recompute(Integer x) {
		return tester.query(x);
		}
		};
		PropertyInvalidatedCache<Integer, Boolean> cache2 =
		new PropertyInvalidatedCache<>(4, CACHE_PROPERTY) {
		@Override
		protected Boolean recompute(Integer x) {
		return tester.query(x);
		}
		};
		PropertyInvalidatedCache<Integer, Boolean> cache3 =
		new PropertyInvalidatedCache<>(4, CACHE_PROPERTY, "cache3") {
		@Override
		protected Boolean recompute(Integer x) {
		return tester.query(x);
		}
		};

		// Caches are enabled upon creation.
		assertEquals(false, cache1.getDisabledState());
		assertEquals(false, cache2.getDisabledState());
		assertEquals(false, cache3.getDisabledState());

		// Disable the cache1 instance. Only cache1 is disabled
		cache1.disableInstance();
		assertEquals(true, cache1.getDisabledState());
		assertEquals(false, cache2.getDisabledState());
		assertEquals(false, cache3.getDisabledState());

		// Disable cache1. This will disable cache1 and cache2 because they share the
		// same name. cache3 has a different name and will not be disabled.
		cache1.disableLocal();
		assertEquals(true, cache1.getDisabledState());
		assertEquals(true, cache2.getDisabledState());
		assertEquals(false, cache3.getDisabledState());

		// Create a new cache1. Verify that the new instance is disabled.
		cache1 = new PropertyInvalidatedCache<>(4, CACHE_PROPERTY) {
		@Override
		protected Boolean recompute(Integer x) {
		return tester.query(x);
		}
		};
		assertEquals(true, cache1.getDisabledState());
		}
		}