| /* |
| * Copyright (C) 2017 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.systemui.util.leak; |
| |
| import android.os.SystemClock; |
| import android.util.ArrayMap; |
| |
| import java.io.PrintWriter; |
| import java.lang.ref.Reference; |
| import java.lang.ref.ReferenceQueue; |
| import java.lang.ref.WeakReference; |
| import java.util.HashSet; |
| import java.util.Map; |
| |
| /** |
| * Tracks objects that have been marked as garbage. |
| */ |
| public class TrackedGarbage { |
| |
| /** Duration after which we consider garbage to be old. */ |
| private static final long GARBAGE_COLLECTION_DEADLINE_MILLIS = 60000; // 1min |
| |
| private final HashSet<LeakReference> mGarbage = new HashSet<>(); |
| private final ReferenceQueue<Object> mRefQueue = new ReferenceQueue<>(); |
| private final TrackedCollections mTrackedCollections; |
| |
| public TrackedGarbage(TrackedCollections trackedCollections) { |
| mTrackedCollections = trackedCollections; |
| } |
| |
| /** |
| * @see LeakDetector#trackGarbage(Object) |
| */ |
| public synchronized void track(Object o) { |
| cleanUp(); |
| mGarbage.add(new LeakReference(o, mRefQueue)); |
| mTrackedCollections.track(mGarbage, "Garbage"); |
| } |
| |
| private void cleanUp() { |
| Reference<?> ref; |
| while ((ref = mRefQueue.poll()) != null) { |
| mGarbage.remove(ref); |
| } |
| } |
| |
| /** |
| * A reference to something we consider leaked if it still has strong references. |
| * |
| * Helpful for finding potential leaks in a heapdump: Simply find an instance of |
| * LeakReference, find the object it refers to, then find a strong path to a GC root. |
| */ |
| private static class LeakReference extends WeakReference<Object> { |
| private final Class<?> clazz; |
| private final long createdUptimeMillis; |
| |
| LeakReference(Object t, ReferenceQueue<Object> queue) { |
| super(t, queue); |
| clazz = t.getClass(); |
| createdUptimeMillis = SystemClock.uptimeMillis(); |
| } |
| } |
| |
| /** |
| * Dump statistics about the garbage. |
| * |
| * For each class, dumps the number of "garbage objects" that have not been collected yet. |
| * A large number of old instances indicates a probable leak. |
| */ |
| public synchronized void dump(PrintWriter pw) { |
| cleanUp(); |
| |
| long now = SystemClock.uptimeMillis(); |
| |
| ArrayMap<Class<?>, Integer> acc = new ArrayMap<>(); |
| ArrayMap<Class<?>, Integer> accOld = new ArrayMap<>(); |
| for (LeakReference ref : mGarbage) { |
| acc.put(ref.clazz, acc.getOrDefault(ref.clazz, 0) + 1); |
| if (isOld(ref.createdUptimeMillis, now)) { |
| accOld.put(ref.clazz, accOld.getOrDefault(ref.clazz, 0) + 1); |
| } |
| } |
| |
| for (Map.Entry<Class<?>, Integer> entry : acc.entrySet()) { |
| pw.print(entry.getKey().getName()); |
| pw.print(": "); |
| pw.print(entry.getValue()); |
| pw.print(" total, "); |
| pw.print(accOld.getOrDefault(entry.getKey(), 0)); |
| pw.print(" old"); |
| pw.println(); |
| } |
| } |
| |
| private boolean isOld(long createdUptimeMillis, long now) { |
| return createdUptimeMillis + GARBAGE_COLLECTION_DEADLINE_MILLIS < now; |
| } |
| } |