| /* |
| * Copyright (C) 2015 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 benchmarks; |
| |
| import java.lang.ref.PhantomReference; |
| import java.lang.ref.ReferenceQueue; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| /** |
| * Benchmark to evaluate the performance of References. |
| */ |
| public class ReferenceBenchmark { |
| |
| private Object object; |
| |
| // How fast can references can be allocated? |
| public void timeAlloc(int reps) { |
| ReferenceQueue<Object> queue = new ReferenceQueue<Object>(); |
| for (int i = 0; i < reps; i++) { |
| new PhantomReference(object, queue); |
| } |
| } |
| |
| // How fast can references can be allocated and manually enqueued? |
| public void timeAllocAndEnqueue(int reps) { |
| ReferenceQueue<Object> queue = new ReferenceQueue<Object>(); |
| for (int i = 0; i < reps; i++) { |
| (new PhantomReference<Object>(object, queue)).enqueue(); |
| } |
| } |
| |
| // How fast can references can be allocated, enqueued, and polled? |
| public void timeAllocEnqueueAndPoll(int reps) { |
| ReferenceQueue<Object> queue = new ReferenceQueue<Object>(); |
| for (int i = 0; i < reps; i++) { |
| (new PhantomReference<Object>(object, queue)).enqueue(); |
| } |
| for (int i = 0; i < reps; i++) { |
| queue.poll(); |
| } |
| } |
| |
| // How fast can references can be allocated, enqueued, and removed? |
| public void timeAllocEnqueueAndRemove(int reps) { |
| ReferenceQueue<Object> queue = new ReferenceQueue<Object>(); |
| for (int i = 0; i < reps; i++) { |
| (new PhantomReference<Object>(object, queue)).enqueue(); |
| } |
| for (int i = 0; i < reps; i++) { |
| try { |
| queue.remove(); |
| } catch (InterruptedException ie) { |
| i--; |
| } |
| } |
| } |
| |
| // How fast can references can be implicitly allocated, enqueued, and |
| // removed? |
| public void timeAllocImplicitEnqueueAndRemove(int reps) { |
| ReferenceQueue<Object> queue = new ReferenceQueue<Object>(); |
| List<Object> refs = new ArrayList<Object>(); |
| for (int i = 0; i < reps; i++) { |
| refs.add(new PhantomReference<Object>(new Object(), queue)); |
| } |
| Runtime.getRuntime().gc(); |
| for (int i = 0; i < reps; i++) { |
| try { |
| queue.remove(); |
| } catch (InterruptedException ie) { |
| i--; |
| } |
| } |
| } |
| |
| static private class FinalizableObject { |
| AtomicInteger count; |
| |
| public FinalizableObject(AtomicInteger count) { |
| this.count = count; |
| } |
| |
| @Override |
| protected void finalize() { |
| count.incrementAndGet(); |
| } |
| } |
| |
| // How fast does finalization run? |
| public void timeFinalization(int reps) { |
| // Allocate a bunch of finalizable objects. |
| int n = reps; |
| AtomicInteger count = new AtomicInteger(0); |
| for (int i = 0; i < n; i++) { |
| new FinalizableObject(count); |
| } |
| |
| // Run GC so the objects will be collected for finalization. |
| Runtime.getRuntime().gc(); |
| |
| // Wait for finalization. |
| Runtime.getRuntime().runFinalization(); |
| |
| // Double check all the objects were finalized. |
| int got = count.get(); |
| if (n != got) { |
| throw new IllegalStateException( |
| String.format("Only %i of %i objects finalized?", got, n)); |
| } |
| } |
| } |