| /* |
| * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /** |
| * @test |
| * @bug 6857566 |
| * @summary DirectByteBuffer garbage creation can outpace reclamation |
| * |
| * @run main/othervm -XX:MaxDirectMemorySize=128m -XX:-ExplicitGCInvokesConcurrent DirectBufferAllocTest |
| */ |
| |
| import java.nio.ByteBuffer; |
| import java.util.List; |
| import java.util.concurrent.*; |
| import java.util.stream.Collectors; |
| import java.util.stream.IntStream; |
| |
| public class DirectBufferAllocTest { |
| // defaults |
| static final int RUN_TIME_SECONDS = 5; |
| static final int MIN_THREADS = 4; |
| static final int MAX_THREADS = 64; |
| static final int CAPACITY = 1024 * 1024; // bytes |
| |
| /** |
| * This test spawns multiple threads that constantly allocate direct |
| * {@link ByteBuffer}s in a loop, trying to provoke {@link OutOfMemoryError}.<p> |
| * When run without command-line arguments, it runs as a regression test |
| * for at most 5 seconds.<p> |
| * Command line arguments: |
| * <pre> |
| * -r run-time-seconds <i>(duration of successful test - default 5 s)</i> |
| * -t threads <i>(default is 2 * # of CPUs, at least 4 but no more than 64)</i> |
| * -c capacity <i>(of direct buffers in bytes - default is 1MB)</i> |
| * -p print-alloc-time-batch-size <i>(every "batch size" iterations, |
| * average time per allocation is printed)</i> |
| * </pre> |
| * Use something like the following to run a 10 minute stress test and |
| * print allocation times as it goes: |
| * <pre> |
| * java -XX:MaxDirectMemorySize=128m DirectBufferAllocTest -r 600 -t 32 -p 5000 |
| * </pre> |
| */ |
| public static void main(String[] args) throws Exception { |
| int runTimeSeconds = RUN_TIME_SECONDS; |
| int threads = Math.max( |
| Math.min( |
| Runtime.getRuntime().availableProcessors() * 2, |
| MAX_THREADS |
| ), |
| MIN_THREADS |
| ); |
| int capacity = CAPACITY; |
| int printBatchSize = 0; |
| |
| // override with command line arguments |
| for (int i = 0; i < args.length; i++) { |
| switch (args[i]) { |
| case "-r": |
| runTimeSeconds = Integer.parseInt(args[++i]); |
| break; |
| case "-t": |
| threads = Integer.parseInt(args[++i]); |
| break; |
| case "-c": |
| capacity = Integer.parseInt(args[++i]); |
| break; |
| case "-p": |
| printBatchSize = Integer.parseInt(args[++i]); |
| break; |
| default: |
| System.err.println( |
| "Usage: java" + |
| " [-XX:MaxDirectMemorySize=XXXm]" + |
| " DirectBufferAllocTest" + |
| " [-r run-time-seconds]" + |
| " [-t threads]" + |
| " [-c capacity-of-direct-buffers]" + |
| " [-p print-alloc-time-batch-size]" |
| ); |
| System.exit(-1); |
| } |
| } |
| |
| System.out.printf( |
| "Allocating direct ByteBuffers with capacity %d bytes, using %d threads for %d seconds...\n", |
| capacity, threads, runTimeSeconds |
| ); |
| |
| ExecutorService executor = Executors.newFixedThreadPool(threads); |
| |
| int pbs = printBatchSize; |
| int cap = capacity; |
| |
| List<Future<Void>> futures = |
| IntStream.range(0, threads) |
| .mapToObj( |
| i -> (Callable<Void>) () -> { |
| long t0 = System.nanoTime(); |
| loop: |
| while (true) { |
| for (int n = 0; pbs == 0 || n < pbs; n++) { |
| if (Thread.interrupted()) { |
| break loop; |
| } |
| ByteBuffer.allocateDirect(cap); |
| } |
| long t1 = System.nanoTime(); |
| if (pbs > 0) { |
| System.out.printf( |
| "Thread %2d: %5.2f ms/allocation\n", |
| i, ((double) (t1 - t0) / (1_000_000d * pbs)) |
| ); |
| } |
| t0 = t1; |
| } |
| return null; |
| } |
| ) |
| .map(executor::submit) |
| .collect(Collectors.toList()); |
| |
| for (int i = 0; i < runTimeSeconds; i++) { |
| if (futures.stream().anyMatch(Future::isDone)) { |
| break; |
| } |
| Thread.sleep(1000L); |
| } |
| |
| Exception exception = null; |
| for (Future<Void> future : futures) { |
| if (future.isDone()) { |
| try { |
| future.get(); |
| } catch (ExecutionException e) { |
| if (exception == null) { |
| exception = new RuntimeException("Errors encountered!"); |
| } |
| exception.addSuppressed(e.getCause()); |
| } |
| } else { |
| future.cancel(true); |
| } |
| } |
| |
| executor.shutdown(); |
| |
| if (exception != null) { |
| throw exception; |
| } else { |
| System.out.printf("No errors after %d seconds.\n", runTimeSeconds); |
| } |
| } |
| } |