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/*
* 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 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);
}
}
}
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