1 /*
   2  * Copyright (c) 2014 Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package org.openjdk.bench.java.lang;
  24 
  25 import org.openjdk.jmh.annotations.Benchmark;
  26 import org.openjdk.jmh.annotations.BenchmarkMode;
  27 import org.openjdk.jmh.annotations.Mode;
  28 import org.openjdk.jmh.annotations.OutputTimeUnit;
  29 import org.openjdk.jmh.annotations.Scope;
  30 import org.openjdk.jmh.annotations.State;
  31 import org.openjdk.jmh.annotations.TearDown;
  32 
  33 import java.util.concurrent.TimeUnit;
  34 
  35 /**
  36  * Test to launch and gather threads. Measure time for different parts.
  37  */
  38 @BenchmarkMode(Mode.AverageTime)
  39 @OutputTimeUnit(TimeUnit.MICROSECONDS)
  40 @State(Scope.Benchmark)
  41 public class ThreadStartJoin {
  42 
  43     private static final int THREADS = Runtime.getRuntime().availableProcessors();
  44 
  45     private Thread[] ts;
  46 
  47     @Benchmark
  48     public void test() throws InterruptedException {
  49         ts = new TestThread[THREADS];
  50 
  51         for (int i = 0; i < THREADS; i++) {
  52             ts[i] = new TestThread();
  53         }
  54 
  55         for (int i = 0; i < THREADS; i++) {
  56             ts[i].start();
  57         }
  58 
  59         for (Thread mythread : ts) {
  60             mythread.join();
  61 
  62             if (mythread.isAlive()) {
  63                 throw new IllegalStateException("Couldn't join in time in LPHhello.");
  64             }
  65         }
  66     }
  67 
  68     @TearDown
  69     public final void cleanup() {
  70         if (ts != null) {
  71             for (Thread t : ts) {
  72                 if (t != null) {
  73                     t.interrupt();
  74                 }
  75             }
  76             ts = null;
  77         }
  78     }
  79 
  80     static final class TestThread extends Thread {
  81         private static int num = 0;
  82 
  83         public TestThread() {
  84             super(TestThread.name());
  85         }
  86 
  87         private synchronized static String name() {
  88             return "TestThread-" + num++;
  89         }
  90 
  91         public void run() {
  92             // do nothing
  93         }
  94 
  95     }
  96 
  97 }