1 /*
   2  * Copyright (c) 2013, 2015, 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 
  24 import sun.jvmstat.monitor.Monitor;
  25 import sun.jvmstat.monitor.MonitorException;
  26 import sun.jvmstat.monitor.MonitoredHost;
  27 import sun.jvmstat.monitor.MonitoredVm;
  28 import sun.jvmstat.monitor.VmIdentifier;
  29 import jdk.test.lib.ProcessTools;
  30 
  31 /**
  32  * PerfCounters can be used to get a performance counter from the currently
  33  * executing VM.
  34  *
  35  * Throws a runtime exception if an error occurs while communicating with the
  36  * currently executing VM.
  37  */
  38 public class PerfCounters {
  39     private final static MonitoredVm vm;
  40 
  41     static {
  42         try {
  43             String pid = Long.toString(ProcessTools.getProcessId());
  44             VmIdentifier vmId = new VmIdentifier(pid);
  45             MonitoredHost host = MonitoredHost.getMonitoredHost(vmId);
  46             vm = host.getMonitoredVm(vmId);
  47         } catch (Exception e) {
  48             throw new RuntimeException("Could not connect to the VM");
  49         }
  50     }
  51 
  52     /**
  53      * Returns the performance counter with the given name.
  54      *
  55      * @param name The name of the performance counter.
  56      * @throws IllegalArgumentException If no counter with the given name exists.
  57      * @throws MonitorException If an error occurs while communicating with the VM.
  58      * @return The performance counter with the given name.
  59      */
  60     public static PerfCounter findByName(String name)
  61         throws MonitorException, IllegalArgumentException {
  62         Monitor m = vm.findByName(name);
  63         if (m == null) {
  64             throw new IllegalArgumentException("Did not find a performance counter with name " + name);
  65         }
  66         return new PerfCounter(m, name);
  67     }
  68 }