test/hotspot/jtreg/gc/testlibrary/PerfCounters.java
changeset 48117 d64722b0b371
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/gc/testlibrary/PerfCounters.java	Mon Nov 27 10:51:31 2017 +0100
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2013, 2016, 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.
+ */
+
+package gc.testlibrary;
+
+import sun.jvmstat.monitor.Monitor;
+import sun.jvmstat.monitor.MonitorException;
+import sun.jvmstat.monitor.MonitoredHost;
+import sun.jvmstat.monitor.MonitoredVm;
+import sun.jvmstat.monitor.VmIdentifier;
+import jdk.test.lib.process.ProcessTools;
+
+/**
+ * PerfCounters can be used to get a performance counter from the currently
+ * executing VM.
+ *
+ * Throws a runtime exception if an error occurs while communicating with the
+ * currently executing VM.
+ */
+public class PerfCounters {
+    private final static MonitoredVm vm;
+
+    static {
+        try {
+            String pid = Long.toString(ProcessTools.getProcessId());
+            VmIdentifier vmId = new VmIdentifier(pid);
+            MonitoredHost host = MonitoredHost.getMonitoredHost(vmId);
+            vm = host.getMonitoredVm(vmId);
+        } catch (Exception e) {
+            throw new RuntimeException("Could not connect to the VM");
+        }
+    }
+
+    /**
+     * Returns the performance counter with the given name.
+     *
+     * @param name The name of the performance counter.
+     * @throws IllegalArgumentException If no counter with the given name exists.
+     * @throws MonitorException If an error occurs while communicating with the VM.
+     * @return The performance counter with the given name.
+     */
+    public static PerfCounter findByName(String name)
+        throws MonitorException, IllegalArgumentException {
+        Monitor m = vm.findByName(name);
+        if (m == null) {
+            throw new IllegalArgumentException("Did not find a performance counter with name " + name);
+        }
+        return new PerfCounter(m, name);
+    }
+}