test/hotspot/jtreg/gc/metaspace/InputArguments.java
changeset 47216 71c04702a3d5
parent 40631 ed82623d7831
child 53523 4c5184c56dc2
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/gc/metaspace/InputArguments.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,74 @@
+/*
+ * 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.
+ */
+
+import java.lang.management.RuntimeMXBean;
+import java.lang.management.ManagementFactory;
+import java.util.List;
+
+/**
+ * This class provides access to the input arguments to the VM.
+ */
+public class InputArguments {
+    private static final List<String> args;
+
+    static {
+        RuntimeMXBean runtimeMxBean = ManagementFactory.getRuntimeMXBean();
+        args = runtimeMxBean.getInputArguments();
+    }
+
+    /**
+     * Returns true if {@code arg} is an input argument to the VM.
+     *
+     * This is useful for checking boolean flags such as -XX:+UseSerialGC or
+     * -XX:-UsePerfData.
+     *
+     * @param arg The name of the argument.
+     * @return {@code true} if the given argument is an input argument,
+     *         otherwise {@code false}.
+     */
+    public static boolean contains(String arg) {
+        return args.contains(arg);
+    }
+
+    /**
+     * Returns true if {@code prefix} is the start of an input argument to the
+     * VM.
+     *
+     * This is useful for checking if flags describing a quantity, such as
+     * -XX:+MaxMetaspaceSize=100m, is set without having to know the quantity.
+     * To check if the flag -XX:MaxMetaspaceSize is set, use
+     * {@code InputArguments.containsPrefix("-XX:MaxMetaspaceSize")}.
+     *
+     * @param prefix The start of the argument.
+     * @return {@code true} if the given argument is the start of an input
+     *         argument, otherwise {@code false}.
+     */
+    public static boolean containsPrefix(String prefix) {
+        for (String arg : args) {
+            if (arg.startsWith(prefix)) {
+                return true;
+            }
+        }
+        return false;
+    }
+}