1 /* 2 * Copyright (c) 2003, 2008, 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package sun.management; 27 28 import java.util.*; 29 import com.sun.management.VMOption; 30 import com.sun.management.VMOption.Origin; 31 32 /** 33 * Flag class is a helper class for constructing a VMOption. 34 * It has the static methods for getting the Flag objects, each 35 * corresponds to one VMOption. 36 * 37 */ 38 class Flag { 39 private String name; 40 private Object value; 41 private Origin origin; 42 private boolean writeable; 43 private boolean external; 44 45 Flag(String name, Object value, boolean writeable, 46 boolean external, Origin origin) { 47 this.name = name; 48 this.value = value == null ? "" : value ; 49 this.origin = origin; 50 this.writeable = writeable; 51 this.external = external; 52 } 53 54 Object getValue() { 55 return value; 56 } 57 58 boolean isWriteable() { 59 return writeable; 60 } 61 62 boolean isExternal() { 63 return external; 64 } 65 66 VMOption getVMOption() { 67 return new VMOption(name, value.toString(), writeable, origin); 68 } 69 70 static Flag getFlag(String name) { 71 String[] names = new String[1]; 72 names[0] = name; 73 74 List<Flag> flags = getFlags(names, 1); 75 if (flags.isEmpty()) { 76 return null; 77 } else { 78 // flags should have only one element 79 return flags.get(0); 80 } 81 } 82 83 static List<Flag> getAllFlags() { 84 int numFlags = getInternalFlagCount(); 85 86 // Get all internal flags with names = null 87 return getFlags(null, numFlags); 88 } 89 90 private static List<Flag> getFlags(String[] names, int numFlags) { 91 Flag[] flags = new Flag[numFlags]; 92 int count = getFlags(names, flags, numFlags); 93 94 List<Flag> result = new ArrayList<Flag>(); 95 for (Flag f : flags) { 96 if (f != null) { 97 result.add(f); 98 } 99 } 100 return result; 101 } 102 103 private static native String[] getAllFlagNames(); 104 // getFlags sets each element in the given flags array 105 // with a Flag object only if the name is valid and the 106 // type is supported. The flags array may contain null elements. 107 private static native int getFlags(String[] names, Flag[] flags, int count); 108 private static native int getInternalFlagCount(); 109 110 // These set* methods are synchronized on the class object 111 // to avoid multiple threads updating the same flag at the same time. 112 static synchronized native void setLongValue(String name, long value); 113 static synchronized native void setBooleanValue(String name, boolean value); 114 static synchronized native void setStringValue(String name, String value); 115 116 static { 117 initialize(); 118 } 119 private static native void initialize(); 120 }