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Diffstat (limited to 'libjava/classpath/java/lang/management/MonitorInfo.java')
| -rw-r--r-- | libjava/classpath/java/lang/management/MonitorInfo.java | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/libjava/classpath/java/lang/management/MonitorInfo.java b/libjava/classpath/java/lang/management/MonitorInfo.java new file mode 100644 index 000000000..fd7233716 --- /dev/null +++ b/libjava/classpath/java/lang/management/MonitorInfo.java @@ -0,0 +1,179 @@ +/* MonitorInfo.java - Information on a monitor lock. + Copyright (C) 2006 Free Software Foundation + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + +package java.lang.management; + +import javax.management.openmbean.CompositeData; +import javax.management.openmbean.CompositeType; +import javax.management.openmbean.SimpleType; + +/** + * Provides information on a monitor lock held by a thread. + * A monitor lock is obtained when a thread enters a synchronized + * block or method. + * + * @author Andrew John Hughes (gnu_andrew@member.fsf.org) + * @since 1.6 + */ +public class MonitorInfo + extends LockInfo +{ + + /** + * The stack depth at which the lock was obtained. + */ + private int stackDepth; + + /** + * The stack frame at which the lock was obtained. + */ + private StackTraceElement stackFrame; + + /** + * Constructs a new {@link MonitorInfo} using the specified + * lock class name and identity hash code, and the given + * stack depth and frame. + * + * @param className the class name of the lock object. + * @param identityHashCode the identity hash code of the lock object. + * @param stackDepth the depth of the stack at which the lock + * was obtained. + * @param stackFrame the frame of the stack at which the lock was + * obtained. + * @throws IllegalArgumentException if the stack depth and frame are + * inconsistent i.e. the frame is + * <code>null</code> but the depth is + * ≥ 0, or the frame is not + * <code>null</code> but the depth is + * < 0. + */ + public MonitorInfo(String className, int identityHashCode, int stackDepth, + StackTraceElement stackFrame) + { + super(className, identityHashCode); + if (stackFrame == null && stackDepth >= 0) + throw new IllegalArgumentException("The stack frame is null, but the " + + "stack depth is greater than or equal " + + "to zero."); + if (stackFrame != null && stackDepth < 0) + throw new IllegalArgumentException("The stack frame is not null, but the " + + "stack depth is less than zero."); + this.stackDepth = stackDepth; + this.stackFrame = stackFrame; + } + + /** + * <p> + * Returns a {@link MonitorInfo} instance using the values + * given in the supplied + * {@link javax.management.openmbean.CompositeData} object. + * The composite data instance should contain the following + * attributes with the specified types: + * </p> + * <table> + * <th><td>Name</td><td>Type</td></th> + * <tr><td>className</td><td>java.lang.String</td></tr> + * <tr><td>identityHashCode</td><td>java.lang.Integer</td></tr> + * <tr><td>lockedStackDepth</td><td>java.lang.Integer</td></tr> + * <tr><td>lockedStackFrame</td><td>javax.management.openmbean.CompositeData + * </td></tr> + * </table> + * <p> + * The stack trace is further described as: + * </p> + * <table> + * <th><td>Name</td><td>Type</td></th> + * <tr><td>className</td><td>java.lang.String</td></tr> + * <tr><td>methodName</td><td>java.lang.String</td></tr> + * <tr><td>fileName</td><td>java.lang.String</td></tr> + * <tr><td>lineNumber</td><td>java.lang.Integer</td></tr> + * <tr><td>nativeMethod</td><td>java.lang.Boolean</td></tr> + * </table> + * + * @param data the composite data structure to take values from. + * @return a new instance containing the values from the + * composite data structure, or <code>null</code> + * if the data structure was also <code>null</code>. + * @throws IllegalArgumentException if the composite data structure + * does not match the structure + * outlined above. + */ + public static MonitorInfo from(CompositeData data) + { + if (data == null) + return null; + CompositeType type = data.getCompositeType(); + ThreadInfo.checkAttribute(type, "ClassName", SimpleType.STRING); + ThreadInfo.checkAttribute(type, "IdentityHashCode", SimpleType.INTEGER); + ThreadInfo.checkAttribute(type, "LockedStackDepth", SimpleType.INTEGER); + ThreadInfo.checkAttribute(type, "LockedStackFrame", + ThreadInfo.getStackTraceType()); + CompositeData frame = (CompositeData) data.get("LockedStackFrame"); + return new MonitorInfo((String) data.get("ClassName"), + (Integer) data.get("IdentityHashCode"), + (Integer) data.get("LockedStackDepth"), + new StackTraceElement((String) frame.get("ClassName"), + (String) frame.get("MethodName"), + (String) frame.get("FileName"), + (Integer) frame.get("LineNumber"))); + } + + /** + * Returns the depth of the stack at which the lock was obtained. + * This works as an index into the array returned by + * {@link ThreadInfo#getStackTrace()}. + * + * @return the depth of the stack at which the lock was obtained, + * or a negative number if this information is unavailable. + */ + public int getLockedStackDepth() + { + return stackDepth; + } + + /** + * Returns the stack frame at which the lock was obtained. + * + * @return the stack frame at which the lock was obtained, + * or <code>null</code> if this informati0on is unavailable. + */ + public StackTraceElement getLockedStackFrame() + { + return stackFrame; + } + +} |