From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001 From: upstream source tree Date: Sun, 15 Mar 2015 20:14:05 -0400 Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository. --- libjava/classpath/java/rmi/server/UID.java | 225 +++++++++++++++++++++++++++++ 1 file changed, 225 insertions(+) create mode 100644 libjava/classpath/java/rmi/server/UID.java (limited to 'libjava/classpath/java/rmi/server/UID.java') diff --git a/libjava/classpath/java/rmi/server/UID.java b/libjava/classpath/java/rmi/server/UID.java new file mode 100644 index 000000000..464d3d860 --- /dev/null +++ b/libjava/classpath/java/rmi/server/UID.java @@ -0,0 +1,225 @@ +/* UID.java -- The unique object Id + Copyright (c) 2006 Free Software Foundation, Inc. + +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.rmi.server; + +import java.io.DataInput; +import java.io.DataOutput; +import java.io.IOException; +import java.io.Serializable; +import java.net.InetAddress; + +/** + * Represents the unique identifier over time for the host which has generated + * it. It contains time (when created), counter (the number of the UID + * creation order) and virtual machine id components. The UID can also be + * constructed specifying a "well known" identifier in the for of short: + * this identifier defines the UID uniqueness alone. + * + * @author Audrius Meskauskas (audriusa@bioinformatics.org) + */ +public final class UID + implements Serializable +{ + /** + * Use the serial version uid for interoperability. + */ + private static final long serialVersionUID = 1086053664494604050L; + + /** + * The UID counter (the ordinary number in the sequence of number of UID's, + * created during the recent millisecond). In the next millisecond, it + * starts from the minimal value again. In the unlikely case of creating + * more than 65536 uids per millisecond the process pauses till the next + * ms. + */ + private static short uidCounter = Short.MIN_VALUE; + + /** + * The time, when the last UID has been created. + */ + private static long last; + + /** + * This constant tries to be the unique identifier of the virtual machine. + */ + private static final int machineId = getMachineId(); + + /** + * The UID number in the UID creation sequence. + */ + private short count; + + /** + * Always gets the uniqueNr value. + */ + private int unique; + + /** + * The time stamp, when the UID was created. + */ + private long time; + + /** + * Create the new UID that would have the described features of the + * uniqueness. + */ + public UID() + { + synchronized (UID.class) + { + time = System.currentTimeMillis(); + unique = machineId; + if (time > last) + { + last = time; + count = uidCounter = Short.MIN_VALUE; + } + else + { + if (uidCounter == Short.MAX_VALUE) + { + // Make a 2 ms pause if the counter has reached the maximal + // value. This should seldom happen. + try + { + Thread.sleep(2); + } + catch (InterruptedException e) + { + } + uidCounter = Short.MIN_VALUE; + time = last = System.currentTimeMillis(); + } + count = ++uidCounter; + } + } + } + + /** + * Create the new UID with the well known id (number). All UIDs, creates + * with the this constructor having the same parameter are equal to each + * other (regardless to the host and time where they were created. + * + * @param wellKnownId the well known UID. + */ + public UID(short wellKnownId) + { + unique = wellKnownId; + } + + /** + * Get the hashCode of this UID. + */ + public int hashCode() + { + return (int) (unique ^ time ^ count); + } + + /** + * Compare this UID with another UID for equality (not equal to other types of + * objects). + */ + public boolean equals(Object other) + { + if (other instanceof UID) + { + UID ui = (UID) other; + return unique == ui.unique && time == ui.time && count == ui.count; + } + else + return false; + } + + public static UID read(DataInput in) throws IOException + { + UID uid = new UID(); + uid.unique = in.readInt(); + uid.time = in.readLong(); + uid.count = in.readShort(); + return (uid); + } + + public void write(DataOutput out) throws IOException + { + out.writeInt(unique); + out.writeLong(time); + out.writeShort(count); + } + + /** + * Do our best to get the Id of this virtual machine. + */ + static int getMachineId() + { + int hostIpHash; + + try + { + // Try to get the host IP. + String host = InetAddress.getLocalHost().toString(); + // This hash is content - based, not the address based. + hostIpHash = host.hashCode(); + } + catch (Exception e) + { + // Failed due some reason. + hostIpHash = 0; + } + + // Should be the unque address if hashcodes are addresses. + // Additionally, add the time when the RMI system was probably started + // (this class was first instantiated). + return new Object().hashCode() ^ (int) System.currentTimeMillis() + ^ hostIpHash; + } + + /** + * Get the string representation of this UID. + * + * @return a string, uniquely identifying this id. + */ + public String toString() + { + int max = Character.MAX_RADIX; + // Translate into object count, counting from 0. + long lc = (count - Short.MIN_VALUE) & 0xFFFF; + return Long.toString(unique, max) + ":" + Long.toString(time, max) + "." + + Long.toString(lc, max); + } +} -- cgit v1.2.3