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1: /* DGCImpl.java -- 2: Copyright (c) 1996, 1997, 1998, 1999, 2002, 2005 3: Free Software Foundation, Inc. 4: 5: This file is part of GNU Classpath. 6: 7: GNU Classpath is free software; you can redistribute it and/or modify 8: it under the terms of the GNU General Public License as published by 9: the Free Software Foundation; either version 2, or (at your option) 10: any later version. 11: 12: GNU Classpath is distributed in the hope that it will be useful, but 13: WITHOUT ANY WARRANTY; without even the implied warranty of 14: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15: General Public License for more details. 16: 17: You should have received a copy of the GNU General Public License 18: along with GNU Classpath; see the file COPYING. If not, write to the 19: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 20: 02110-1301 USA. 21: 22: Linking this library statically or dynamically with other modules is 23: making a combined work based on this library. Thus, the terms and 24: conditions of the GNU General Public License cover the whole 25: combination. 26: 27: As a special exception, the copyright holders of this library give you 28: permission to link this library with independent modules to produce an 29: executable, regardless of the license terms of these independent 30: modules, and to copy and distribute the resulting executable under 31: terms of your choice, provided that you also meet, for each linked 32: independent module, the terms and conditions of the license of that 33: module. An independent module is a module which is not derived from 34: or based on this library. If you modify this library, you may extend 35: this exception to your version of the library, but you are not 36: obligated to do so. If you do not wish to do so, delete this 37: exception statement from your version. */ 38: 39: package gnu.java.rmi.dgc; 40: 41: import gnu.java.rmi.server.UnicastServerRef; 42: 43: import java.rmi.RemoteException; 44: import java.rmi.dgc.DGC; 45: import java.rmi.dgc.Lease; 46: import java.rmi.dgc.VMID; 47: import java.rmi.server.ObjID; 48: import java.rmi.server.RMISocketFactory; 49: import java.util.Hashtable; 50: 51: /** 52: * I let DGCImpl to extend UnicastServerRef, but not 53: * UnicastRemoteObject, because UnicastRemoteObject must 54: * exportObject automatically. 55: */ 56: public class DGCImpl 57: extends UnicastServerRef implements DGC { 58: 59: private static final long LEASE_VALUE = 600000L; 60: // leaseCache caches a LeaseRecord associated with a vmid 61: private Hashtable leaseCache = new Hashtable(); 62: 63: public DGCImpl() throws RemoteException { 64: super(new ObjID(ObjID.DGC_ID), 0, RMISocketFactory.getSocketFactory()); 65: } 66: 67: public Lease dirty(ObjID[] ids, long sequenceNum, Lease lease) throws RemoteException { 68: VMID vmid = lease.getVMID(); 69: if (vmid == null) 70: vmid = new VMID(); 71: long leaseValue = LEASE_VALUE; 72: //long leaseValue = lease.getValue(); 73: lease = new Lease(vmid, leaseValue); 74: synchronized(leaseCache){ 75: LeaseRecord lr = (LeaseRecord)leaseCache.get(vmid); 76: if (lr != null) 77: lr.reset(leaseValue); 78: else{ 79: lr = new LeaseRecord(vmid, leaseValue); 80: leaseCache.put(vmid, lr); 81: } 82: } 83: 84: return (lease); 85: } 86: 87: public void clean(ObjID[] ids, long sequenceNum, VMID vmid, boolean strong) throws RemoteException { 88: // Not implemented 89: } 90: 91: /** 92: * LeaseRecord associates a vmid to expireTime. 93: */ 94: private static class LeaseRecord{ 95: private VMID vmid; 96: private long expireTime; 97: 98: LeaseRecord(VMID vmid, long leaseValue){ 99: this.vmid = vmid; 100: reset(leaseValue); 101: } 102: 103: // reset expireTime 104: void reset(long leaseValue){ 105: long l = System.currentTimeMillis(); 106: expireTime = l + leaseValue; 107: } 108: 109: boolean isExpired(){ 110: long l = System.currentTimeMillis(); 111: if ( l > expireTime) 112: return true; 113: return false; 114: } 115: 116: } //End of LeaseRecord 117: 118: } //End of DGCImpl