| 1 | package desmoj.core.simulator; |
| 2 | |
| 3 | import java.util.Observable; |
| 4 | |
| 5 | /** |
| 6 | * The simulation clock shows the actual simulation time. The actual simulation |
| 7 | * time can be polled by any object but can only be set by the scheduler |
| 8 | * responsible for the actual model. The simulation clock is extending class |
| 9 | * <code>java.util.Observable</code> thus representing the 'observable' part in |
| 10 | * a 'observer'-design pattern as described in [Gamm95] page 107. This enables |
| 11 | * observers to register themselves at the simulation clock to be notified |
| 12 | * whenever the simulation time changes. This can be easily used to provide |
| 13 | * fully automatic statistical counters. Each time the simulation time changes, |
| 14 | * a counter registered at the simulation clock is notofied and can poll the |
| 15 | * value it is observing (most likely from a special <code>ValueSupplier</code> |
| 16 | * object). This way, no explicit calls for the counter to update its observed |
| 17 | * value are needed. Note that on the other hand this might reduce performance |
| 18 | * in comparison to explicit update call since the value under observation might |
| 19 | * not change each time the simulation time is changed. |
| 20 | * |
| 21 | * @see java.util.Observable |
| 22 | * |
| 23 | * @version DESMO-J, Ver. 2.3.3 copyright (c) 2011 |
| 24 | * @author Tim Lechler |
| 25 | * @author modified by Soenke Claassen |
| 26 | * @author modified by Felix Klueckmann |
| 27 | * |
| 28 | * Licensed under the Apache License, Version 2.0 (the "License"); you |
| 29 | * may not use this file except in compliance with the License. You may |
| 30 | * obtain a copy of the License at |
| 31 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 32 | * |
| 33 | * Unless required by applicable law or agreed to in writing, software |
| 34 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 35 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or |
| 36 | * implied. See the License for the specific language governing |
| 37 | * permissions and limitations under the License. |
| 38 | * |
| 39 | */ |
| 40 | public class SimClock extends Observable { |
| 41 | |
| 42 | /** |
| 43 | * The Simclock's Name |
| 44 | */ |
| 45 | String name; |
| 46 | |
| 47 | /** |
| 48 | * Stores internally the actual simulation time. |
| 49 | */ |
| 50 | private TimeInstant _timeNow; |
| 51 | |
| 52 | /** |
| 53 | * Constructs a simulation clock with no parameters given. By default the |
| 54 | * actual simulation time is set to zero. |
| 55 | * |
| 56 | * @author Tim Lechler |
| 57 | * @author modified by Felix Klueckmann |
| 58 | * @param name |
| 59 | * String : The name of the simulation clock |
| 60 | */ |
| 61 | public SimClock(String name) { |
| 62 | |
| 63 | super(); // create a NamedObject |
| 64 | this.name = name + "_clock"; |
| 65 | // set the simulation clock to 0 |
| 66 | _timeNow = new TimeInstant(0); // the birth of time ;-) |
| 67 | |
| 68 | } |
| 69 | /** |
| 70 | * Returns the clock's name as string. This method has become necessary |
| 71 | * since the simulation clock does not extend class |
| 72 | * <code>NamedObjectImp</code>. |
| 73 | * |
| 74 | * @return java.lang.String : The clock's name |
| 75 | */ |
| 76 | public String getName() { |
| 77 | |
| 78 | return name; |
| 79 | |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * Returns the actual simulation time. |
| 84 | * |
| 85 | * @return TimeInstant : The actual simulation time |
| 86 | */ |
| 87 | public TimeInstant getTime() { |
| 88 | return _timeNow; |
| 89 | } |
| 90 | |
| 91 | /** |
| 92 | * Sets the actual simulation time to a new value. This method has to be |
| 93 | * protected from user access since it must not be manipulated by anyone but |
| 94 | * the scheduler. |
| 95 | * |
| 96 | * @param newTime |
| 97 | * TimeInstant : The new simulation time |
| 98 | */ |
| 99 | void setTime(TimeInstant newTime) { |
| 100 | //check if newTime is in the future |
| 101 | if(TimeInstant.isBeforeOrEqual(newTime, _timeNow)){ |
| 102 | // check for legal parameter (newTime>oldTime) |
| 103 | if (TimeInstant.isBefore(newTime, _timeNow)) { |
| 104 | //TODO Exception (Wrong Time) |
| 105 | } |
| 106 | return; |
| 107 | } |
| 108 | |
| 109 | |
| 110 | // note all observers of change before setting the new time!!!! |
| 111 | setChanged(); // set the status to changed |
| 112 | |
| 113 | // tell every Observer registered the actual TimeInstant which will be |
| 114 | // changed now |
| 115 | notifyObservers(_timeNow); |
| 116 | |
| 117 | _timeNow = newTime; // now make the move for the next time change. |
| 118 | } |
| 119 | |
| 120 | /** |
| 121 | * Sets the initial simulation time. Allows negative values. This method has to be |
| 122 | * protected from user access since it must not be manipulated by anyone but |
| 123 | * the scheduler. |
| 124 | * |
| 125 | * @param initTime |
| 126 | * TimeInstant : The initial simulation time |
| 127 | */ |
| 128 | void setInitTime(TimeInstant initTime){ |
| 129 | _timeNow= initTime; |
| 130 | } |
| 131 | |
| 132 | /** |
| 133 | * Returns the clock's name as string. This method has become necessary |
| 134 | * since the simulation clock does not extend class |
| 135 | * <code>NamedObjectImp</code>. |
| 136 | * |
| 137 | * @return java.lang.String : The clock's name |
| 138 | */ |
| 139 | public String toString() { |
| 140 | |
| 141 | return name; |
| 142 | |
| 143 | } |
| 144 | } |