001 // DebugScheduler.java, created by wbeebee
002 // Copyright (C) 2002 Wes Beebee <wbeebee@mit.edu>
003 // Licensed under the terms of the GNU GPL; see COPYING for details.
004 package javax.realtime;
005
006 import java.util.List;
007 import java.util.ArrayList;
008 import java.util.NoSuchElementException;
009 import java.util.Iterator;
010
011 /** <code>DebugScheduler</code> is a scheduler designed to test the rest of the system.
012 * It produces a prodigious amount of debugging output as well as asserting many invariants.
013 */
014 public class DebugScheduler extends Scheduler {
015 static DebugScheduler instance = null;
016 RefList threadList = new RefList();
017 RefList disabledThreads = new RefList();
018 Iterator iterator = threadList.roundIterator();
019
020 protected DebugScheduler() {
021 super();
022 setQuanta(1); // Start switching after a specified number of milliseconds
023 }
024
025 /** Return an instance of a DebugScheduler */
026 public static DebugScheduler instance() {
027 if (instance == null) {
028 ImmortalMemory.instance().enter(new Runnable() {
029 public void run() {
030 instance = new DebugScheduler();
031 }
032 });
033 }
034
035 return instance;
036 }
037
038 /** It is always feasible to add another thread to a DebugScheduler. */
039 protected void addToFeasibility(Schedulable schedulable) {}
040
041 public void fireSchedulable(Schedulable schedulable) {
042 schedulable.run();
043 }
044
045 /** Used to determine the policy of the <code>Scheduler</code>. */
046 public String getPolicyName() {
047 return "Debug scheduler";
048 }
049
050 /** It is always feasible to add another thread to a DebugScheduler. */
051 public boolean isFeasible() {
052 return true;
053 }
054
055 /** It is always feasible to add another thread to a DebugScheduler. */
056 protected boolean isFeasible(Schedulable s, ReleaseParameters rp) {
057 return true;
058 }
059
060 /** It is always feasible to add another thread to a DebugScheduler. */
061 protected void removeFromFeasibility(Schedulable schedulable) {}
062
063 /** It is always feasible to add another thread to a DebugScheduler. */
064 public boolean setIfFeasible(Schedulable schedulable,
065 ReleaseParameters release,
066 MemoryParameters memory) {
067 return true;
068 }
069
070 /** It is always feasible to add another thread to a DebugScheduler. */
071 public boolean setIfFeasible(Schedulable schedulable,
072 ReleaseParameters release,
073 MemoryParameters memory,
074 ProcessingGroupParameters group) {
075 return true;
076 }
077
078 protected long chooseThread(long currentTime) {
079 setQuanta(1); // Switch again after a specified number of milliseconds.
080 try {
081 return ((Long)iterator.next()).longValue();
082 } catch (NoSuchElementException e) {
083 NoHeapRealtimeThread.print("No threads left to run!");
084 System.exit(-1);
085 return 0;
086 }
087 }
088
089 protected void addThread(RealtimeThread thread) {
090 NoHeapRealtimeThread.print("\naddThread1("+thread.getUID()+")");
091 if (thread.getUID()<0) {
092 NoHeapRealtimeThread.print("assert: addThread 2");
093 print();
094 System.exit(-1);
095 }
096 if (disabledThreads.contains(thread.getUID())) {
097 NoHeapRealtimeThread.print("assert: addThread ");
098 print();
099 System.exit(-1);
100 }
101 threadList.add(thread.getUID());
102 }
103
104 protected void removeThread(RealtimeThread thread) {
105 NoHeapRealtimeThread.print("\nremoveThread1("+thread.getUID()+")");
106 if (thread.getUID()<0) {
107 NoHeapRealtimeThread.print("assert: removeThread 2");
108 print();
109 System.exit(-1);
110 }
111 if (!threadList.contains(thread.getUID())) {
112 NoHeapRealtimeThread.print("assert: removeThread ");
113 print();
114 System.exit(-1);
115 }
116 threadList.remove(thread.getUID());
117 }
118
119 protected void addThread(long threadID) {
120 NoHeapRealtimeThread.print("\naddThread2("+threadID+")");
121 if (threadID>0) {
122 NoHeapRealtimeThread.print("assert: addThread 1");
123 print();
124 System.exit(-1);
125 }
126 threadList.add(threadID);
127 }
128
129 protected void removeThread(long threadID) {
130 NoHeapRealtimeThread.print("\nremoveThread2("+threadID+")");
131 if (threadID>0) {
132 NoHeapRealtimeThread.print("assert: removeThread 1");
133 print();
134 System.exit(-1);
135 }
136 threadList.remove(threadID);
137 }
138
139 protected void disableThread(long threadID) {
140 NoHeapRealtimeThread.print("\ndisableThread("+threadID+")");
141 if (!threadList.contains(threadID)) {
142 NoHeapRealtimeThread.print("assert: disableThread ");
143 print();
144 System.exit(-1);
145 }
146 threadList.remove(threadID);
147 disabledThreads.add(threadID);
148 }
149
150 protected void enableThread(long threadID) {
151 NoHeapRealtimeThread.print("\nenableThread("+threadID+")");
152 if (!disabledThreads.contains(threadID)) {
153 NoHeapRealtimeThread.print("assert: enableThread ");
154 print();
155 System.exit(-1);
156 }
157 threadList.add(threadID);
158 disabledThreads.remove(threadID);
159 }
160
161 protected void waitForNextPeriod(RealtimeThread rt) {
162 }
163
164 public String toString() {
165 return "["+threadList+","+disabledThreads+"]";
166 }
167 }