001 // Schedulable.java, created by cata
002 // Copyright (C) 2001 Catalin Francu <cata@mit.edu>
003 // Licensed under the terms of the GNU GPL; see COPYING for details.
004
005 package javax.realtime;
006 import java.io.*;
007
008 /** Handlers and other objects can be run by a <code>Scheduler</code> if they
009 * provide a <code>run()</code> method and the methods defined below. The
010 * <code>Scheduler</code> uses this information to create a suitable context
011 * to execute the <code>run()</code> method.
012 */
013 public interface Schedulable extends java.lang.Runnable {
014
015 /** Add the scheduling and release characteristics of <code>this</code>
016 * to the set of such chracteristics already being considered, if the
017 * addition would result in the new, larger set being feasible.
018 *
019 * @return True, if the addition would result in the set of considered
020 * characteristics being feasible. False, if the addition would
021 * result in the sed of considered characteristics being infeasible
022 * or there is no assigned instance of <code>Scheduler</code>.
023 */
024 public boolean addIfFeasible();
025
026 /** Inform the scheduler and cooperating facilities that scheduling and
027 * release characteristics of this instance of <code>Schedulable</code>
028 * should be considered in feasibility analysis until further notified.
029 *
030 * @return True, if the addition was successful. False, if not.
031 */
032 public boolean addToFeasibility();
033
034 /** Gets a reference to the <code>MemoryParameters</code> object.
035 *
036 * @return A reference to the current <code>MemoryParameters</code> object.
037 */
038 public MemoryParameters getMemoryParameters();
039
040 /** Gets a reference to the <code>ProcessingGroupParameters</code> object.
041 *
042 * @return A reference to the current <code>ProcessingGroupParameters</code> object.
043 */
044 public ProcessingGroupParameters getProcessingGroupParameters();
045
046 /** Gets a reference to the <code>ReleaseParameters</code> object.
047 *
048 * @return A reference to the current <code>ReleaseParameters</code> object.
049 */
050 public ReleaseParameters getReleaseParameters();
051
052 /** Gets a reference to the <code>SchedulingParameters</code> object.
053 *
054 * @return A reference to the current <code>SchedulingParameters</code> object.
055 */
056 public SchedulingParameters getSchedulingParameters();
057
058 /** Gets a reference to the <code>Scheduler</code> object.
059 *
060 * @return A reference to the current <code>Scheduler</code> object.
061 */
062 public Scheduler getScheduler();
063
064 /** Inform the scheduler and cooperating facilities that scheduling and
065 * release characteristics of this instance of <code>Schedulable</code> should
066 * <i>not</i> be considered in feasibility analysis until further notified.
067 *
068 * @return True, if the removal was successful. False, if not.
069 */
070 public void removeFromFeasibility();
071
072 /** This method appears in many classes in the RTSJ and with various parameters.
073 * The parameters are either new scheduling characteristics for an instance of
074 * <code>Schedulable</code> or an instance of <code>Schedulable</code>. The
075 * method first performs a feasibility analysis using the new scheduling
076 * characteristics of either <code>this</code> or the given instance of
077 * <code>Schedulable</code>. If the resulting system is feasible the method
078 * replaces the current sheduling characteristics, of either <code>this</code>
079 * or the given instance of <code>Schedulable</code> as appropriate, with the
080 * new scheduling characteristics.
081 *
082 * @param release The proposed release parameters.
083 * @param memory The proposed memory parameters.
084 * @return True, if the resulting system is feasible and the changes are made.
085 * False, if the resulting system is not feasible and no changes are made.
086 */
087 public boolean setIfFeasible(ReleaseParameters release, MemoryParameters memory);
088
089 /** This method appears in many classes in the RTSJ and with various parameters.
090 * The parameters are either new scheduling characteristics for an instance of
091 * <code>Schedulable</code> or an instance of <code>Schedulable</code>. The
092 * method first performs a feasibility analysis using the new scheduling
093 * characteristics of either <code>this</code> or the given instance of
094 * <code>Schedulable</code>. If the resulting system is feasible the method
095 * replaces the current sheduling characteristics, of either <code>this</code>
096 * or the given instance of <code>Schedulable</code> as appropriate, with the
097 * new scheduling characteristics.
098 *
099 * @param release The proposed release parameters.
100 * @param memory The proposed memory parameters.
101 * @param group The proposed processing group parameters.
102 * @return True, if the resulting system is feasible and the changes are made.
103 * False, if the resulting system is not feasible and no changes are made.
104 */
105 public boolean setIfFeasible(ReleaseParameters release, MemoryParameters memory,
106 ProcessingGroupParameters group);
107
108 /** This method appears in many classes in the RTSJ and with various parameters.
109 * The parameters are either new scheduling characteristics for an instance of
110 * <code>Schedulable</code> or an instance of <code>Schedulable</code>. The
111 * method first performs a feasibility analysis using the new scheduling
112 * characteristics of either <code>this</code> or the given instance of
113 * <code>Schedulable</code>. If the resulting system is feasible the method
114 * replaces the current sheduling characteristics, of either <code>this</code>
115 * or the given instance of <code>Schedulable</code> as appropriate, with the
116 * new scheduling characteristics.
117 *
118 * @param release The proposed release parameters.
119 * @param group The proposed processing group parameters.
120 * @return True, if the resulting system is fesible and the changes are made.
121 * False, if the resulting system is not feasible and no changes are made.
122 */
123 public boolean setIfFeasible(ReleaseParameters release, ProcessingGroupParameters group);
124
125 /** Sets the memory parameters associated with this instance of <code>Schedulable</code>.
126 *
127 * @param memory A <code>MemoryParameters</code> object which will become the
128 * memory parameters associated with <code>this</code> after
129 * the method call.
130 */
131 public void setMemoryParameters(MemoryParameters memory);
132
133 /** The method first performs a feasibility analysis using the given memory
134 * parameters as replacements for the memory parameters of <code>this</code>.
135 * If the resulting system is feasible the method replaces the current
136 * memory parameterers of <code>this</code> with the new memory parameters.
137 *
138 * @param memParam The proposed memory Parameters
139 * @return True, if the resulting system is feasible and the changes are made.
140 * False, if the resulting system is not feasible and no changes are made.
141 */
142 public boolean setMemoryParametersIfFeasible(MemoryParameters memParam);
143
144 /** Sets the <code>ProcessingGroupParameters</code> of <code>this</code> only
145 * if the resulting set of scheduling and release characteristics is feasible.
146 *
147 * @param pgp The <code>ProcessingGroupParameters</code> object. If null,
148 * nothing happens.
149 * @return True, if the resulting system is feasible and the changes are made.
150 * False, if the resulting system is not feasible and no changes are made.
151 */
152 public void setProcessingGroupParameters(ProcessingGroupParameters pgp);
153
154 /** Sets the <code>ProcessingGroupParameters</code> of <code>this</code> only
155 * if the resulting set of scheduling and release characteristics is feasible.
156 *
157 * @param groupParameters The <code>ProcessingGroupParameters</code> object.
158 * If null, nothing happens.
159 * @return True, if the resulting system is feasible and the changes are made.
160 * False, if the resulting system is not feasible and no changes are made.
161 */
162 public boolean setProcessingGroupParametersIfFeasible(ProcessingGroupParameters groupParameters);
163
164 /** Sets the release parameters associated with this instance of <code>Schedulable</code>.
165 * Since this affects the constraints expressed in the release parameters of the
166 * existing schedulable objects, this may change the feasibility of the current schedule.
167 *
168 * @param release A <code>ReleaseParameters</code> object which will become the
169 * release parameters associated with this after the method call.
170 */
171 public void setReleaseParameters(ReleaseParameters release);
172
173 /** Set the <code>ReleaseParameters</code> for this schedulable object only if
174 * the resulting set of scheduling and release characteristics is feasible.
175 *
176 * @param release The <code>ReleaseParameters</code> object. If null, nothing happens.
177 * @return True, if the resulting system is feasible and the changes are made.
178 * False, if the resulting system is not feasible and no changes are made.
179 */
180 public boolean setReleaseParametersIfFeasible(ReleaseParameters release);
181
182 /** Sets the reference to the <code>SchedulingParameters</code> object.
183 *
184 * @param scheduling A reference to the <code>SchedulingParameters</code> object.
185 * @throws java.lang.IllegalThreadStateException Thrown when:
186 * <code>((Thread.isAlive() &&
187 * Not Blocked) == true)</code>.
188 * (Where blocked means waiting in
189 * <code>Thread.wait(), Thread.join()
190 * </code> or <code>Thread.sleep()</code>).
191 */
192 public void setSchedulingParameters(SchedulingParameters scheduling);
193
194 /** The method first performs a feasibility analysis using the given scheduling
195 * parameters as replacements for the scheduling parameters of <code>this</code>.
196 * If the resulting system is feasible the method replaces the current scheduling
197 * parameters of <code>this</code> with the new scheduling parameters.
198 *
199 * @param scheduling The proposed scheduling parameters.
200 * @return True, if the resulting system is feasible and the chagens are made.
201 * False, if the resulting system is not feasible and no changes are made.
202 */
203 public boolean setSchedulingParametersIfFeasible(SchedulingParameters scheduling);
204
205 /** Sets the reference to the <code>Scheduler</code> object.
206 *
207 * @param scheduler A reference to the <code>Scheduler</code> object.
208 * @throws java.lang.IllegalThreadStateException Thrown when:
209 * <code>((Thread.isAlive() &&
210 * Not Blocked) == true)</code>.
211 * (Where blocked means waiting
212 * in <code>Thread.wait(),
213 * Thread.join()</code> or
214 * <code>Thread.sleep()</code>).
215 */
216 public void setScheduler(Scheduler scheduler)
217 throws IllegalThreadStateException;
218
219 /** Sets the reference to the <code>Scheduler</code> object.
220 *
221 * @param scheduler A reference to the <code>Scheduler</code> object.
222 * @param scheduling A reference to the <code>SchedulingParameters</code> which
223 * will be associated with <code>this</code>. If null, no
224 * changes to current value of this parameter is made.
225 * @param release A reference to the <code>ReleaseParameters</code> which will
226 * be associated with <code>this</code>. If null, no change to
227 * current value of this parameter is made.
228 * @param memoryParameters A reference to the <code>MemoryParaemters</code>
229 * which will be associated with <code>this</code>. If
230 * null, no change to current value of this parameter
231 * is made.
232 * @param processingGroup A reference to the <code>ProcessingGroupParameters</code>
233 * which will be associated with <code>this</code>. If null,
234 * no change to current value of this parameter is made.
235 * @throws java.lang.IllegalThreadStateException Thrown when:
236 * <code>((Thread.isAlive() &&
237 * Not Blocked) == true)</code>.
238 * (Where blocked means waiting
239 * in <code>Thread.wait(),
240 * Thread.join()</code> or
241 * <code>Thread.sleep()</code>).
242 */
243 public void setScheduler(Scheduler scheduler,
244 SchedulingParameters scheduling,
245 ReleaseParameters release,
246 MemoryParameters memoryParameters,
247 ProcessingGroupParameters processingGroup)
248 throws IllegalThreadStateException;
249
250 /** Return a UID for this Schedulable object. */
251 public long getUID();
252
253 }