1 /*
2 * Copyright (c) 1998, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.jdi;
27
28 import java.util.List;
29
30 /**
31 * A mirror of a class in the target VM. A ClassType is a refinement
32 * of {@link ReferenceType} that applies to true classes in the JLS
33 * sense of the definition (not an interface, not an array type). Any
34 * {@link ObjectReference} that mirrors an instance of such a class
35 * will have a ClassType as its type.
36 *
37 * @see ObjectReference
38 *
39 * @author Robert Field
40 * @author Gordon Hirsch
41 * @author James McIlree
42 * @since 1.3
43 */
44 public interface ClassType extends ReferenceType {
45
46 /**
47 * Gets the superclass of this class.
48 *
49 * @return a {@link ClassType} that mirrors the superclass
50 * of this class in the target VM. If no such class exists,
51 * returns null
52 */
53 ClassType superclass();
54
55 /**
56 * Gets the interfaces directly implemented by this class.
57 * Only the interfaces that are declared with the "implements"
58 * keyword in this class are included.
59 *
60 * @return a List of {@link InterfaceType} objects each mirroring
61 * a direct interface this ClassType in the target VM.
62 * If none exist, returns a zero length List.
63 * @throws ClassNotPreparedException if this class not yet been
64 * prepared.
65 */
66 List<InterfaceType> interfaces();
67
68 /**
69 * Gets the interfaces directly and indirectly implemented
70 * by this class. Interfaces returned by {@link ClassType#interfaces}
71 * are returned as well all superinterfaces.
72 *
73 * @return a List of {@link InterfaceType} objects each mirroring
74 * an interface of this ClassType in the target VM.
75 * If none exist, returns a zero length List.
76 * @throws ClassNotPreparedException if this class not yet been
77 * prepared.
78 */
79 List<InterfaceType> allInterfaces();
80
81 /**
82 * Gets the currently loaded, direct subclasses of this class.
83 * No ordering of this list is guaranteed.
84 *
85 * @return a List of {@link ClassType} objects each mirroring a loaded
86 * subclass of this class in the target VM. If no such classes
87 * exist, this method returns a zero-length list.
88 */
89 List<ClassType> subclasses();
90
91 /**
92 * Determine if this class was declared as an enum.
93 * @return <code>true</code> if this class was declared as an enum; false
94 * otherwise.
95 */
96 boolean isEnum();
97
98 /**
99 * Assigns a value to a static field.
100 * The {@link Field} must be valid for this ClassType; that is,
101 * it must be from the mirrored object's class or a superclass of that class.
102 * The field must not be final.
103 * <p>
104 * Object values must be assignment compatible with the field type
105 * (This implies that the field type must be loaded through the
106 * enclosing class' class loader). Primitive values must be
107 * either assignment compatible with the field type or must be
108 * convertible to the field type without loss of information.
109 * See JLS section 5.2 for more information on assignment
110 * compatibility.
111 *
112 * @param field the field to set.
113 * @param value the value to be assigned.
114 * @throws java.lang.IllegalArgumentException if the field is
115 * not static, the field is final, or the field does not exist
116 * in this class.
117 * @throws ClassNotLoadedException if the field type has not yet been loaded
118 * through the appropriate class loader.
119 * @throws InvalidTypeException if the value's type does not match
120 * the field's declared type.
121 * @throws VMCannotBeModifiedException if the VirtualMachine is read-only - see {@link VirtualMachine#canBeModified()}.
122 */
123 void setValue(Field field, Value value)
124 throws InvalidTypeException, ClassNotLoadedException;
125
126 /** Perform method invocation with only the invoking thread resumed */
127 static final int INVOKE_SINGLE_THREADED = 0x1;
128
129 /**
130 * Invokes the specified static {@link Method} in the
131 * target VM. The
132 * specified method can be defined in this class,
133 * or in a superclass.
134 * The method must be a static method
135 * but not a static initializer.
136 * Use {@link ClassType#newInstance} to create a new object and
137 * run its constructor.
138 * <p>
139 * The method invocation will occur in the specified thread.
140 * Method invocation can occur only if the specified thread
141 * has been suspended by an event which occurred in that thread.
142 * Method invocation is not supported
143 * when the target VM has been suspended through
144 * {@link VirtualMachine#suspend} or when the specified thread
145 * is suspended through {@link ThreadReference#suspend}.
146 * <p>
147 * The specified method is invoked with the arguments in the specified
148 * argument list. The method invocation is synchronous; this method
149 * does not return until the invoked method returns in the target VM.
150 * If the invoked method throws an exception, this method will throw
151 * an {@link InvocationException} which contains a mirror to the exception
152 * object thrown.
153 * <p>
154 * Object arguments must be assignment compatible with the argument type
155 * (This implies that the argument type must be loaded through the
156 * enclosing class' class loader). Primitive arguments must be
157 * either assignment compatible with the argument type or must be
158 * convertible to the argument type without loss of information.
159 * If the method being called accepts a variable number of arguments,
160 * then the last argument type is an array of some component type.
161 * The argument in the matching position can be omitted, or can be null,
162 * an array of the same component type, or an argument of the
163 * component type followed by any number of other arguments of the same
164 * type. If the argument is omitted, then a 0 length array of the
165 * component type is passed. The component type can be a primitive type.
166 * Autoboxing is not supported.
167 *
168 * See Section 5.2 of
169 * <cite>The Java™ Language Specification</cite>
170 * for more information on assignment compatibility.
171 * <p>
172 * By default, all threads in the target VM are resumed while
173 * the method is being invoked if they were previously
174 * suspended by an event or by {@link VirtualMachine#suspend} or
175 * {@link ThreadReference#suspend}. This is done to prevent the deadlocks
176 * that will occur if any of the threads own monitors
177 * that will be needed by the invoked method.
178 * Note, however, that this implicit resume acts exactly like
179 * {@link ThreadReference#resume}, so if the thread's suspend
180 * count is greater than 1, it will remain in a suspended state
181 * during the invocation and thus a deadlock could still occur.
182 * By default, when the invocation completes,
183 * all threads in the target VM are suspended, regardless their state
184 * before the invocation.
185 * It is possible that
186 * breakpoints or other events might occur during the invocation.
187 * This can cause deadlocks as described above. It can also cause a deadlock
188 * if invokeMethod is called from the client's event handler thread. In this
189 * case, this thread will be waiting for the invokeMethod to complete and
190 * won't read the EventSet that comes in for the new event. If this
191 * new EventSet is SUSPEND_ALL, then a deadlock will occur because no
192 * one will resume the EventSet. To avoid this, all EventRequests should
193 * be disabled before doing the invokeMethod, or the invokeMethod should
194 * not be done from the client's event handler thread.
195 * <p>
196 * The resumption of other threads during the invocation can be prevented
197 * by specifying the {@link #INVOKE_SINGLE_THREADED}
198 * bit flag in the <code>options</code> argument; however,
199 * there is no protection against or recovery from the deadlocks
200 * described above, so this option should be used with great caution.
201 * Only the specified thread will be resumed (as described for all
202 * threads above). Upon completion of a single threaded invoke, the invoking thread
203 * will be suspended once again. Note that any threads started during
204 * the single threaded invocation will not be suspended when the
205 * invocation completes.
206 * <p>
207 * If the target VM is disconnected during the invoke (for example, through
208 * {@link VirtualMachine#dispose}) the method invocation continues.
209 *
210 * @param thread the thread in which to invoke.
211 * @param method the {@link Method} to invoke.
212 * @param arguments the list of {@link Value} arguments bound to the
213 * invoked method. Values from the list are assigned to arguments
214 * in the order they appear in the method signature.
215 * @param options the integer bit flag options.
216 * @return a {@link Value} mirror of the invoked method's return value.
217 * @throws java.lang.IllegalArgumentException if the method is not
218 * a member of this class or a superclass, if the size of the argument list
219 * does not match the number of declared arguments for the method, or
220 * if the method is an initializer, constructor or static intializer.
221 * @throws ClassNotLoadedException if any argument type has not yet been loaded
222 * through the appropriate class loader.
223 * @throws IncompatibleThreadStateException if the specified thread has not
224 * been suspended by an event.
225 * @throws InvocationException if the method invocation resulted in
226 * an exception in the target VM.
227 * @throws InvalidTypeException If the arguments do not meet this requirement --
228 * Object arguments must be assignment compatible with the argument
229 * type. This implies that the argument type must be
230 * loaded through the enclosing class' class loader.
231 * Primitive arguments must be either assignment compatible with the
232 * argument type or must be convertible to the argument type without loss
233 * of information. See JLS section 5.2 for more information on assignment
234 * compatibility.
235 * @throws VMCannotBeModifiedException if the VirtualMachine is read-only - see {@link VirtualMachine#canBeModified()}.
236 */
237 Value invokeMethod(ThreadReference thread, Method method,
238 List<? extends Value> arguments, int options)
239 throws InvalidTypeException,
240 ClassNotLoadedException,
241 IncompatibleThreadStateException,
242 InvocationException;
243
244 /**
245 * Constructs a new instance of this type, using
246 * the given constructor {@link Method} in the
247 * target VM. The
248 * specified constructor must be defined in this class.
249 * <p>
250 * Instance creation will occur in the specified thread.
251 * Instance creation can occur only if the specified thread
252 * has been suspended by an event which occurred in that thread.
253 * Instance creation is not supported
254 * when the target VM has been suspended through
255 * {@link VirtualMachine#suspend} or when the specified thread
256 * is suspended through {@link ThreadReference#suspend}.
257 * <p>
258 * The specified constructor is invoked with the arguments in the specified
259 * argument list. The invocation is synchronous; this method
260 * does not return until the constructor returns in the target VM.
261 * If the invoked method throws an
262 * exception, this method will throw an {@link InvocationException}
263 * which contains a mirror to the exception object thrown.
264 * <p>
265 * Object arguments must be assignment compatible with the argument type
266 * (This implies that the argument type must be loaded through the
267 * enclosing class' class loader). Primitive arguments must be
268 * either assignment compatible with the argument type or must be
269 * convertible to the argument type without loss of information.
270 * If the method being called accepts a variable number of arguments,
271 * then the last argument type is an array of some component type.
272 * The argument in the matching position can be omitted, or can be null,
273 * an array of the same component type, or an argument of the
274 * component type, followed by any number of other arguments of the same
275 * type. If the argument is omitted, then a 0 length array of the
276 * component type is passed. The component type can be a primitive type.
277 * Autoboxing is not supported.
278 *
279 * See section 5.2 of
280 * <cite>The Java™ Language Specification</cite>
281 * for more information on assignment compatibility.
282 * <p>
283 * By default, all threads in the target VM are resumed while
284 * the method is being invoked if they were previously
285 * suspended by an event or by {@link VirtualMachine#suspend} or
286 * {@link ThreadReference#suspend}. This is done to prevent the deadlocks
287 * that will occur if any of the threads own monitors
288 * that will be needed by the invoked method. It is possible that
289 * breakpoints or other events might occur during the invocation.
290 * Note, however, that this implicit resume acts exactly like
291 * {@link ThreadReference#resume}, so if the thread's suspend
292 * count is greater than 1, it will remain in a suspended state
293 * during the invocation. By default, when the invocation completes,
294 * all threads in the target VM are suspended, regardless their state
295 * before the invocation.
296 * <p>
297 * The resumption of other threads during the invocation can be prevented
298 * by specifying the {@link #INVOKE_SINGLE_THREADED}
299 * bit flag in the <code>options</code> argument; however,
300 * there is no protection against or recovery from the deadlocks
301 * described above, so this option should be used with great caution.
302 * Only the specified thread will be resumed (as described for all
303 * threads above). Upon completion of a single threaded invoke, the invoking thread
304 * will be suspended once again. Note that any threads started during
305 * the single threaded invocation will not be suspended when the
306 * invocation completes.
307 * <p>
308 * If the target VM is disconnected during the invoke (for example, through
309 * {@link VirtualMachine#dispose}) the method invocation continues.
310 *
311 * @param thread the thread in which to invoke.
312 * @param method the constructor {@link Method} to invoke.
313 * @param arguments the list of {@link Value} arguments bound to the
314 * invoked constructor. Values from the list are assigned to arguments
315 * in the order they appear in the constructor signature.
316 * @param options the integer bit flag options.
317 * @return an {@link ObjectReference} mirror of the newly created
318 * object.
319 * @throws java.lang.IllegalArgumentException if the method is not
320 * a member of this class, if the size of the argument list
321 * does not match the number of declared arguments for the constructor,
322 * or if the method is not a constructor.
323 * @throws ClassNotLoadedException if any argument type has not yet been loaded
324 * through the appropriate class loader.
325 * @throws IncompatibleThreadStateException if the specified thread has not
326 * been suspended by an event.
327 * @throws InvocationException if the method invocation resulted in
328 * an exception in the target VM.
329 * @throws InvalidTypeException If the arguments do not meet this requirement --
330 * Object arguments must be assignment compatible with the argument
331 * type. This implies that the argument type must be
332 * loaded through the enclosing class' class loader.
333 * Primitive arguments must be either assignment compatible with the
334 * argument type or must be convertible to the argument type without loss
335 * of information. See JLS section 5.2 for more information on assignment
336 * compatibility.
337 * @throws VMCannotBeModifiedException if the VirtualMachine is read-only
338 * - see {@link VirtualMachine#canBeModified()}.
339 */
340 ObjectReference newInstance(ThreadReference thread, Method method,
341 List<? extends Value> arguments, int options)
342 throws InvalidTypeException,
343 ClassNotLoadedException,
344 IncompatibleThreadStateException,
345 InvocationException;
346
347 /**
348 * Returns a the single non-abstract {@link Method} visible from
349 * this class that has the given name and signature.
350 * See {@link ReferenceType#methodsByName(java.lang.String, java.lang.String)}
351 * for information on signature format.
352 * <p>
353 * The returned method (if non-null) is a component of
354 * {@link ClassType}.
355 *
356 * @see ReferenceType#visibleMethods
357 * @see ReferenceType#methodsByName(java.lang.String name)
358 * @see ReferenceType#methodsByName(java.lang.String name, java.lang.String signature)
359 * @param name the name of the method to find.
360 * @param signature the signature of the method to find
361 * @return the {@link Method} that matches the given
362 * name and signature or <code>null</code> if there is no match.
363 * @throws ClassNotPreparedException if methods are not yet available
364 * because the class has not yet been prepared.
365 */
366 Method concreteMethodByName(String name, String signature);
367 }