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