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 26package com.sun.jdi; 27 28import 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 */ 44public 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} 367