/*

 * Copyright (c) 1998, 2017, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package com.sun.jdi;

import java.util.List;

/**

 * A mirror of a class in the target VM. A ClassType is a refinement

 * of {@link ReferenceType} that applies to true classes in the JLS

 * sense of the definition (not an interface, not an array type). Any

 * {@link ObjectReference} that mirrors an instance of such a class

 * will have a ClassType as its type.

 *

 * @see ObjectReference

 *

 * @author Robert Field

 * @author Gordon Hirsch

 * @author James McIlree

 * @since  1.3

 */

public interface ClassType extends ReferenceType {

    /**

     * Gets the superclass of this class.

     *

     * @return a {@link ClassType} that mirrors the superclass

     * of this class in the target VM. If no such class exists,

     * returns null

     */

    ClassType superclass();

    /**

     * Gets the interfaces directly implemented by this class.

     * Only the interfaces that are declared with the "implements"

     * keyword in this class are included.

     *

     * @return a List of {@link InterfaceType} objects each mirroring

     * a direct interface this ClassType in the target VM.

     * If none exist, returns a zero length List.

     * @throws ClassNotPreparedException if this class not yet been

     * prepared.

     */

    List<InterfaceType> interfaces();

    /**

     * Gets the interfaces directly and indirectly implemented

     * by this class. Interfaces returned by {@link ClassType#interfaces}

     * are returned as well all superinterfaces.

     *

     * @return a List of {@link InterfaceType} objects each mirroring

     * an interface of this ClassType in the target VM.

     * If none exist, returns a zero length List.

     * @throws ClassNotPreparedException if this class not yet been

     * prepared.

     */

    List<InterfaceType> allInterfaces();

    /**

     * Gets the currently loaded, direct subclasses of this class.

     * No ordering of this list is guaranteed.

     *

     * @return a List of {@link ClassType} objects each mirroring a loaded

     * subclass of this class in the target VM. If no such classes

     * exist, this method returns a zero-length list.

     */

    List<ClassType> subclasses();

    /**

     * Determine if this class was declared as an enum.

     * @return <code>true</code> if this class was declared as an enum; false

     * otherwise.

     */

    boolean isEnum();

    /**

     * Assigns a value to a static field.

     * The {@link Field} must be valid for this ClassType; that is,

     * it must be from the mirrored object's class or a superclass of that class.

     * The field must not be final.

     * <p>

     * Object values must be assignment compatible with the field type

     * (This implies that the field type must be loaded through the

     * enclosing class' class loader). Primitive values must be

     * either assignment compatible with the field type or must be

     * convertible to the field type without loss of information.

     * See JLS section 5.2 for more information on assignment

     * compatibility.

     *

     * @param field the field to set.

     * @param value the value to be assigned.

     * @throws java.lang.IllegalArgumentException if the field is

     * not static, the field is final, or the field does not exist

     * in this class.

     * @throws ClassNotLoadedException if the field type has not yet been loaded

     * through the appropriate class loader.

     * @throws InvalidTypeException if the value's type does not match

     * the field's declared type.

     * @throws VMCannotBeModifiedException if the VirtualMachine is read-only - see {@link VirtualMachine#canBeModified()}.

     */

    void setValue(Field field, Value value)

        throws InvalidTypeException, ClassNotLoadedException;

    /** Perform method invocation with only the invoking thread resumed */

    static final int INVOKE_SINGLE_THREADED = 0x1;

    /**

     * Invokes the specified static {@link Method} in the

     * target VM. The

     * specified method can be defined in this class,

     * or in a superclass.

     * The method must be a static method

     * but not a static initializer.

     * Use {@link ClassType#newInstance} to create a new object and

     * run its constructor.

     * <p>

     * The method invocation will occur in the specified thread.

     * Method invocation can occur only if the specified thread

     * has been suspended by an event which occurred in that thread.

     * Method invocation is not supported

     * when the target VM has been suspended through

     * {@link VirtualMachine#suspend} or when the specified thread

     * is suspended through {@link ThreadReference#suspend}.

     * <p>

     * The specified method is invoked with the arguments in the specified

     * argument list.  The method invocation is synchronous; this method

     * does not return until the invoked method returns in the target VM.

     * If the invoked method throws an exception, this method will throw

     * an {@link InvocationException} which contains a mirror to the exception

     * object thrown.

     * <p>

     * Object arguments must be assignment compatible with the argument type

     * (This implies that the argument type must be loaded through the

     * enclosing class' class loader). Primitive arguments must be

     * either assignment compatible with the argument type or must be

     * convertible to the argument type without loss of information.

     * If the method being called accepts a variable number of arguments,

     * then the last argument type is an array of some component type.

     * The argument in the matching position can be omitted, or can be null,

     * an array of the same component type, or an argument of the

     * component type followed by any number of other arguments of the same

     * type. If the argument is omitted, then a 0 length array of the

     * component type is passed.  The component type can be a primitive type.

     * Autoboxing is not supported.

     *

     * See Section 5.2 of

     * <cite>The Java&trade; Language Specification</cite>

     * for more information on assignment compatibility.

     * <p>

     * By default, all threads in the target VM are resumed while

     * the method is being invoked if they were previously

     * suspended by an event or by {@link VirtualMachine#suspend} or

     * {@link ThreadReference#suspend}. This is done to prevent the deadlocks

     * that will occur if any of the threads own monitors

     * that will be needed by the invoked method.

     * Note, however, that this implicit resume acts exactly like

     * {@link ThreadReference#resume}, so if the thread's suspend

     * count is greater than 1, it will remain in a suspended state

     * during the invocation and thus a deadlock could still occur.

     * By default, when the invocation completes,

     * all threads in the target VM are suspended, regardless their state

     * before the invocation.

     * It is possible that

     * breakpoints or other events might occur during the invocation.

     * This can cause deadlocks as described above. It can also cause a deadlock

     * if invokeMethod is called from the client's event handler thread.  In this

     * case, this thread will be waiting for the invokeMethod to complete and

     * won't read the EventSet that comes in for the new event.  If this

     * new EventSet is SUSPEND_ALL, then a deadlock will occur because no

     * one will resume the EventSet.  To avoid this, all EventRequests should

     * be disabled before doing the invokeMethod, or the invokeMethod should

     * not be done from the client's event handler thread.

     * <p>

     * The resumption of other threads during the invocation can be prevented

     * by specifying the {@link #INVOKE_SINGLE_THREADED}

     * bit flag in the <code>options</code> argument; however,

     * there is no protection against or recovery from the deadlocks

     * described above, so this option should be used with great caution.

     * Only the specified thread will be resumed (as described for all

     * threads above). Upon completion of a single threaded invoke, the invoking thread

     * will be suspended once again. Note that any threads started during

     * the single threaded invocation will not be suspended when the

     * invocation completes.

     * <p>

     * If the target VM is disconnected during the invoke (for example, through

     * {@link VirtualMachine#dispose}) the method invocation continues.

     *

     * @param thread the thread in which to invoke.

     * @param method the {@link Method} to invoke.

     * @param arguments the list of {@link Value} arguments bound to the

     * invoked method. Values from the list are assigned to arguments

     * in the order they appear in the method signature.

     * @param options the integer bit flag options.

     * @return a {@link Value} mirror of the invoked method's return value.

     * @throws java.lang.IllegalArgumentException if the method is not

     * a member of this class or a superclass, if the size of the argument list

     * does not match the number of declared arguments for the method, or

     * if the method is an initializer, constructor or static intializer.

     * @throws ClassNotLoadedException if any argument type has not yet been loaded

     * through the appropriate class loader.

     * @throws IncompatibleThreadStateException if the specified thread has not

     * been suspended by an event.

     * @throws InvocationException if the method invocation resulted in

     * an exception in the target VM.

     * @throws InvalidTypeException If the arguments do not meet this requirement --

     *         Object arguments must be assignment compatible with the argument

     *         type.  This implies that the argument type must be

     *         loaded through the enclosing class' class loader.

     *         Primitive arguments must be either assignment compatible with the

     *         argument type or must be convertible to the argument type without loss

     *         of information. See JLS section 5.2 for more information on assignment

     *         compatibility.

     * @throws VMCannotBeModifiedException if the VirtualMachine is read-only - see {@link VirtualMachine#canBeModified()}.

     */

    Value invokeMethod(ThreadReference thread, Method method,

                       List<? extends Value> arguments, int options)

                                   throws InvalidTypeException,

                                          ClassNotLoadedException,

                                          IncompatibleThreadStateException,

                                          InvocationException;

    /**

     * Constructs a new instance of this type, using

     * the given constructor {@link Method} in the

     * target VM. The

     * specified constructor must be defined in this class.

     * <p>

     * Instance creation will occur in the specified thread.

     * Instance creation can occur only if the specified thread

     * has been suspended by an event which occurred in that thread.

     * Instance creation is not supported

     * when the target VM has been suspended through

     * {@link VirtualMachine#suspend} or when the specified thread

     * is suspended through {@link ThreadReference#suspend}.

     * <p>

     * The specified constructor is invoked with the arguments in the specified

     * argument list.  The invocation is synchronous; this method

     * does not return until the constructor returns in the target VM.

     * If the invoked method throws an

     * exception, this method will throw an {@link InvocationException}

     * which contains a mirror to the exception object thrown.

     * <p>

     * Object arguments must be assignment compatible with the argument type

     * (This implies that the argument type must be loaded through the

     * enclosing class' class loader). Primitive arguments must be

     * either assignment compatible with the argument type or must be

     * convertible to the argument type without loss of information.

     * If the method being called accepts a variable number of arguments,

     * then the last argument type is an array of some component type.

     * The argument in the matching position can be omitted, or can be null,

     * an array of the same component type, or an argument of the

     * component type, followed by any number of other arguments of the same

     * type. If the argument is omitted, then a 0 length array of the

     * component type is passed.  The component type can be a primitive type.

     * Autoboxing is not supported.

     *

     * See section 5.2 of

     * <cite>The Java&trade; Language Specification</cite>

     * for more information on assignment compatibility.

     * <p>

     * By default, all threads in the target VM are resumed while

     * the method is being invoked if they were previously

     * suspended by an event or by {@link VirtualMachine#suspend} or

     * {@link ThreadReference#suspend}. This is done to prevent the deadlocks

     * that will occur if any of the threads own monitors

     * that will be needed by the invoked method. It is possible that

     * breakpoints or other events might occur during the invocation.

     * Note, however, that this implicit resume acts exactly like

     * {@link ThreadReference#resume}, so if the thread's suspend

     * count is greater than 1, it will remain in a suspended state

     * during the invocation. By default, when the invocation completes,

     * all threads in the target VM are suspended, regardless their state

     * before the invocation.

     * <p>

     * The resumption of other threads during the invocation can be prevented

     * by specifying the {@link #INVOKE_SINGLE_THREADED}

     * bit flag in the <code>options</code> argument; however,

     * there is no protection against or recovery from the deadlocks

     * described above, so this option should be used with great caution.

     * Only the specified thread will be resumed (as described for all

     * threads above). Upon completion of a single threaded invoke, the invoking thread

     * will be suspended once again. Note that any threads started during

     * the single threaded invocation will not be suspended when the

     * invocation completes.

     * <p>

     * If the target VM is disconnected during the invoke (for example, through

     * {@link VirtualMachine#dispose}) the method invocation continues.

     *

     * @param thread the thread in which to invoke.

     * @param method the constructor {@link Method} to invoke.

     * @param arguments the list of {@link Value} arguments bound to the

     * invoked constructor. Values from the list are assigned to arguments

     * in the order they appear in the constructor signature.

     * @param options the integer bit flag options.

     * @return an {@link ObjectReference} mirror of the newly created

     * object.

     * @throws java.lang.IllegalArgumentException if the method is not

     * a member of this class, if the size of the argument list

     * does not match the number of declared arguments for the constructor,

     * or if the method is not a constructor.

     * @throws ClassNotLoadedException if any argument type has not yet been loaded

     * through the appropriate class loader.

     * @throws IncompatibleThreadStateException if the specified thread has not

     * been suspended by an event.

     * @throws InvocationException if the method invocation resulted in

     * an exception in the target VM.

     * @throws InvalidTypeException If the arguments do not meet this requirement --

     *         Object arguments must be assignment compatible with the argument

     *         type.  This implies that the argument type must be

     *         loaded through the enclosing class' class loader.

     *         Primitive arguments must be either assignment compatible with the

     *         argument type or must be convertible to the argument type without loss

     *         of information. See JLS section 5.2 for more information on assignment

     *         compatibility.

     * @throws VMCannotBeModifiedException if the VirtualMachine is read-only

     * - see {@link VirtualMachine#canBeModified()}.

     */

    ObjectReference newInstance(ThreadReference thread, Method method,

                                List<? extends Value> arguments, int options)

                                   throws InvalidTypeException,

                                          ClassNotLoadedException,

                                          IncompatibleThreadStateException,

                                          InvocationException;

    /**

     * Returns a the single non-abstract {@link Method} visible from

     * this class that has the given name and signature.

     * See {@link ReferenceType#methodsByName(java.lang.String, java.lang.String)}

     * for information on signature format.

     * <p>

     * The returned method (if non-null) is a component of

     * {@link ClassType}.

     *

     * @see ReferenceType#visibleMethods

     * @see ReferenceType#methodsByName(java.lang.String name)

     * @see ReferenceType#methodsByName(java.lang.String name, java.lang.String signature)

     * @param name the name of the method to find.

     * @param signature the signature of the method to find

     * @return the {@link Method} that matches the given

     * name and signature or <code>null</code> if there is no match.

     * @throws ClassNotPreparedException if methods are not yet available

     * because the class has not yet been prepared.

     */

    Method concreteMethodByName(String name, String signature);

}