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1   /*
2    * Copyright (c) 2000, 2002, 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.
8    *
9    * This code is distributed in the hope that it will be useful, but WITHOUT
10   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12   * version 2 for more details (a copy is included in the LICENSE file that
13   * accompanied this code).
14   *
15   * You should have received a copy of the GNU General Public License version
16   * 2 along with this work; if not, write to the Free Software Foundation,
17   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18   *
19   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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24  
25  package sun.jvm.hotspot.debugger;
26  
27  /** <P> This interface abstracts raw access to operating system-level
28      threads. In a debugging environment these methods map to, for
29      example, thread_db calls on Solaris (see /usr/include/thread_db.h)
30      or the Win32 debugging API calls. In a runtime environment these
31      might map directly to pthread calls. </P>
32  
33      <P> Implementors of this interface must provide equals() and
34      hashCode() methods which work properly regardless of how the
35      ThreadProxy is obtained, in particular either through {@link
36      sun.jvm.hotspot.debugger.ThreadAccess} or the thread list provided
37      by {@link sun.jvm.hotspot.debugger.cdbg.CDebugger}. This allows
38      matching up of the OS's notion of the thread list of the target
39      process with any user-level lists that may be present (i.e., the
40      JavaThread list in the HotSpot VM). </P>
41  
42      <P> Implementors of this interface should also provide a
43      toString() which converts the ThreadProxy to a value easily
44      recognizable in the platform's debugger. (For example, on Solaris,
45      "t@&lt;id&gt;".) </P>
46  
47      <P> FIXME: had to be renamed from "Thread" to avoid numerous
48      clashes with java.lang.Thread -- would be nice to pick a more
49      consistent name with the rest of the system. </P> */
50  
51  public interface ThreadProxy {
52    /** Retrieves the context for the given thread. It is only valid to
53        call this method if the thread is suspended (i.e., the process
54        has not been resumed via ProcessControl); throws an
55        IllegalThreadStateException if it is not. */
56    public ThreadContext getContext() throws IllegalThreadStateException;
57  
58    /** Indicates whether calls to setContext() are valid. */
59    public boolean canSetContext() throws DebuggerException;
60  
61    /** Sets the context for the given thread. The passed ThreadContext
62        must be a modified version of one returned from a previous call
63        to getContext(). It is only valid to call this method if the
64        thread is suspended (i.e., the process has not been resumed via
65        ProcessControl); throws an IllegalThreadStateException if it is
66        not. Throws a DebuggerException if the target process can not be
67        modified, for example because it is a core file. */
68    public void setContext(ThreadContext context)
69      throws IllegalThreadStateException, DebuggerException;
70  }