javaFrameAnchor.hpp revision 1472:c18cbe5936b8 
1/*
2 * Copyright (c) 2002, 2005, 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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
24//
25// An object for encapsulating the machine/os dependent part of a JavaThread frame state
26//
27class JavaThread;
28
29class JavaFrameAnchor VALUE_OBJ_CLASS_SPEC {
30// Too many friends...
31friend class CallNativeDirectNode;
32friend class OptoRuntime;
33friend class Runtime1;
34friend class StubAssembler;
35friend class CallRuntimeDirectNode;
36friend class MacroAssembler;
37friend class InterpreterGenerator;
38friend class LIR_Assembler;
39friend class GraphKit;
40friend class StubGenerator;
41friend class JavaThread;
42friend class frame;
43friend class VMStructs;
44friend class BytecodeInterpreter;
45friend class JavaCallWrapper;
46
47 private:
48  //
49  // Whenever _last_Java_sp != NULL other anchor fields MUST be valid!
50  // The stack may not be walkable [check with walkable() ] but the values must be valid.
51  // The profiler apparently depends on this.
52  //
53  intptr_t* volatile _last_Java_sp;
54
55  // Whenever we call from Java to native we can not be assured that the return
56  // address that composes the last_Java_frame will be in an accessible location
57  // so calls from Java to native store that pc (or one good enough to locate
58  // the oopmap) in the frame anchor. Since the frames that call from Java to
59  // native are never deoptimized we never need to patch the pc and so this
60  // is acceptable.
61  volatile  address _last_Java_pc;
62
63  // tells whether the last Java frame is set
64  // It is important that when last_Java_sp != NULL that the rest of the frame
65  // anchor (including platform specific) all be valid.
66
67  bool has_last_Java_frame() const                   { return _last_Java_sp != NULL; }
68  // This is very dangerous unless sp == NULL
69  // Invalidate the anchor so that has_last_frame is false
70  // and no one should look at the other fields.
71  void zap(void)                                     { _last_Java_sp = NULL; }
72
73#include "incls/_javaFrameAnchor_pd.hpp.incl"
74
75public:
76  JavaFrameAnchor()                              { clear(); }
77  JavaFrameAnchor(JavaFrameAnchor *src)          { copy(src); }
78
79  address last_Java_pc(void)                     { return _last_Java_pc; }
80  void set_last_Java_pc(address pc)              { _last_Java_pc = pc; }
81
82  // Assembly stub generation helpers
83
84  static ByteSize last_Java_sp_offset()          { return byte_offset_of(JavaFrameAnchor, _last_Java_sp); }
85  static ByteSize last_Java_pc_offset()          { return byte_offset_of(JavaFrameAnchor, _last_Java_pc); }
86
87};
88