1/*
2 * Copyright (c) 2002, 2016, 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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24
25#ifndef SHARE_VM_RUNTIME_JAVAFRAMEANCHOR_HPP
26#define SHARE_VM_RUNTIME_JAVAFRAMEANCHOR_HPP
27
28#include "runtime/orderAccess.inline.hpp"
29#include "utilities/globalDefinitions.hpp"
30#include "utilities/macros.hpp"
31
32//
33// An object for encapsulating the machine/os dependent part of a JavaThread frame state
34//
35class JavaThread;
36
37class JavaFrameAnchor VALUE_OBJ_CLASS_SPEC {
38// Too many friends...
39friend class CallNativeDirectNode;
40friend class OptoRuntime;
41friend class Runtime1;
42friend class StubAssembler;
43friend class CallRuntimeDirectNode;
44friend class MacroAssembler;
45friend class LIR_Assembler;
46friend class GraphKit;
47friend class StubGenerator;
48friend class JavaThread;
49friend class frame;
50friend class VMStructs;
51friend class JVMCIVMStructs;
52friend class BytecodeInterpreter;
53friend class JavaCallWrapper;
54
55 private:
56  //
57  // Whenever _last_Java_sp != NULL other anchor fields MUST be valid!
58  // The stack may not be walkable [check with walkable() ] but the values must be valid.
59  // The profiler apparently depends on this.
60  //
61  intptr_t* volatile _last_Java_sp;
62
63  // Whenever we call from Java to native we can not be assured that the return
64  // address that composes the last_Java_frame will be in an accessible location
65  // so calls from Java to native store that pc (or one good enough to locate
66  // the oopmap) in the frame anchor. Since the frames that call from Java to
67  // native are never deoptimized we never need to patch the pc and so this
68  // is acceptable.
69  volatile  address _last_Java_pc;
70
71  // tells whether the last Java frame is set
72  // It is important that when last_Java_sp != NULL that the rest of the frame
73  // anchor (including platform specific) all be valid.
74
75  bool has_last_Java_frame() const                   { return _last_Java_sp != NULL; }
76  // This is very dangerous unless sp == NULL
77  // Invalidate the anchor so that has_last_frame is false
78  // and no one should look at the other fields.
79  void zap(void)                                     { _last_Java_sp = NULL; }
80
81#include CPU_HEADER(javaFrameAnchor)
82
83public:
84  JavaFrameAnchor()                              { clear(); }
85  JavaFrameAnchor(JavaFrameAnchor *src)          { copy(src); }
86
87  void set_last_Java_pc(address pc)              { _last_Java_pc = pc; }
88
89  // Assembly stub generation helpers
90
91  static ByteSize last_Java_sp_offset()          { return byte_offset_of(JavaFrameAnchor, _last_Java_sp); }
92  static ByteSize last_Java_pc_offset()          { return byte_offset_of(JavaFrameAnchor, _last_Java_pc); }
93
94};
95
96#endif // SHARE_VM_RUNTIME_JAVAFRAMEANCHOR_HPP
97