1 /*
 2  * Copyright (c) 2002, 2020, 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
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17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18  *
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24 
25 #ifndef CPU_X86_JAVAFRAMEANCHOR_X86_HPP
26 #define CPU_X86_JAVAFRAMEANCHOR_X86_HPP
27 
28 private:
29 
30   // FP value associated with _last_Java_sp:
31   intptr_t* volatile        _last_Java_fp;           // pointer is volatile not what it points to
32 
33 public:
34   // Each arch must define reset, save, restore
35   // These are used by objects that only care about:
36   //  1 - initializing a new state (thread creation, javaCalls)
37   //  2 - saving a current state (javaCalls)
38   //  3 - restoring an old state (javaCalls)
39 
40   void clear(void) {
41     // clearing _last_Java_sp must be first
42     _last_Java_sp = NULL;
43     // fence?
44     _last_Java_fp = NULL;
45     _last_Java_pc = NULL;
46   }
47 
48   void copy(JavaFrameAnchor* src) {
49     // In order to make sure the transition state is valid for "this"
50     // We must clear _last_Java_sp before copying the rest of the new data
51     //
52     // Hack Alert: Temporary bugfix for 4717480/4721647
53     // To act like previous version (pd_cache_state) don't NULL _last_Java_sp
54     // unless the value is changing
55     //
56     if (_last_Java_sp != src->_last_Java_sp)
57       _last_Java_sp = NULL;
58 
59     _last_Java_fp = src->_last_Java_fp;
60     _last_Java_pc = src->_last_Java_pc;
61     // Must be last so profiler will always see valid frame if has_last_frame() is true
62     _last_Java_sp = src->_last_Java_sp;
63   }
64 
65   bool walkable(void)                            { return _last_Java_sp != NULL && _last_Java_pc != NULL; }
66   void make_walkable(JavaThread* thread);
67   void capture_last_Java_pc(void);
68 
69   intptr_t* last_Java_sp(void) const             { return _last_Java_sp; }
70 
71   address last_Java_pc(void)                     { return _last_Java_pc; }
72 
73   static ByteSize last_Java_fp_offset()          { return byte_offset_of(JavaFrameAnchor, _last_Java_fp); }
74 
75 public:
76 
77   void set_last_Java_sp(intptr_t* sp)            { _last_Java_sp = sp; }
78 
79   intptr_t*   last_Java_fp(void)                 { return _last_Java_fp; }
80 
81 #endif // CPU_X86_JAVAFRAMEANCHOR_X86_HPP