1 /*
 2  * Copyright (c) 2002, 2020, Oracle and/or its affiliates. All rights reserved.
 3  * Copyright (c) 2014, Red Hat Inc. All rights reserved.
 4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 5  *
 6  * This code is free software; you can redistribute it and/or modify it
 7  * under the terms of the GNU General Public License version 2 only, as
 8  * published by the Free Software Foundation.
 9  *
10  * This code is distributed in the hope that it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13  * version 2 for more details (a copy is included in the LICENSE file that
14  * accompanied this code).
15  *
16  * You should have received a copy of the GNU General Public License version
17  * 2 along with this work; if not, write to the Free Software Foundation,
18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19  *
20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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25 
26 #ifndef CPU_AARCH64_JAVAFRAMEANCHOR_AARCH64_HPP
27 #define CPU_AARCH64_JAVAFRAMEANCHOR_AARCH64_HPP
28 
29 private:
30 
31   // FP value associated with _last_Java_sp:
32   intptr_t* volatile        _last_Java_fp;           // pointer is volatile not what it points to
33 
34 public:
35   // Each arch must define reset, save, restore
36   // These are used by objects that only care about:
37   //  1 - initializing a new state (thread creation, javaCalls)
38   //  2 - saving a current state (javaCalls)
39   //  3 - restoring an old state (javaCalls)
40 
41   void clear(void) {
42     // clearing _last_Java_sp must be first
43     _last_Java_sp = NULL;
44     OrderAccess::release();
45     _last_Java_fp = NULL;
46     _last_Java_pc = NULL;
47   }
48 
49   void copy(JavaFrameAnchor* src) {
50     // In order to make sure the transition state is valid for "this"
51     // We must clear _last_Java_sp before copying the rest of the new data
52     //
53     // Hack Alert: Temporary bugfix for 4717480/4721647
54     // To act like previous version (pd_cache_state) don't NULL _last_Java_sp
55     // unless the value is changing
56     //
57     if (_last_Java_sp != src->_last_Java_sp) {
58       _last_Java_sp = NULL;
59       OrderAccess::release();
60     }
61     _last_Java_fp = src->_last_Java_fp;
62     _last_Java_pc = src->_last_Java_pc;
63     // Must be last so profiler will always see valid frame if has_last_frame() is true
64     _last_Java_sp = src->_last_Java_sp;
65   }
66 
67   bool walkable(void)                            { return _last_Java_sp != NULL && _last_Java_pc != NULL; }
68   void make_walkable(JavaThread* thread);
69   void capture_last_Java_pc(void);
70 
71   intptr_t* last_Java_sp(void) const             { return _last_Java_sp; }
72 
73   address last_Java_pc(void)                     { return _last_Java_pc; }
74 
75 private:
76 
77   static ByteSize last_Java_fp_offset()          { return byte_offset_of(JavaFrameAnchor, _last_Java_fp); }
78 
79 public:
80 
81   void set_last_Java_sp(intptr_t* sp)            { _last_Java_sp = sp; OrderAccess::release(); }
82 
83   intptr_t*   last_Java_fp(void)                 { return _last_Java_fp; }
84 
85 #endif // CPU_AARCH64_JAVAFRAMEANCHOR_AARCH64_HPP