javaFrameAnchor_zero.hpp revision 1472:c18cbe5936b8 
1/*
2 * Copyright (c) 2003, 2005, Oracle and/or its affiliates. All rights reserved.
3 * Copyright 2007, 2008, 2010 Red Hat, Inc.
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
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 private:
27  ZeroFrame* volatile _last_Java_fp;
28
29 public:
30  // Each arch must define reset, save, restore
31  // These are used by objects that only care about:
32  //  1 - initializing a new state (thread creation, javaCalls)
33  //  2 - saving a current state (javaCalls)
34  //  3 - restoring an old state (javaCalls)
35  // Note that whenever _last_Java_sp != NULL other anchor fields
36  // must be valid.  The profiler apparently depends on this.
37
38  void clear() {
39    // clearing _last_Java_sp must be first
40    _last_Java_sp = NULL;
41    // fence?
42    _last_Java_fp = NULL;
43    _last_Java_pc = NULL;
44  }
45
46  void copy(JavaFrameAnchor* src) {
47    set(src->_last_Java_sp, src->_last_Java_pc, src->_last_Java_fp);
48  }
49
50  void set(intptr_t* sp, address pc, ZeroFrame* fp) {
51    // In order to make sure the transition state is valid for "this"
52    // We must clear _last_Java_sp before copying the rest of the new
53    // data
54    //
55    // Hack Alert: Temporary bugfix for 4717480/4721647 To act like
56    // previous version (pd_cache_state) don't NULL _last_Java_sp
57    // unless the value is changing
58    //
59    if (_last_Java_sp != sp)
60      _last_Java_sp = NULL;
61
62    _last_Java_fp = fp;
63    _last_Java_pc = pc;
64    // Must be last so profiler will always see valid frame if
65    // has_last_frame() is true
66    _last_Java_sp = sp;
67  }
68
69  bool walkable() {
70    return true;
71  }
72
73  void make_walkable(JavaThread* thread) {
74    // nothing to do
75  }
76
77  intptr_t* last_Java_sp() const {
78    return _last_Java_sp;
79  }
80
81  ZeroFrame* last_Java_fp() const {
82    return _last_Java_fp;
83  }
84
85  static ByteSize last_Java_fp_offset() {
86    return byte_offset_of(JavaFrameAnchor, _last_Java_fp);
87  }
88