1 /*
2 * Copyright (c) 2013, Red Hat Inc.
3 * Copyright (c) 2002, 2010, Oracle and/or its affiliates.
4 * All rights reserved.
5 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 *
7 * This code is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 only, as
9 * published by the Free Software Foundation.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 *
25 */
26
27 #ifndef CPU_AARCH64_VM_JAVAFRAMEANCHOR_AARCH64_HPP
28 #define CPU_AARCH64_VM_JAVAFRAMEANCHOR_AARCH64_HPP
29
30 private:
31
32 // FP value associated with _last_Java_sp:
33 intptr_t* volatile _last_Java_fp; // pointer is volatile not what it points to
34
35 public:
36 // Each arch must define reset, save, restore
37 // These are used by objects that only care about:
38 // 1 - initializing a new state (thread creation, javaCalls)
39 // 2 - saving a current state (javaCalls)
40 // 3 - restoring an old state (javaCalls)
41
42 void clear(void) {
43 // clearing _last_Java_sp must be first
44 _last_Java_sp = NULL;
45 OrderAccess::release();
46 _last_Java_fp = NULL;
47 _last_Java_pc = NULL;
48 }
49
50 void copy(JavaFrameAnchor* src) {
51 // n.b. the writes to fp and pc do not require any preceding
52 // release(). when copying into the thread anchor, which only
53 // happens under ~JavaCallWrapper(), sp will have been NULLed by a
54 // call to zap() and the NULL write will have been published by a
55 // fence in the state transition to in_vm. contrariwise, when
56 // copying into the wrapper anchor, which only happens under
57 // JavaCallWrapper(), there is no ordering requirement at all
58 // since that object is thread local until the subsequent entry
59 // into java. JavaCallWrapper() call clear() after copy() thus
60 // ensuring that all 3 writes are visible() before the wrapper is
61 // accessible to other threads.
62 _last_Java_fp = src->_last_Java_fp;
63 _last_Java_pc = src->_last_Java_pc;
64 // Must be last so profiler will always see valid frame if
65 // has_last_frame() is true
66 OrderAccess::release();
67 _last_Java_sp = src->_last_Java_sp;
68 }
69
70 bool walkable(void) { return _last_Java_sp != NULL && _last_Java_pc != NULL; }
71 void make_walkable(JavaThread* thread);
72 void capture_last_Java_pc(void);
73
74 intptr_t* last_Java_sp(void) const { return _last_Java_sp; }
75
76 address last_Java_pc(void) { return _last_Java_pc; }
77
78 private:
79
80 static ByteSize last_Java_fp_offset() { return byte_offset_of(JavaFrameAnchor, _last_Java_fp); }
81
82 public:
83
84 // n.b. set_last_Java_sp and set_last_Java_fp are never called
85 // (which is good because they would need a preceding or following
86 // call to OrderAccess::release() to make sure the writes are
87 // visible in the correct order).
88 void set_last_Java_sp(intptr_t* sp) { assert(false, "should not be called"); _last_Java_sp = sp; }
89
90 intptr_t* last_Java_fp(void) { return _last_Java_fp; }
91 // Assert (last_Java_sp == NULL || fp == NULL)
92 void set_last_Java_fp(intptr_t* fp) { assert(false, "should not be called"); _last_Java_fp = fp; }
93
94 #endif // CPU_AARCH64_VM_JAVAFRAMEANCHOR_AARCH64_HPP