1 /*
2 * Copyright (c) 2016, 2019, 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.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_JFR_RECORDER_CHECKPOINT_TYPES_TRACEID_JFRTRACEIDBITS_INLINE_HPP
26 #define SHARE_JFR_RECORDER_CHECKPOINT_TYPES_TRACEID_JFRTRACEIDBITS_INLINE_HPP
27
28 #include "jfr/utilities/jfrTypes.hpp"
29 #include "runtime/atomic.hpp"
30 #include "utilities/macros.hpp"
31
32 #ifdef VM_LITTLE_ENDIAN
33 static const int low_offset = 0;
34 static const int meta_offset = low_offset + 1;
35 #else
36 static const int low_offset = 7;
37 static const int meta_offset = low_offset - 1;
38 #endif
39
set_bits(jbyte bits,jbyte volatile * const dest)40 inline void set_bits(jbyte bits, jbyte volatile* const dest) {
41 assert(dest != NULL, "invariant");
42 if (bits != (*dest & bits)) {
43 *dest |= bits;
44 }
45 }
46
traceid_and(jbyte current,jbyte bits)47 inline jbyte traceid_and(jbyte current, jbyte bits) {
48 return current & bits;
49 }
50
traceid_or(jbyte current,jbyte bits)51 inline jbyte traceid_or(jbyte current, jbyte bits) {
52 return current | bits;
53 }
54
traceid_xor(jbyte current,jbyte bits)55 inline jbyte traceid_xor(jbyte current, jbyte bits) {
56 return current ^ bits;
57 }
58
59 template <jbyte op(jbyte, jbyte)>
set_bits_cas_form(jbyte bits,jbyte * const dest)60 inline void set_bits_cas_form(jbyte bits, jbyte* const dest) {
61 assert(dest != NULL, "invariant");
62 do {
63 const jbyte current = *dest;
64 const jbyte new_value = op(current, bits);
65 if (Atomic::cmpxchg(new_value, dest, current) == current) {
66 return;
67 }
68 } while (true);
69 }
70
set_bits_cas(jbyte bits,jbyte * const dest)71 inline void set_bits_cas(jbyte bits, jbyte* const dest) {
72 set_bits_cas_form<traceid_or>(bits, dest);
73 }
74
clear_bits_cas(jbyte bits,jbyte * const dest)75 inline void clear_bits_cas(jbyte bits, jbyte* const dest) {
76 set_bits_cas_form<traceid_xor>(bits, dest);
77 }
78
set_mask(jbyte mask,jbyte * const dest)79 inline void set_mask(jbyte mask, jbyte* const dest) {
80 set_bits_cas_form<traceid_and>(mask, dest);
81 }
82
set_traceid_bits(jbyte bits,traceid * dest)83 inline void set_traceid_bits(jbyte bits, traceid* dest) {
84 set_bits(bits, ((jbyte*)dest) + low_offset);
85 }
86
set_traceid_bits_cas(jbyte bits,traceid * dest)87 inline void set_traceid_bits_cas(jbyte bits, traceid* dest) {
88 set_bits_cas(bits, ((jbyte*)dest) + low_offset);
89 }
90
set_traceid_mask(jbyte mask,traceid * dest)91 inline void set_traceid_mask(jbyte mask, traceid* dest) {
92 set_mask(mask, ((jbyte*)dest) + low_offset);
93 }
94
set_meta_bits(jbyte bits,jbyte * const dest)95 inline void set_meta_bits(jbyte bits, jbyte* const dest) {
96 assert(dest != NULL, "invariant");
97 *dest |= bits;
98 }
99
set_traceid_meta_bits(jbyte bits,traceid * dest)100 inline void set_traceid_meta_bits(jbyte bits, traceid* dest) {
101 set_meta_bits(bits, ((jbyte*)dest) + meta_offset);
102 }
103
set_meta_mask(jbyte mask,jbyte * const dest)104 inline void set_meta_mask(jbyte mask, jbyte* const dest) {
105 assert(dest != NULL, "invariant");
106 *dest &= mask;
107 }
108
set_traceid_meta_mask(jbyte mask,traceid * dest)109 inline void set_traceid_meta_mask(jbyte mask, traceid* dest) {
110 set_meta_mask(mask, ((jbyte*)dest) + meta_offset);
111 }
112
113 // only used by a single thread with no visibility requirements
clear_meta_bits(jbyte bits,jbyte * const dest)114 inline void clear_meta_bits(jbyte bits, jbyte* const dest) {
115 assert(dest != NULL, "invariant");
116 *dest ^= bits;
117 }
118
119 #endif // SHARE_JFR_RECORDER_CHECKPOINT_TYPES_TRACEID_JFRTRACEIDBITS_INLINE_HPP
120