1 /*
2 * Copyright (c) 2011, 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 #include "precompiled.hpp"
26 #include "classfile/classLoaderData.inline.hpp"
27 #include "classfile/symbolTable.hpp"
28 #include "jfr/recorder/checkpoint/constant/traceid/jfrTraceId.inline.hpp"
29 #include "oops/arrayKlass.hpp"
30 #include "oops/klass.inline.hpp"
31 #include "oops/instanceKlass.hpp"
32 #include "oops/method.hpp"
33 #include "oops/oop.inline.hpp"
34 #include "runtime/atomic.hpp"
35 #include "runtime/orderAccess.inline.hpp"
36 #include "runtime/vm_version.hpp"
37 #include "tracefiles/traceEventIds.hpp"
38 #include "runtime/jniHandles.hpp"
39 #include "runtime/thread.inline.hpp"
40 #include "utilities/debug.hpp"
41 #include "jfr/utilities/jfrLog.hpp"
42
43 // returns updated value
44 static traceid atomic_inc(traceid volatile* const dest) {
45 assert(VM_Version::supports_cx8(), "invariant");
46 traceid compare_value;
47 traceid exchange_value;
48 do {
49 compare_value = OrderAccess::load_acquire(dest);
50 exchange_value = compare_value + 1;
51 } while (Atomic::cmpxchg(exchange_value, dest, compare_value) != compare_value);
52 return exchange_value;
53 }
54
55 static traceid next_class_id() {
56 static volatile traceid class_id_counter = MaxTraceEventId + 100;
57 return atomic_inc(&class_id_counter) << TRACE_ID_SHIFT;
58 }
59
60 static traceid next_thread_id() {
61 static volatile traceid thread_id_counter = 0;
62 return atomic_inc(&thread_id_counter);
63 }
64
65 static traceid next_class_loader_data_id() {
66 static volatile traceid cld_id_counter = 1;
67 return atomic_inc(&cld_id_counter) << TRACE_ID_SHIFT;
68 }
69
70 static bool found_jdk_jfr_event_klass = false;
71
72 static void check_klass(const Klass* klass) {
73 assert(klass != NULL, "invariant");
74 if (found_jdk_jfr_event_klass) {
75 return;
76 }
77 static const Symbol* jdk_jfr_event_sym = NULL;
78 if (jdk_jfr_event_sym == NULL) {
79 // setup when loading the first TypeArrayKlass (Universe::genesis) hence single threaded invariant
80 jdk_jfr_event_sym = SymbolTable::new_permanent_symbol("jdk/jfr/Event", Thread::current());
81 }
82 assert(jdk_jfr_event_sym != NULL, "invariant");
83 if (jdk_jfr_event_sym == klass->name() && klass->class_loader() == NULL) {
84 found_jdk_jfr_event_klass = true;
85 JfrTraceId::tag_as_jdk_jfr_event(klass);
86 }
87 }
88
89 void JfrTraceId::assign(const Klass* klass) {
90 assert(klass != NULL, "invariant");
91 klass->set_trace_id(next_class_id());
92 check_klass(klass);
93 const Klass* const super = klass->super();
94 if (super == NULL) {
95 return;
96 }
97 if (IS_EVENT_KLASS(super)) {
98 tag_as_jdk_jfr_event_sub(klass);
99 }
100 }
101
102 void JfrTraceId::assign(const ClassLoaderData* cld) {
103 assert(cld != NULL, "invariant");
104 if (cld->is_anonymous()) {
105 cld->set_trace_id(0);
106 return;
107 }
108 cld->set_trace_id(next_class_loader_data_id());
109 }
110
111 traceid JfrTraceId::assign_thread_id() {
112 return next_thread_id();
113 }
114
115 // used by CDS / APPCDS as part of "remove_unshareable_info"
116 void JfrTraceId::remove(const Klass* k) {
117 assert(k != NULL, "invariant");
118 // Mask off and store the event flags.
119 // This mechanism will retain the event specific flags
120 // in the archive, allowing for event flag restoration
121 // when renewing the traceid on klass revival.
122 k->set_trace_id(EVENT_FLAGS_MASK(k));
123 }
124
125 // used by CDS / APPCDS as part of "restore_unshareable_info"
126 void JfrTraceId::restore(const Klass* k) {
127 assert(k != NULL, "invariant");
128 if (IS_JDK_JFR_EVENT_KLASS(k)) {
129 found_jdk_jfr_event_klass = true;
130 }
131 const traceid event_flags = k->trace_id();
132 // get a fresh traceid and restore the original event flags
133 k->set_trace_id(next_class_id() | event_flags);
134 }
135
136 traceid JfrTraceId::get(jclass jc) {
137 assert(jc != NULL, "invariant");
138 assert(((JavaThread*)Thread::current())->thread_state() == _thread_in_vm, "invariant");
139 const oop my_oop = JNIHandles::resolve(jc);
140 assert(my_oop != NULL, "invariant");
141 return get(java_lang_Class::as_Klass(my_oop));
142 }
143
144 traceid JfrTraceId::use(jclass jc, bool leakp /* false */) {
145 assert(jc != NULL, "invariant");
146 assert(((JavaThread*)Thread::current())->thread_state() == _thread_in_vm, "invariant");
147 const oop my_oop = JNIHandles::resolve(jc);
148 assert(my_oop != NULL, "invariant");
149 return use(java_lang_Class::as_Klass(my_oop), leakp);
150 }
151
152 bool JfrTraceId::in_visible_set(const jclass jc) {
153 assert(jc != NULL, "invariant");
154 assert(((JavaThread*)Thread::current())->thread_state() == _thread_in_vm, "invariant");
155 const oop mirror = JNIHandles::resolve(jc);
156 assert(mirror != NULL, "invariant");
157 return in_visible_set(java_lang_Class::as_Klass(mirror));
158 }
159
160 bool JfrTraceId::in_jdk_jfr_event_hierarchy(const jclass jc) {
161 assert(jc != NULL, "invariant");
162 const oop mirror = JNIHandles::resolve(jc);
163 assert(mirror != NULL, "invariant");
164 return in_jdk_jfr_event_hierarchy(java_lang_Class::as_Klass(mirror));
165 }
166
167 bool JfrTraceId::is_jdk_jfr_event_sub(const jclass jc) {
168 assert(jc != NULL, "invariant");
169 const oop mirror = JNIHandles::resolve(jc);
170 assert(mirror != NULL, "invariant");
171 return is_jdk_jfr_event_sub(java_lang_Class::as_Klass(mirror));
172 }
173
174 bool JfrTraceId::is_jdk_jfr_event(const jclass jc) {
175 assert(jc != NULL, "invariant");
176 const oop mirror = JNIHandles::resolve(jc);
177 assert(mirror != NULL, "invariant");
178 return is_jdk_jfr_event(java_lang_Class::as_Klass(mirror));
179 }
180
181 bool JfrTraceId::is_event_host(const jclass jc) {
182 assert(jc != NULL, "invariant");
183 const oop mirror = JNIHandles::resolve(jc);
184 assert(mirror != NULL, "invariant");
185 return is_event_host(java_lang_Class::as_Klass(mirror));
186 }
187
188 void JfrTraceId::tag_as_jdk_jfr_event_sub(const jclass jc) {
189 assert(jc != NULL, "invariant");
190 const oop mirror = JNIHandles::resolve(jc);
191 assert(mirror != NULL, "invariant");
192 const Klass* const k = java_lang_Class::as_Klass(mirror);
193 tag_as_jdk_jfr_event_sub(k);
194 assert(IS_JDK_JFR_EVENT_SUBKLASS(k), "invariant");
195 }
196
197 void JfrTraceId::tag_as_event_host(const jclass jc) {
198 assert(jc != NULL, "invariant");
199 const oop mirror = JNIHandles::resolve(jc);
200 assert(mirror != NULL, "invariant");
201 const Klass* const k = java_lang_Class::as_Klass(mirror);
202 tag_as_event_host(k);
203 assert(IS_EVENT_HOST_KLASS(k), "invariant");
204 }