1 /*
2 * Copyright (c) 2019, 2024, 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 #include "precompiled.hpp"
25 #include "classfile/vmClasses.hpp"
26 #include "memory/resourceArea.hpp"
27 #include "memory/universe.hpp"
28 #include "oops/instanceKlass.hpp"
29 #include "oops/oop.inline.hpp"
30 #include "runtime/atomic.hpp"
31 #include "runtime/interfaceSupport.inline.hpp"
32 #include "runtime/orderAccess.hpp"
33 #include "runtime/os.hpp"
34 #include "runtime/semaphore.inline.hpp"
35 #include "runtime/synchronizer.hpp"
36 #include "threadHelper.inline.hpp"
37 #include "unittest.hpp"
38 #include "utilities/globalDefinitions.hpp"
39 #include "utilities/ostream.hpp"
40
41 // The test doesn't work for PRODUCT because it needs WizardMode
42 #ifndef PRODUCT
43
44 static void assert_test_pattern(Handle object, const char* pattern) {
45 stringStream st;
46 object->print_on(&st);
47 ASSERT_THAT(st.base(), testing::HasSubstr(pattern));
48 }
49
50 static void assert_mark_word_print_pattern(Handle object, const char* pattern) {
51 if (LockingMode == LM_MONITOR) {
52 // With heavy monitors, we do not use the mark word. Printing the oop only shows "monitor" regardless of the
53 // locking state.
54 assert_test_pattern(object, "monitor");
55 } else {
56 assert_test_pattern(object, pattern);
57 }
58 }
59
60 class LockerThread : public JavaTestThread {
61 oop _obj;
62 public:
63 LockerThread(Semaphore* post, oop obj) : JavaTestThread(post), _obj(obj) {}
64 virtual ~LockerThread() {}
65
66 void main_run() {
67 JavaThread* THREAD = JavaThread::current();
68 HandleMark hm(THREAD);
69 Handle h_obj(THREAD, _obj);
70 ResourceMark rm(THREAD);
71
72 // Wait gets the lock inflated.
73 // The object will stay locked for the context of 'ol' so the lock will
74 // still be inflated after the notify_all() call. Deflation can't happen
75 // while an ObjectMonitor is "busy" and being locked is the most "busy"
76 // state we have...
77 ObjectLocker ol(h_obj, THREAD);
78 ol.notify_all(THREAD);
79 assert_test_pattern(h_obj, "monitor");
80 }
81 };
82
83
84 TEST_VM(markWord, printing) {
85 JavaThread* THREAD = JavaThread::current();
86 ThreadInVMfromNative invm(THREAD);
87 ResourceMark rm(THREAD);
88
89 oop obj = vmClasses::Byte_klass()->allocate_instance(THREAD);
90
91 FlagSetting fs(WizardMode, true);
92
93 HandleMark hm(THREAD);
94 Handle h_obj(THREAD, obj);
95
96 // Thread tries to lock it.
97 {
98 ObjectLocker ol(h_obj, THREAD);
99 assert_mark_word_print_pattern(h_obj, "locked");
100 }
101 assert_mark_word_print_pattern(h_obj, "is_unlocked no_hash");
102
103 // Hash the object then print it.
104 intx hash = h_obj->identity_hash();
105 assert_mark_word_print_pattern(h_obj, "is_unlocked hash=0x");
106
107 // Wait gets the lock inflated.
108 {
109 ObjectLocker ol(h_obj, THREAD);
110
111 Semaphore done(0);
112 LockerThread* st;
113 st = new LockerThread(&done, h_obj());
114 st->doit();
115
116 ol.wait(THREAD);
117 assert_test_pattern(h_obj, "monitor");
118 done.wait_with_safepoint_check(THREAD); // wait till the thread is done.
119 }
120 }
121
122 static void assert_unlocked_state(markWord mark) {
123 EXPECT_FALSE(mark.has_displaced_mark_helper());
124 if (LockingMode == LM_LEGACY) {
125 EXPECT_FALSE(mark.has_locker());
126 } else if (LockingMode == LM_LIGHTWEIGHT) {
127 EXPECT_FALSE(mark.is_fast_locked());
128 }
129 EXPECT_FALSE(mark.has_monitor());
130 EXPECT_FALSE(mark.is_being_inflated());
131 EXPECT_FALSE(mark.is_locked());
132 EXPECT_TRUE(mark.is_unlocked());
133 }
134
135 static void assert_copy_set_hash(markWord mark) {
136 const intptr_t hash = 4711;
137 EXPECT_TRUE(mark.has_no_hash());
138 markWord copy = mark.copy_set_hash(hash);
139 EXPECT_EQ(hash, copy.hash());
140 EXPECT_FALSE(copy.has_no_hash());
141 }
142
143 static void assert_type(markWord mark) {
144 EXPECT_FALSE(mark.is_flat_array());
145 EXPECT_FALSE(mark.is_inline_type());
146 EXPECT_FALSE(mark.is_larval_state());
147 EXPECT_FALSE(mark.is_null_free_array());
148 }
149
150 TEST_VM(markWord, prototype) {
151 markWord mark = markWord::prototype();
152 assert_unlocked_state(mark);
153 EXPECT_TRUE(mark.is_neutral());
154
155 assert_type(mark);
156
157 EXPECT_TRUE(mark.has_no_hash());
158 EXPECT_FALSE(mark.is_marked());
159 EXPECT_TRUE(mark.decode_pointer() == NULL);
160
161 assert_copy_set_hash(mark);
162 assert_type(mark);
163 }
164
165 static void assert_inline_type(markWord mark) {
166 EXPECT_FALSE(mark.is_flat_array());
167 EXPECT_TRUE(mark.is_inline_type());
168 EXPECT_FALSE(mark.is_null_free_array());
169 }
170
171 TEST_VM(markWord, inline_type_prototype) {
172 markWord mark = markWord::inline_type_prototype();
173 assert_unlocked_state(mark);
174 EXPECT_FALSE(mark.is_neutral());
175
176 assert_inline_type(mark);
177 EXPECT_FALSE(mark.is_larval_state());
178
179 EXPECT_TRUE(mark.has_no_hash());
180 EXPECT_FALSE(mark.is_marked());
181 EXPECT_TRUE(mark.decode_pointer() == NULL);
182
183 markWord larval = mark.enter_larval_state();
184 EXPECT_TRUE(larval.is_larval_state());
185 assert_inline_type(larval);
186 mark = larval.exit_larval_state();
187 EXPECT_FALSE(mark.is_larval_state());
188 assert_inline_type(mark);
189
190 EXPECT_TRUE(mark.has_no_hash());
191 EXPECT_FALSE(mark.is_marked());
192 EXPECT_TRUE(mark.decode_pointer() == NULL);
193 }
194
195 #if _LP64
196
197 static void assert_flat_array_type(markWord mark) {
198 EXPECT_TRUE(mark.is_flat_array());
199 EXPECT_FALSE(mark.is_inline_type());
200 EXPECT_FALSE(mark.is_larval_state());
201 EXPECT_TRUE(mark.is_null_free_array());
202 }
203
204 TEST_VM(markWord, flat_array_prototype) {
205 markWord mark = markWord::flat_array_prototype();
206 assert_unlocked_state(mark);
207 EXPECT_TRUE(mark.is_neutral());
208
209 assert_flat_array_type(mark);
210
211 EXPECT_TRUE(mark.has_no_hash());
212 EXPECT_FALSE(mark.is_marked());
213 EXPECT_TRUE(mark.decode_pointer() == NULL);
214
215 assert_copy_set_hash(mark);
216 assert_flat_array_type(mark);
217 }
218
219 static void assert_null_free_array_type(markWord mark) {
220 EXPECT_FALSE(mark.is_flat_array());
221 EXPECT_FALSE(mark.is_inline_type());
222 EXPECT_FALSE(mark.is_larval_state());
223 EXPECT_TRUE(mark.is_null_free_array());
224 }
225
226 TEST_VM(markWord, null_free_array_prototype) {
227 markWord mark = markWord::null_free_array_prototype();
228 assert_unlocked_state(mark);
229 EXPECT_TRUE(mark.is_neutral());
230
231 assert_null_free_array_type(mark);
232
233 EXPECT_TRUE(mark.has_no_hash());
234 EXPECT_FALSE(mark.is_marked());
235 EXPECT_TRUE(mark.decode_pointer() == NULL);
236
237 assert_copy_set_hash(mark);
238 assert_null_free_array_type(mark);
239 }
240 #endif // _LP64
241
242 #endif // PRODUCT