1 /*
  2  * Copyright (c) 2019, 2025, 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 "classfile/vmClasses.hpp"
 25 #include "memory/resourceArea.hpp"
 26 #include "memory/universe.hpp"
 27 #include "oops/instanceKlass.hpp"
 28 #include "oops/oop.inline.hpp"
 29 #include "runtime/atomicAccess.hpp"
 30 #include "runtime/interfaceSupport.inline.hpp"
 31 #include "runtime/orderAccess.hpp"
 32 #include "runtime/os.hpp"
 33 #include "runtime/semaphore.inline.hpp"
 34 #include "runtime/synchronizer.hpp"
 35 #include "threadHelper.inline.hpp"
 36 #include "unittest.hpp"
 37 #include "utilities/globalDefinitions.hpp"
 38 #include "utilities/ostream.hpp"
 39 
 40 // The test doesn't work for PRODUCT because it needs WizardMode
 41 #ifndef PRODUCT
 42 
 43 template<typename Printable>
 44 static void assert_test_pattern(Printable object, const char* pattern) {
 45   stringStream st;
 46   object->print_on(&st);
 47   ASSERT_THAT(st.base(), testing::HasSubstr(pattern));
 48 }
 49 
 50 template<typename Printable>
 51 static void assert_mark_word_print_pattern(Printable object, const char* pattern) {
 52   assert_test_pattern(object, pattern);
 53 }
 54 
 55 class LockerThread : public JavaTestThread {
 56   oop _obj;
 57   public:
 58   LockerThread(Semaphore* post, oop obj) : JavaTestThread(post), _obj(obj) {}
 59   virtual ~LockerThread() {}
 60 
 61   void main_run() {
 62     JavaThread* THREAD = JavaThread::current();
 63     HandleMark hm(THREAD);
 64     Handle h_obj(THREAD, _obj);
 65     ResourceMark rm(THREAD);
 66 
 67     // Wait gets the lock inflated.
 68     // The object will stay locked for the context of 'ol' so the lock will
 69     // still be inflated after the notify_all() call. Deflation can't happen
 70     // while an ObjectMonitor is "busy" and being locked is the most "busy"
 71     // state we have...
 72     ObjectLocker ol(h_obj, THREAD);
 73     ol.notify_all(THREAD);
 74     assert_test_pattern(h_obj, "monitor");
 75   }
 76 };
 77 
 78 
 79 TEST_VM(markWord, printing) {
 80   JavaThread* THREAD = JavaThread::current();
 81   ThreadInVMfromNative invm(THREAD);
 82   ResourceMark rm(THREAD);
 83 
 84   oop obj = vmClasses::Byte_klass()->allocate_instance(THREAD);
 85 
 86   FlagSetting fs(WizardMode, true);
 87 
 88   HandleMark hm(THREAD);
 89   Handle h_obj(THREAD, obj);
 90 
 91   // Thread tries to lock it.
 92   {
 93     ObjectLocker ol(h_obj, THREAD);
 94     assert_mark_word_print_pattern(h_obj, "locked");
 95   }
 96   assert_mark_word_print_pattern(h_obj, "is_unlocked no_hash");
 97 
 98   // Hash the object then print it.
 99   intx hash = h_obj->identity_hash();
100   assert_mark_word_print_pattern(h_obj, "is_unlocked hash=0x");
101 
102   // Wait gets the lock inflated.
103   {
104     ObjectLocker ol(h_obj, THREAD);
105 
106     Semaphore done(0);
107     LockerThread* st;
108     st = new LockerThread(&done, h_obj());
109     st->doit();
110 
111     ol.wait(THREAD);
112     assert_test_pattern(h_obj, "monitor");
113     done.wait_with_safepoint_check(THREAD);  // wait till the thread is done.
114   }
115 }
116 
117 static void assert_unlocked_state(markWord mark) {
118   EXPECT_FALSE(mark.has_displaced_mark_helper());
119   EXPECT_FALSE(mark.is_fast_locked());
120   EXPECT_FALSE(mark.has_monitor());
121   EXPECT_FALSE(mark.is_being_inflated());
122   EXPECT_FALSE(mark.is_locked());
123   EXPECT_TRUE(mark.is_unlocked());
124 }
125 
126 static void assert_copy_set_hash(markWord mark) {
127   const intptr_t hash = 4711;
128   EXPECT_TRUE(mark.has_no_hash());
129   markWord copy = mark.copy_set_hash(hash);
130   EXPECT_EQ(hash, copy.hash());
131   EXPECT_FALSE(copy.has_no_hash());
132 }
133 
134 static void assert_type(markWord mark) {
135   EXPECT_FALSE(mark.is_flat_array());
136   EXPECT_FALSE(mark.is_inline_type());
137   EXPECT_FALSE(mark.is_larval_state());
138   EXPECT_FALSE(mark.is_null_free_array());
139 }
140 
141 TEST_VM(markWord, prototype) {
142   markWord mark = markWord::prototype();
143   assert_unlocked_state(mark);
144   EXPECT_TRUE(mark.is_neutral());
145 
146   assert_type(mark);
147 
148   EXPECT_TRUE(mark.has_no_hash());
149   EXPECT_FALSE(mark.is_marked());
150 
151   assert_copy_set_hash(mark);
152   assert_type(mark);
153 }
154 
155 static void assert_inline_type(markWord mark) {
156   EXPECT_FALSE(mark.is_flat_array());
157   EXPECT_TRUE(mark.is_inline_type());
158   EXPECT_FALSE(mark.is_null_free_array());
159 }
160 
161 TEST_VM(markWord, inline_type_prototype) {
162   markWord mark = markWord::inline_type_prototype();
163   assert_unlocked_state(mark);
164   EXPECT_FALSE(mark.is_neutral());
165   assert_test_pattern(&mark, " inline_type");
166 
167   assert_inline_type(mark);
168   EXPECT_FALSE(mark.is_larval_state());
169 
170   EXPECT_TRUE(mark.has_no_hash());
171   EXPECT_FALSE(mark.is_marked());
172 
173   markWord larval = mark.enter_larval_state();
174   EXPECT_TRUE(larval.is_larval_state());
175   assert_inline_type(larval);
176   assert_test_pattern(&larval, " inline_type=larval");
177 
178   mark = larval.exit_larval_state();
179   EXPECT_FALSE(mark.is_larval_state());
180   assert_inline_type(mark);
181 
182   EXPECT_TRUE(mark.has_no_hash());
183   EXPECT_FALSE(mark.is_marked());
184 }
185 
186 #if _LP64
187 
188 static void assert_flat_array_type(markWord mark) {
189   EXPECT_TRUE(mark.is_flat_array());
190   EXPECT_FALSE(mark.is_inline_type());
191   EXPECT_FALSE(mark.is_larval_state());
192 }
193 
194 TEST_VM(markWord, null_free_flat_array_prototype) {
195   markWord mark = markWord::flat_array_prototype(LayoutKind::NON_ATOMIC_FLAT);
196   assert_unlocked_state(mark);
197   EXPECT_TRUE(mark.is_neutral());
198 
199   assert_flat_array_type(mark);
200   EXPECT_TRUE(mark.is_null_free_array());
201 
202   EXPECT_TRUE(mark.has_no_hash());
203   EXPECT_FALSE(mark.is_marked());
204 
205   assert_copy_set_hash(mark);
206   assert_flat_array_type(mark);
207   EXPECT_TRUE(mark.is_null_free_array());
208 
209   assert_test_pattern(&mark, " flat_null_free_array");
210 }
211 
212 TEST_VM(markWord, nullable_flat_array_prototype) {
213   markWord mark = markWord::flat_array_prototype(LayoutKind::NULLABLE_ATOMIC_FLAT);
214   assert_unlocked_state(mark);
215   EXPECT_TRUE(mark.is_neutral());
216 
217   assert_flat_array_type(mark);
218   EXPECT_FALSE(mark.is_null_free_array());
219 
220   EXPECT_TRUE(mark.has_no_hash());
221   EXPECT_FALSE(mark.is_marked());
222 
223   assert_copy_set_hash(mark);
224   assert_flat_array_type(mark);
225   EXPECT_FALSE(mark.is_null_free_array());
226 
227   assert_test_pattern(&mark, " flat_array");
228 }
229 
230 static void assert_null_free_array_type(markWord mark) {
231   EXPECT_FALSE(mark.is_flat_array());
232   EXPECT_FALSE(mark.is_inline_type());
233   EXPECT_FALSE(mark.is_larval_state());
234   EXPECT_TRUE(mark.is_null_free_array());
235 }
236 
237 TEST_VM(markWord, null_free_array_prototype) {
238   markWord mark = markWord::null_free_array_prototype();
239   assert_unlocked_state(mark);
240   EXPECT_TRUE(mark.is_neutral());
241 
242   assert_null_free_array_type(mark);
243 
244   EXPECT_TRUE(mark.has_no_hash());
245   EXPECT_FALSE(mark.is_marked());
246 
247   assert_copy_set_hash(mark);
248   assert_null_free_array_type(mark);
249 
250   assert_test_pattern(&mark, " null_free_array");
251 }
252 #endif // _LP64
253 
254 #endif // PRODUCT
--- EOF ---