1 /*
  2  * Copyright (c) 2019, 2021, 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/synchronizer.hpp"
 35 #include "runtime/semaphore.inline.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 static bool test_pattern(stringStream* st, const char* pattern) {
 44   return (strstr(st->as_string(), pattern) != NULL);
 45 }
 46 
 47 static void assert_test_pattern(Handle object, const char* pattern) {
 48   stringStream st;
 49   object->print_on(&st);
 50   ASSERT_TRUE(test_pattern(&st, pattern)) << pattern << " not in " << st.as_string();
 51 }
 52 
 53 class LockerThread : public JavaTestThread {
 54   oop _obj;
 55   public:
 56   LockerThread(Semaphore* post, oop obj) : JavaTestThread(post), _obj(obj) {}
 57   virtual ~LockerThread() {}
 58 
 59   void main_run() {
 60     JavaThread* THREAD = JavaThread::current();
 61     HandleMark hm(THREAD);
 62     Handle h_obj(THREAD, _obj);
 63     ResourceMark rm(THREAD);
 64 
 65     // Wait gets the lock inflated.
 66     // The object will stay locked for the context of 'ol' so the lock will
 67     // still be inflated after the notify_all() call. Deflation can't happen
 68     // while an ObjectMonitor is "busy" and being locked is the most "busy"
 69     // state we have...
 70     ObjectLocker ol(h_obj, THREAD);
 71     ol.notify_all(THREAD);
 72     assert_test_pattern(h_obj, "monitor");
 73   }
 74 };
 75 
 76 
 77 TEST_VM(markWord, printing) {
 78   JavaThread* THREAD = JavaThread::current();
 79   ThreadInVMfromNative invm(THREAD);
 80   ResourceMark rm(THREAD);
 81 
 82   oop obj = vmClasses::Byte_klass()->allocate_instance(THREAD);
 83 
 84   FlagSetting fs(WizardMode, true);
 85 
 86   HandleMark hm(THREAD);
 87   Handle h_obj(THREAD, obj);
 88 
 89   // Thread tries to lock it.
 90   {
 91     ObjectLocker ol(h_obj, THREAD);
 92     assert_test_pattern(h_obj, "locked");
 93   }
 94   assert_test_pattern(h_obj, "is_neutral no_hash");
 95 
 96   // Hash the object then print it.
 97   intx hash = h_obj->identity_hash();
 98   assert_test_pattern(h_obj, "is_neutral hash=0x");
 99 
100   // Wait gets the lock inflated.
101   {
102     ObjectLocker ol(h_obj, THREAD);
103 
104     Semaphore done(0);
105     LockerThread* st;
106     st = new LockerThread(&done, h_obj());
107     st->doit();
108 
109     ol.wait(THREAD);
110     assert_test_pattern(h_obj, "monitor");
111     done.wait_with_safepoint_check(THREAD);  // wait till the thread is done.
112   }
113 }
114 
115 static void assert_unlocked_state(markWord mark) {
116   EXPECT_FALSE(mark.has_displaced_mark_helper());
117   EXPECT_FALSE(mark.has_locker());
118   EXPECT_FALSE(mark.has_monitor());
119   EXPECT_FALSE(mark.is_being_inflated());
120   EXPECT_FALSE(mark.is_locked());
121   EXPECT_TRUE(mark.is_unlocked());
122 }
123 
124 static void assert_copy_set_hash(markWord mark) {
125   const intptr_t hash = 4711;
126   EXPECT_TRUE(mark.has_no_hash());
127   markWord copy = mark.copy_set_hash(hash);
128   EXPECT_EQ(hash, copy.hash());
129   EXPECT_FALSE(copy.has_no_hash());
130 }
131 
132 static void assert_type(markWord mark) {
133   EXPECT_FALSE(mark.is_flat_array());
134   EXPECT_FALSE(mark.is_inline_type());
135   EXPECT_FALSE(mark.is_larval_state());
136   EXPECT_FALSE(mark.is_null_free_array());
137 }
138 
139 TEST_VM(markWord, prototype) {
140   markWord mark = markWord::prototype();
141   assert_unlocked_state(mark);
142   EXPECT_TRUE(mark.is_neutral());
143 
144   assert_type(mark);
145 
146   EXPECT_TRUE(mark.has_no_hash());
147   EXPECT_FALSE(mark.is_marked());
148   EXPECT_TRUE(mark.decode_pointer() == NULL);
149 
150   assert_copy_set_hash(mark);
151   assert_type(mark);
152 }
153 
154 static void assert_inline_type(markWord mark) {
155   EXPECT_FALSE(mark.is_flat_array());
156   EXPECT_TRUE(mark.is_inline_type());
157   EXPECT_FALSE(mark.is_null_free_array());
158 }
159 
160 TEST_VM(markWord, inline_type_prototype) {
161   markWord mark = markWord::inline_type_prototype();
162   assert_unlocked_state(mark);
163   EXPECT_FALSE(mark.is_neutral());
164 
165   assert_inline_type(mark);
166   EXPECT_FALSE(mark.is_larval_state());
167 
168   EXPECT_TRUE(mark.has_no_hash());
169   EXPECT_FALSE(mark.is_marked());
170   EXPECT_TRUE(mark.decode_pointer() == NULL);
171 
172   markWord larval = mark.enter_larval_state();
173   EXPECT_TRUE(larval.is_larval_state());
174   assert_inline_type(larval);
175   mark = larval.exit_larval_state();
176   EXPECT_FALSE(mark.is_larval_state());
177   assert_inline_type(mark);
178 
179   EXPECT_TRUE(mark.has_no_hash());
180   EXPECT_FALSE(mark.is_marked());
181   EXPECT_TRUE(mark.decode_pointer() == NULL);
182 }
183 
184 #if _LP64
185 
186 static void assert_flat_array_type(markWord mark) {
187   EXPECT_TRUE(mark.is_flat_array());
188   EXPECT_FALSE(mark.is_inline_type());
189   EXPECT_FALSE(mark.is_larval_state());
190   EXPECT_TRUE(mark.is_null_free_array());
191 }
192 
193 TEST_VM(markWord, flat_array_prototype) {
194   markWord mark = markWord::flat_array_prototype();
195   assert_unlocked_state(mark);
196   EXPECT_TRUE(mark.is_neutral());
197 
198   assert_flat_array_type(mark);
199 
200   EXPECT_TRUE(mark.has_no_hash());
201   EXPECT_FALSE(mark.is_marked());
202   EXPECT_TRUE(mark.decode_pointer() == NULL);
203 
204   assert_copy_set_hash(mark);
205   assert_flat_array_type(mark);
206 }
207 
208 static void assert_null_free_array_type(markWord mark) {
209   EXPECT_FALSE(mark.is_flat_array());
210   EXPECT_FALSE(mark.is_inline_type());
211   EXPECT_FALSE(mark.is_larval_state());
212   EXPECT_TRUE(mark.is_null_free_array());
213 }
214 
215 TEST_VM(markWord, null_free_array_prototype) {
216   markWord mark = markWord::null_free_array_prototype();
217   assert_unlocked_state(mark);
218   EXPECT_TRUE(mark.is_neutral());
219 
220   assert_null_free_array_type(mark);
221 
222   EXPECT_TRUE(mark.has_no_hash());
223   EXPECT_FALSE(mark.is_marked());
224   EXPECT_TRUE(mark.decode_pointer() == NULL);
225 
226   assert_copy_set_hash(mark);
227   assert_null_free_array_type(mark);
228 }
229 #endif // _LP64
230 
231 #endif // PRODUCT