Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2008 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
Elliott Hughes | 54e7df1 | 2011-09-16 11:47:04 -0700 | [diff] [blame] | 17 | #include "monitor.h" |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 18 | |
Elliott Hughes | 08fc03a | 2012-06-26 17:34:00 -0700 | [diff] [blame] | 19 | #include <vector> |
| 20 | |
Elliott Hughes | 76b6167 | 2012-12-12 17:47:30 -0800 | [diff] [blame] | 21 | #include "base/mutex.h" |
Elliott Hughes | 1aa246d | 2012-12-13 09:29:36 -0800 | [diff] [blame] | 22 | #include "base/stl_util.h" |
jeffhao | 33dc771 | 2011-11-09 17:54:24 -0800 | [diff] [blame] | 23 | #include "class_linker.h" |
Ian Rogers | 4f6ad8a | 2013-03-18 15:27:28 -0700 | [diff] [blame] | 24 | #include "dex_file-inl.h" |
Elliott Hughes | 08fc03a | 2012-06-26 17:34:00 -0700 | [diff] [blame] | 25 | #include "dex_instruction.h" |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 26 | #include "mirror/abstract_method-inl.h" |
Ian Rogers | 4f6ad8a | 2013-03-18 15:27:28 -0700 | [diff] [blame] | 27 | #include "mirror/class-inl.h" |
Ian Rogers | 05f3057 | 2013-02-20 12:13:11 -0800 | [diff] [blame] | 28 | #include "mirror/object-inl.h" |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 29 | #include "mirror/object_array-inl.h" |
Ian Rogers | 6d4d9fc | 2011-11-30 16:24:48 -0800 | [diff] [blame] | 30 | #include "object_utils.h" |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 31 | #include "scoped_thread_state_change.h" |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 32 | #include "thread.h" |
Elliott Hughes | 8e4aac5 | 2011-09-26 17:03:36 -0700 | [diff] [blame] | 33 | #include "thread_list.h" |
Elliott Hughes | 08fc03a | 2012-06-26 17:34:00 -0700 | [diff] [blame] | 34 | #include "verifier/method_verifier.h" |
Elliott Hughes | 044288f | 2012-06-25 14:46:39 -0700 | [diff] [blame] | 35 | #include "well_known_classes.h" |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 36 | |
| 37 | namespace art { |
| 38 | |
| 39 | /* |
| 40 | * Every Object has a monitor associated with it, but not every Object is |
| 41 | * actually locked. Even the ones that are locked do not need a |
| 42 | * full-fledged monitor until a) there is actual contention or b) wait() |
| 43 | * is called on the Object. |
| 44 | * |
| 45 | * For Android, we have implemented a scheme similar to the one described |
| 46 | * in Bacon et al.'s "Thin locks: featherweight synchronization for Java" |
| 47 | * (ACM 1998). Things are even easier for us, though, because we have |
| 48 | * a full 32 bits to work with. |
| 49 | * |
| 50 | * The two states of an Object's lock are referred to as "thin" and |
| 51 | * "fat". A lock may transition from the "thin" state to the "fat" |
| 52 | * state and this transition is referred to as inflation. Once a lock |
| 53 | * has been inflated it remains in the "fat" state indefinitely. |
| 54 | * |
| 55 | * The lock value itself is stored in Object.lock. The LSB of the |
| 56 | * lock encodes its state. When cleared, the lock is in the "thin" |
| 57 | * state and its bits are formatted as follows: |
| 58 | * |
| 59 | * [31 ---- 19] [18 ---- 3] [2 ---- 1] [0] |
| 60 | * lock count thread id hash state 0 |
| 61 | * |
| 62 | * When set, the lock is in the "fat" state and its bits are formatted |
| 63 | * as follows: |
| 64 | * |
| 65 | * [31 ---- 3] [2 ---- 1] [0] |
| 66 | * pointer hash state 1 |
| 67 | * |
| 68 | * For an in-depth description of the mechanics of thin-vs-fat locking, |
| 69 | * read the paper referred to above. |
Elliott Hughes | 54e7df1 | 2011-09-16 11:47:04 -0700 | [diff] [blame] | 70 | * |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 71 | * Monitors provide: |
| 72 | * - mutually exclusive access to resources |
| 73 | * - a way for multiple threads to wait for notification |
| 74 | * |
| 75 | * In effect, they fill the role of both mutexes and condition variables. |
| 76 | * |
| 77 | * Only one thread can own the monitor at any time. There may be several |
| 78 | * threads waiting on it (the wait call unlocks it). One or more waiting |
| 79 | * threads may be getting interrupted or notified at any given time. |
| 80 | * |
| 81 | * TODO: the various members of monitor are not SMP-safe. |
| 82 | */ |
Elliott Hughes | 54e7df1 | 2011-09-16 11:47:04 -0700 | [diff] [blame] | 83 | |
Elliott Hughes | f327e07 | 2013-01-09 16:01:26 -0800 | [diff] [blame] | 84 | // The shape is the bottom bit; either LW_SHAPE_THIN or LW_SHAPE_FAT. |
| 85 | #define LW_SHAPE_MASK 0x1 |
| 86 | #define LW_SHAPE(x) static_cast<int>((x) & LW_SHAPE_MASK) |
Elliott Hughes | 54e7df1 | 2011-09-16 11:47:04 -0700 | [diff] [blame] | 87 | |
| 88 | /* |
| 89 | * Monitor accessor. Extracts a monitor structure pointer from a fat |
| 90 | * lock. Performs no error checking. |
| 91 | */ |
| 92 | #define LW_MONITOR(x) \ |
Elliott Hughes | 398f64b | 2012-03-26 18:05:48 -0700 | [diff] [blame] | 93 | (reinterpret_cast<Monitor*>((x) & ~((LW_HASH_STATE_MASK << LW_HASH_STATE_SHIFT) | LW_SHAPE_MASK))) |
Elliott Hughes | 54e7df1 | 2011-09-16 11:47:04 -0700 | [diff] [blame] | 94 | |
| 95 | /* |
| 96 | * Lock recursion count field. Contains a count of the number of times |
| 97 | * a lock has been recursively acquired. |
| 98 | */ |
| 99 | #define LW_LOCK_COUNT_MASK 0x1fff |
| 100 | #define LW_LOCK_COUNT_SHIFT 19 |
| 101 | #define LW_LOCK_COUNT(x) (((x) >> LW_LOCK_COUNT_SHIFT) & LW_LOCK_COUNT_MASK) |
| 102 | |
Elliott Hughes | fc86162 | 2011-10-17 17:57:47 -0700 | [diff] [blame] | 103 | bool (*Monitor::is_sensitive_thread_hook_)() = NULL; |
Elliott Hughes | fc86162 | 2011-10-17 17:57:47 -0700 | [diff] [blame] | 104 | uint32_t Monitor::lock_profiling_threshold_ = 0; |
Elliott Hughes | 32d6e1e | 2011-10-11 14:47:44 -0700 | [diff] [blame] | 105 | |
Elliott Hughes | fc86162 | 2011-10-17 17:57:47 -0700 | [diff] [blame] | 106 | bool Monitor::IsSensitiveThread() { |
| 107 | if (is_sensitive_thread_hook_ != NULL) { |
| 108 | return (*is_sensitive_thread_hook_)(); |
| 109 | } |
| 110 | return false; |
| 111 | } |
| 112 | |
Elliott Hughes | 4dd9b4d | 2011-12-12 18:29:24 -0800 | [diff] [blame] | 113 | void Monitor::Init(uint32_t lock_profiling_threshold, bool (*is_sensitive_thread_hook)()) { |
Elliott Hughes | fc86162 | 2011-10-17 17:57:47 -0700 | [diff] [blame] | 114 | lock_profiling_threshold_ = lock_profiling_threshold; |
| 115 | is_sensitive_thread_hook_ = is_sensitive_thread_hook; |
Elliott Hughes | 32d6e1e | 2011-10-11 14:47:44 -0700 | [diff] [blame] | 116 | } |
| 117 | |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 118 | Monitor::Monitor(Thread* owner, mirror::Object* obj) |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 119 | : monitor_lock_("a monitor lock", kMonitorLock), |
| 120 | owner_(owner), |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 121 | lock_count_(0), |
| 122 | obj_(obj), |
| 123 | wait_set_(NULL), |
jeffhao | 33dc771 | 2011-11-09 17:54:24 -0800 | [diff] [blame] | 124 | locking_method_(NULL), |
Ian Rogers | 0399dde | 2012-06-06 17:09:28 -0700 | [diff] [blame] | 125 | locking_dex_pc_(0) { |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 126 | monitor_lock_.Lock(owner); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 127 | // Propagate the lock state. |
| 128 | uint32_t thin = *obj->GetRawLockWordAddress(); |
| 129 | lock_count_ = LW_LOCK_COUNT(thin); |
| 130 | thin &= LW_HASH_STATE_MASK << LW_HASH_STATE_SHIFT; |
| 131 | thin |= reinterpret_cast<uint32_t>(this) | LW_SHAPE_FAT; |
| 132 | // Publish the updated lock word. |
| 133 | android_atomic_release_store(thin, obj->GetRawLockWordAddress()); |
| 134 | // Lock profiling. |
| 135 | if (lock_profiling_threshold_ != 0) { |
| 136 | locking_method_ = owner->GetCurrentMethod(&locking_dex_pc_); |
| 137 | } |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 138 | } |
| 139 | |
| 140 | Monitor::~Monitor() { |
| 141 | DCHECK(obj_ != NULL); |
| 142 | DCHECK_EQ(LW_SHAPE(*obj_->GetRawLockWordAddress()), LW_SHAPE_FAT); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 143 | } |
| 144 | |
| 145 | /* |
| 146 | * Links a thread into a monitor's wait set. The monitor lock must be |
| 147 | * held by the caller of this routine. |
| 148 | */ |
| 149 | void Monitor::AppendToWaitSet(Thread* thread) { |
| 150 | DCHECK(owner_ == Thread::Current()); |
| 151 | DCHECK(thread != NULL); |
Elliott Hughes | dc33ad5 | 2011-09-16 19:46:51 -0700 | [diff] [blame] | 152 | DCHECK(thread->wait_next_ == NULL) << thread->wait_next_; |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 153 | if (wait_set_ == NULL) { |
| 154 | wait_set_ = thread; |
| 155 | return; |
| 156 | } |
| 157 | |
| 158 | // push_back. |
| 159 | Thread* t = wait_set_; |
| 160 | while (t->wait_next_ != NULL) { |
| 161 | t = t->wait_next_; |
| 162 | } |
| 163 | t->wait_next_ = thread; |
| 164 | } |
| 165 | |
| 166 | /* |
| 167 | * Unlinks a thread from a monitor's wait set. The monitor lock must |
| 168 | * be held by the caller of this routine. |
| 169 | */ |
| 170 | void Monitor::RemoveFromWaitSet(Thread *thread) { |
| 171 | DCHECK(owner_ == Thread::Current()); |
| 172 | DCHECK(thread != NULL); |
| 173 | if (wait_set_ == NULL) { |
| 174 | return; |
| 175 | } |
| 176 | if (wait_set_ == thread) { |
| 177 | wait_set_ = thread->wait_next_; |
| 178 | thread->wait_next_ = NULL; |
| 179 | return; |
| 180 | } |
| 181 | |
| 182 | Thread* t = wait_set_; |
| 183 | while (t->wait_next_ != NULL) { |
| 184 | if (t->wait_next_ == thread) { |
| 185 | t->wait_next_ = thread->wait_next_; |
| 186 | thread->wait_next_ = NULL; |
| 187 | return; |
| 188 | } |
| 189 | t = t->wait_next_; |
| 190 | } |
| 191 | } |
| 192 | |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 193 | mirror::Object* Monitor::GetObject() { |
Elliott Hughes | c33a32b | 2011-10-11 18:18:07 -0700 | [diff] [blame] | 194 | return obj_; |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 195 | } |
| 196 | |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 197 | void Monitor::Lock(Thread* self) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 198 | if (owner_ == self) { |
| 199 | lock_count_++; |
| 200 | return; |
| 201 | } |
Elliott Hughes | fc86162 | 2011-10-17 17:57:47 -0700 | [diff] [blame] | 202 | |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 203 | if (!monitor_lock_.TryLock(self)) { |
Mathieu Chartier | 2542d66 | 2012-06-21 17:14:11 -0700 | [diff] [blame] | 204 | uint64_t waitStart = 0; |
| 205 | uint64_t waitEnd = 0; |
Elliott Hughes | fc86162 | 2011-10-17 17:57:47 -0700 | [diff] [blame] | 206 | uint32_t wait_threshold = lock_profiling_threshold_; |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 207 | const mirror::AbstractMethod* current_locking_method = NULL; |
Ian Rogers | 0399dde | 2012-06-06 17:09:28 -0700 | [diff] [blame] | 208 | uint32_t current_locking_dex_pc = 0; |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 209 | { |
Elliott Hughes | 34e0696 | 2012-04-09 13:55:55 -0700 | [diff] [blame] | 210 | ScopedThreadStateChange tsc(self, kBlocked); |
Elliott Hughes | fc86162 | 2011-10-17 17:57:47 -0700 | [diff] [blame] | 211 | if (wait_threshold != 0) { |
| 212 | waitStart = NanoTime() / 1000; |
| 213 | } |
jeffhao | 33dc771 | 2011-11-09 17:54:24 -0800 | [diff] [blame] | 214 | current_locking_method = locking_method_; |
Ian Rogers | 0399dde | 2012-06-06 17:09:28 -0700 | [diff] [blame] | 215 | current_locking_dex_pc = locking_dex_pc_; |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 216 | |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 217 | monitor_lock_.Lock(self); |
Elliott Hughes | fc86162 | 2011-10-17 17:57:47 -0700 | [diff] [blame] | 218 | if (wait_threshold != 0) { |
| 219 | waitEnd = NanoTime() / 1000; |
| 220 | } |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 221 | } |
Elliott Hughes | fc86162 | 2011-10-17 17:57:47 -0700 | [diff] [blame] | 222 | |
| 223 | if (wait_threshold != 0) { |
| 224 | uint64_t wait_ms = (waitEnd - waitStart) / 1000; |
| 225 | uint32_t sample_percent; |
| 226 | if (wait_ms >= wait_threshold) { |
| 227 | sample_percent = 100; |
| 228 | } else { |
| 229 | sample_percent = 100 * wait_ms / wait_threshold; |
| 230 | } |
| 231 | if (sample_percent != 0 && (static_cast<uint32_t>(rand() % 100) < sample_percent)) { |
jeffhao | 33dc771 | 2011-11-09 17:54:24 -0800 | [diff] [blame] | 232 | const char* current_locking_filename; |
| 233 | uint32_t current_locking_line_number; |
Ian Rogers | 0399dde | 2012-06-06 17:09:28 -0700 | [diff] [blame] | 234 | TranslateLocation(current_locking_method, current_locking_dex_pc, |
jeffhao | 33dc771 | 2011-11-09 17:54:24 -0800 | [diff] [blame] | 235 | current_locking_filename, current_locking_line_number); |
| 236 | LogContentionEvent(self, wait_ms, sample_percent, current_locking_filename, current_locking_line_number); |
Elliott Hughes | fc86162 | 2011-10-17 17:57:47 -0700 | [diff] [blame] | 237 | } |
| 238 | } |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 239 | } |
| 240 | owner_ = self; |
| 241 | DCHECK_EQ(lock_count_, 0); |
| 242 | |
| 243 | // When debugging, save the current monitor holder for future |
| 244 | // acquisition failures to use in sampled logging. |
Elliott Hughes | fc86162 | 2011-10-17 17:57:47 -0700 | [diff] [blame] | 245 | if (lock_profiling_threshold_ != 0) { |
Ian Rogers | 0399dde | 2012-06-06 17:09:28 -0700 | [diff] [blame] | 246 | locking_method_ = self->GetCurrentMethod(&locking_dex_pc_); |
Elliott Hughes | fc86162 | 2011-10-17 17:57:47 -0700 | [diff] [blame] | 247 | } |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 248 | } |
| 249 | |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 250 | static void ThrowIllegalMonitorStateExceptionF(const char* fmt, ...) |
| 251 | __attribute__((format(printf, 1, 2))); |
| 252 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 253 | static void ThrowIllegalMonitorStateExceptionF(const char* fmt, ...) |
Ian Rogers | b726dcb | 2012-09-05 08:57:23 -0700 | [diff] [blame] | 254 | SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 255 | va_list args; |
| 256 | va_start(args, fmt); |
Ian Rogers | 62d6c77 | 2013-02-27 08:32:07 -0800 | [diff] [blame] | 257 | Thread* self = Thread::Current(); |
| 258 | ThrowLocation throw_location = self->GetCurrentLocationForThrow(); |
| 259 | self->ThrowNewExceptionV(throw_location, "Ljava/lang/IllegalMonitorStateException;", fmt, args); |
Brian Carlstrom | 64277f3 | 2012-03-26 23:53:34 -0700 | [diff] [blame] | 260 | if (!Runtime::Current()->IsStarted()) { |
| 261 | std::ostringstream ss; |
Ian Rogers | 62d6c77 | 2013-02-27 08:32:07 -0800 | [diff] [blame] | 262 | self->Dump(ss); |
Brian Carlstrom | 64277f3 | 2012-03-26 23:53:34 -0700 | [diff] [blame] | 263 | std::string str(ss.str()); |
| 264 | LOG(ERROR) << "IllegalMonitorStateException: " << str; |
| 265 | } |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 266 | va_end(args); |
| 267 | } |
| 268 | |
Elliott Hughes | d423741 | 2012-02-21 11:24:45 -0800 | [diff] [blame] | 269 | static std::string ThreadToString(Thread* thread) { |
| 270 | if (thread == NULL) { |
| 271 | return "NULL"; |
| 272 | } |
| 273 | std::ostringstream oss; |
| 274 | // TODO: alternatively, we could just return the thread's name. |
| 275 | oss << *thread; |
| 276 | return oss.str(); |
| 277 | } |
| 278 | |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 279 | void Monitor::FailedUnlock(mirror::Object* o, Thread* expected_owner, Thread* found_owner, |
Elliott Hughes | ffb465f | 2012-03-01 18:46:05 -0800 | [diff] [blame] | 280 | Monitor* monitor) { |
| 281 | Thread* current_owner = NULL; |
| 282 | std::string current_owner_string; |
| 283 | std::string expected_owner_string; |
| 284 | std::string found_owner_string; |
| 285 | { |
| 286 | // TODO: isn't this too late to prevent threads from disappearing? |
| 287 | // Acquire thread list lock so threads won't disappear from under us. |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 288 | MutexLock mu(Thread::Current(), *Locks::thread_list_lock_); |
Elliott Hughes | ffb465f | 2012-03-01 18:46:05 -0800 | [diff] [blame] | 289 | // Re-read owner now that we hold lock. |
| 290 | current_owner = (monitor != NULL) ? monitor->owner_ : NULL; |
| 291 | // Get short descriptions of the threads involved. |
| 292 | current_owner_string = ThreadToString(current_owner); |
| 293 | expected_owner_string = ThreadToString(expected_owner); |
| 294 | found_owner_string = ThreadToString(found_owner); |
| 295 | } |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 296 | if (current_owner == NULL) { |
| 297 | if (found_owner == NULL) { |
| 298 | ThrowIllegalMonitorStateExceptionF("unlock of unowned monitor on object of type '%s'" |
| 299 | " on thread '%s'", |
Elliott Hughes | ffb465f | 2012-03-01 18:46:05 -0800 | [diff] [blame] | 300 | PrettyTypeOf(o).c_str(), |
| 301 | expected_owner_string.c_str()); |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 302 | } else { |
| 303 | // Race: the original read found an owner but now there is none |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 304 | ThrowIllegalMonitorStateExceptionF("unlock of monitor owned by '%s' on object of type '%s'" |
| 305 | " (where now the monitor appears unowned) on thread '%s'", |
Elliott Hughes | ffb465f | 2012-03-01 18:46:05 -0800 | [diff] [blame] | 306 | found_owner_string.c_str(), |
| 307 | PrettyTypeOf(o).c_str(), |
| 308 | expected_owner_string.c_str()); |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 309 | } |
| 310 | } else { |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 311 | if (found_owner == NULL) { |
| 312 | // Race: originally there was no owner, there is now |
| 313 | ThrowIllegalMonitorStateExceptionF("unlock of monitor owned by '%s' on object of type '%s'" |
| 314 | " (originally believed to be unowned) on thread '%s'", |
Elliott Hughes | ffb465f | 2012-03-01 18:46:05 -0800 | [diff] [blame] | 315 | current_owner_string.c_str(), |
| 316 | PrettyTypeOf(o).c_str(), |
| 317 | expected_owner_string.c_str()); |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 318 | } else { |
| 319 | if (found_owner != current_owner) { |
| 320 | // Race: originally found and current owner have changed |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 321 | ThrowIllegalMonitorStateExceptionF("unlock of monitor originally owned by '%s' (now" |
| 322 | " owned by '%s') on object of type '%s' on thread '%s'", |
Elliott Hughes | ffb465f | 2012-03-01 18:46:05 -0800 | [diff] [blame] | 323 | found_owner_string.c_str(), |
| 324 | current_owner_string.c_str(), |
| 325 | PrettyTypeOf(o).c_str(), |
| 326 | expected_owner_string.c_str()); |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 327 | } else { |
| 328 | ThrowIllegalMonitorStateExceptionF("unlock of monitor owned by '%s' on object of type '%s'" |
| 329 | " on thread '%s", |
Elliott Hughes | ffb465f | 2012-03-01 18:46:05 -0800 | [diff] [blame] | 330 | current_owner_string.c_str(), |
| 331 | PrettyTypeOf(o).c_str(), |
| 332 | expected_owner_string.c_str()); |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 333 | } |
| 334 | } |
| 335 | } |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 336 | } |
| 337 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 338 | bool Monitor::Unlock(Thread* self, bool for_wait) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 339 | DCHECK(self != NULL); |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 340 | Thread* owner = owner_; |
| 341 | if (owner == self) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 342 | // We own the monitor, so nobody else can be in here. |
| 343 | if (lock_count_ == 0) { |
| 344 | owner_ = NULL; |
jeffhao | 33dc771 | 2011-11-09 17:54:24 -0800 | [diff] [blame] | 345 | locking_method_ = NULL; |
Ian Rogers | 0399dde | 2012-06-06 17:09:28 -0700 | [diff] [blame] | 346 | locking_dex_pc_ = 0; |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 347 | monitor_lock_.Unlock(self); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 348 | } else { |
| 349 | --lock_count_; |
| 350 | } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 351 | } else if (for_wait) { |
| 352 | // Wait should have already cleared the fields. |
| 353 | DCHECK_EQ(lock_count_, 0); |
| 354 | DCHECK(owner == NULL); |
| 355 | DCHECK(locking_method_ == NULL); |
| 356 | DCHECK_EQ(locking_dex_pc_, 0u); |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 357 | monitor_lock_.Unlock(self); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 358 | } else { |
| 359 | // We don't own this, so we're not allowed to unlock it. |
| 360 | // The JNI spec says that we should throw IllegalMonitorStateException |
| 361 | // in this case. |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 362 | FailedUnlock(obj_, self, owner, this); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 363 | return false; |
| 364 | } |
| 365 | return true; |
| 366 | } |
| 367 | |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 368 | /* |
| 369 | * Wait on a monitor until timeout, interrupt, or notification. Used for |
| 370 | * Object.wait() and (somewhat indirectly) Thread.sleep() and Thread.join(). |
| 371 | * |
| 372 | * If another thread calls Thread.interrupt(), we throw InterruptedException |
| 373 | * and return immediately if one of the following are true: |
| 374 | * - blocked in wait(), wait(long), or wait(long, int) methods of Object |
| 375 | * - blocked in join(), join(long), or join(long, int) methods of Thread |
| 376 | * - blocked in sleep(long), or sleep(long, int) methods of Thread |
| 377 | * Otherwise, we set the "interrupted" flag. |
| 378 | * |
| 379 | * Checks to make sure that "ns" is in the range 0-999999 |
| 380 | * (i.e. fractions of a millisecond) and throws the appropriate |
| 381 | * exception if it isn't. |
| 382 | * |
| 383 | * The spec allows "spurious wakeups", and recommends that all code using |
| 384 | * Object.wait() do so in a loop. This appears to derive from concerns |
| 385 | * about pthread_cond_wait() on multiprocessor systems. Some commentary |
| 386 | * on the web casts doubt on whether these can/should occur. |
| 387 | * |
| 388 | * Since we're allowed to wake up "early", we clamp extremely long durations |
| 389 | * to return at the end of the 32-bit time epoch. |
| 390 | */ |
Elliott Hughes | 4cd121e | 2013-01-07 17:35:41 -0800 | [diff] [blame] | 391 | void Monitor::Wait(Thread* self, int64_t ms, int32_t ns, |
| 392 | bool interruptShouldThrow, ThreadState why) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 393 | DCHECK(self != NULL); |
Elliott Hughes | 4cd121e | 2013-01-07 17:35:41 -0800 | [diff] [blame] | 394 | DCHECK(why == kTimedWaiting || why == kWaiting || why == kSleeping); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 395 | |
| 396 | // Make sure that we hold the lock. |
| 397 | if (owner_ != self) { |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 398 | ThrowIllegalMonitorStateExceptionF("object not locked by thread before wait()"); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 399 | return; |
| 400 | } |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 401 | monitor_lock_.AssertHeld(self); |
Elliott Hughes | 4cd121e | 2013-01-07 17:35:41 -0800 | [diff] [blame] | 402 | |
Elliott Hughes | df42c48 | 2013-01-09 12:49:02 -0800 | [diff] [blame] | 403 | // We need to turn a zero-length timed wait into a regular wait because |
| 404 | // Object.wait(0, 0) is defined as Object.wait(0), which is defined as Object.wait(). |
| 405 | if (why == kTimedWaiting && (ms == 0 && ns == 0)) { |
| 406 | why = kWaiting; |
| 407 | } |
| 408 | |
Elliott Hughes | 4cd121e | 2013-01-07 17:35:41 -0800 | [diff] [blame] | 409 | WaitWithLock(self, ms, ns, interruptShouldThrow, why); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 410 | } |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 411 | |
Elliott Hughes | 4cd121e | 2013-01-07 17:35:41 -0800 | [diff] [blame] | 412 | void Monitor::WaitWithLock(Thread* self, int64_t ms, int32_t ns, |
| 413 | bool interruptShouldThrow, ThreadState why) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 414 | // Enforce the timeout range. |
| 415 | if (ms < 0 || ns < 0 || ns > 999999) { |
Ian Rogers | 62d6c77 | 2013-02-27 08:32:07 -0800 | [diff] [blame] | 416 | ThrowLocation throw_location = self->GetCurrentLocationForThrow(); |
| 417 | self->ThrowNewExceptionF(throw_location, "Ljava/lang/IllegalArgumentException;", |
| 418 | "timeout arguments out of range: ms=%lld ns=%d", ms, ns); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 419 | return; |
| 420 | } |
| 421 | |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 422 | /* |
| 423 | * Add ourselves to the set of threads waiting on this monitor, and |
| 424 | * release our hold. We need to let it go even if we're a few levels |
| 425 | * deep in a recursive lock, and we need to restore that later. |
| 426 | * |
| 427 | * We append to the wait set ahead of clearing the count and owner |
| 428 | * fields so the subroutine can check that the calling thread owns |
| 429 | * the monitor. Aside from that, the order of member updates is |
| 430 | * not order sensitive as we hold the pthread mutex. |
| 431 | */ |
| 432 | AppendToWaitSet(self); |
Ian Rogers | 0399dde | 2012-06-06 17:09:28 -0700 | [diff] [blame] | 433 | int prev_lock_count = lock_count_; |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 434 | lock_count_ = 0; |
| 435 | owner_ = NULL; |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 436 | const mirror::AbstractMethod* saved_method = locking_method_; |
jeffhao | 33dc771 | 2011-11-09 17:54:24 -0800 | [diff] [blame] | 437 | locking_method_ = NULL; |
Ian Rogers | 0399dde | 2012-06-06 17:09:28 -0700 | [diff] [blame] | 438 | uintptr_t saved_dex_pc = locking_dex_pc_; |
| 439 | locking_dex_pc_ = 0; |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 440 | |
| 441 | /* |
Elliott Hughes | 4cd121e | 2013-01-07 17:35:41 -0800 | [diff] [blame] | 442 | * Update thread state. If the GC wakes up, it'll ignore us, knowing |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 443 | * that we won't touch any references in this state, and we'll check |
| 444 | * our suspend mode before we transition out. |
| 445 | */ |
Elliott Hughes | 4cd121e | 2013-01-07 17:35:41 -0800 | [diff] [blame] | 446 | self->TransitionFromRunnableToSuspended(why); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 447 | |
Elliott Hughes | b4e94fd | 2013-01-08 14:41:26 -0800 | [diff] [blame] | 448 | bool was_interrupted = false; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 449 | { |
| 450 | // Pseudo-atomically wait on self's wait_cond_ and release the monitor lock. |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 451 | MutexLock mu(self, *self->wait_mutex_); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 452 | |
| 453 | // Set wait_monitor_ to the monitor object we will be waiting on. When wait_monitor_ is |
| 454 | // non-NULL a notifying or interrupting thread must signal the thread's wait_cond_ to wake it |
| 455 | // up. |
| 456 | DCHECK(self->wait_monitor_ == NULL); |
| 457 | self->wait_monitor_ = this; |
| 458 | |
| 459 | // Release the monitor lock. |
| 460 | Unlock(self, true); |
| 461 | |
Elliott Hughes | b4e94fd | 2013-01-08 14:41:26 -0800 | [diff] [blame] | 462 | // Handle the case where the thread was interrupted before we called wait(). |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 463 | if (self->interrupted_) { |
Elliott Hughes | b4e94fd | 2013-01-08 14:41:26 -0800 | [diff] [blame] | 464 | was_interrupted = true; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 465 | } else { |
| 466 | // Wait for a notification or a timeout to occur. |
Elliott Hughes | 4cd121e | 2013-01-07 17:35:41 -0800 | [diff] [blame] | 467 | if (why == kWaiting) { |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 468 | self->wait_cond_->Wait(self); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 469 | } else { |
Elliott Hughes | 4cd121e | 2013-01-07 17:35:41 -0800 | [diff] [blame] | 470 | DCHECK(why == kTimedWaiting || why == kSleeping) << why; |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 471 | self->wait_cond_->TimedWait(self, ms, ns); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 472 | } |
| 473 | if (self->interrupted_) { |
Elliott Hughes | b4e94fd | 2013-01-08 14:41:26 -0800 | [diff] [blame] | 474 | was_interrupted = true; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 475 | } |
| 476 | self->interrupted_ = false; |
| 477 | } |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 478 | } |
| 479 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 480 | // Set self->status back to kRunnable, and self-suspend if needed. |
| 481 | self->TransitionFromSuspendedToRunnable(); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 482 | |
Elliott Hughes | b4e94fd | 2013-01-08 14:41:26 -0800 | [diff] [blame] | 483 | { |
| 484 | // We reset the thread's wait_monitor_ field after transitioning back to runnable so |
| 485 | // that a thread in a waiting/sleeping state has a non-null wait_monitor_ for debugging |
| 486 | // and diagnostic purposes. (If you reset this earlier, stack dumps will claim that threads |
| 487 | // are waiting on "null".) |
| 488 | MutexLock mu(self, *self->wait_mutex_); |
| 489 | DCHECK(self->wait_monitor_ != NULL); |
| 490 | self->wait_monitor_ = NULL; |
| 491 | } |
| 492 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 493 | // Re-acquire the monitor lock. |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 494 | Lock(self); |
| 495 | |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 496 | self->wait_mutex_->AssertNotHeld(self); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 497 | |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 498 | /* |
| 499 | * We remove our thread from wait set after restoring the count |
| 500 | * and owner fields so the subroutine can check that the calling |
| 501 | * thread owns the monitor. Aside from that, the order of member |
| 502 | * updates is not order sensitive as we hold the pthread mutex. |
| 503 | */ |
| 504 | owner_ = self; |
Ian Rogers | 0399dde | 2012-06-06 17:09:28 -0700 | [diff] [blame] | 505 | lock_count_ = prev_lock_count; |
| 506 | locking_method_ = saved_method; |
| 507 | locking_dex_pc_ = saved_dex_pc; |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 508 | RemoveFromWaitSet(self); |
| 509 | |
Elliott Hughes | b4e94fd | 2013-01-08 14:41:26 -0800 | [diff] [blame] | 510 | if (was_interrupted) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 511 | /* |
| 512 | * We were interrupted while waiting, or somebody interrupted an |
| 513 | * un-interruptible thread earlier and we're bailing out immediately. |
| 514 | * |
| 515 | * The doc sayeth: "The interrupted status of the current thread is |
| 516 | * cleared when this exception is thrown." |
| 517 | */ |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 518 | { |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 519 | MutexLock mu(self, *self->wait_mutex_); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 520 | self->interrupted_ = false; |
| 521 | } |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 522 | if (interruptShouldThrow) { |
Ian Rogers | 62d6c77 | 2013-02-27 08:32:07 -0800 | [diff] [blame] | 523 | ThrowLocation throw_location = self->GetCurrentLocationForThrow(); |
| 524 | self->ThrowNewException(throw_location, "Ljava/lang/InterruptedException;", NULL); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 525 | } |
| 526 | } |
| 527 | } |
| 528 | |
| 529 | void Monitor::Notify(Thread* self) { |
| 530 | DCHECK(self != NULL); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 531 | // Make sure that we hold the lock. |
| 532 | if (owner_ != self) { |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 533 | ThrowIllegalMonitorStateExceptionF("object not locked by thread before notify()"); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 534 | return; |
| 535 | } |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 536 | monitor_lock_.AssertHeld(self); |
| 537 | NotifyWithLock(self); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 538 | } |
| 539 | |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 540 | void Monitor::NotifyWithLock(Thread* self) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 541 | // Signal the first waiting thread in the wait set. |
| 542 | while (wait_set_ != NULL) { |
| 543 | Thread* thread = wait_set_; |
| 544 | wait_set_ = thread->wait_next_; |
| 545 | thread->wait_next_ = NULL; |
| 546 | |
| 547 | // Check to see if the thread is still waiting. |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 548 | MutexLock mu(self, *thread->wait_mutex_); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 549 | if (thread->wait_monitor_ != NULL) { |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 550 | thread->wait_cond_->Signal(self); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 551 | return; |
| 552 | } |
| 553 | } |
| 554 | } |
| 555 | |
| 556 | void Monitor::NotifyAll(Thread* self) { |
| 557 | DCHECK(self != NULL); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 558 | // Make sure that we hold the lock. |
| 559 | if (owner_ != self) { |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 560 | ThrowIllegalMonitorStateExceptionF("object not locked by thread before notifyAll()"); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 561 | return; |
| 562 | } |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 563 | monitor_lock_.AssertHeld(self); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 564 | NotifyAllWithLock(); |
| 565 | } |
| 566 | |
| 567 | void Monitor::NotifyAllWithLock() { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 568 | // Signal all threads in the wait set. |
| 569 | while (wait_set_ != NULL) { |
| 570 | Thread* thread = wait_set_; |
| 571 | wait_set_ = thread->wait_next_; |
| 572 | thread->wait_next_ = NULL; |
| 573 | thread->Notify(); |
| 574 | } |
| 575 | } |
| 576 | |
| 577 | /* |
| 578 | * Changes the shape of a monitor from thin to fat, preserving the |
| 579 | * internal lock state. The calling thread must own the lock. |
| 580 | */ |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 581 | void Monitor::Inflate(Thread* self, mirror::Object* obj) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 582 | DCHECK(self != NULL); |
| 583 | DCHECK(obj != NULL); |
| 584 | DCHECK_EQ(LW_SHAPE(*obj->GetRawLockWordAddress()), LW_SHAPE_THIN); |
Elliott Hughes | f8e0127 | 2011-10-17 11:29:05 -0700 | [diff] [blame] | 585 | DCHECK_EQ(LW_LOCK_OWNER(*obj->GetRawLockWordAddress()), static_cast<int32_t>(self->GetThinLockId())); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 586 | |
| 587 | // Allocate and acquire a new monitor. |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 588 | Monitor* m = new Monitor(self, obj); |
Elliott Hughes | 4dd9b4d | 2011-12-12 18:29:24 -0800 | [diff] [blame] | 589 | VLOG(monitor) << "monitor: thread " << self->GetThinLockId() |
| 590 | << " created monitor " << m << " for object " << obj; |
Elliott Hughes | c33a32b | 2011-10-11 18:18:07 -0700 | [diff] [blame] | 591 | Runtime::Current()->GetMonitorList()->Add(m); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 592 | } |
| 593 | |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 594 | void Monitor::MonitorEnter(Thread* self, mirror::Object* obj) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 595 | volatile int32_t* thinp = obj->GetRawLockWordAddress(); |
Elliott Hughes | 398f64b | 2012-03-26 18:05:48 -0700 | [diff] [blame] | 596 | uint32_t sleepDelayNs; |
| 597 | uint32_t minSleepDelayNs = 1000000; /* 1 millisecond */ |
| 598 | uint32_t maxSleepDelayNs = 1000000000; /* 1 second */ |
Elliott Hughes | f8e0127 | 2011-10-17 11:29:05 -0700 | [diff] [blame] | 599 | uint32_t thin, newThin; |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 600 | |
Elliott Hughes | 4681c80 | 2011-09-25 18:04:37 -0700 | [diff] [blame] | 601 | DCHECK(self != NULL); |
| 602 | DCHECK(obj != NULL); |
Elliott Hughes | f8e0127 | 2011-10-17 11:29:05 -0700 | [diff] [blame] | 603 | uint32_t threadId = self->GetThinLockId(); |
Elliott Hughes | a21039c | 2012-06-21 12:09:25 -0700 | [diff] [blame] | 604 | retry: |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 605 | thin = *thinp; |
| 606 | if (LW_SHAPE(thin) == LW_SHAPE_THIN) { |
| 607 | /* |
| 608 | * The lock is a thin lock. The owner field is used to |
| 609 | * determine the acquire method, ordered by cost. |
| 610 | */ |
| 611 | if (LW_LOCK_OWNER(thin) == threadId) { |
| 612 | /* |
| 613 | * The calling thread owns the lock. Increment the |
| 614 | * value of the recursion count field. |
| 615 | */ |
| 616 | *thinp += 1 << LW_LOCK_COUNT_SHIFT; |
| 617 | if (LW_LOCK_COUNT(*thinp) == LW_LOCK_COUNT_MASK) { |
| 618 | /* |
| 619 | * The reacquisition limit has been reached. Inflate |
| 620 | * the lock so the next acquire will not overflow the |
| 621 | * recursion count field. |
| 622 | */ |
| 623 | Inflate(self, obj); |
| 624 | } |
| 625 | } else if (LW_LOCK_OWNER(thin) == 0) { |
Elliott Hughes | 81ff318 | 2012-03-23 20:35:56 -0700 | [diff] [blame] | 626 | // The lock is unowned. Install the thread id of the calling thread into the owner field. |
| 627 | // This is the common case: compiled code will have tried this before calling back into |
| 628 | // the runtime. |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 629 | newThin = thin | (threadId << LW_LOCK_OWNER_SHIFT); |
| 630 | if (android_atomic_acquire_cas(thin, newThin, thinp) != 0) { |
| 631 | // The acquire failed. Try again. |
| 632 | goto retry; |
| 633 | } |
| 634 | } else { |
Elliott Hughes | 4dd9b4d | 2011-12-12 18:29:24 -0800 | [diff] [blame] | 635 | VLOG(monitor) << StringPrintf("monitor: thread %d spin on lock %p (a %s) owned by %d", |
Elliott Hughes | 81ff318 | 2012-03-23 20:35:56 -0700 | [diff] [blame] | 636 | threadId, thinp, PrettyTypeOf(obj).c_str(), LW_LOCK_OWNER(thin)); |
| 637 | // The lock is owned by another thread. Notify the runtime that we are about to wait. |
Elliott Hughes | 8e4aac5 | 2011-09-26 17:03:36 -0700 | [diff] [blame] | 638 | self->monitor_enter_object_ = obj; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 639 | self->TransitionFromRunnableToSuspended(kBlocked); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 640 | // Spin until the thin lock is released or inflated. |
| 641 | sleepDelayNs = 0; |
| 642 | for (;;) { |
| 643 | thin = *thinp; |
| 644 | // Check the shape of the lock word. Another thread |
| 645 | // may have inflated the lock while we were waiting. |
| 646 | if (LW_SHAPE(thin) == LW_SHAPE_THIN) { |
| 647 | if (LW_LOCK_OWNER(thin) == 0) { |
| 648 | // The lock has been released. Install the thread id of the |
| 649 | // calling thread into the owner field. |
| 650 | newThin = thin | (threadId << LW_LOCK_OWNER_SHIFT); |
| 651 | if (android_atomic_acquire_cas(thin, newThin, thinp) == 0) { |
| 652 | // The acquire succeed. Break out of the loop and proceed to inflate the lock. |
| 653 | break; |
| 654 | } |
| 655 | } else { |
| 656 | // The lock has not been released. Yield so the owning thread can run. |
| 657 | if (sleepDelayNs == 0) { |
| 658 | sched_yield(); |
| 659 | sleepDelayNs = minSleepDelayNs; |
| 660 | } else { |
Ian Rogers | 56edc43 | 2013-01-18 16:51:51 -0800 | [diff] [blame] | 661 | NanoSleep(sleepDelayNs); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 662 | // Prepare the next delay value. Wrap to avoid once a second polls for eternity. |
| 663 | if (sleepDelayNs < maxSleepDelayNs / 2) { |
| 664 | sleepDelayNs *= 2; |
| 665 | } else { |
| 666 | sleepDelayNs = minSleepDelayNs; |
| 667 | } |
| 668 | } |
| 669 | } |
| 670 | } else { |
Elliott Hughes | 81ff318 | 2012-03-23 20:35:56 -0700 | [diff] [blame] | 671 | // The thin lock was inflated by another thread. Let the runtime know we are no longer |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 672 | // waiting and try again. |
Elliott Hughes | 398f64b | 2012-03-26 18:05:48 -0700 | [diff] [blame] | 673 | VLOG(monitor) << StringPrintf("monitor: thread %d found lock %p surprise-fattened by another thread", threadId, thinp); |
Elliott Hughes | 8e4aac5 | 2011-09-26 17:03:36 -0700 | [diff] [blame] | 674 | self->monitor_enter_object_ = NULL; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 675 | self->TransitionFromSuspendedToRunnable(); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 676 | goto retry; |
| 677 | } |
| 678 | } |
Elliott Hughes | 4dd9b4d | 2011-12-12 18:29:24 -0800 | [diff] [blame] | 679 | VLOG(monitor) << StringPrintf("monitor: thread %d spin on lock %p done", threadId, thinp); |
Elliott Hughes | 81ff318 | 2012-03-23 20:35:56 -0700 | [diff] [blame] | 680 | // We have acquired the thin lock. Let the runtime know that we are no longer waiting. |
Elliott Hughes | 8e4aac5 | 2011-09-26 17:03:36 -0700 | [diff] [blame] | 681 | self->monitor_enter_object_ = NULL; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 682 | self->TransitionFromSuspendedToRunnable(); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 683 | // Fatten the lock. |
| 684 | Inflate(self, obj); |
Elliott Hughes | 4dd9b4d | 2011-12-12 18:29:24 -0800 | [diff] [blame] | 685 | VLOG(monitor) << StringPrintf("monitor: thread %d fattened lock %p", threadId, thinp); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 686 | } |
| 687 | } else { |
| 688 | // The lock is a fat lock. |
Elliott Hughes | 4dd9b4d | 2011-12-12 18:29:24 -0800 | [diff] [blame] | 689 | VLOG(monitor) << StringPrintf("monitor: thread %d locking fat lock %p (%p) %p on a %s", |
Elliott Hughes | 398f64b | 2012-03-26 18:05:48 -0700 | [diff] [blame] | 690 | threadId, thinp, LW_MONITOR(*thinp), |
| 691 | reinterpret_cast<void*>(*thinp), PrettyTypeOf(obj).c_str()); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 692 | DCHECK(LW_MONITOR(*thinp) != NULL); |
| 693 | LW_MONITOR(*thinp)->Lock(self); |
| 694 | } |
| 695 | } |
| 696 | |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 697 | bool Monitor::MonitorExit(Thread* self, mirror::Object* obj) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 698 | volatile int32_t* thinp = obj->GetRawLockWordAddress(); |
| 699 | |
| 700 | DCHECK(self != NULL); |
Brian Carlstrom | 7934ac2 | 2013-07-26 10:54:15 -0700 | [diff] [blame] | 701 | // DCHECK_EQ(self->GetState(), kRunnable); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 702 | DCHECK(obj != NULL); |
| 703 | |
| 704 | /* |
| 705 | * Cache the lock word as its value can change while we are |
| 706 | * examining its state. |
| 707 | */ |
| 708 | uint32_t thin = *thinp; |
| 709 | if (LW_SHAPE(thin) == LW_SHAPE_THIN) { |
| 710 | /* |
| 711 | * The lock is thin. We must ensure that the lock is owned |
| 712 | * by the given thread before unlocking it. |
| 713 | */ |
Elliott Hughes | f8e0127 | 2011-10-17 11:29:05 -0700 | [diff] [blame] | 714 | if (LW_LOCK_OWNER(thin) == self->GetThinLockId()) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 715 | /* |
| 716 | * We are the lock owner. It is safe to update the lock |
| 717 | * without CAS as lock ownership guards the lock itself. |
| 718 | */ |
| 719 | if (LW_LOCK_COUNT(thin) == 0) { |
| 720 | /* |
| 721 | * The lock was not recursively acquired, the common |
| 722 | * case. Unlock by clearing all bits except for the |
| 723 | * hash state. |
| 724 | */ |
| 725 | thin &= (LW_HASH_STATE_MASK << LW_HASH_STATE_SHIFT); |
| 726 | android_atomic_release_store(thin, thinp); |
| 727 | } else { |
| 728 | /* |
| 729 | * The object was recursively acquired. Decrement the |
| 730 | * lock recursion count field. |
| 731 | */ |
| 732 | *thinp -= 1 << LW_LOCK_COUNT_SHIFT; |
| 733 | } |
| 734 | } else { |
| 735 | /* |
| 736 | * We do not own the lock. The JVM spec requires that we |
| 737 | * throw an exception in this case. |
| 738 | */ |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 739 | FailedUnlock(obj, self, NULL, NULL); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 740 | return false; |
| 741 | } |
| 742 | } else { |
| 743 | /* |
| 744 | * The lock is fat. We must check to see if Unlock has |
| 745 | * raised any exceptions before continuing. |
| 746 | */ |
| 747 | DCHECK(LW_MONITOR(*thinp) != NULL); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 748 | if (!LW_MONITOR(*thinp)->Unlock(self, false)) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 749 | // An exception has been raised. Do not fall through. |
| 750 | return false; |
| 751 | } |
| 752 | } |
| 753 | return true; |
| 754 | } |
| 755 | |
| 756 | /* |
| 757 | * Object.wait(). Also called for class init. |
| 758 | */ |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 759 | void Monitor::Wait(Thread* self, mirror::Object *obj, int64_t ms, int32_t ns, |
Elliott Hughes | 4cd121e | 2013-01-07 17:35:41 -0800 | [diff] [blame] | 760 | bool interruptShouldThrow, ThreadState why) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 761 | volatile int32_t* thinp = obj->GetRawLockWordAddress(); |
| 762 | |
| 763 | // If the lock is still thin, we need to fatten it. |
| 764 | uint32_t thin = *thinp; |
| 765 | if (LW_SHAPE(thin) == LW_SHAPE_THIN) { |
| 766 | // Make sure that 'self' holds the lock. |
Elliott Hughes | f8e0127 | 2011-10-17 11:29:05 -0700 | [diff] [blame] | 767 | if (LW_LOCK_OWNER(thin) != self->GetThinLockId()) { |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 768 | ThrowIllegalMonitorStateExceptionF("object not locked by thread before wait()"); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 769 | return; |
| 770 | } |
| 771 | |
| 772 | /* This thread holds the lock. We need to fatten the lock |
| 773 | * so 'self' can block on it. Don't update the object lock |
| 774 | * field yet, because 'self' needs to acquire the lock before |
| 775 | * any other thread gets a chance. |
| 776 | */ |
| 777 | Inflate(self, obj); |
Elliott Hughes | 4dd9b4d | 2011-12-12 18:29:24 -0800 | [diff] [blame] | 778 | VLOG(monitor) << StringPrintf("monitor: thread %d fattened lock %p by wait()", self->GetThinLockId(), thinp); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 779 | } |
Elliott Hughes | 4cd121e | 2013-01-07 17:35:41 -0800 | [diff] [blame] | 780 | LW_MONITOR(*thinp)->Wait(self, ms, ns, interruptShouldThrow, why); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 781 | } |
| 782 | |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 783 | void Monitor::Notify(Thread* self, mirror::Object *obj) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 784 | uint32_t thin = *obj->GetRawLockWordAddress(); |
| 785 | |
| 786 | // If the lock is still thin, there aren't any waiters; |
| 787 | // waiting on an object forces lock fattening. |
| 788 | if (LW_SHAPE(thin) == LW_SHAPE_THIN) { |
| 789 | // Make sure that 'self' holds the lock. |
Elliott Hughes | f8e0127 | 2011-10-17 11:29:05 -0700 | [diff] [blame] | 790 | if (LW_LOCK_OWNER(thin) != self->GetThinLockId()) { |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 791 | ThrowIllegalMonitorStateExceptionF("object not locked by thread before notify()"); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 792 | return; |
| 793 | } |
| 794 | // no-op; there are no waiters to notify. |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 795 | Inflate(self, obj); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 796 | } else { |
| 797 | // It's a fat lock. |
| 798 | LW_MONITOR(thin)->Notify(self); |
| 799 | } |
| 800 | } |
| 801 | |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 802 | void Monitor::NotifyAll(Thread* self, mirror::Object *obj) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 803 | uint32_t thin = *obj->GetRawLockWordAddress(); |
| 804 | |
| 805 | // If the lock is still thin, there aren't any waiters; |
| 806 | // waiting on an object forces lock fattening. |
| 807 | if (LW_SHAPE(thin) == LW_SHAPE_THIN) { |
| 808 | // Make sure that 'self' holds the lock. |
Elliott Hughes | f8e0127 | 2011-10-17 11:29:05 -0700 | [diff] [blame] | 809 | if (LW_LOCK_OWNER(thin) != self->GetThinLockId()) { |
Ian Rogers | 6d0b13e | 2012-02-07 09:25:29 -0800 | [diff] [blame] | 810 | ThrowIllegalMonitorStateExceptionF("object not locked by thread before notifyAll()"); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 811 | return; |
| 812 | } |
| 813 | // no-op; there are no waiters to notify. |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 814 | Inflate(self, obj); |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 815 | } else { |
| 816 | // It's a fat lock. |
| 817 | LW_MONITOR(thin)->NotifyAll(self); |
| 818 | } |
| 819 | } |
| 820 | |
Brian Carlstrom | 24a3c2e | 2011-10-17 18:07:52 -0700 | [diff] [blame] | 821 | uint32_t Monitor::GetThinLockId(uint32_t raw_lock_word) { |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 822 | if (LW_SHAPE(raw_lock_word) == LW_SHAPE_THIN) { |
| 823 | return LW_LOCK_OWNER(raw_lock_word); |
| 824 | } else { |
| 825 | Thread* owner = LW_MONITOR(raw_lock_word)->owner_; |
| 826 | return owner ? owner->GetThinLockId() : 0; |
| 827 | } |
| 828 | } |
| 829 | |
Elliott Hughes | 8e4aac5 | 2011-09-26 17:03:36 -0700 | [diff] [blame] | 830 | void Monitor::DescribeWait(std::ostream& os, const Thread* thread) { |
Elliott Hughes | f950170 | 2013-01-11 11:22:27 -0800 | [diff] [blame] | 831 | ThreadState state = thread->GetState(); |
Elliott Hughes | 8e4aac5 | 2011-09-26 17:03:36 -0700 | [diff] [blame] | 832 | |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 833 | mirror::Object* object = NULL; |
Elliott Hughes | 8e4aac5 | 2011-09-26 17:03:36 -0700 | [diff] [blame] | 834 | uint32_t lock_owner = ThreadList::kInvalidId; |
Elliott Hughes | b4e94fd | 2013-01-08 14:41:26 -0800 | [diff] [blame] | 835 | if (state == kWaiting || state == kTimedWaiting || state == kSleeping) { |
| 836 | if (state == kSleeping) { |
| 837 | os << " - sleeping on "; |
| 838 | } else { |
| 839 | os << " - waiting on "; |
| 840 | } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 841 | { |
Elliott Hughes | f950170 | 2013-01-11 11:22:27 -0800 | [diff] [blame] | 842 | Thread* self = Thread::Current(); |
| 843 | MutexLock mu(self, *thread->wait_mutex_); |
Elliott Hughes | b4e94fd | 2013-01-08 14:41:26 -0800 | [diff] [blame] | 844 | Monitor* monitor = thread->wait_monitor_; |
| 845 | if (monitor != NULL) { |
| 846 | object = monitor->obj_; |
| 847 | } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 848 | } |
Elliott Hughes | 34e0696 | 2012-04-09 13:55:55 -0700 | [diff] [blame] | 849 | } else if (state == kBlocked) { |
Elliott Hughes | 8e4aac5 | 2011-09-26 17:03:36 -0700 | [diff] [blame] | 850 | os << " - waiting to lock "; |
| 851 | object = thread->monitor_enter_object_; |
| 852 | if (object != NULL) { |
Brian Carlstrom | 24a3c2e | 2011-10-17 18:07:52 -0700 | [diff] [blame] | 853 | lock_owner = object->GetThinLockId(); |
Elliott Hughes | 8e4aac5 | 2011-09-26 17:03:36 -0700 | [diff] [blame] | 854 | } |
| 855 | } else { |
| 856 | // We're not waiting on anything. |
| 857 | return; |
| 858 | } |
Elliott Hughes | 8e4aac5 | 2011-09-26 17:03:36 -0700 | [diff] [blame] | 859 | |
Elliott Hughes | 8e4aac5 | 2011-09-26 17:03:36 -0700 | [diff] [blame] | 860 | // - waiting on <0x6008c468> (a java.lang.Class<java.lang.ref.ReferenceQueue>) |
Elliott Hughes | 08fc03a | 2012-06-26 17:34:00 -0700 | [diff] [blame] | 861 | os << "<" << object << "> (a " << PrettyTypeOf(object) << ")"; |
Elliott Hughes | 8e4aac5 | 2011-09-26 17:03:36 -0700 | [diff] [blame] | 862 | |
Elliott Hughes | c5dc2ff | 2013-01-09 13:44:30 -0800 | [diff] [blame] | 863 | // - waiting to lock <0x613f83d8> (a java.lang.Object) held by thread 5 |
Elliott Hughes | 8e4aac5 | 2011-09-26 17:03:36 -0700 | [diff] [blame] | 864 | if (lock_owner != ThreadList::kInvalidId) { |
| 865 | os << " held by thread " << lock_owner; |
| 866 | } |
| 867 | |
| 868 | os << "\n"; |
| 869 | } |
| 870 | |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 871 | mirror::Object* Monitor::GetContendedMonitor(Thread* thread) { |
Elliott Hughes | f950170 | 2013-01-11 11:22:27 -0800 | [diff] [blame] | 872 | // This is used to implement JDWP's ThreadReference.CurrentContendedMonitor, and has a bizarre |
| 873 | // definition of contended that includes a monitor a thread is trying to enter... |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 874 | mirror::Object* result = thread->monitor_enter_object_; |
Elliott Hughes | f950170 | 2013-01-11 11:22:27 -0800 | [diff] [blame] | 875 | if (result != NULL) { |
| 876 | return result; |
| 877 | } |
| 878 | // ...but also a monitor that the thread is waiting on. |
| 879 | { |
| 880 | MutexLock mu(Thread::Current(), *thread->wait_mutex_); |
| 881 | Monitor* monitor = thread->wait_monitor_; |
| 882 | if (monitor != NULL) { |
| 883 | return monitor->obj_; |
| 884 | } |
| 885 | } |
| 886 | return NULL; |
| 887 | } |
| 888 | |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 889 | void Monitor::VisitLocks(StackVisitor* stack_visitor, void (*callback)(mirror::Object*, void*), |
| 890 | void* callback_context) { |
| 891 | mirror::AbstractMethod* m = stack_visitor->GetMethod(); |
Elliott Hughes | 08fc03a | 2012-06-26 17:34:00 -0700 | [diff] [blame] | 892 | CHECK(m != NULL); |
| 893 | |
| 894 | // Native methods are an easy special case. |
| 895 | // TODO: use the JNI implementation's table of explicit MonitorEnter calls and dump those too. |
| 896 | if (m->IsNative()) { |
| 897 | if (m->IsSynchronized()) { |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 898 | mirror::Object* jni_this = stack_visitor->GetCurrentSirt()->GetReference(0); |
Elliott Hughes | 4993bbc | 2013-01-10 15:41:25 -0800 | [diff] [blame] | 899 | callback(jni_this, callback_context); |
Elliott Hughes | 08fc03a | 2012-06-26 17:34:00 -0700 | [diff] [blame] | 900 | } |
| 901 | return; |
| 902 | } |
| 903 | |
jeffhao | 61f916c | 2012-10-25 17:48:51 -0700 | [diff] [blame] | 904 | // Proxy methods should not be synchronized. |
| 905 | if (m->IsProxyMethod()) { |
| 906 | CHECK(!m->IsSynchronized()); |
| 907 | return; |
| 908 | } |
| 909 | |
Elliott Hughes | 08fc03a | 2012-06-26 17:34:00 -0700 | [diff] [blame] | 910 | // <clinit> is another special case. The runtime holds the class lock while calling <clinit>. |
| 911 | MethodHelper mh(m); |
| 912 | if (mh.IsClassInitializer()) { |
Elliott Hughes | 4993bbc | 2013-01-10 15:41:25 -0800 | [diff] [blame] | 913 | callback(m->GetDeclaringClass(), callback_context); |
Elliott Hughes | 08fc03a | 2012-06-26 17:34:00 -0700 | [diff] [blame] | 914 | // Fall through because there might be synchronization in the user code too. |
| 915 | } |
| 916 | |
| 917 | // Is there any reason to believe there's any synchronization in this method? |
| 918 | const DexFile::CodeItem* code_item = mh.GetCodeItem(); |
Elliott Hughes | caf7654 | 2012-06-28 16:08:22 -0700 | [diff] [blame] | 919 | CHECK(code_item != NULL) << PrettyMethod(m); |
Elliott Hughes | 08fc03a | 2012-06-26 17:34:00 -0700 | [diff] [blame] | 920 | if (code_item->tries_size_ == 0) { |
Brian Carlstrom | 7934ac2 | 2013-07-26 10:54:15 -0700 | [diff] [blame] | 921 | return; // No "tries" implies no synchronization, so no held locks to report. |
Elliott Hughes | 08fc03a | 2012-06-26 17:34:00 -0700 | [diff] [blame] | 922 | } |
| 923 | |
Elliott Hughes | 80537bb | 2013-01-04 16:37:26 -0800 | [diff] [blame] | 924 | // Ask the verifier for the dex pcs of all the monitor-enter instructions corresponding to |
| 925 | // the locks held in this stack frame. |
| 926 | std::vector<uint32_t> monitor_enter_dex_pcs; |
| 927 | verifier::MethodVerifier::FindLocksAtDexPc(m, stack_visitor->GetDexPc(), monitor_enter_dex_pcs); |
| 928 | if (monitor_enter_dex_pcs.empty()) { |
| 929 | return; |
| 930 | } |
| 931 | |
Elliott Hughes | 80537bb | 2013-01-04 16:37:26 -0800 | [diff] [blame] | 932 | for (size_t i = 0; i < monitor_enter_dex_pcs.size(); ++i) { |
| 933 | // The verifier works in terms of the dex pcs of the monitor-enter instructions. |
| 934 | // We want the registers used by those instructions (so we can read the values out of them). |
| 935 | uint32_t dex_pc = monitor_enter_dex_pcs[i]; |
| 936 | uint16_t monitor_enter_instruction = code_item->insns_[dex_pc]; |
| 937 | |
| 938 | // Quick sanity check. |
| 939 | if ((monitor_enter_instruction & 0xff) != Instruction::MONITOR_ENTER) { |
| 940 | LOG(FATAL) << "expected monitor-enter @" << dex_pc << "; was " |
| 941 | << reinterpret_cast<void*>(monitor_enter_instruction); |
Elliott Hughes | 08fc03a | 2012-06-26 17:34:00 -0700 | [diff] [blame] | 942 | } |
| 943 | |
Elliott Hughes | 80537bb | 2013-01-04 16:37:26 -0800 | [diff] [blame] | 944 | uint16_t monitor_register = ((monitor_enter_instruction >> 8) & 0xff); |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 945 | mirror::Object* o = reinterpret_cast<mirror::Object*>(stack_visitor->GetVReg(m, monitor_register, |
| 946 | kReferenceVReg)); |
Elliott Hughes | 4993bbc | 2013-01-10 15:41:25 -0800 | [diff] [blame] | 947 | callback(o, callback_context); |
Elliott Hughes | 08fc03a | 2012-06-26 17:34:00 -0700 | [diff] [blame] | 948 | } |
| 949 | } |
| 950 | |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 951 | void Monitor::TranslateLocation(const mirror::AbstractMethod* method, uint32_t dex_pc, |
jeffhao | 33dc771 | 2011-11-09 17:54:24 -0800 | [diff] [blame] | 952 | const char*& source_file, uint32_t& line_number) const { |
| 953 | // If method is null, location is unknown |
| 954 | if (method == NULL) { |
Elliott Hughes | 12c51e3 | 2012-01-17 20:25:05 -0800 | [diff] [blame] | 955 | source_file = ""; |
jeffhao | 33dc771 | 2011-11-09 17:54:24 -0800 | [diff] [blame] | 956 | line_number = 0; |
| 957 | return; |
| 958 | } |
Ian Rogers | 6d4d9fc | 2011-11-30 16:24:48 -0800 | [diff] [blame] | 959 | MethodHelper mh(method); |
| 960 | source_file = mh.GetDeclaringClassSourceFile(); |
Elliott Hughes | 12c51e3 | 2012-01-17 20:25:05 -0800 | [diff] [blame] | 961 | if (source_file == NULL) { |
| 962 | source_file = ""; |
| 963 | } |
Ian Rogers | 0399dde | 2012-06-06 17:09:28 -0700 | [diff] [blame] | 964 | line_number = mh.GetLineNumFromDexPC(dex_pc); |
jeffhao | 33dc771 | 2011-11-09 17:54:24 -0800 | [diff] [blame] | 965 | } |
| 966 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 967 | MonitorList::MonitorList() : monitor_list_lock_("MonitorList lock") { |
Elliott Hughes | c33a32b | 2011-10-11 18:18:07 -0700 | [diff] [blame] | 968 | } |
| 969 | |
| 970 | MonitorList::~MonitorList() { |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 971 | MutexLock mu(Thread::Current(), monitor_list_lock_); |
Elliott Hughes | c33a32b | 2011-10-11 18:18:07 -0700 | [diff] [blame] | 972 | STLDeleteElements(&list_); |
| 973 | } |
| 974 | |
| 975 | void MonitorList::Add(Monitor* m) { |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 976 | MutexLock mu(Thread::Current(), monitor_list_lock_); |
Elliott Hughes | c33a32b | 2011-10-11 18:18:07 -0700 | [diff] [blame] | 977 | list_.push_front(m); |
| 978 | } |
| 979 | |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 980 | void MonitorList::SweepMonitorList(IsMarkedTester is_marked, void* arg) { |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 981 | MutexLock mu(Thread::Current(), monitor_list_lock_); |
Brian Carlstrom | 7934ac2 | 2013-07-26 10:54:15 -0700 | [diff] [blame] | 982 | typedef std::list<Monitor*>::iterator It; // TODO: C++0x auto |
Elliott Hughes | c33a32b | 2011-10-11 18:18:07 -0700 | [diff] [blame] | 983 | It it = list_.begin(); |
| 984 | while (it != list_.end()) { |
| 985 | Monitor* m = *it; |
| 986 | if (!is_marked(m->GetObject(), arg)) { |
Elliott Hughes | 4dd9b4d | 2011-12-12 18:29:24 -0800 | [diff] [blame] | 987 | VLOG(monitor) << "freeing monitor " << m << " belonging to unmarked object " << m->GetObject(); |
Elliott Hughes | c33a32b | 2011-10-11 18:18:07 -0700 | [diff] [blame] | 988 | delete m; |
| 989 | it = list_.erase(it); |
| 990 | } else { |
| 991 | ++it; |
| 992 | } |
| 993 | } |
| 994 | } |
| 995 | |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 996 | MonitorInfo::MonitorInfo(mirror::Object* o) : owner(NULL), entry_count(0) { |
Elliott Hughes | f327e07 | 2013-01-09 16:01:26 -0800 | [diff] [blame] | 997 | uint32_t lock_word = *o->GetRawLockWordAddress(); |
| 998 | if (LW_SHAPE(lock_word) == LW_SHAPE_THIN) { |
| 999 | uint32_t owner_thin_lock_id = LW_LOCK_OWNER(lock_word); |
| 1000 | if (owner_thin_lock_id != 0) { |
| 1001 | owner = Runtime::Current()->GetThreadList()->FindThreadByThinLockId(owner_thin_lock_id); |
| 1002 | entry_count = 1 + LW_LOCK_COUNT(lock_word); |
| 1003 | } |
| 1004 | // Thin locks have no waiters. |
| 1005 | } else { |
| 1006 | CHECK_EQ(LW_SHAPE(lock_word), LW_SHAPE_FAT); |
| 1007 | Monitor* monitor = LW_MONITOR(lock_word); |
| 1008 | owner = monitor->owner_; |
| 1009 | entry_count = 1 + monitor->lock_count_; |
| 1010 | for (Thread* waiter = monitor->wait_set_; waiter != NULL; waiter = waiter->wait_next_) { |
| 1011 | waiters.push_back(waiter); |
| 1012 | } |
| 1013 | } |
| 1014 | } |
| 1015 | |
Elliott Hughes | 5f79133 | 2011-09-15 17:45:30 -0700 | [diff] [blame] | 1016 | } // namespace art |