Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2011 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 | |
| 17 | #include "thread_list.h" |
| 18 | |
Mathieu Chartier | 6f365cc | 2014-04-23 12:42:27 -0700 | [diff] [blame] | 19 | #define ATRACE_TAG ATRACE_TAG_DALVIK |
| 20 | |
Christopher Ferris | 6cff48f | 2014-01-26 21:36:13 -0800 | [diff] [blame] | 21 | #include <backtrace/BacktraceMap.h> |
Mathieu Chartier | 6f365cc | 2014-04-23 12:42:27 -0700 | [diff] [blame] | 22 | #include <cutils/trace.h> |
Elliott Hughes | abbe07d | 2012-06-05 17:42:23 -0700 | [diff] [blame] | 23 | #include <dirent.h> |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 24 | #include <ScopedLocalRef.h> |
| 25 | #include <ScopedUtfChars.h> |
Elliott Hughes | abbe07d | 2012-06-05 17:42:23 -0700 | [diff] [blame] | 26 | #include <sys/types.h> |
Elliott Hughes | 038a806 | 2011-09-18 14:12:41 -0700 | [diff] [blame] | 27 | #include <unistd.h> |
| 28 | |
Ian Rogers | c7dd295 | 2014-10-21 23:31:19 -0700 | [diff] [blame] | 29 | #include <sstream> |
| 30 | |
Mathieu Chartier | 70a596d | 2014-12-17 14:56:47 -0800 | [diff] [blame] | 31 | #include "base/histogram-inl.h" |
Hiroshi Yamauchi | 967a0ad | 2013-09-10 16:24:21 -0700 | [diff] [blame] | 32 | #include "base/mutex-inl.h" |
Vladimir Marko | 80afd02 | 2015-05-19 18:08:00 +0100 | [diff] [blame] | 33 | #include "base/time_utils.h" |
Sameer Abu Asal | a843954 | 2013-02-14 16:06:42 -0800 | [diff] [blame] | 34 | #include "base/timing_logger.h" |
Elliott Hughes | 475fc23 | 2011-10-25 15:00:35 -0700 | [diff] [blame] | 35 | #include "debugger.h" |
Hiroshi Yamauchi | 0b71357 | 2015-06-16 18:29:23 -0700 | [diff] [blame] | 36 | #include "gc/collector/concurrent_copying.h" |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 37 | #include "jni_internal.h" |
| 38 | #include "lock_word.h" |
| 39 | #include "monitor.h" |
| 40 | #include "scoped_thread_state_change.h" |
Ian Rogers | 2dd0e2c | 2013-01-24 12:42:14 -0800 | [diff] [blame] | 41 | #include "thread.h" |
Jeff Hao | e094b87 | 2014-10-14 13:12:01 -0700 | [diff] [blame] | 42 | #include "trace.h" |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 43 | #include "well_known_classes.h" |
Elliott Hughes | 475fc23 | 2011-10-25 15:00:35 -0700 | [diff] [blame] | 44 | |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 45 | #if ART_USE_FUTEXES |
| 46 | #include "linux/futex.h" |
| 47 | #include "sys/syscall.h" |
| 48 | #ifndef SYS_futex |
| 49 | #define SYS_futex __NR_futex |
| 50 | #endif |
| 51 | #endif // ART_USE_FUTEXES |
| 52 | |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 53 | namespace art { |
| 54 | |
Mathieu Chartier | 251755c | 2014-07-15 18:10:25 -0700 | [diff] [blame] | 55 | static constexpr uint64_t kLongThreadSuspendThreshold = MsToNs(5); |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 56 | static constexpr uint64_t kThreadSuspendTimeoutMs = 30 * 1000; // 30s. |
| 57 | // Use 0 since we want to yield to prevent blocking for an unpredictable amount of time. |
| 58 | static constexpr useconds_t kThreadSuspendInitialSleepUs = 0; |
| 59 | static constexpr useconds_t kThreadSuspendMaxYieldUs = 3000; |
| 60 | static constexpr useconds_t kThreadSuspendMaxSleepUs = 5000; |
Mathieu Chartier | 251755c | 2014-07-15 18:10:25 -0700 | [diff] [blame] | 61 | |
Elliott Hughes | 4dd9b4d | 2011-12-12 18:29:24 -0800 | [diff] [blame] | 62 | ThreadList::ThreadList() |
Mathieu Chartier | 91e5669 | 2015-03-03 13:51:04 -0800 | [diff] [blame] | 63 | : suspend_all_count_(0), debug_suspend_all_count_(0), unregistering_count_(0), |
Mathieu Chartier | bf44d42 | 2015-06-02 11:42:18 -0700 | [diff] [blame] | 64 | suspend_all_historam_("suspend all histogram", 16, 64), long_suspend_(false) { |
Hiroshi Yamauchi | e15ea08 | 2015-02-09 17:11:42 -0800 | [diff] [blame] | 65 | CHECK(Monitor::IsValidLockWord(LockWord::FromThinLockId(kMaxThreadId, 1, 0U))); |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 66 | } |
| 67 | |
| 68 | ThreadList::~ThreadList() { |
Elliott Hughes | e52e49b | 2012-04-02 16:05:44 -0700 | [diff] [blame] | 69 | // Detach the current thread if necessary. If we failed to start, there might not be any threads. |
Elliott Hughes | 6a14433 | 2012-04-03 13:07:11 -0700 | [diff] [blame] | 70 | // We need to detach the current thread here in case there's another thread waiting to join with |
| 71 | // us. |
Mathieu Chartier | fec72f4 | 2014-10-09 12:57:58 -0700 | [diff] [blame] | 72 | bool contains = false; |
| 73 | { |
| 74 | Thread* self = Thread::Current(); |
| 75 | MutexLock mu(self, *Locks::thread_list_lock_); |
| 76 | contains = Contains(self); |
| 77 | } |
| 78 | if (contains) { |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 79 | Runtime::Current()->DetachCurrentThread(); |
| 80 | } |
Elliott Hughes | 6a14433 | 2012-04-03 13:07:11 -0700 | [diff] [blame] | 81 | WaitForOtherNonDaemonThreadsToExit(); |
Mathieu Chartier | 5116837 | 2015-08-12 16:40:32 -0700 | [diff] [blame] | 82 | // Disable GC and wait for GC to complete in case there are still daemon threads doing |
| 83 | // allocations. |
| 84 | gc::Heap* const heap = Runtime::Current()->GetHeap(); |
| 85 | heap->DisableGCForShutdown(); |
| 86 | // In case a GC is in progress, wait for it to finish. |
| 87 | heap->WaitForGcToComplete(gc::kGcCauseBackground, Thread::Current()); |
| 88 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 89 | // TODO: there's an unaddressed race here where a thread may attach during shutdown, see |
| 90 | // Thread::Init. |
Elliott Hughes | 6a14433 | 2012-04-03 13:07:11 -0700 | [diff] [blame] | 91 | SuspendAllDaemonThreads(); |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 92 | } |
| 93 | |
| 94 | bool ThreadList::Contains(Thread* thread) { |
| 95 | return find(list_.begin(), list_.end(), thread) != list_.end(); |
| 96 | } |
| 97 | |
Elliott Hughes | abbe07d | 2012-06-05 17:42:23 -0700 | [diff] [blame] | 98 | bool ThreadList::Contains(pid_t tid) { |
Mathieu Chartier | 02e2511 | 2013-08-14 16:14:24 -0700 | [diff] [blame] | 99 | for (const auto& thread : list_) { |
Ian Rogers | dd7624d | 2014-03-14 17:43:00 -0700 | [diff] [blame] | 100 | if (thread->GetTid() == tid) { |
Elliott Hughes | abbe07d | 2012-06-05 17:42:23 -0700 | [diff] [blame] | 101 | return true; |
| 102 | } |
| 103 | } |
| 104 | return false; |
| 105 | } |
| 106 | |
Brian Carlstrom | 24a3c2e | 2011-10-17 18:07:52 -0700 | [diff] [blame] | 107 | pid_t ThreadList::GetLockOwner() { |
Ian Rogers | b726dcb | 2012-09-05 08:57:23 -0700 | [diff] [blame] | 108 | return Locks::thread_list_lock_->GetExclusiveOwnerTid(); |
Elliott Hughes | accd83d | 2011-10-17 14:25:58 -0700 | [diff] [blame] | 109 | } |
| 110 | |
Mathieu Chartier | 590fee9 | 2013-09-13 13:46:47 -0700 | [diff] [blame] | 111 | void ThreadList::DumpNativeStacks(std::ostream& os) { |
| 112 | MutexLock mu(Thread::Current(), *Locks::thread_list_lock_); |
Christopher Ferris | 6cff48f | 2014-01-26 21:36:13 -0800 | [diff] [blame] | 113 | std::unique_ptr<BacktraceMap> map(BacktraceMap::Create(getpid())); |
Mathieu Chartier | 590fee9 | 2013-09-13 13:46:47 -0700 | [diff] [blame] | 114 | for (const auto& thread : list_) { |
Ian Rogers | dd7624d | 2014-03-14 17:43:00 -0700 | [diff] [blame] | 115 | os << "DUMPING THREAD " << thread->GetTid() << "\n"; |
Christopher Ferris | 6cff48f | 2014-01-26 21:36:13 -0800 | [diff] [blame] | 116 | DumpNativeStack(os, thread->GetTid(), map.get(), "\t"); |
Mathieu Chartier | 590fee9 | 2013-09-13 13:46:47 -0700 | [diff] [blame] | 117 | os << "\n"; |
| 118 | } |
| 119 | } |
| 120 | |
Elliott Hughes | c967f78 | 2012-04-16 10:23:15 -0700 | [diff] [blame] | 121 | void ThreadList::DumpForSigQuit(std::ostream& os) { |
Mathieu Chartier | 70a596d | 2014-12-17 14:56:47 -0800 | [diff] [blame] | 122 | { |
| 123 | ScopedObjectAccess soa(Thread::Current()); |
Mathieu Chartier | 23f6e69 | 2014-12-18 18:24:39 -0800 | [diff] [blame] | 124 | // Only print if we have samples. |
| 125 | if (suspend_all_historam_.SampleSize() > 0) { |
| 126 | Histogram<uint64_t>::CumulativeData data; |
| 127 | suspend_all_historam_.CreateHistogram(&data); |
| 128 | suspend_all_historam_.PrintConfidenceIntervals(os, 0.99, data); // Dump time to suspend. |
| 129 | } |
Mathieu Chartier | 70a596d | 2014-12-17 14:56:47 -0800 | [diff] [blame] | 130 | } |
Ian Rogers | 7b078e8 | 2014-09-10 14:44:24 -0700 | [diff] [blame] | 131 | Dump(os); |
Elliott Hughes | abbe07d | 2012-06-05 17:42:23 -0700 | [diff] [blame] | 132 | DumpUnattachedThreads(os); |
| 133 | } |
| 134 | |
Ian Rogers | cfaa455 | 2012-11-26 21:00:08 -0800 | [diff] [blame] | 135 | static void DumpUnattachedThread(std::ostream& os, pid_t tid) NO_THREAD_SAFETY_ANALYSIS { |
Mathieu Chartier | 2cebb24 | 2015-04-21 16:50:40 -0700 | [diff] [blame] | 136 | // TODO: No thread safety analysis as DumpState with a null thread won't access fields, should |
Ian Rogers | cfaa455 | 2012-11-26 21:00:08 -0800 | [diff] [blame] | 137 | // refactor DumpState to avoid skipping analysis. |
Mathieu Chartier | 2cebb24 | 2015-04-21 16:50:40 -0700 | [diff] [blame] | 138 | Thread::DumpState(os, nullptr, tid); |
Elliott Hughes | abbe07d | 2012-06-05 17:42:23 -0700 | [diff] [blame] | 139 | DumpKernelStack(os, tid, " kernel: ", false); |
Brian Carlstrom | ed8b723 | 2012-06-27 17:54:47 -0700 | [diff] [blame] | 140 | // TODO: Reenable this when the native code in system_server can handle it. |
| 141 | // Currently "adb shell kill -3 `pid system_server`" will cause it to exit. |
| 142 | if (false) { |
Christopher Ferris | 6cff48f | 2014-01-26 21:36:13 -0800 | [diff] [blame] | 143 | DumpNativeStack(os, tid, nullptr, " native: "); |
Brian Carlstrom | ed8b723 | 2012-06-27 17:54:47 -0700 | [diff] [blame] | 144 | } |
Elliott Hughes | abbe07d | 2012-06-05 17:42:23 -0700 | [diff] [blame] | 145 | os << "\n"; |
| 146 | } |
| 147 | |
| 148 | void ThreadList::DumpUnattachedThreads(std::ostream& os) { |
| 149 | DIR* d = opendir("/proc/self/task"); |
| 150 | if (!d) { |
| 151 | return; |
| 152 | } |
| 153 | |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 154 | Thread* self = Thread::Current(); |
Elliott Hughes | 4696b5b | 2012-10-30 10:35:10 -0700 | [diff] [blame] | 155 | dirent* e; |
Mathieu Chartier | 2cebb24 | 2015-04-21 16:50:40 -0700 | [diff] [blame] | 156 | while ((e = readdir(d)) != nullptr) { |
Elliott Hughes | abbe07d | 2012-06-05 17:42:23 -0700 | [diff] [blame] | 157 | char* end; |
Elliott Hughes | 4696b5b | 2012-10-30 10:35:10 -0700 | [diff] [blame] | 158 | pid_t tid = strtol(e->d_name, &end, 10); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 159 | if (!*end) { |
| 160 | bool contains; |
| 161 | { |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 162 | MutexLock mu(self, *Locks::thread_list_lock_); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 163 | contains = Contains(tid); |
| 164 | } |
| 165 | if (!contains) { |
| 166 | DumpUnattachedThread(os, tid); |
| 167 | } |
Elliott Hughes | abbe07d | 2012-06-05 17:42:23 -0700 | [diff] [blame] | 168 | } |
| 169 | } |
| 170 | closedir(d); |
Elliott Hughes | ff73806 | 2012-02-03 15:00:42 -0800 | [diff] [blame] | 171 | } |
| 172 | |
Andreas Gampe | 4a3d19b | 2015-01-09 17:54:51 -0800 | [diff] [blame] | 173 | // Dump checkpoint timeout in milliseconds. Larger amount on the host, as dumping will invoke |
| 174 | // addr2line when available. |
Andreas Gampe | 1e4b0ca | 2015-01-14 09:06:32 -0800 | [diff] [blame] | 175 | static constexpr uint32_t kDumpWaitTimeout = kIsTargetBuild ? 10000 : 20000; |
Andreas Gampe | 4a3d19b | 2015-01-09 17:54:51 -0800 | [diff] [blame] | 176 | |
Ian Rogers | 7b078e8 | 2014-09-10 14:44:24 -0700 | [diff] [blame] | 177 | // A closure used by Thread::Dump. |
| 178 | class DumpCheckpoint FINAL : public Closure { |
| 179 | public: |
Christopher Ferris | 6cff48f | 2014-01-26 21:36:13 -0800 | [diff] [blame] | 180 | explicit DumpCheckpoint(std::ostream* os) |
| 181 | : os_(os), barrier_(0), backtrace_map_(BacktraceMap::Create(GetTid())) {} |
Ian Rogers | 7b078e8 | 2014-09-10 14:44:24 -0700 | [diff] [blame] | 182 | |
| 183 | void Run(Thread* thread) OVERRIDE { |
| 184 | // Note thread and self may not be equal if thread was already suspended at the point of the |
| 185 | // request. |
| 186 | Thread* self = Thread::Current(); |
| 187 | std::ostringstream local_os; |
| 188 | { |
| 189 | ScopedObjectAccess soa(self); |
Christopher Ferris | 6cff48f | 2014-01-26 21:36:13 -0800 | [diff] [blame] | 190 | thread->Dump(local_os, backtrace_map_.get()); |
Ian Rogers | 7b078e8 | 2014-09-10 14:44:24 -0700 | [diff] [blame] | 191 | } |
| 192 | local_os << "\n"; |
| 193 | { |
| 194 | // Use the logging lock to ensure serialization when writing to the common ostream. |
| 195 | MutexLock mu(self, *Locks::logging_lock_); |
| 196 | *os_ << local_os.str(); |
| 197 | } |
Mathieu Chartier | 10d2508 | 2015-10-28 18:36:09 -0700 | [diff] [blame] | 198 | barrier_.Pass(self); |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 199 | } |
Ian Rogers | 7b078e8 | 2014-09-10 14:44:24 -0700 | [diff] [blame] | 200 | |
| 201 | void WaitForThreadsToRunThroughCheckpoint(size_t threads_running_checkpoint) { |
| 202 | Thread* self = Thread::Current(); |
| 203 | ScopedThreadStateChange tsc(self, kWaitingForCheckPointsToRun); |
Andreas Gampe | 1e4b0ca | 2015-01-14 09:06:32 -0800 | [diff] [blame] | 204 | bool timed_out = barrier_.Increment(self, threads_running_checkpoint, kDumpWaitTimeout); |
Ian Rogers | 2156ff1 | 2014-09-13 19:20:54 -0700 | [diff] [blame] | 205 | if (timed_out) { |
Nicolas Geoffray | db97871 | 2014-12-09 13:33:38 +0000 | [diff] [blame] | 206 | // Avoid a recursive abort. |
| 207 | LOG((kIsDebugBuild && (gAborting == 0)) ? FATAL : ERROR) |
| 208 | << "Unexpected time out during dump checkpoint."; |
Ian Rogers | 2156ff1 | 2014-09-13 19:20:54 -0700 | [diff] [blame] | 209 | } |
Ian Rogers | 7b078e8 | 2014-09-10 14:44:24 -0700 | [diff] [blame] | 210 | } |
| 211 | |
| 212 | private: |
| 213 | // The common stream that will accumulate all the dumps. |
| 214 | std::ostream* const os_; |
| 215 | // The barrier to be passed through and for the requestor to wait upon. |
| 216 | Barrier barrier_; |
Christopher Ferris | 6cff48f | 2014-01-26 21:36:13 -0800 | [diff] [blame] | 217 | // A backtrace map, so that all threads use a shared info and don't reacquire/parse separately. |
| 218 | std::unique_ptr<BacktraceMap> backtrace_map_; |
Ian Rogers | 7b078e8 | 2014-09-10 14:44:24 -0700 | [diff] [blame] | 219 | }; |
| 220 | |
| 221 | void ThreadList::Dump(std::ostream& os) { |
| 222 | { |
| 223 | MutexLock mu(Thread::Current(), *Locks::thread_list_lock_); |
| 224 | os << "DALVIK THREADS (" << list_.size() << "):\n"; |
| 225 | } |
| 226 | DumpCheckpoint checkpoint(&os); |
| 227 | size_t threads_running_checkpoint = RunCheckpoint(&checkpoint); |
Lei Li | dd9943d | 2015-02-02 14:24:44 +0800 | [diff] [blame] | 228 | if (threads_running_checkpoint != 0) { |
| 229 | checkpoint.WaitForThreadsToRunThroughCheckpoint(threads_running_checkpoint); |
| 230 | } |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 231 | } |
| 232 | |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 233 | void ThreadList::AssertThreadsAreSuspended(Thread* self, Thread* ignore1, Thread* ignore2) { |
| 234 | MutexLock mu(self, *Locks::thread_list_lock_); |
| 235 | MutexLock mu2(self, *Locks::thread_suspend_count_lock_); |
Mathieu Chartier | 02e2511 | 2013-08-14 16:14:24 -0700 | [diff] [blame] | 236 | for (const auto& thread : list_) { |
jeffhao | 725a957 | 2012-11-13 18:20:12 -0800 | [diff] [blame] | 237 | if (thread != ignore1 && thread != ignore2) { |
Ian Rogers | 01ae580 | 2012-09-28 16:14:01 -0700 | [diff] [blame] | 238 | CHECK(thread->IsSuspended()) |
| 239 | << "\nUnsuspended thread: <<" << *thread << "\n" |
| 240 | << "self: <<" << *Thread::Current(); |
| 241 | } |
Elliott Hughes | 8d768a9 | 2011-09-14 16:35:25 -0700 | [diff] [blame] | 242 | } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 243 | } |
| 244 | |
Ian Rogers | 66aee5c | 2012-08-15 17:17:47 -0700 | [diff] [blame] | 245 | #if HAVE_TIMED_RWLOCK |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 246 | // Attempt to rectify locks so that we dump thread list with required locks before exiting. |
Andreas Gampe | 794ad76 | 2015-02-23 08:12:24 -0800 | [diff] [blame] | 247 | NO_RETURN static void UnsafeLogFatalForThreadSuspendAllTimeout() { |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 248 | Runtime* runtime = Runtime::Current(); |
| 249 | std::ostringstream ss; |
| 250 | ss << "Thread suspend timeout\n"; |
Mathieu Chartier | 5869a2c | 2014-10-08 14:26:23 -0700 | [diff] [blame] | 251 | Locks::mutator_lock_->Dump(ss); |
| 252 | ss << "\n"; |
Ian Rogers | 7b078e8 | 2014-09-10 14:44:24 -0700 | [diff] [blame] | 253 | runtime->GetThreadList()->Dump(ss); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 254 | LOG(FATAL) << ss.str(); |
Ian Rogers | 719d1a3 | 2014-03-06 12:13:39 -0800 | [diff] [blame] | 255 | exit(0); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 256 | } |
Ian Rogers | 66aee5c | 2012-08-15 17:17:47 -0700 | [diff] [blame] | 257 | #endif |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 258 | |
Mathieu Chartier | 5f51d4b | 2013-12-03 14:24:05 -0800 | [diff] [blame] | 259 | // Unlike suspending all threads where we can wait to acquire the mutator_lock_, suspending an |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 260 | // individual thread requires polling. delay_us is the requested sleep wait. If delay_us is 0 then |
| 261 | // we use sched_yield instead of calling usleep. |
| 262 | static void ThreadSuspendSleep(useconds_t delay_us) { |
| 263 | if (delay_us == 0) { |
Mathieu Chartier | 5f51d4b | 2013-12-03 14:24:05 -0800 | [diff] [blame] | 264 | sched_yield(); |
Mathieu Chartier | 5f51d4b | 2013-12-03 14:24:05 -0800 | [diff] [blame] | 265 | } else { |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 266 | usleep(delay_us); |
Mathieu Chartier | 5f51d4b | 2013-12-03 14:24:05 -0800 | [diff] [blame] | 267 | } |
| 268 | } |
| 269 | |
Mathieu Chartier | 0e4627e | 2012-10-23 16:13:36 -0700 | [diff] [blame] | 270 | size_t ThreadList::RunCheckpoint(Closure* checkpoint_function) { |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 271 | Thread* self = Thread::Current(); |
Mathieu Chartier | 6dda898 | 2014-03-06 11:11:48 -0800 | [diff] [blame] | 272 | Locks::mutator_lock_->AssertNotExclusiveHeld(self); |
| 273 | Locks::thread_list_lock_->AssertNotHeld(self); |
| 274 | Locks::thread_suspend_count_lock_->AssertNotHeld(self); |
Nicolas Geoffray | db97871 | 2014-12-09 13:33:38 +0000 | [diff] [blame] | 275 | if (kDebugLocking && gAborting == 0) { |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 276 | CHECK_NE(self->GetState(), kRunnable); |
| 277 | } |
| 278 | |
| 279 | std::vector<Thread*> suspended_count_modified_threads; |
| 280 | size_t count = 0; |
| 281 | { |
| 282 | // Call a checkpoint function for each thread, threads which are suspend get their checkpoint |
| 283 | // manually called. |
| 284 | MutexLock mu(self, *Locks::thread_list_lock_); |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 285 | MutexLock mu2(self, *Locks::thread_suspend_count_lock_); |
Mathieu Chartier | 10d2508 | 2015-10-28 18:36:09 -0700 | [diff] [blame] | 286 | count = list_.size(); |
Mathieu Chartier | 02e2511 | 2013-08-14 16:14:24 -0700 | [diff] [blame] | 287 | for (const auto& thread : list_) { |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 288 | if (thread != self) { |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 289 | while (true) { |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 290 | if (thread->RequestCheckpoint(checkpoint_function)) { |
Dave Allison | 0aded08 | 2013-11-07 13:15:11 -0800 | [diff] [blame] | 291 | // This thread will run its checkpoint some time in the near future. |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 292 | break; |
| 293 | } else { |
| 294 | // We are probably suspended, try to make sure that we stay suspended. |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 295 | // The thread switched back to runnable. |
| 296 | if (thread->GetState() == kRunnable) { |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 297 | // Spurious fail, try again. |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 298 | continue; |
| 299 | } |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 300 | thread->ModifySuspendCount(self, +1, nullptr, false); |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 301 | suspended_count_modified_threads.push_back(thread); |
| 302 | break; |
| 303 | } |
| 304 | } |
| 305 | } |
| 306 | } |
| 307 | } |
| 308 | |
| 309 | // Run the checkpoint on ourself while we wait for threads to suspend. |
| 310 | checkpoint_function->Run(self); |
| 311 | |
| 312 | // Run the checkpoint on the suspended threads. |
Mathieu Chartier | 02e2511 | 2013-08-14 16:14:24 -0700 | [diff] [blame] | 313 | for (const auto& thread : suspended_count_modified_threads) { |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 314 | if (!thread->IsSuspended()) { |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 315 | if (ATRACE_ENABLED()) { |
| 316 | std::ostringstream oss; |
| 317 | thread->ShortDump(oss); |
| 318 | ATRACE_BEGIN((std::string("Waiting for suspension of thread ") + oss.str()).c_str()); |
| 319 | } |
| 320 | // Busy wait until the thread is suspended. |
| 321 | const uint64_t start_time = NanoTime(); |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 322 | do { |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 323 | ThreadSuspendSleep(kThreadSuspendInitialSleepUs); |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 324 | } while (!thread->IsSuspended()); |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 325 | const uint64_t total_delay = NanoTime() - start_time; |
Mathieu Chartier | 5f51d4b | 2013-12-03 14:24:05 -0800 | [diff] [blame] | 326 | // Shouldn't need to wait for longer than 1000 microseconds. |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 327 | constexpr uint64_t kLongWaitThreshold = MsToNs(1); |
| 328 | ATRACE_END(); |
| 329 | if (UNLIKELY(total_delay > kLongWaitThreshold)) { |
| 330 | LOG(WARNING) << "Long wait of " << PrettyDuration(total_delay) << " for " |
| 331 | << *thread << " suspension!"; |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 332 | } |
| 333 | } |
| 334 | // We know for sure that the thread is suspended at this point. |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 335 | checkpoint_function->Run(thread); |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 336 | { |
| 337 | MutexLock mu2(self, *Locks::thread_suspend_count_lock_); |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 338 | thread->ModifySuspendCount(self, -1, nullptr, false); |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 339 | } |
| 340 | } |
| 341 | |
Mathieu Chartier | 664bebf | 2012-11-12 16:54:11 -0800 | [diff] [blame] | 342 | { |
| 343 | // Imitate ResumeAll, threads may be waiting on Thread::resume_cond_ since we raised their |
| 344 | // suspend count. Now the suspend_count_ is lowered so we must do the broadcast. |
| 345 | MutexLock mu2(self, *Locks::thread_suspend_count_lock_); |
| 346 | Thread::resume_cond_->Broadcast(self); |
| 347 | } |
| 348 | |
Lei Li | dd9943d | 2015-02-02 14:24:44 +0800 | [diff] [blame] | 349 | return count; |
Mathieu Chartier | 858f1c5 | 2012-10-17 17:45:55 -0700 | [diff] [blame] | 350 | } |
| 351 | |
Dave Allison | 39c3bfb | 2014-01-28 18:33:52 -0800 | [diff] [blame] | 352 | // Request that a checkpoint function be run on all active (non-suspended) |
| 353 | // threads. Returns the number of successful requests. |
| 354 | size_t ThreadList::RunCheckpointOnRunnableThreads(Closure* checkpoint_function) { |
| 355 | Thread* self = Thread::Current(); |
Ian Rogers | 7b078e8 | 2014-09-10 14:44:24 -0700 | [diff] [blame] | 356 | Locks::mutator_lock_->AssertNotExclusiveHeld(self); |
| 357 | Locks::thread_list_lock_->AssertNotHeld(self); |
| 358 | Locks::thread_suspend_count_lock_->AssertNotHeld(self); |
| 359 | CHECK_NE(self->GetState(), kRunnable); |
Dave Allison | 39c3bfb | 2014-01-28 18:33:52 -0800 | [diff] [blame] | 360 | |
| 361 | size_t count = 0; |
| 362 | { |
| 363 | // Call a checkpoint function for each non-suspended thread. |
| 364 | MutexLock mu(self, *Locks::thread_list_lock_); |
| 365 | MutexLock mu2(self, *Locks::thread_suspend_count_lock_); |
| 366 | for (const auto& thread : list_) { |
| 367 | if (thread != self) { |
| 368 | if (thread->RequestCheckpoint(checkpoint_function)) { |
| 369 | // This thread will run its checkpoint some time in the near future. |
| 370 | count++; |
| 371 | } |
| 372 | } |
| 373 | } |
| 374 | } |
| 375 | |
| 376 | // Return the number of threads that will run the checkpoint function. |
| 377 | return count; |
| 378 | } |
| 379 | |
Hiroshi Yamauchi | 2cd334a | 2015-01-09 14:03:35 -0800 | [diff] [blame] | 380 | // A checkpoint/suspend-all hybrid to switch thread roots from |
| 381 | // from-space to to-space refs. Used to synchronize threads at a point |
| 382 | // to mark the initiation of marking while maintaining the to-space |
| 383 | // invariant. |
| 384 | size_t ThreadList::FlipThreadRoots(Closure* thread_flip_visitor, Closure* flip_callback, |
| 385 | gc::collector::GarbageCollector* collector) { |
| 386 | TimingLogger::ScopedTiming split("ThreadListFlip", collector->GetTimings()); |
| 387 | const uint64_t start_time = NanoTime(); |
| 388 | Thread* self = Thread::Current(); |
| 389 | Locks::mutator_lock_->AssertNotHeld(self); |
| 390 | Locks::thread_list_lock_->AssertNotHeld(self); |
| 391 | Locks::thread_suspend_count_lock_->AssertNotHeld(self); |
| 392 | CHECK_NE(self->GetState(), kRunnable); |
| 393 | |
Mathieu Chartier | b19ccb1 | 2015-07-15 10:24:16 -0700 | [diff] [blame] | 394 | SuspendAllInternal(self, self, nullptr); |
Hiroshi Yamauchi | 2cd334a | 2015-01-09 14:03:35 -0800 | [diff] [blame] | 395 | |
| 396 | // Run the flip callback for the collector. |
| 397 | Locks::mutator_lock_->ExclusiveLock(self); |
| 398 | flip_callback->Run(self); |
| 399 | Locks::mutator_lock_->ExclusiveUnlock(self); |
| 400 | collector->RegisterPause(NanoTime() - start_time); |
| 401 | |
| 402 | // Resume runnable threads. |
Mathieu Chartier | b19ccb1 | 2015-07-15 10:24:16 -0700 | [diff] [blame] | 403 | std::vector<Thread*> runnable_threads; |
| 404 | std::vector<Thread*> other_threads; |
Hiroshi Yamauchi | 2cd334a | 2015-01-09 14:03:35 -0800 | [diff] [blame] | 405 | { |
| 406 | MutexLock mu(self, *Locks::thread_list_lock_); |
| 407 | MutexLock mu2(self, *Locks::thread_suspend_count_lock_); |
| 408 | --suspend_all_count_; |
| 409 | for (const auto& thread : list_) { |
| 410 | if (thread == self) { |
| 411 | continue; |
| 412 | } |
| 413 | // Set the flip function for both runnable and suspended threads |
| 414 | // because Thread::DumpState/DumpJavaStack() (invoked by a |
| 415 | // checkpoint) may cause the flip function to be run for a |
| 416 | // runnable/suspended thread before a runnable threads runs it |
| 417 | // for itself or we run it for a suspended thread below. |
| 418 | thread->SetFlipFunction(thread_flip_visitor); |
| 419 | if (thread->IsSuspendedAtSuspendCheck()) { |
| 420 | // The thread will resume right after the broadcast. |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 421 | thread->ModifySuspendCount(self, -1, nullptr, false); |
Hiroshi Yamauchi | 2cd334a | 2015-01-09 14:03:35 -0800 | [diff] [blame] | 422 | runnable_threads.push_back(thread); |
| 423 | } else { |
| 424 | other_threads.push_back(thread); |
| 425 | } |
| 426 | } |
| 427 | Thread::resume_cond_->Broadcast(self); |
| 428 | } |
| 429 | |
| 430 | // Run the closure on the other threads and let them resume. |
| 431 | { |
| 432 | ReaderMutexLock mu(self, *Locks::mutator_lock_); |
| 433 | for (const auto& thread : other_threads) { |
| 434 | Closure* flip_func = thread->GetFlipFunction(); |
| 435 | if (flip_func != nullptr) { |
| 436 | flip_func->Run(thread); |
| 437 | } |
| 438 | } |
| 439 | // Run it for self. |
| 440 | thread_flip_visitor->Run(self); |
| 441 | } |
| 442 | |
| 443 | // Resume other threads. |
| 444 | { |
| 445 | MutexLock mu2(self, *Locks::thread_suspend_count_lock_); |
| 446 | for (const auto& thread : other_threads) { |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 447 | thread->ModifySuspendCount(self, -1, nullptr, false); |
Hiroshi Yamauchi | 2cd334a | 2015-01-09 14:03:35 -0800 | [diff] [blame] | 448 | } |
| 449 | Thread::resume_cond_->Broadcast(self); |
| 450 | } |
| 451 | |
| 452 | return runnable_threads.size() + other_threads.size() + 1; // +1 for self. |
| 453 | } |
| 454 | |
Mathieu Chartier | bf44d42 | 2015-06-02 11:42:18 -0700 | [diff] [blame] | 455 | void ThreadList::SuspendAll(const char* cause, bool long_suspend) { |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 456 | Thread* self = Thread::Current(); |
| 457 | |
Jeff Hao | c5d824a | 2014-07-28 18:35:38 -0700 | [diff] [blame] | 458 | if (self != nullptr) { |
Mathieu Chartier | bf9fc58 | 2015-03-13 17:21:25 -0700 | [diff] [blame] | 459 | VLOG(threads) << *self << " SuspendAll for " << cause << " starting..."; |
Jeff Hao | c5d824a | 2014-07-28 18:35:38 -0700 | [diff] [blame] | 460 | } else { |
Mathieu Chartier | bf9fc58 | 2015-03-13 17:21:25 -0700 | [diff] [blame] | 461 | VLOG(threads) << "Thread[null] SuspendAll for " << cause << " starting..."; |
Jeff Hao | c5d824a | 2014-07-28 18:35:38 -0700 | [diff] [blame] | 462 | } |
Mathieu Chartier | 6f365cc | 2014-04-23 12:42:27 -0700 | [diff] [blame] | 463 | ATRACE_BEGIN("Suspending mutator threads"); |
Mathieu Chartier | 70a596d | 2014-12-17 14:56:47 -0800 | [diff] [blame] | 464 | const uint64_t start_time = NanoTime(); |
Mathieu Chartier | 6f365cc | 2014-04-23 12:42:27 -0700 | [diff] [blame] | 465 | |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 466 | SuspendAllInternal(self, self); |
| 467 | // All threads are known to have suspended (but a thread may still own the mutator lock) |
| 468 | // Make sure this thread grabs exclusive access to the mutator lock and its protected data. |
Ian Rogers | 66aee5c | 2012-08-15 17:17:47 -0700 | [diff] [blame] | 469 | #if HAVE_TIMED_RWLOCK |
Mathieu Chartier | bf44d42 | 2015-06-02 11:42:18 -0700 | [diff] [blame] | 470 | while (true) { |
| 471 | if (Locks::mutator_lock_->ExclusiveLockWithTimeout(self, kThreadSuspendTimeoutMs, 0)) { |
| 472 | break; |
| 473 | } else if (!long_suspend_) { |
| 474 | // Reading long_suspend without the mutator lock is slightly racy, in some rare cases, this |
| 475 | // could result in a thread suspend timeout. |
| 476 | // Timeout if we wait more than kThreadSuspendTimeoutMs seconds. |
| 477 | UnsafeLogFatalForThreadSuspendAllTimeout(); |
| 478 | } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 479 | } |
Ian Rogers | 66aee5c | 2012-08-15 17:17:47 -0700 | [diff] [blame] | 480 | #else |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 481 | Locks::mutator_lock_->ExclusiveLock(self); |
Ian Rogers | 66aee5c | 2012-08-15 17:17:47 -0700 | [diff] [blame] | 482 | #endif |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 483 | |
Mathieu Chartier | bf44d42 | 2015-06-02 11:42:18 -0700 | [diff] [blame] | 484 | long_suspend_ = long_suspend; |
| 485 | |
Mathieu Chartier | 70a596d | 2014-12-17 14:56:47 -0800 | [diff] [blame] | 486 | const uint64_t end_time = NanoTime(); |
| 487 | const uint64_t suspend_time = end_time - start_time; |
| 488 | suspend_all_historam_.AdjustAndAddValue(suspend_time); |
| 489 | if (suspend_time > kLongThreadSuspendThreshold) { |
| 490 | LOG(WARNING) << "Suspending all threads took: " << PrettyDuration(suspend_time); |
Mathieu Chartier | 251755c | 2014-07-15 18:10:25 -0700 | [diff] [blame] | 491 | } |
| 492 | |
Mathieu Chartier | 6dda898 | 2014-03-06 11:11:48 -0800 | [diff] [blame] | 493 | if (kDebugLocking) { |
| 494 | // Debug check that all threads are suspended. |
| 495 | AssertThreadsAreSuspended(self, self); |
| 496 | } |
Elliott Hughes | 8d768a9 | 2011-09-14 16:35:25 -0700 | [diff] [blame] | 497 | |
Mathieu Chartier | 6f365cc | 2014-04-23 12:42:27 -0700 | [diff] [blame] | 498 | ATRACE_END(); |
Mathieu Chartier | bf9fc58 | 2015-03-13 17:21:25 -0700 | [diff] [blame] | 499 | ATRACE_BEGIN((std::string("Mutator threads suspended for ") + cause).c_str()); |
Mathieu Chartier | 6f365cc | 2014-04-23 12:42:27 -0700 | [diff] [blame] | 500 | |
Jeff Hao | c5d824a | 2014-07-28 18:35:38 -0700 | [diff] [blame] | 501 | if (self != nullptr) { |
| 502 | VLOG(threads) << *self << " SuspendAll complete"; |
| 503 | } else { |
| 504 | VLOG(threads) << "Thread[null] SuspendAll complete"; |
| 505 | } |
Elliott Hughes | 8d768a9 | 2011-09-14 16:35:25 -0700 | [diff] [blame] | 506 | } |
| 507 | |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 508 | // Ensures all threads running Java suspend and that those not running Java don't start. |
| 509 | // Debugger thread might be set to kRunnable for a short period of time after the |
| 510 | // SuspendAllInternal. This is safe because it will be set back to suspended state before |
| 511 | // the SuspendAll returns. |
| 512 | void ThreadList::SuspendAllInternal(Thread* self, Thread* ignore1, Thread* ignore2, |
| 513 | bool debug_suspend) { |
| 514 | Locks::mutator_lock_->AssertNotExclusiveHeld(self); |
| 515 | Locks::thread_list_lock_->AssertNotHeld(self); |
| 516 | Locks::thread_suspend_count_lock_->AssertNotHeld(self); |
| 517 | if (kDebugLocking && self != nullptr) { |
| 518 | CHECK_NE(self->GetState(), kRunnable); |
| 519 | } |
| 520 | |
| 521 | // First request that all threads suspend, then wait for them to suspend before |
| 522 | // returning. This suspension scheme also relies on other behaviour: |
| 523 | // 1. Threads cannot be deleted while they are suspended or have a suspend- |
| 524 | // request flag set - (see Unregister() below). |
| 525 | // 2. When threads are created, they are created in a suspended state (actually |
| 526 | // kNative) and will never begin executing Java code without first checking |
| 527 | // the suspend-request flag. |
| 528 | |
| 529 | // The atomic counter for number of threads that need to pass the barrier. |
| 530 | AtomicInteger pending_threads; |
| 531 | uint32_t num_ignored = 0; |
| 532 | if (ignore1 != nullptr) { |
| 533 | ++num_ignored; |
| 534 | } |
| 535 | if (ignore2 != nullptr && ignore1 != ignore2) { |
| 536 | ++num_ignored; |
| 537 | } |
| 538 | { |
| 539 | MutexLock mu(self, *Locks::thread_list_lock_); |
| 540 | MutexLock mu2(self, *Locks::thread_suspend_count_lock_); |
| 541 | // Update global suspend all state for attaching threads. |
| 542 | ++suspend_all_count_; |
| 543 | if (debug_suspend) |
| 544 | ++debug_suspend_all_count_; |
| 545 | pending_threads.StoreRelaxed(list_.size() - num_ignored); |
| 546 | // Increment everybody's suspend count (except those that should be ignored). |
| 547 | for (const auto& thread : list_) { |
| 548 | if (thread == ignore1 || thread == ignore2) { |
| 549 | continue; |
| 550 | } |
| 551 | VLOG(threads) << "requesting thread suspend: " << *thread; |
| 552 | while (true) { |
| 553 | if (LIKELY(thread->ModifySuspendCount(self, +1, &pending_threads, debug_suspend))) { |
| 554 | break; |
| 555 | } else { |
| 556 | // Failure means the list of active_suspend_barriers is full, we should release the |
| 557 | // thread_suspend_count_lock_ (to avoid deadlock) and wait till the target thread has |
| 558 | // executed Thread::PassActiveSuspendBarriers(). Note that we could not simply wait for |
| 559 | // the thread to change to a suspended state, because it might need to run checkpoint |
| 560 | // function before the state change, which also needs thread_suspend_count_lock_. |
| 561 | |
| 562 | // This is very unlikely to happen since more than kMaxSuspendBarriers threads need to |
| 563 | // execute SuspendAllInternal() simultaneously, and target thread stays in kRunnable |
| 564 | // in the mean time. |
| 565 | Locks::thread_suspend_count_lock_->ExclusiveUnlock(self); |
| 566 | NanoSleep(100000); |
| 567 | Locks::thread_suspend_count_lock_->ExclusiveLock(self); |
| 568 | } |
| 569 | } |
| 570 | |
| 571 | // Must install the pending_threads counter first, then check thread->IsSuspend() and clear |
| 572 | // the counter. Otherwise there's a race with Thread::TransitionFromRunnableToSuspended() |
| 573 | // that can lead a thread to miss a call to PassActiveSuspendBarriers(). |
| 574 | if (thread->IsSuspended()) { |
| 575 | // Only clear the counter for the current thread. |
| 576 | thread->ClearSuspendBarrier(&pending_threads); |
| 577 | pending_threads.FetchAndSubSequentiallyConsistent(1); |
| 578 | } |
| 579 | } |
| 580 | } |
| 581 | |
| 582 | // Wait for the barrier to be passed by all runnable threads. This wait |
| 583 | // is done with a timeout so that we can detect problems. |
Mathieu Chartier | 19af117 | 2015-07-14 10:05:45 -0700 | [diff] [blame] | 584 | #if ART_USE_FUTEXES |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 585 | timespec wait_timeout; |
| 586 | InitTimeSpec(true, CLOCK_MONOTONIC, 10000, 0, &wait_timeout); |
Mathieu Chartier | 19af117 | 2015-07-14 10:05:45 -0700 | [diff] [blame] | 587 | #endif |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 588 | while (true) { |
| 589 | int32_t cur_val = pending_threads.LoadRelaxed(); |
| 590 | if (LIKELY(cur_val > 0)) { |
| 591 | #if ART_USE_FUTEXES |
| 592 | if (futex(pending_threads.Address(), FUTEX_WAIT, cur_val, &wait_timeout, nullptr, 0) != 0) { |
| 593 | // EAGAIN and EINTR both indicate a spurious failure, try again from the beginning. |
| 594 | if ((errno != EAGAIN) && (errno != EINTR)) { |
| 595 | if (errno == ETIMEDOUT) { |
| 596 | LOG(kIsDebugBuild ? FATAL : ERROR) << "Unexpected time out during suspend all."; |
| 597 | } else { |
| 598 | PLOG(FATAL) << "futex wait failed for SuspendAllInternal()"; |
| 599 | } |
| 600 | } |
| 601 | } else { |
| 602 | cur_val = pending_threads.LoadRelaxed(); |
| 603 | CHECK_EQ(cur_val, 0); |
| 604 | break; |
| 605 | } |
| 606 | #else |
| 607 | // Spin wait. This is likely to be slow, but on most architecture ART_USE_FUTEXES is set. |
| 608 | #endif |
| 609 | } else { |
| 610 | CHECK_EQ(cur_val, 0); |
| 611 | break; |
| 612 | } |
| 613 | } |
| 614 | } |
| 615 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 616 | void ThreadList::ResumeAll() { |
| 617 | Thread* self = Thread::Current(); |
| 618 | |
Jeff Hao | c5d824a | 2014-07-28 18:35:38 -0700 | [diff] [blame] | 619 | if (self != nullptr) { |
| 620 | VLOG(threads) << *self << " ResumeAll starting"; |
| 621 | } else { |
| 622 | VLOG(threads) << "Thread[null] ResumeAll starting"; |
| 623 | } |
Ian Rogers | 01ae580 | 2012-09-28 16:14:01 -0700 | [diff] [blame] | 624 | |
Mathieu Chartier | 6f365cc | 2014-04-23 12:42:27 -0700 | [diff] [blame] | 625 | ATRACE_END(); |
| 626 | ATRACE_BEGIN("Resuming mutator threads"); |
| 627 | |
Mathieu Chartier | 6dda898 | 2014-03-06 11:11:48 -0800 | [diff] [blame] | 628 | if (kDebugLocking) { |
| 629 | // Debug check that all threads are suspended. |
| 630 | AssertThreadsAreSuspended(self, self); |
| 631 | } |
Ian Rogers | 01ae580 | 2012-09-28 16:14:01 -0700 | [diff] [blame] | 632 | |
Mathieu Chartier | bf44d42 | 2015-06-02 11:42:18 -0700 | [diff] [blame] | 633 | long_suspend_ = false; |
| 634 | |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 635 | Locks::mutator_lock_->ExclusiveUnlock(self); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 636 | { |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 637 | MutexLock mu(self, *Locks::thread_list_lock_); |
| 638 | MutexLock mu2(self, *Locks::thread_suspend_count_lock_); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 639 | // Update global suspend all state for attaching threads. |
| 640 | --suspend_all_count_; |
| 641 | // Decrement the suspend counts for all threads. |
Mathieu Chartier | 02e2511 | 2013-08-14 16:14:24 -0700 | [diff] [blame] | 642 | for (const auto& thread : list_) { |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 643 | if (thread == self) { |
| 644 | continue; |
| 645 | } |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 646 | thread->ModifySuspendCount(self, -1, nullptr, false); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 647 | } |
| 648 | |
| 649 | // Broadcast a notification to all suspended threads, some or all of |
| 650 | // which may choose to wake up. No need to wait for them. |
Jeff Hao | c5d824a | 2014-07-28 18:35:38 -0700 | [diff] [blame] | 651 | if (self != nullptr) { |
| 652 | VLOG(threads) << *self << " ResumeAll waking others"; |
| 653 | } else { |
| 654 | VLOG(threads) << "Thread[null] ResumeAll waking others"; |
| 655 | } |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 656 | Thread::resume_cond_->Broadcast(self); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 657 | } |
Mathieu Chartier | 6f365cc | 2014-04-23 12:42:27 -0700 | [diff] [blame] | 658 | ATRACE_END(); |
Jeff Hao | c5d824a | 2014-07-28 18:35:38 -0700 | [diff] [blame] | 659 | |
| 660 | if (self != nullptr) { |
| 661 | VLOG(threads) << *self << " ResumeAll complete"; |
| 662 | } else { |
| 663 | VLOG(threads) << "Thread[null] ResumeAll complete"; |
| 664 | } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 665 | } |
| 666 | |
| 667 | void ThreadList::Resume(Thread* thread, bool for_debugger) { |
Mathieu Chartier | f0dc8b5 | 2014-12-17 10:13:30 -0800 | [diff] [blame] | 668 | // This assumes there was an ATRACE_BEGIN when we suspended the thread. |
| 669 | ATRACE_END(); |
| 670 | |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 671 | Thread* self = Thread::Current(); |
| 672 | DCHECK_NE(thread, self); |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 673 | VLOG(threads) << "Resume(" << reinterpret_cast<void*>(thread) << ") starting..." |
| 674 | << (for_debugger ? " (debugger)" : ""); |
Elliott Hughes | 01158d7 | 2011-09-19 19:47:10 -0700 | [diff] [blame] | 675 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 676 | { |
| 677 | // To check Contains. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 678 | MutexLock mu(self, *Locks::thread_list_lock_); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 679 | // To check IsSuspended. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 680 | MutexLock mu2(self, *Locks::thread_suspend_count_lock_); |
| 681 | DCHECK(thread->IsSuspended()); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 682 | if (!Contains(thread)) { |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 683 | // We only expect threads within the thread-list to have been suspended otherwise we can't |
| 684 | // stop such threads from delete-ing themselves. |
| 685 | LOG(ERROR) << "Resume(" << reinterpret_cast<void*>(thread) |
| 686 | << ") thread not within thread list"; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 687 | return; |
| 688 | } |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 689 | thread->ModifySuspendCount(self, -1, nullptr, for_debugger); |
Elliott Hughes | 01158d7 | 2011-09-19 19:47:10 -0700 | [diff] [blame] | 690 | } |
| 691 | |
| 692 | { |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 693 | VLOG(threads) << "Resume(" << reinterpret_cast<void*>(thread) << ") waking others"; |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 694 | MutexLock mu(self, *Locks::thread_suspend_count_lock_); |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 695 | Thread::resume_cond_->Broadcast(self); |
Elliott Hughes | 01158d7 | 2011-09-19 19:47:10 -0700 | [diff] [blame] | 696 | } |
| 697 | |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 698 | VLOG(threads) << "Resume(" << reinterpret_cast<void*>(thread) << ") complete"; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 699 | } |
Elliott Hughes | 01158d7 | 2011-09-19 19:47:10 -0700 | [diff] [blame] | 700 | |
Ian Rogers | c7dd295 | 2014-10-21 23:31:19 -0700 | [diff] [blame] | 701 | static void ThreadSuspendByPeerWarning(Thread* self, LogSeverity severity, const char* message, |
| 702 | jobject peer) { |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 703 | JNIEnvExt* env = self->GetJniEnv(); |
| 704 | ScopedLocalRef<jstring> |
Mathieu Chartier | bf44d42 | 2015-06-02 11:42:18 -0700 | [diff] [blame] | 705 | scoped_name_string(env, (jstring)env->GetObjectField( |
| 706 | peer, WellKnownClasses::java_lang_Thread_name)); |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 707 | ScopedUtfChars scoped_name_chars(env, scoped_name_string.get()); |
Mathieu Chartier | 2cebb24 | 2015-04-21 16:50:40 -0700 | [diff] [blame] | 708 | if (scoped_name_chars.c_str() == nullptr) { |
Ian Rogers | c7dd295 | 2014-10-21 23:31:19 -0700 | [diff] [blame] | 709 | LOG(severity) << message << ": " << peer; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 710 | env->ExceptionClear(); |
| 711 | } else { |
Ian Rogers | c7dd295 | 2014-10-21 23:31:19 -0700 | [diff] [blame] | 712 | LOG(severity) << message << ": " << peer << ":" << scoped_name_chars.c_str(); |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 713 | } |
| 714 | } |
| 715 | |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 716 | Thread* ThreadList::SuspendThreadByPeer(jobject peer, bool request_suspension, |
| 717 | bool debug_suspension, bool* timed_out) { |
Mathieu Chartier | 3a958aa | 2015-02-04 12:52:34 -0800 | [diff] [blame] | 718 | const uint64_t start_time = NanoTime(); |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 719 | useconds_t sleep_us = kThreadSuspendInitialSleepUs; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 720 | *timed_out = false; |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 721 | Thread* const self = Thread::Current(); |
Mathieu Chartier | 82a800d | 2014-12-15 15:59:49 -0800 | [diff] [blame] | 722 | Thread* suspended_thread = nullptr; |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 723 | VLOG(threads) << "SuspendThreadByPeer starting"; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 724 | while (true) { |
| 725 | Thread* thread; |
| 726 | { |
Ian Rogers | f3d874c | 2014-07-17 18:52:42 -0700 | [diff] [blame] | 727 | // Note: this will transition to runnable and potentially suspend. We ensure only one thread |
| 728 | // is requesting another suspend, to avoid deadlock, by requiring this function be called |
| 729 | // holding Locks::thread_list_suspend_thread_lock_. Its important this thread suspend rather |
| 730 | // than request thread suspension, to avoid potential cycles in threads requesting each other |
| 731 | // suspend. |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 732 | ScopedObjectAccess soa(self); |
Andreas Gampe | 277ccbd | 2014-11-03 21:36:10 -0800 | [diff] [blame] | 733 | MutexLock thread_list_mu(self, *Locks::thread_list_lock_); |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 734 | thread = Thread::FromManagedThread(soa, peer); |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 735 | if (thread == nullptr) { |
Mathieu Chartier | 82a800d | 2014-12-15 15:59:49 -0800 | [diff] [blame] | 736 | if (suspended_thread != nullptr) { |
| 737 | MutexLock suspend_count_mu(self, *Locks::thread_suspend_count_lock_); |
| 738 | // If we incremented the suspend count but the thread reset its peer, we need to |
| 739 | // re-decrement it since it is shutting down and may deadlock the runtime in |
| 740 | // ThreadList::WaitForOtherNonDaemonThreadsToExit. |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 741 | suspended_thread->ModifySuspendCount(soa.Self(), -1, nullptr, debug_suspension); |
Mathieu Chartier | 82a800d | 2014-12-15 15:59:49 -0800 | [diff] [blame] | 742 | } |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 743 | ThreadSuspendByPeerWarning(self, WARNING, "No such thread for suspend", peer); |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 744 | return nullptr; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 745 | } |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 746 | if (!Contains(thread)) { |
Mathieu Chartier | 82a800d | 2014-12-15 15:59:49 -0800 | [diff] [blame] | 747 | CHECK(suspended_thread == nullptr); |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 748 | VLOG(threads) << "SuspendThreadByPeer failed for unattached thread: " |
| 749 | << reinterpret_cast<void*>(thread); |
| 750 | return nullptr; |
| 751 | } |
| 752 | VLOG(threads) << "SuspendThreadByPeer found thread: " << *thread; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 753 | { |
Andreas Gampe | 277ccbd | 2014-11-03 21:36:10 -0800 | [diff] [blame] | 754 | MutexLock suspend_count_mu(self, *Locks::thread_suspend_count_lock_); |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 755 | if (request_suspension) { |
Ian Rogers | 4ad5cd3 | 2014-11-11 23:08:07 -0800 | [diff] [blame] | 756 | if (self->GetSuspendCount() > 0) { |
| 757 | // We hold the suspend count lock but another thread is trying to suspend us. Its not |
| 758 | // safe to try to suspend another thread in case we get a cycle. Start the loop again |
| 759 | // which will allow this thread to be suspended. |
| 760 | continue; |
| 761 | } |
Mathieu Chartier | 82a800d | 2014-12-15 15:59:49 -0800 | [diff] [blame] | 762 | CHECK(suspended_thread == nullptr); |
| 763 | suspended_thread = thread; |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 764 | suspended_thread->ModifySuspendCount(self, +1, nullptr, debug_suspension); |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 765 | request_suspension = false; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 766 | } else { |
| 767 | // If the caller isn't requesting suspension, a suspension should have already occurred. |
| 768 | CHECK_GT(thread->GetSuspendCount(), 0); |
| 769 | } |
| 770 | // IsSuspended on the current thread will fail as the current thread is changed into |
| 771 | // Runnable above. As the suspend count is now raised if this is the current thread |
| 772 | // it will self suspend on transition to Runnable, making it hard to work with. It's simpler |
| 773 | // to just explicitly handle the current thread in the callers to this code. |
| 774 | CHECK_NE(thread, self) << "Attempt to suspend the current thread for the debugger"; |
| 775 | // If thread is suspended (perhaps it was already not Runnable but didn't have a suspend |
| 776 | // count, or else we've waited and it has self suspended) or is the current thread, we're |
| 777 | // done. |
| 778 | if (thread->IsSuspended()) { |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 779 | VLOG(threads) << "SuspendThreadByPeer thread suspended: " << *thread; |
Mathieu Chartier | f0dc8b5 | 2014-12-17 10:13:30 -0800 | [diff] [blame] | 780 | if (ATRACE_ENABLED()) { |
| 781 | std::string name; |
| 782 | thread->GetThreadName(name); |
| 783 | ATRACE_BEGIN(StringPrintf("SuspendThreadByPeer suspended %s for peer=%p", name.c_str(), |
| 784 | peer).c_str()); |
| 785 | } |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 786 | return thread; |
| 787 | } |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 788 | const uint64_t total_delay = NanoTime() - start_time; |
| 789 | if (total_delay >= MsToNs(kThreadSuspendTimeoutMs)) { |
Mathieu Chartier | 590fee9 | 2013-09-13 13:46:47 -0700 | [diff] [blame] | 790 | ThreadSuspendByPeerWarning(self, FATAL, "Thread suspension timed out", peer); |
Mathieu Chartier | 82a800d | 2014-12-15 15:59:49 -0800 | [diff] [blame] | 791 | if (suspended_thread != nullptr) { |
| 792 | CHECK_EQ(suspended_thread, thread); |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 793 | suspended_thread->ModifySuspendCount(soa.Self(), -1, nullptr, debug_suspension); |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 794 | } |
| 795 | *timed_out = true; |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 796 | return nullptr; |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 797 | } else if (sleep_us == 0 && |
| 798 | total_delay > static_cast<uint64_t>(kThreadSuspendMaxYieldUs) * 1000) { |
| 799 | // We have spun for kThreadSuspendMaxYieldUs time, switch to sleeps to prevent |
| 800 | // excessive CPU usage. |
| 801 | sleep_us = kThreadSuspendMaxYieldUs / 2; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 802 | } |
| 803 | } |
| 804 | // Release locks and come out of runnable state. |
| 805 | } |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 806 | VLOG(threads) << "SuspendThreadByPeer waiting to allow thread chance to suspend"; |
| 807 | ThreadSuspendSleep(sleep_us); |
| 808 | // This may stay at 0 if sleep_us == 0, but this is WAI since we want to avoid using usleep at |
| 809 | // all if possible. This shouldn't be an issue since time to suspend should always be small. |
| 810 | sleep_us = std::min(sleep_us * 2, kThreadSuspendMaxSleepUs); |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 811 | } |
| 812 | } |
| 813 | |
Ian Rogers | c7dd295 | 2014-10-21 23:31:19 -0700 | [diff] [blame] | 814 | static void ThreadSuspendByThreadIdWarning(LogSeverity severity, const char* message, |
| 815 | uint32_t thread_id) { |
| 816 | LOG(severity) << StringPrintf("%s: %d", message, thread_id); |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 817 | } |
| 818 | |
| 819 | Thread* ThreadList::SuspendThreadByThreadId(uint32_t thread_id, bool debug_suspension, |
| 820 | bool* timed_out) { |
Mathieu Chartier | 3a958aa | 2015-02-04 12:52:34 -0800 | [diff] [blame] | 821 | const uint64_t start_time = NanoTime(); |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 822 | useconds_t sleep_us = kThreadSuspendInitialSleepUs; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 823 | *timed_out = false; |
Mathieu Chartier | 5f51d4b | 2013-12-03 14:24:05 -0800 | [diff] [blame] | 824 | Thread* suspended_thread = nullptr; |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 825 | Thread* const self = Thread::Current(); |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 826 | CHECK_NE(thread_id, kInvalidThreadId); |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 827 | VLOG(threads) << "SuspendThreadByThreadId starting"; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 828 | while (true) { |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 829 | { |
Ian Rogers | f3d874c | 2014-07-17 18:52:42 -0700 | [diff] [blame] | 830 | // Note: this will transition to runnable and potentially suspend. We ensure only one thread |
| 831 | // is requesting another suspend, to avoid deadlock, by requiring this function be called |
| 832 | // holding Locks::thread_list_suspend_thread_lock_. Its important this thread suspend rather |
| 833 | // than request thread suspension, to avoid potential cycles in threads requesting each other |
| 834 | // suspend. |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 835 | ScopedObjectAccess soa(self); |
Andreas Gampe | 277ccbd | 2014-11-03 21:36:10 -0800 | [diff] [blame] | 836 | MutexLock thread_list_mu(self, *Locks::thread_list_lock_); |
Ian Rogers | f3d874c | 2014-07-17 18:52:42 -0700 | [diff] [blame] | 837 | Thread* thread = nullptr; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 838 | for (const auto& it : list_) { |
| 839 | if (it->GetThreadId() == thread_id) { |
| 840 | thread = it; |
| 841 | break; |
| 842 | } |
| 843 | } |
Mathieu Chartier | 5f51d4b | 2013-12-03 14:24:05 -0800 | [diff] [blame] | 844 | if (thread == nullptr) { |
| 845 | CHECK(suspended_thread == nullptr) << "Suspended thread " << suspended_thread |
| 846 | << " no longer in thread list"; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 847 | // There's a race in inflating a lock and the owner giving up ownership and then dying. |
| 848 | ThreadSuspendByThreadIdWarning(WARNING, "No such thread id for suspend", thread_id); |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 849 | return nullptr; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 850 | } |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 851 | VLOG(threads) << "SuspendThreadByThreadId found thread: " << *thread; |
| 852 | DCHECK(Contains(thread)); |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 853 | { |
Andreas Gampe | 277ccbd | 2014-11-03 21:36:10 -0800 | [diff] [blame] | 854 | MutexLock suspend_count_mu(self, *Locks::thread_suspend_count_lock_); |
Mathieu Chartier | 5f51d4b | 2013-12-03 14:24:05 -0800 | [diff] [blame] | 855 | if (suspended_thread == nullptr) { |
Ian Rogers | 4ad5cd3 | 2014-11-11 23:08:07 -0800 | [diff] [blame] | 856 | if (self->GetSuspendCount() > 0) { |
| 857 | // We hold the suspend count lock but another thread is trying to suspend us. Its not |
| 858 | // safe to try to suspend another thread in case we get a cycle. Start the loop again |
| 859 | // which will allow this thread to be suspended. |
| 860 | continue; |
| 861 | } |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 862 | thread->ModifySuspendCount(self, +1, nullptr, debug_suspension); |
Mathieu Chartier | 5f51d4b | 2013-12-03 14:24:05 -0800 | [diff] [blame] | 863 | suspended_thread = thread; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 864 | } else { |
Mathieu Chartier | 5f51d4b | 2013-12-03 14:24:05 -0800 | [diff] [blame] | 865 | CHECK_EQ(suspended_thread, thread); |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 866 | // If the caller isn't requesting suspension, a suspension should have already occurred. |
| 867 | CHECK_GT(thread->GetSuspendCount(), 0); |
| 868 | } |
| 869 | // IsSuspended on the current thread will fail as the current thread is changed into |
| 870 | // Runnable above. As the suspend count is now raised if this is the current thread |
| 871 | // it will self suspend on transition to Runnable, making it hard to work with. It's simpler |
| 872 | // to just explicitly handle the current thread in the callers to this code. |
| 873 | CHECK_NE(thread, self) << "Attempt to suspend the current thread for the debugger"; |
| 874 | // If thread is suspended (perhaps it was already not Runnable but didn't have a suspend |
| 875 | // count, or else we've waited and it has self suspended) or is the current thread, we're |
| 876 | // done. |
| 877 | if (thread->IsSuspended()) { |
Mathieu Chartier | f0dc8b5 | 2014-12-17 10:13:30 -0800 | [diff] [blame] | 878 | if (ATRACE_ENABLED()) { |
| 879 | std::string name; |
| 880 | thread->GetThreadName(name); |
| 881 | ATRACE_BEGIN(StringPrintf("SuspendThreadByThreadId suspended %s id=%d", |
| 882 | name.c_str(), thread_id).c_str()); |
| 883 | } |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 884 | VLOG(threads) << "SuspendThreadByThreadId thread suspended: " << *thread; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 885 | return thread; |
| 886 | } |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 887 | const uint64_t total_delay = NanoTime() - start_time; |
| 888 | if (total_delay >= MsToNs(kThreadSuspendTimeoutMs)) { |
Mathieu Chartier | 590fee9 | 2013-09-13 13:46:47 -0700 | [diff] [blame] | 889 | ThreadSuspendByThreadIdWarning(WARNING, "Thread suspension timed out", thread_id); |
Mathieu Chartier | 5f51d4b | 2013-12-03 14:24:05 -0800 | [diff] [blame] | 890 | if (suspended_thread != nullptr) { |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 891 | thread->ModifySuspendCount(soa.Self(), -1, nullptr, debug_suspension); |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 892 | } |
| 893 | *timed_out = true; |
Brian Carlstrom | ba32de4 | 2014-08-27 23:43:46 -0700 | [diff] [blame] | 894 | return nullptr; |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 895 | } else if (sleep_us == 0 && |
| 896 | total_delay > static_cast<uint64_t>(kThreadSuspendMaxYieldUs) * 1000) { |
| 897 | // We have spun for kThreadSuspendMaxYieldUs time, switch to sleeps to prevent |
| 898 | // excessive CPU usage. |
| 899 | sleep_us = kThreadSuspendMaxYieldUs / 2; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 900 | } |
| 901 | } |
| 902 | // Release locks and come out of runnable state. |
| 903 | } |
Mathieu Chartier | 9914386 | 2015-02-03 14:26:46 -0800 | [diff] [blame] | 904 | VLOG(threads) << "SuspendThreadByThreadId waiting to allow thread chance to suspend"; |
| 905 | ThreadSuspendSleep(sleep_us); |
| 906 | sleep_us = std::min(sleep_us * 2, kThreadSuspendMaxSleepUs); |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 907 | } |
| 908 | } |
| 909 | |
| 910 | Thread* ThreadList::FindThreadByThreadId(uint32_t thin_lock_id) { |
| 911 | Thread* self = Thread::Current(); |
| 912 | MutexLock mu(self, *Locks::thread_list_lock_); |
| 913 | for (const auto& thread : list_) { |
| 914 | if (thread->GetThreadId() == thin_lock_id) { |
| 915 | CHECK(thread == self || thread->IsSuspended()); |
| 916 | return thread; |
| 917 | } |
| 918 | } |
Mathieu Chartier | 2cebb24 | 2015-04-21 16:50:40 -0700 | [diff] [blame] | 919 | return nullptr; |
Ian Rogers | d9c4fc9 | 2013-10-01 19:45:43 -0700 | [diff] [blame] | 920 | } |
| 921 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 922 | void ThreadList::SuspendAllForDebugger() { |
| 923 | Thread* self = Thread::Current(); |
| 924 | Thread* debug_thread = Dbg::GetDebugThread(); |
| 925 | |
| 926 | VLOG(threads) << *self << " SuspendAllForDebugger starting..."; |
| 927 | |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 928 | SuspendAllInternal(self, self, debug_thread, true); |
Ian Rogers | 66aee5c | 2012-08-15 17:17:47 -0700 | [diff] [blame] | 929 | // Block on the mutator lock until all Runnable threads release their share of access then |
| 930 | // immediately unlock again. |
| 931 | #if HAVE_TIMED_RWLOCK |
| 932 | // Timeout if we wait more than 30 seconds. |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 933 | if (!Locks::mutator_lock_->ExclusiveLockWithTimeout(self, 30 * 1000, 0)) { |
Sebastien Hertz | bae182c | 2013-12-17 10:42:03 +0100 | [diff] [blame] | 934 | UnsafeLogFatalForThreadSuspendAllTimeout(); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 935 | } else { |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 936 | Locks::mutator_lock_->ExclusiveUnlock(self); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 937 | } |
Ian Rogers | 66aee5c | 2012-08-15 17:17:47 -0700 | [diff] [blame] | 938 | #else |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 939 | Locks::mutator_lock_->ExclusiveLock(self); |
| 940 | Locks::mutator_lock_->ExclusiveUnlock(self); |
Ian Rogers | 66aee5c | 2012-08-15 17:17:47 -0700 | [diff] [blame] | 941 | #endif |
Ian Rogers | 50b35e2 | 2012-10-04 10:09:15 -0700 | [diff] [blame] | 942 | AssertThreadsAreSuspended(self, self, debug_thread); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 943 | |
Sebastien Hertz | ed2be17 | 2014-08-19 15:33:43 +0200 | [diff] [blame] | 944 | VLOG(threads) << *self << " SuspendAllForDebugger complete"; |
Elliott Hughes | 01158d7 | 2011-09-19 19:47:10 -0700 | [diff] [blame] | 945 | } |
| 946 | |
Elliott Hughes | 475fc23 | 2011-10-25 15:00:35 -0700 | [diff] [blame] | 947 | void ThreadList::SuspendSelfForDebugger() { |
Sebastien Hertz | 1558b57 | 2015-02-25 15:05:59 +0100 | [diff] [blame] | 948 | Thread* const self = Thread::Current(); |
| 949 | self->SetReadyForDebugInvoke(true); |
Elliott Hughes | 01158d7 | 2011-09-19 19:47:10 -0700 | [diff] [blame] | 950 | |
Elliott Hughes | 475fc23 | 2011-10-25 15:00:35 -0700 | [diff] [blame] | 951 | // The debugger thread must not suspend itself due to debugger activity! |
| 952 | Thread* debug_thread = Dbg::GetDebugThread(); |
Elliott Hughes | 475fc23 | 2011-10-25 15:00:35 -0700 | [diff] [blame] | 953 | CHECK(self != debug_thread); |
jeffhao | a77f0f6 | 2012-12-05 17:19:31 -0800 | [diff] [blame] | 954 | CHECK_NE(self->GetState(), kRunnable); |
| 955 | Locks::mutator_lock_->AssertNotHeld(self); |
Elliott Hughes | 475fc23 | 2011-10-25 15:00:35 -0700 | [diff] [blame] | 956 | |
Sebastien Hertz | cbc5064 | 2015-06-01 17:33:12 +0200 | [diff] [blame] | 957 | // The debugger may have detached while we were executing an invoke request. In that case, we |
| 958 | // must not suspend ourself. |
| 959 | DebugInvokeReq* pReq = self->GetInvokeReq(); |
| 960 | const bool skip_thread_suspension = (pReq != nullptr && !Dbg::IsDebuggerActive()); |
| 961 | if (!skip_thread_suspension) { |
jeffhao | a77f0f6 | 2012-12-05 17:19:31 -0800 | [diff] [blame] | 962 | // Collisions with other suspends aren't really interesting. We want |
| 963 | // to ensure that we're the only one fiddling with the suspend count |
| 964 | // though. |
| 965 | MutexLock mu(self, *Locks::thread_suspend_count_lock_); |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 966 | self->ModifySuspendCount(self, +1, nullptr, true); |
Ian Rogers | dd7624d | 2014-03-14 17:43:00 -0700 | [diff] [blame] | 967 | CHECK_GT(self->GetSuspendCount(), 0); |
Sebastien Hertz | cbc5064 | 2015-06-01 17:33:12 +0200 | [diff] [blame] | 968 | |
| 969 | VLOG(threads) << *self << " self-suspending (debugger)"; |
| 970 | } else { |
| 971 | // We must no longer be subject to debugger suspension. |
| 972 | MutexLock mu(self, *Locks::thread_suspend_count_lock_); |
| 973 | CHECK_EQ(self->GetDebugSuspendCount(), 0) << "Debugger detached without resuming us"; |
| 974 | |
| 975 | VLOG(threads) << *self << " not self-suspending because debugger detached during invoke"; |
jeffhao | a77f0f6 | 2012-12-05 17:19:31 -0800 | [diff] [blame] | 976 | } |
Elliott Hughes | 475fc23 | 2011-10-25 15:00:35 -0700 | [diff] [blame] | 977 | |
Sebastien Hertz | cbc5064 | 2015-06-01 17:33:12 +0200 | [diff] [blame] | 978 | // If the debugger requested an invoke, we need to send the reply and clear the request. |
Sebastien Hertz | 1558b57 | 2015-02-25 15:05:59 +0100 | [diff] [blame] | 979 | if (pReq != nullptr) { |
Sebastien Hertz | cbc5064 | 2015-06-01 17:33:12 +0200 | [diff] [blame] | 980 | Dbg::FinishInvokeMethod(pReq); |
Sebastien Hertz | 1558b57 | 2015-02-25 15:05:59 +0100 | [diff] [blame] | 981 | self->ClearDebugInvokeReq(); |
Sebastien Hertz | cbc5064 | 2015-06-01 17:33:12 +0200 | [diff] [blame] | 982 | pReq = nullptr; // object has been deleted, clear it for safety. |
Sebastien Hertz | 21e729c | 2014-02-18 14:16:00 +0100 | [diff] [blame] | 983 | } |
| 984 | |
Elliott Hughes | 475fc23 | 2011-10-25 15:00:35 -0700 | [diff] [blame] | 985 | // Tell JDWP that we've completed suspension. The JDWP thread can't |
| 986 | // tell us to resume before we're fully asleep because we hold the |
| 987 | // suspend count lock. |
| 988 | Dbg::ClearWaitForEventThread(); |
| 989 | |
jeffhao | a77f0f6 | 2012-12-05 17:19:31 -0800 | [diff] [blame] | 990 | { |
| 991 | MutexLock mu(self, *Locks::thread_suspend_count_lock_); |
Ian Rogers | dd7624d | 2014-03-14 17:43:00 -0700 | [diff] [blame] | 992 | while (self->GetSuspendCount() != 0) { |
jeffhao | a77f0f6 | 2012-12-05 17:19:31 -0800 | [diff] [blame] | 993 | Thread::resume_cond_->Wait(self); |
Ian Rogers | dd7624d | 2014-03-14 17:43:00 -0700 | [diff] [blame] | 994 | if (self->GetSuspendCount() != 0) { |
jeffhao | a77f0f6 | 2012-12-05 17:19:31 -0800 | [diff] [blame] | 995 | // The condition was signaled but we're still suspended. This |
Sebastien Hertz | f272af4 | 2014-09-18 10:20:42 +0200 | [diff] [blame] | 996 | // can happen when we suspend then resume all threads to |
| 997 | // update instrumentation or compute monitor info. This can |
| 998 | // also happen if the debugger lets go while a SIGQUIT thread |
jeffhao | a77f0f6 | 2012-12-05 17:19:31 -0800 | [diff] [blame] | 999 | // dump event is pending (assuming SignalCatcher was resumed for |
| 1000 | // just long enough to try to grab the thread-suspend lock). |
Sebastien Hertz | f272af4 | 2014-09-18 10:20:42 +0200 | [diff] [blame] | 1001 | VLOG(jdwp) << *self << " still suspended after undo " |
| 1002 | << "(suspend count=" << self->GetSuspendCount() << ", " |
| 1003 | << "debug suspend count=" << self->GetDebugSuspendCount() << ")"; |
jeffhao | a77f0f6 | 2012-12-05 17:19:31 -0800 | [diff] [blame] | 1004 | } |
Elliott Hughes | 475fc23 | 2011-10-25 15:00:35 -0700 | [diff] [blame] | 1005 | } |
Ian Rogers | dd7624d | 2014-03-14 17:43:00 -0700 | [diff] [blame] | 1006 | CHECK_EQ(self->GetSuspendCount(), 0); |
Elliott Hughes | 475fc23 | 2011-10-25 15:00:35 -0700 | [diff] [blame] | 1007 | } |
jeffhao | a77f0f6 | 2012-12-05 17:19:31 -0800 | [diff] [blame] | 1008 | |
Sebastien Hertz | 1558b57 | 2015-02-25 15:05:59 +0100 | [diff] [blame] | 1009 | self->SetReadyForDebugInvoke(false); |
Elliott Hughes | 1f729aa | 2012-03-02 13:55:41 -0800 | [diff] [blame] | 1010 | VLOG(threads) << *self << " self-reviving (debugger)"; |
Elliott Hughes | 475fc23 | 2011-10-25 15:00:35 -0700 | [diff] [blame] | 1011 | } |
| 1012 | |
Sebastien Hertz | 253fa55 | 2014-10-14 17:27:15 +0200 | [diff] [blame] | 1013 | void ThreadList::ResumeAllForDebugger() { |
| 1014 | Thread* self = Thread::Current(); |
| 1015 | Thread* debug_thread = Dbg::GetDebugThread(); |
Sebastien Hertz | 253fa55 | 2014-10-14 17:27:15 +0200 | [diff] [blame] | 1016 | |
| 1017 | VLOG(threads) << *self << " ResumeAllForDebugger starting..."; |
| 1018 | |
| 1019 | // Threads can't resume if we exclusively hold the mutator lock. |
| 1020 | Locks::mutator_lock_->AssertNotExclusiveHeld(self); |
| 1021 | |
| 1022 | { |
Andreas Gampe | 277ccbd | 2014-11-03 21:36:10 -0800 | [diff] [blame] | 1023 | MutexLock thread_list_mu(self, *Locks::thread_list_lock_); |
Sebastien Hertz | 253fa55 | 2014-10-14 17:27:15 +0200 | [diff] [blame] | 1024 | { |
Andreas Gampe | 277ccbd | 2014-11-03 21:36:10 -0800 | [diff] [blame] | 1025 | MutexLock suspend_count_mu(self, *Locks::thread_suspend_count_lock_); |
Sebastien Hertz | 253fa55 | 2014-10-14 17:27:15 +0200 | [diff] [blame] | 1026 | // Update global suspend all state for attaching threads. |
| 1027 | DCHECK_GE(suspend_all_count_, debug_suspend_all_count_); |
Sebastien Hertz | f9d233d | 2015-01-09 14:51:41 +0100 | [diff] [blame] | 1028 | if (debug_suspend_all_count_ > 0) { |
Sebastien Hertz | 253fa55 | 2014-10-14 17:27:15 +0200 | [diff] [blame] | 1029 | --suspend_all_count_; |
| 1030 | --debug_suspend_all_count_; |
Sebastien Hertz | 253fa55 | 2014-10-14 17:27:15 +0200 | [diff] [blame] | 1031 | } else { |
| 1032 | // We've been asked to resume all threads without being asked to |
Sebastien Hertz | f9d233d | 2015-01-09 14:51:41 +0100 | [diff] [blame] | 1033 | // suspend them all before. That may happen if a debugger tries |
| 1034 | // to resume some suspended threads (with suspend count == 1) |
| 1035 | // at once with a VirtualMachine.Resume command. Let's print a |
| 1036 | // warning. |
Sebastien Hertz | 253fa55 | 2014-10-14 17:27:15 +0200 | [diff] [blame] | 1037 | LOG(WARNING) << "Debugger attempted to resume all threads without " |
| 1038 | << "having suspended them all before."; |
| 1039 | } |
Sebastien Hertz | f9d233d | 2015-01-09 14:51:41 +0100 | [diff] [blame] | 1040 | // Decrement everybody's suspend count (except our own). |
| 1041 | for (const auto& thread : list_) { |
| 1042 | if (thread == self || thread == debug_thread) { |
| 1043 | continue; |
| 1044 | } |
| 1045 | if (thread->GetDebugSuspendCount() == 0) { |
| 1046 | // This thread may have been individually resumed with ThreadReference.Resume. |
| 1047 | continue; |
| 1048 | } |
| 1049 | VLOG(threads) << "requesting thread resume: " << *thread; |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 1050 | thread->ModifySuspendCount(self, -1, nullptr, true); |
Sebastien Hertz | f9d233d | 2015-01-09 14:51:41 +0100 | [diff] [blame] | 1051 | } |
Sebastien Hertz | 253fa55 | 2014-10-14 17:27:15 +0200 | [diff] [blame] | 1052 | } |
| 1053 | } |
| 1054 | |
Sebastien Hertz | f9d233d | 2015-01-09 14:51:41 +0100 | [diff] [blame] | 1055 | { |
Sebastien Hertz | 253fa55 | 2014-10-14 17:27:15 +0200 | [diff] [blame] | 1056 | MutexLock mu(self, *Locks::thread_suspend_count_lock_); |
| 1057 | Thread::resume_cond_->Broadcast(self); |
| 1058 | } |
| 1059 | |
| 1060 | VLOG(threads) << *self << " ResumeAllForDebugger complete"; |
| 1061 | } |
| 1062 | |
Elliott Hughes | 234ab15 | 2011-10-26 14:02:26 -0700 | [diff] [blame] | 1063 | void ThreadList::UndoDebuggerSuspensions() { |
| 1064 | Thread* self = Thread::Current(); |
| 1065 | |
Elliott Hughes | 4dd9b4d | 2011-12-12 18:29:24 -0800 | [diff] [blame] | 1066 | VLOG(threads) << *self << " UndoDebuggerSuspensions starting"; |
Elliott Hughes | 234ab15 | 2011-10-26 14:02:26 -0700 | [diff] [blame] | 1067 | |
| 1068 | { |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 1069 | MutexLock mu(self, *Locks::thread_list_lock_); |
| 1070 | MutexLock mu2(self, *Locks::thread_suspend_count_lock_); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1071 | // Update global suspend all state for attaching threads. |
| 1072 | suspend_all_count_ -= debug_suspend_all_count_; |
| 1073 | debug_suspend_all_count_ = 0; |
| 1074 | // Update running threads. |
Mathieu Chartier | 02e2511 | 2013-08-14 16:14:24 -0700 | [diff] [blame] | 1075 | for (const auto& thread : list_) { |
Ian Rogers | dd7624d | 2014-03-14 17:43:00 -0700 | [diff] [blame] | 1076 | if (thread == self || thread->GetDebugSuspendCount() == 0) { |
Elliott Hughes | 234ab15 | 2011-10-26 14:02:26 -0700 | [diff] [blame] | 1077 | continue; |
| 1078 | } |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 1079 | thread->ModifySuspendCount(self, -thread->GetDebugSuspendCount(), nullptr, true); |
Elliott Hughes | 234ab15 | 2011-10-26 14:02:26 -0700 | [diff] [blame] | 1080 | } |
| 1081 | } |
| 1082 | |
| 1083 | { |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 1084 | MutexLock mu(self, *Locks::thread_suspend_count_lock_); |
Ian Rogers | c604d73 | 2012-10-14 16:09:54 -0700 | [diff] [blame] | 1085 | Thread::resume_cond_->Broadcast(self); |
Elliott Hughes | 234ab15 | 2011-10-26 14:02:26 -0700 | [diff] [blame] | 1086 | } |
| 1087 | |
Elliott Hughes | 4dd9b4d | 2011-12-12 18:29:24 -0800 | [diff] [blame] | 1088 | VLOG(threads) << "UndoDebuggerSuspensions(" << *self << ") complete"; |
Elliott Hughes | 234ab15 | 2011-10-26 14:02:26 -0700 | [diff] [blame] | 1089 | } |
| 1090 | |
Elliott Hughes | e52e49b | 2012-04-02 16:05:44 -0700 | [diff] [blame] | 1091 | void ThreadList::WaitForOtherNonDaemonThreadsToExit() { |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 1092 | Thread* self = Thread::Current(); |
| 1093 | Locks::mutator_lock_->AssertNotHeld(self); |
Mathieu Chartier | 91e5669 | 2015-03-03 13:51:04 -0800 | [diff] [blame] | 1094 | while (true) { |
Ian Rogers | 120f1c7 | 2012-09-28 17:17:10 -0700 | [diff] [blame] | 1095 | { |
| 1096 | // No more threads can be born after we start to shutdown. |
| 1097 | MutexLock mu(self, *Locks::runtime_shutdown_lock_); |
Mathieu Chartier | 590fee9 | 2013-09-13 13:46:47 -0700 | [diff] [blame] | 1098 | CHECK(Runtime::Current()->IsShuttingDownLocked()); |
Ian Rogers | 120f1c7 | 2012-09-28 17:17:10 -0700 | [diff] [blame] | 1099 | CHECK_EQ(Runtime::Current()->NumberOfThreadsBeingBorn(), 0U); |
| 1100 | } |
Ian Rogers | 120f1c7 | 2012-09-28 17:17:10 -0700 | [diff] [blame] | 1101 | MutexLock mu(self, *Locks::thread_list_lock_); |
Mathieu Chartier | 91e5669 | 2015-03-03 13:51:04 -0800 | [diff] [blame] | 1102 | // Also wait for any threads that are unregistering to finish. This is required so that no |
| 1103 | // threads access the thread list after it is deleted. TODO: This may not work for user daemon |
| 1104 | // threads since they could unregister at the wrong time. |
| 1105 | bool done = unregistering_count_ == 0; |
| 1106 | if (done) { |
| 1107 | for (const auto& thread : list_) { |
| 1108 | if (thread != self && !thread->IsDaemon()) { |
| 1109 | done = false; |
| 1110 | break; |
| 1111 | } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1112 | } |
| 1113 | } |
Mathieu Chartier | 91e5669 | 2015-03-03 13:51:04 -0800 | [diff] [blame] | 1114 | if (done) { |
| 1115 | break; |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1116 | } |
Mathieu Chartier | 91e5669 | 2015-03-03 13:51:04 -0800 | [diff] [blame] | 1117 | // Wait for another thread to exit before re-checking. |
| 1118 | Locks::thread_exit_cond_->Wait(self); |
| 1119 | } |
Elliott Hughes | 038a806 | 2011-09-18 14:12:41 -0700 | [diff] [blame] | 1120 | } |
| 1121 | |
| 1122 | void ThreadList::SuspendAllDaemonThreads() { |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 1123 | Thread* self = Thread::Current(); |
| 1124 | MutexLock mu(self, *Locks::thread_list_lock_); |
Brian Carlstrom | 7934ac2 | 2013-07-26 10:54:15 -0700 | [diff] [blame] | 1125 | { // Tell all the daemons it's time to suspend. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 1126 | MutexLock mu2(self, *Locks::thread_suspend_count_lock_); |
Mathieu Chartier | 02e2511 | 2013-08-14 16:14:24 -0700 | [diff] [blame] | 1127 | for (const auto& thread : list_) { |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1128 | // This is only run after all non-daemon threads have exited, so the remainder should all be |
| 1129 | // daemons. |
Ian Rogers | 7e76286 | 2012-10-22 15:45:08 -0700 | [diff] [blame] | 1130 | CHECK(thread->IsDaemon()) << *thread; |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 1131 | if (thread != self) { |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 1132 | thread->ModifySuspendCount(self, +1, nullptr, false); |
Elliott Hughes | e52e49b | 2012-04-02 16:05:44 -0700 | [diff] [blame] | 1133 | } |
Elliott Hughes | 038a806 | 2011-09-18 14:12:41 -0700 | [diff] [blame] | 1134 | } |
| 1135 | } |
Elliott Hughes | 038a806 | 2011-09-18 14:12:41 -0700 | [diff] [blame] | 1136 | // Give the threads a chance to suspend, complaining if they're slow. |
| 1137 | bool have_complained = false; |
| 1138 | for (int i = 0; i < 10; ++i) { |
| 1139 | usleep(200 * 1000); |
| 1140 | bool all_suspended = true; |
Mathieu Chartier | 02e2511 | 2013-08-14 16:14:24 -0700 | [diff] [blame] | 1141 | for (const auto& thread : list_) { |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 1142 | if (thread != self && thread->GetState() == kRunnable) { |
Elliott Hughes | 038a806 | 2011-09-18 14:12:41 -0700 | [diff] [blame] | 1143 | if (!have_complained) { |
| 1144 | LOG(WARNING) << "daemon thread not yet suspended: " << *thread; |
| 1145 | have_complained = true; |
| 1146 | } |
| 1147 | all_suspended = false; |
| 1148 | } |
| 1149 | } |
| 1150 | if (all_suspended) { |
| 1151 | return; |
| 1152 | } |
| 1153 | } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1154 | LOG(ERROR) << "suspend all daemons failed"; |
| 1155 | } |
| 1156 | void ThreadList::Register(Thread* self) { |
| 1157 | DCHECK_EQ(self, Thread::Current()); |
| 1158 | |
| 1159 | if (VLOG_IS_ON(threads)) { |
| 1160 | std::ostringstream oss; |
| 1161 | self->ShortDump(oss); // We don't hold the mutator_lock_ yet and so cannot call Dump. |
Ian Rogers | 5a9ba01 | 2014-05-19 13:28:52 -0700 | [diff] [blame] | 1162 | LOG(INFO) << "ThreadList::Register() " << *self << "\n" << oss.str(); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1163 | } |
| 1164 | |
| 1165 | // Atomically add self to the thread list and make its thread_suspend_count_ reflect ongoing |
| 1166 | // SuspendAll requests. |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 1167 | MutexLock mu(self, *Locks::thread_list_lock_); |
| 1168 | MutexLock mu2(self, *Locks::thread_suspend_count_lock_); |
Ian Rogers | dd7624d | 2014-03-14 17:43:00 -0700 | [diff] [blame] | 1169 | CHECK_GE(suspend_all_count_, debug_suspend_all_count_); |
Ian Rogers | 2966e13 | 2014-04-02 08:34:36 -0700 | [diff] [blame] | 1170 | // Modify suspend count in increments of 1 to maintain invariants in ModifySuspendCount. While |
| 1171 | // this isn't particularly efficient the suspend counts are most commonly 0 or 1. |
| 1172 | for (int delta = debug_suspend_all_count_; delta > 0; delta--) { |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 1173 | self->ModifySuspendCount(self, +1, nullptr, true); |
Ian Rogers | dd7624d | 2014-03-14 17:43:00 -0700 | [diff] [blame] | 1174 | } |
Ian Rogers | 2966e13 | 2014-04-02 08:34:36 -0700 | [diff] [blame] | 1175 | for (int delta = suspend_all_count_ - debug_suspend_all_count_; delta > 0; delta--) { |
Yu Li | eac4424 | 2015-06-29 10:50:03 +0800 | [diff] [blame] | 1176 | self->ModifySuspendCount(self, +1, nullptr, false); |
Ian Rogers | 01ae580 | 2012-09-28 16:14:01 -0700 | [diff] [blame] | 1177 | } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1178 | CHECK(!Contains(self)); |
| 1179 | list_.push_back(self); |
Hiroshi Yamauchi | 0b71357 | 2015-06-16 18:29:23 -0700 | [diff] [blame] | 1180 | if (kUseReadBarrier) { |
Hiroshi Yamauchi | 0037082 | 2015-08-18 14:47:25 -0700 | [diff] [blame] | 1181 | // Initialize according to the state of the CC collector. |
| 1182 | bool is_gc_marking = |
| 1183 | Runtime::Current()->GetHeap()->ConcurrentCopyingCollector()->IsMarking(); |
| 1184 | self->SetIsGcMarking(is_gc_marking); |
Hiroshi Yamauchi | 0b71357 | 2015-06-16 18:29:23 -0700 | [diff] [blame] | 1185 | bool weak_ref_access_enabled = |
| 1186 | Runtime::Current()->GetHeap()->ConcurrentCopyingCollector()->IsWeakRefAccessEnabled(); |
| 1187 | self->SetWeakRefAccessEnabled(weak_ref_access_enabled); |
| 1188 | } |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1189 | } |
| 1190 | |
| 1191 | void ThreadList::Unregister(Thread* self) { |
| 1192 | DCHECK_EQ(self, Thread::Current()); |
Ian Rogers | 68d8b42 | 2014-07-17 11:09:10 -0700 | [diff] [blame] | 1193 | CHECK_NE(self->GetState(), kRunnable); |
| 1194 | Locks::mutator_lock_->AssertNotHeld(self); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1195 | |
| 1196 | VLOG(threads) << "ThreadList::Unregister() " << *self; |
| 1197 | |
Mathieu Chartier | 91e5669 | 2015-03-03 13:51:04 -0800 | [diff] [blame] | 1198 | { |
| 1199 | MutexLock mu(self, *Locks::thread_list_lock_); |
| 1200 | ++unregistering_count_; |
| 1201 | } |
| 1202 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1203 | // Any time-consuming destruction, plus anything that can call back into managed code or |
Mathieu Chartier | 91e5669 | 2015-03-03 13:51:04 -0800 | [diff] [blame] | 1204 | // suspend and so on, must happen at this point, and not in ~Thread. The self->Destroy is what |
| 1205 | // causes the threads to join. It is important to do this after incrementing unregistering_count_ |
| 1206 | // since we want the runtime to wait for the daemon threads to exit before deleting the thread |
| 1207 | // list. |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1208 | self->Destroy(); |
| 1209 | |
Jeff Hao | e094b87 | 2014-10-14 13:12:01 -0700 | [diff] [blame] | 1210 | // If tracing, remember thread id and name before thread exits. |
| 1211 | Trace::StoreExitingThreadInfo(self); |
| 1212 | |
Ian Rogers | dd7624d | 2014-03-14 17:43:00 -0700 | [diff] [blame] | 1213 | uint32_t thin_lock_id = self->GetThreadId(); |
Mathieu Chartier | 91e5669 | 2015-03-03 13:51:04 -0800 | [diff] [blame] | 1214 | while (true) { |
Ian Rogers | cfaa455 | 2012-11-26 21:00:08 -0800 | [diff] [blame] | 1215 | // Remove and delete the Thread* while holding the thread_list_lock_ and |
| 1216 | // thread_suspend_count_lock_ so that the unregistering thread cannot be suspended. |
Ian Rogers | 0878d65 | 2013-04-18 17:38:35 -0700 | [diff] [blame] | 1217 | // Note: deliberately not using MutexLock that could hold a stale self pointer. |
Mathieu Chartier | 91e5669 | 2015-03-03 13:51:04 -0800 | [diff] [blame] | 1218 | MutexLock mu(self, *Locks::thread_list_lock_); |
Ian Rogers | a2af5c7 | 2014-09-15 15:17:07 -0700 | [diff] [blame] | 1219 | if (!Contains(self)) { |
Mathieu Chartier | 9db831a | 2015-02-24 17:20:30 -0800 | [diff] [blame] | 1220 | std::string thread_name; |
| 1221 | self->GetThreadName(thread_name); |
Ian Rogers | a2af5c7 | 2014-09-15 15:17:07 -0700 | [diff] [blame] | 1222 | std::ostringstream os; |
Christopher Ferris | 6cff48f | 2014-01-26 21:36:13 -0800 | [diff] [blame] | 1223 | DumpNativeStack(os, GetTid(), nullptr, " native: ", nullptr); |
Mathieu Chartier | 9db831a | 2015-02-24 17:20:30 -0800 | [diff] [blame] | 1224 | LOG(ERROR) << "Request to unregister unattached thread " << thread_name << "\n" << os.str(); |
Mathieu Chartier | 91e5669 | 2015-03-03 13:51:04 -0800 | [diff] [blame] | 1225 | break; |
Ian Rogers | a2af5c7 | 2014-09-15 15:17:07 -0700 | [diff] [blame] | 1226 | } else { |
Mathieu Chartier | 91e5669 | 2015-03-03 13:51:04 -0800 | [diff] [blame] | 1227 | MutexLock mu2(self, *Locks::thread_suspend_count_lock_); |
Ian Rogers | a2af5c7 | 2014-09-15 15:17:07 -0700 | [diff] [blame] | 1228 | if (!self->IsSuspended()) { |
| 1229 | list_.remove(self); |
Mathieu Chartier | 91e5669 | 2015-03-03 13:51:04 -0800 | [diff] [blame] | 1230 | break; |
Ian Rogers | a2af5c7 | 2014-09-15 15:17:07 -0700 | [diff] [blame] | 1231 | } |
Ian Rogers | 68d8b42 | 2014-07-17 11:09:10 -0700 | [diff] [blame] | 1232 | } |
Mathieu Chartier | 91e5669 | 2015-03-03 13:51:04 -0800 | [diff] [blame] | 1233 | // We failed to remove the thread due to a suspend request, loop and try again. |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1234 | } |
Mathieu Chartier | 91e5669 | 2015-03-03 13:51:04 -0800 | [diff] [blame] | 1235 | delete self; |
| 1236 | |
Mathieu Chartier | 5f51d4b | 2013-12-03 14:24:05 -0800 | [diff] [blame] | 1237 | // Release the thread ID after the thread is finished and deleted to avoid cases where we can |
| 1238 | // temporarily have multiple threads with the same thread id. When this occurs, it causes |
| 1239 | // problems in FindThreadByThreadId / SuspendThreadByThreadId. |
| 1240 | ReleaseThreadId(nullptr, thin_lock_id); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1241 | |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1242 | // Clear the TLS data, so that the underlying native thread is recognizably detached. |
| 1243 | // (It may wish to reattach later.) |
Andreas Gampe | 4382f1e | 2015-08-05 01:08:53 +0000 | [diff] [blame] | 1244 | #ifdef __ANDROID__ |
| 1245 | __get_tls()[TLS_SLOT_ART_THREAD_SELF] = nullptr; |
| 1246 | #else |
Mathieu Chartier | 2cebb24 | 2015-04-21 16:50:40 -0700 | [diff] [blame] | 1247 | CHECK_PTHREAD_CALL(pthread_setspecific, (Thread::pthread_key_self_, nullptr), "detach self"); |
Andreas Gampe | 4382f1e | 2015-08-05 01:08:53 +0000 | [diff] [blame] | 1248 | #endif |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1249 | |
| 1250 | // Signal that a thread just detached. |
Mathieu Chartier | 91e5669 | 2015-03-03 13:51:04 -0800 | [diff] [blame] | 1251 | MutexLock mu(nullptr, *Locks::thread_list_lock_); |
| 1252 | --unregistering_count_; |
| 1253 | Locks::thread_exit_cond_->Broadcast(nullptr); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1254 | } |
| 1255 | |
| 1256 | void ThreadList::ForEach(void (*callback)(Thread*, void*), void* context) { |
Mathieu Chartier | 02e2511 | 2013-08-14 16:14:24 -0700 | [diff] [blame] | 1257 | for (const auto& thread : list_) { |
| 1258 | callback(thread, context); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1259 | } |
| 1260 | } |
| 1261 | |
Mathieu Chartier | bb87e0f | 2015-04-03 11:21:55 -0700 | [diff] [blame] | 1262 | void ThreadList::VisitRoots(RootVisitor* visitor) const { |
Ian Rogers | 81d425b | 2012-09-27 16:03:43 -0700 | [diff] [blame] | 1263 | MutexLock mu(Thread::Current(), *Locks::thread_list_lock_); |
Mathieu Chartier | 02e2511 | 2013-08-14 16:14:24 -0700 | [diff] [blame] | 1264 | for (const auto& thread : list_) { |
Mathieu Chartier | bb87e0f | 2015-04-03 11:21:55 -0700 | [diff] [blame] | 1265 | thread->VisitRoots(visitor); |
Ian Rogers | 00f7d0e | 2012-07-19 15:28:27 -0700 | [diff] [blame] | 1266 | } |
Elliott Hughes | 038a806 | 2011-09-18 14:12:41 -0700 | [diff] [blame] | 1267 | } |
| 1268 | |
Ian Rogers | cfaa455 | 2012-11-26 21:00:08 -0800 | [diff] [blame] | 1269 | uint32_t ThreadList::AllocThreadId(Thread* self) { |
Chao-ying Fu | 9e36931 | 2014-05-21 11:20:52 -0700 | [diff] [blame] | 1270 | MutexLock mu(self, *Locks::allocated_thread_ids_lock_); |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 1271 | for (size_t i = 0; i < allocated_ids_.size(); ++i) { |
| 1272 | if (!allocated_ids_[i]) { |
| 1273 | allocated_ids_.set(i); |
Brian Carlstrom | 7934ac2 | 2013-07-26 10:54:15 -0700 | [diff] [blame] | 1274 | return i + 1; // Zero is reserved to mean "invalid". |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 1275 | } |
| 1276 | } |
| 1277 | LOG(FATAL) << "Out of internal thread ids"; |
| 1278 | return 0; |
| 1279 | } |
| 1280 | |
Ian Rogers | cfaa455 | 2012-11-26 21:00:08 -0800 | [diff] [blame] | 1281 | void ThreadList::ReleaseThreadId(Thread* self, uint32_t id) { |
Chao-ying Fu | 9e36931 | 2014-05-21 11:20:52 -0700 | [diff] [blame] | 1282 | MutexLock mu(self, *Locks::allocated_thread_ids_lock_); |
Brian Carlstrom | 7934ac2 | 2013-07-26 10:54:15 -0700 | [diff] [blame] | 1283 | --id; // Zero is reserved to mean "invalid". |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 1284 | DCHECK(allocated_ids_[id]) << id; |
| 1285 | allocated_ids_.reset(id); |
| 1286 | } |
| 1287 | |
Mathieu Chartier | 4f55e22 | 2015-09-04 13:26:21 -0700 | [diff] [blame] | 1288 | ScopedSuspendAll::ScopedSuspendAll(const char* cause, bool long_suspend) { |
| 1289 | Runtime::Current()->GetThreadList()->SuspendAll(cause, long_suspend); |
| 1290 | } |
| 1291 | |
| 1292 | ScopedSuspendAll::~ScopedSuspendAll() { |
| 1293 | Runtime::Current()->GetThreadList()->ResumeAll(); |
| 1294 | } |
| 1295 | |
Elliott Hughes | 8daa092 | 2011-09-11 13:46:25 -0700 | [diff] [blame] | 1296 | } // namespace art |