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1 // Copyright 2015 The Chromium Authors. All rights reserved. | 1 // Copyright 2015 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #include "base/profiler/stack_sampling_profiler.h" | 5 #include "base/profiler/stack_sampling_profiler.h" |
6 | 6 |
7 #include <algorithm> | 7 #include <algorithm> |
8 #include <map> | |
8 #include <utility> | 9 #include <utility> |
9 | 10 |
11 #include "base/atomic_sequence_num.h" | |
12 #include "base/atomicops.h" | |
10 #include "base/bind.h" | 13 #include "base/bind.h" |
11 #include "base/bind_helpers.h" | 14 #include "base/bind_helpers.h" |
12 #include "base/callback.h" | 15 #include "base/callback.h" |
13 #include "base/lazy_instance.h" | 16 #include "base/lazy_instance.h" |
14 #include "base/location.h" | 17 #include "base/location.h" |
15 #include "base/macros.h" | 18 #include "base/macros.h" |
19 #include "base/memory/ptr_util.h" | |
20 #include "base/memory/singleton.h" | |
16 #include "base/profiler/native_stack_sampler.h" | 21 #include "base/profiler/native_stack_sampler.h" |
17 #include "base/synchronization/lock.h" | 22 #include "base/synchronization/lock.h" |
23 #include "base/threading/thread.h" | |
18 #include "base/threading/thread_task_runner_handle.h" | 24 #include "base/threading/thread_task_runner_handle.h" |
19 #include "base/timer/elapsed_timer.h" | 25 #include "base/timer/elapsed_timer.h" |
20 | 26 |
21 namespace base { | 27 namespace base { |
22 | 28 |
23 namespace { | 29 namespace { |
24 | 30 |
25 // Used to ensure only one profiler is running at a time. | |
26 LazyInstance<Lock>::Leaky concurrent_profiling_lock = LAZY_INSTANCE_INITIALIZER; | |
27 | |
28 // AsyncRunner ---------------------------------------------------------------- | |
29 | |
30 // Helper class to allow a profiler to be run completely asynchronously from the | |
31 // initiator, without being concerned with the profiler's lifetime. | |
32 class AsyncRunner { | |
33 public: | |
34 // Sets up a profiler and arranges for it to be deleted on its completed | |
35 // callback. | |
36 static void Run(PlatformThreadId thread_id, | |
37 const StackSamplingProfiler::SamplingParams& params, | |
38 const StackSamplingProfiler::CompletedCallback& callback); | |
39 | |
40 private: | |
41 AsyncRunner(); | |
42 | |
43 // Runs the callback and deletes the AsyncRunner instance. |profiles| is not | |
44 // const& because it must be passed with std::move. | |
45 static void RunCallbackAndDeleteInstance( | |
46 std::unique_ptr<AsyncRunner> object_to_be_deleted, | |
47 const StackSamplingProfiler::CompletedCallback& callback, | |
48 scoped_refptr<SingleThreadTaskRunner> task_runner, | |
49 StackSamplingProfiler::CallStackProfiles profiles); | |
50 | |
51 std::unique_ptr<StackSamplingProfiler> profiler_; | |
52 | |
53 DISALLOW_COPY_AND_ASSIGN(AsyncRunner); | |
54 }; | |
55 | |
56 // static | |
57 void AsyncRunner::Run( | |
58 PlatformThreadId thread_id, | |
59 const StackSamplingProfiler::SamplingParams& params, | |
60 const StackSamplingProfiler::CompletedCallback &callback) { | |
61 std::unique_ptr<AsyncRunner> runner(new AsyncRunner); | |
62 AsyncRunner* temp_ptr = runner.get(); | |
63 temp_ptr->profiler_.reset( | |
64 new StackSamplingProfiler(thread_id, params, | |
65 Bind(&AsyncRunner::RunCallbackAndDeleteInstance, | |
66 Passed(&runner), callback, | |
67 ThreadTaskRunnerHandle::Get()))); | |
68 // The callback won't be called until after Start(), so temp_ptr will still | |
69 // be valid here. | |
70 temp_ptr->profiler_->Start(); | |
71 } | |
72 | |
73 AsyncRunner::AsyncRunner() {} | |
74 | |
75 void AsyncRunner::RunCallbackAndDeleteInstance( | |
76 std::unique_ptr<AsyncRunner> object_to_be_deleted, | |
77 const StackSamplingProfiler::CompletedCallback& callback, | |
78 scoped_refptr<SingleThreadTaskRunner> task_runner, | |
79 StackSamplingProfiler::CallStackProfiles profiles) { | |
80 callback.Run(std::move(profiles)); | |
81 // Delete the instance on the original calling thread. | |
82 task_runner->DeleteSoon(FROM_HERE, object_to_be_deleted.release()); | |
83 } | |
84 | |
85 void ChangeAtomicFlags(subtle::Atomic32* flags, | 31 void ChangeAtomicFlags(subtle::Atomic32* flags, |
86 subtle::Atomic32 set, | 32 subtle::Atomic32 set, |
87 subtle::Atomic32 clear) { | 33 subtle::Atomic32 clear) { |
88 DCHECK(set != 0 || clear != 0); | 34 DCHECK(set != 0 || clear != 0); |
89 DCHECK_EQ(0, set & clear); | 35 DCHECK_EQ(0, set & clear); |
90 | 36 |
91 subtle::Atomic32 bits = subtle::NoBarrier_Load(flags); | 37 subtle::Atomic32 bits = subtle::NoBarrier_Load(flags); |
92 while (true) { | 38 while (true) { |
93 subtle::Atomic32 existing = | 39 subtle::Atomic32 existing = |
94 subtle::NoBarrier_CompareAndSwap(flags, bits, (bits | set) & ~clear); | 40 subtle::NoBarrier_CompareAndSwap(flags, bits, (bits | set) & ~clear); |
(...skipping 58 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
153 StackSamplingProfiler::CallStackProfile | 99 StackSamplingProfiler::CallStackProfile |
154 StackSamplingProfiler::CallStackProfile::CopyForTesting() const { | 100 StackSamplingProfiler::CallStackProfile::CopyForTesting() const { |
155 return CallStackProfile(*this); | 101 return CallStackProfile(*this); |
156 } | 102 } |
157 | 103 |
158 StackSamplingProfiler::CallStackProfile::CallStackProfile( | 104 StackSamplingProfiler::CallStackProfile::CallStackProfile( |
159 const CallStackProfile& other) = default; | 105 const CallStackProfile& other) = default; |
160 | 106 |
161 // StackSamplingProfiler::SamplingThread -------------------------------------- | 107 // StackSamplingProfiler::SamplingThread -------------------------------------- |
162 | 108 |
163 StackSamplingProfiler::SamplingThread::SamplingThread( | 109 class StackSamplingProfiler::SamplingThread : public Thread { |
164 std::unique_ptr<NativeStackSampler> native_sampler, | 110 public: |
165 const SamplingParams& params, | 111 struct CollectionContext { |
166 const CompletedCallback& completed_callback) | 112 CollectionContext(PlatformThreadId target, |
167 : native_sampler_(std::move(native_sampler)), | 113 const SamplingParams& params, |
168 params_(params), | 114 const CompletedCallback& callback, |
169 stop_event_(WaitableEvent::ResetPolicy::AUTOMATIC, | 115 WaitableEvent* finished, |
170 WaitableEvent::InitialState::NOT_SIGNALED), | 116 std::unique_ptr<NativeStackSampler> sampler) |
171 completed_callback_(completed_callback) {} | 117 : collection_id(next_collection_id_.GetNext()), |
172 | 118 target(target), |
173 StackSamplingProfiler::SamplingThread::~SamplingThread() {} | 119 params(params), |
174 | 120 callback(callback), |
175 void StackSamplingProfiler::SamplingThread::ThreadMain() { | 121 finished(finished), |
176 PlatformThread::SetName("Chrome_SamplingProfilerThread"); | 122 native_sampler(std::move(sampler)) {} |
177 | 123 ~CollectionContext() {} |
178 // For now, just ignore any requests to profile while another profiler is | 124 |
179 // working. | 125 // An identifier for this collection, used to uniquely identify it to |
180 if (!concurrent_profiling_lock.Get().Try()) | 126 // outside interests. |
127 const int collection_id; | |
128 | |
129 Time next_sample_time; // The absolute time for the next sample. | |
130 PlatformThreadId target; // The thread being sampled. | |
Mike Wittman
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const
bcwhite
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Done.
| |
131 SamplingParams params; // Information about how to sample. | |
Mike Wittman
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const
bcwhite
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Done.
| |
132 CompletedCallback callback; // Callback made when sampling is complete. | |
Mike Wittman
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const
bcwhite
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Done.
| |
133 WaitableEvent* finished; // Signaled when all sampling is complete. | |
Mike Wittman
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WaitableEvent* const
bcwhite
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Done.
| |
134 | |
135 // Platform-specific module that does the actual sampling. | |
136 std::unique_ptr<NativeStackSampler> native_sampler; | |
Mike Wittman
2017/02/13 22:35:57
Move all const state before all mutable state, to
Mike Wittman
2017/02/13 22:35:57
const
bcwhite
2017/02/14 14:33:01
Done.
bcwhite
2017/02/14 14:33:02
Done.
| |
137 | |
138 // Counters that indicate the current position along the acquisition. | |
139 int burst = 0; | |
140 int sample = 0; | |
141 | |
142 // The time that a profile was started, for calculating the total duration. | |
143 Time profile_start_time; | |
144 | |
145 // The collected stack samples. The active profile is always at the back(). | |
146 CallStackProfiles profiles; | |
147 | |
148 private: | |
149 static StaticAtomicSequenceNumber next_collection_id_; | |
150 }; | |
151 | |
152 // Gets the single instance of this class. | |
153 static SamplingThread* GetInstance(); | |
154 | |
155 // Starts the thread. | |
156 void Start(); | |
157 | |
158 // Adds a new CollectionContext to the thread. This can be called externally | |
159 // from any thread. This returns an ID that can later be used to stop | |
160 // the sampling. | |
161 int Add(std::unique_ptr<CollectionContext> collection); | |
162 | |
163 // Removes an active collection based on its ID, forcing it to run its | |
164 // callback if any data has been collected. This can be called externally | |
165 // from any thread. | |
166 void Remove(int id); | |
167 | |
168 // Removes all active collections and stops the underlying thread. | |
169 void Shutdown(); | |
170 | |
171 // Begins an idle shutdown as if the idle-timer had expired. | |
172 void ShutdownIfIdle(); | |
173 | |
174 // Undoes the "permanent" effect of Shutdown() so the thread can restart. | |
175 void UndoShutdown(); | |
176 | |
177 // Sets the number of ms to wait after becoming idle before shutting down. | |
178 // Set to zero to disable. | |
179 void SetIdleShutdownTime(int shutdown_ms); | |
180 | |
181 private: | |
182 SamplingThread(); | |
183 ~SamplingThread() override; | |
184 friend struct DefaultSingletonTraits<SamplingThread>; | |
185 | |
186 // Get task runner that is usable from the outside. | |
187 scoped_refptr<SingleThreadTaskRunner> GetOrCreateTaskRunner(); | |
188 scoped_refptr<SingleThreadTaskRunner> GetTaskRunner(); | |
189 | |
190 // Get task runner that is usable from the sampling thread itself. | |
191 scoped_refptr<SingleThreadTaskRunner> GetTaskRunnerOnSamplingThread(); | |
192 | |
193 // Finishes a collection and reports collected data via callback. | |
194 void FinishCollection(CollectionContext* collection); | |
195 | |
196 // Records a single sample of a collection. | |
197 void RecordSample(CollectionContext* collection); | |
198 | |
199 // Check if the sampling thread is idle. | |
200 void CheckForIdle(); | |
201 | |
202 // These methods are tasks that get posted to the internal message queue. | |
203 void AddCollectionTask(std::unique_ptr<CollectionContext> collection_ptr); | |
204 void RemoveCollectionTask(int id); | |
205 void PerformCollectionTask(int id); | |
206 void ShutdownTask(); | |
207 | |
208 // Updates the |next_sample_time| time based on configured parameters. | |
209 bool UpdateNextSampleTime(CollectionContext* collection); | |
210 | |
211 // Thread: | |
212 void CleanUp() override; | |
213 | |
214 // The task-runner for the sampling thread and some information about it. | |
215 // This must always be accessed while holding the lock. The saved task-runner | |
216 // can be freely used by any calling thread. | |
217 scoped_refptr<SingleThreadTaskRunner> task_runner_; | |
218 bool task_runner_forced_shutdown_ = false; | |
219 int task_runner_create_requests_ = 0; | |
220 TimeDelta task_runner_idle_shutdown_time_ = TimeDelta::FromSeconds(5); | |
221 Lock task_runner_lock_; | |
222 | |
223 // A map of IDs to collection contexts. Because this class is a singleton | |
224 // that is never destroyed, context objects will never be destructed except | |
225 // by explicit action. Thus, it's acceptable to pass unretained pointers | |
226 // to these objects when posting tasks. | |
227 std::map<int, std::unique_ptr<CollectionContext>> active_collections_; | |
228 | |
229 DISALLOW_COPY_AND_ASSIGN(SamplingThread); | |
230 }; | |
231 | |
232 StaticAtomicSequenceNumber StackSamplingProfiler::SamplingThread:: | |
233 CollectionContext::next_collection_id_; | |
234 | |
235 StackSamplingProfiler::SamplingThread::SamplingThread() | |
236 : Thread("Chrome_SamplingProfilerThread") {} | |
237 | |
238 StackSamplingProfiler::SamplingThread::~SamplingThread() { | |
239 Thread::Stop(); | |
240 } | |
241 | |
242 StackSamplingProfiler::SamplingThread* | |
243 StackSamplingProfiler::SamplingThread::GetInstance() { | |
244 return Singleton<SamplingThread, LeakySingletonTraits<SamplingThread>>::get(); | |
245 } | |
246 | |
247 void StackSamplingProfiler::SamplingThread::Start() { | |
248 Thread::Options options; | |
249 // Use a higher priority for a more accurate sampling interval. | |
250 options.priority = ThreadPriority::DISPLAY; | |
251 Thread::StartWithOptions(options); | |
252 } | |
253 | |
254 int StackSamplingProfiler::SamplingThread::Add( | |
255 std::unique_ptr<CollectionContext> collection) { | |
256 int id = collection->collection_id; | |
257 scoped_refptr<SingleThreadTaskRunner> task_runner = GetOrCreateTaskRunner(); | |
258 | |
259 // There may be no task-runner if the sampling thread has been permanently | |
260 // shut down. | |
261 if (task_runner) { | |
262 task_runner->PostTask( | |
263 FROM_HERE, Bind(&SamplingThread::AddCollectionTask, Unretained(this), | |
264 Passed(&collection))); | |
265 } | |
266 return id; | |
267 } | |
268 | |
269 void StackSamplingProfiler::SamplingThread::Remove(int id) { | |
270 scoped_refptr<SingleThreadTaskRunner> task_runner = GetTaskRunner(); | |
271 if (!task_runner) | |
272 return; // Everything has already stopped. | |
273 | |
274 // This can fail if the thread were to exit between acquisition of the task | |
275 // runner above and the call below. In that case, however, everything has | |
276 // stopped so there's no need to try to stop it. | |
277 task_runner->PostTask(FROM_HERE, Bind(&SamplingThread::RemoveCollectionTask, | |
278 Unretained(this), id)); | |
279 } | |
280 | |
281 void StackSamplingProfiler::SamplingThread::Shutdown() { | |
282 // Record that a shutdown has been requested so nothing can cause it to | |
283 // start up again. | |
284 { | |
285 AutoLock lock(task_runner_lock_); | |
286 task_runner_forced_shutdown_ = true; | |
287 } | |
288 | |
289 scoped_refptr<SingleThreadTaskRunner> task_runner = GetTaskRunner(); | |
290 if (!task_runner) | |
291 return; // Everything has already stopped. | |
292 | |
293 // This can fail if the thread were to exit between acquisition of the task | |
294 // runner above and the call below. In that case, however, everything has | |
295 // stopped so there's no need to do anything. | |
296 task_runner->PostTask(FROM_HERE, | |
297 Bind(&SamplingThread::ShutdownTask, Unretained(this))); | |
298 | |
299 // Now that a task has been posted, calling Stop() will block until that task | |
300 // has been executed. | |
301 Stop(); | |
302 } | |
303 | |
304 void StackSamplingProfiler::SamplingThread::ShutdownIfIdle() { | |
305 scoped_refptr<SingleThreadTaskRunner> task_runner = GetTaskRunner(); | |
306 if (!task_runner) | |
307 return; // Everything has already stopped. | |
308 | |
309 // ShutdownTask will check if the thread is idle and skip the shutdown if not. | |
310 task_runner->PostTask(FROM_HERE, | |
311 Bind(&SamplingThread::ShutdownTask, Unretained(this))); | |
312 } | |
313 | |
314 void StackSamplingProfiler::SamplingThread::UndoShutdown() { | |
315 { | |
316 AutoLock lock(task_runner_lock_); | |
317 task_runner_forced_shutdown_ = false; | |
318 } | |
319 } | |
320 | |
321 void StackSamplingProfiler::SamplingThread::SetIdleShutdownTime( | |
322 int shutdown_ms) { | |
323 AutoLock lock(task_runner_lock_); | |
324 task_runner_idle_shutdown_time_ = TimeDelta::FromMilliseconds(shutdown_ms); | |
325 } | |
326 | |
327 scoped_refptr<SingleThreadTaskRunner> | |
328 StackSamplingProfiler::SamplingThread::GetOrCreateTaskRunner() { | |
329 AutoLock lock(task_runner_lock_); | |
330 ++task_runner_create_requests_; | |
331 if (!task_runner_) { | |
332 // If a forced shutdown has been done, don't let it restart. | |
333 if (task_runner_forced_shutdown_) | |
334 return nullptr; | |
335 // If this is not the first time the sampling thread has been launched, the | |
336 // previous instance has only been partially cleaned up. It is necessary | |
337 // to call Stop() before Start(). This is safe even the thread has never | |
338 // been started. | |
339 Stop(); | |
340 // The thread is not running. Start it and get associated runner. The task- | |
341 // runner has to be saved for future use because though it can be used from | |
342 // any thread, it can be acquired via task_runner() only on the created | |
343 // thread and the thread that creates it (i.e. this thread). | |
344 Start(); | |
345 task_runner_ = Thread::task_runner(); | |
346 // Detach the sampling thread from the "sequence" (i.e. thread) that | |
347 // started it so that it can be self-managed or stopped on by another | |
348 // thread. | |
349 DetachFromSequence(); | |
350 } else { | |
351 // This shouldn't be called from the sampling thread as it's inefficient. | |
352 // Use GetTaskRunnerOnSamplingThread() instead. | |
353 DCHECK_NE(GetThreadId(), PlatformThread::CurrentId()); | |
354 } | |
355 | |
356 return task_runner_; | |
357 } | |
358 | |
359 scoped_refptr<SingleThreadTaskRunner> | |
360 StackSamplingProfiler::SamplingThread::GetTaskRunner() { | |
361 // This shouldn't be called from the sampling thread as it's inefficient. Use | |
362 // GetTaskRunnerOnSamplingThread() instead. | |
363 DCHECK_NE(GetThreadId(), PlatformThread::CurrentId()); | |
364 | |
365 AutoLock lock(task_runner_lock_); | |
366 return task_runner_; | |
367 } | |
368 | |
369 scoped_refptr<SingleThreadTaskRunner> | |
370 StackSamplingProfiler::SamplingThread::GetTaskRunnerOnSamplingThread() { | |
371 // This should be called only from the sampling thread as it has limited | |
372 // accessibility. | |
373 DCHECK_EQ(GetThreadId(), PlatformThread::CurrentId()); | |
374 | |
375 return Thread::task_runner(); | |
376 } | |
377 | |
378 void StackSamplingProfiler::SamplingThread::FinishCollection( | |
379 CollectionContext* collection) { | |
380 // If there is no duration for the final profile (because it was stopped), | |
381 // calculated it now. | |
382 if (!collection->profiles.empty() && | |
383 collection->profiles.back().profile_duration == TimeDelta()) { | |
384 collection->profiles.back().profile_duration = | |
385 Time::Now() - collection->profile_start_time; | |
386 } | |
387 | |
388 // Run the associated callback, passing the collected profiles. It's okay to | |
389 // move them because this collection is about to be deleted. | |
390 collection->callback.Run(std::move(collection->profiles)); | |
391 | |
392 // Signal that this collection is finished. | |
393 collection->finished->Signal(); | |
394 | |
395 // Remove this collection from the map of known ones. This must be done | |
396 // last as the |collection| parameter is invalid after this point. | |
397 size_t count = active_collections_.erase(collection->collection_id); | |
398 DCHECK_EQ(1U, count); | |
399 } | |
400 | |
401 void StackSamplingProfiler::SamplingThread::RecordSample( | |
402 CollectionContext* collection) { | |
403 DCHECK(collection->native_sampler); | |
404 | |
405 // If this is the first sample of a burst, a new Profile needs to be created | |
406 // and filled. | |
407 if (collection->sample == 0) { | |
408 collection->profiles.push_back(CallStackProfile()); | |
409 CallStackProfile& profile = collection->profiles.back(); | |
410 profile.sampling_period = collection->params.sampling_interval; | |
411 collection->profile_start_time = Time::Now(); | |
412 collection->native_sampler->ProfileRecordingStarting(&profile.modules); | |
413 } | |
414 | |
415 // The currently active profile being acptured. | |
416 CallStackProfile& profile = collection->profiles.back(); | |
417 | |
418 // Record a single sample. | |
419 profile.samples.push_back(Sample()); | |
420 Sample& sample = profile.samples.back(); | |
421 collection->native_sampler->RecordStackSample(&sample); | |
422 | |
423 // If the thread was not suspendable, assume it has exited. | |
424 if (collection->native_sampler->thread_state() == | |
425 NativeStackSampler::THREAD_EXITED) { | |
426 // Indicate that collection is complete so it stops below and finishes. | |
427 // The empty frame remains as an indicator during analysis that the | |
428 // thread exited. | |
429 collection->sample = collection->params.samples_per_burst - 1; | |
430 collection->burst = collection->params.bursts - 1; | |
431 } | |
432 | |
433 // If this is the last sample of a burst, record the total time. | |
434 if (collection->sample == collection->params.samples_per_burst - 1) { | |
435 profile.profile_duration = Time::Now() - collection->profile_start_time; | |
436 collection->native_sampler->ProfileRecordingStopped(); | |
437 } | |
438 } | |
439 | |
440 void StackSamplingProfiler::SamplingThread::CheckForIdle() { | |
441 if (!active_collections_.empty()) | |
181 return; | 442 return; |
182 | 443 |
183 CallStackProfiles profiles; | 444 AutoLock lock(task_runner_lock_); |
184 CollectProfiles(&profiles); | 445 if (!task_runner_idle_shutdown_time_.is_zero()) { |
185 concurrent_profiling_lock.Get().Release(); | 446 GetTaskRunnerOnSamplingThread()->PostDelayedTask( |
186 completed_callback_.Run(std::move(profiles)); | 447 FROM_HERE, Bind(&SamplingThread::ShutdownTask, Unretained(this)), |
187 } | 448 task_runner_idle_shutdown_time_); |
188 | 449 } |
189 // Depending on how long the sampling takes and the length of the sampling | 450 } |
190 // interval, a burst of samples could take arbitrarily longer than | 451 |
191 // samples_per_burst * sampling_interval. In this case, we (somewhat | 452 void StackSamplingProfiler::SamplingThread::AddCollectionTask( |
192 // arbitrarily) honor the number of samples requested rather than strictly | 453 std::unique_ptr<CollectionContext> collection_ptr) { |
193 // adhering to the sampling intervals. Once we have established users for the | 454 // Ownership of the collection is going to be given to a map but a pointer |
194 // StackSamplingProfiler and the collected data to judge, we may go the other | 455 // to it will be needed later. |
195 // way or make this behavior configurable. | 456 CollectionContext* collection = collection_ptr.get(); |
196 void StackSamplingProfiler::SamplingThread::CollectProfile( | 457 active_collections_.insert( |
197 CallStackProfile* profile, | 458 std::make_pair(collection->collection_id, std::move(collection_ptr))); |
198 TimeDelta* elapsed_time, | 459 |
199 bool* was_stopped) { | 460 GetTaskRunnerOnSamplingThread()->PostDelayedTask( |
200 ElapsedTimer profile_timer; | 461 FROM_HERE, Bind(&SamplingThread::PerformCollectionTask, Unretained(this), |
201 native_sampler_->ProfileRecordingStarting(&profile->modules); | 462 collection->collection_id), |
202 profile->sampling_period = params_.sampling_interval; | 463 collection->params.initial_delay); |
203 *was_stopped = false; | 464 } |
204 TimeDelta previous_elapsed_sample_time; | 465 |
205 for (int i = 0; i < params_.samples_per_burst; ++i) { | 466 void StackSamplingProfiler::SamplingThread::RemoveCollectionTask(int id) { |
206 if (i != 0) { | 467 auto found = active_collections_.find(id); |
207 // Always wait, even if for 0 seconds, so we can observe a signal on | 468 if (found == active_collections_.end()) |
208 // stop_event_. | 469 return; |
209 if (stop_event_.TimedWait( | 470 |
210 std::max(params_.sampling_interval - previous_elapsed_sample_time, | 471 FinishCollection(found->second.get()); |
211 TimeDelta()))) { | 472 CheckForIdle(); |
212 *was_stopped = true; | 473 } |
213 break; | 474 |
214 } | 475 void StackSamplingProfiler::SamplingThread::PerformCollectionTask(int id) { |
476 auto found = active_collections_.find(id); | |
477 | |
478 // The task won't be found if it has been stopped. | |
479 if (found == active_collections_.end()) | |
480 return; | |
481 | |
482 CollectionContext* collection = found->second.get(); | |
483 | |
484 // Handle first-run with no "next time". | |
485 if (collection->next_sample_time == Time()) | |
486 collection->next_sample_time = Time::Now(); | |
487 | |
488 // Do the collection of a single sample. | |
489 RecordSample(collection); | |
490 | |
491 // Update the time of the next sample recording. | |
492 if (UpdateNextSampleTime(collection)) { | |
493 bool success = GetTaskRunnerOnSamplingThread()->PostDelayedTask( | |
494 FROM_HERE, | |
495 Bind(&SamplingThread::PerformCollectionTask, Unretained(this), id), | |
496 std::max(collection->next_sample_time - Time::Now(), TimeDelta())); | |
497 DCHECK(success); | |
498 } else { | |
499 // All capturing has completed so finish the collection. Let object expire. | |
500 // The |collection| variable will be invalid after this call. | |
501 FinishCollection(collection); | |
502 CheckForIdle(); | |
503 } | |
504 } | |
505 | |
506 void StackSamplingProfiler::SamplingThread::ShutdownTask() { | |
507 // Holding this lock ensures that any attempt to start another job will | |
508 // get postponed until StopSoon can run thus eliminating the race. | |
509 AutoLock lock(task_runner_lock_); | |
510 | |
511 // If this is a forced, permanent shutdown, stop all active collections. | |
512 if (task_runner_forced_shutdown_) { | |
513 // FinishCollection will remove the entry thus invalidating any iterator. | |
514 while (!active_collections_.empty()) | |
515 FinishCollection(active_collections_.begin()->second.get()); | |
516 } else { | |
517 // If active_collections_ is not empty, something new has arrived since | |
518 // this task got posted. Abort the shutdown so it can be processed. | |
519 if (!active_collections_.empty()) | |
520 return; | |
521 // It's possible that a new AddCollectionTask has been posted after this | |
522 // task. Reset the "create requests" counter and try again after any other | |
523 // pending tasks. | |
524 if (task_runner_create_requests_ > 0 && task_runner_) { | |
525 task_runner_create_requests_ = 0; | |
526 task_runner_->PostTask( | |
527 FROM_HERE, Bind(&SamplingThread::ShutdownTask, Unretained(this))); | |
528 return; | |
215 } | 529 } |
216 ElapsedTimer sample_timer; | 530 // There can be no new AddCollectionTasks at this point because creating |
217 profile->samples.push_back(Sample()); | 531 // those always increments "create requests". There may be other requests, |
218 native_sampler_->RecordStackSample(&profile->samples.back()); | 532 // like Remove, but it's okay to schedule the thread to stop once they've |
219 previous_elapsed_sample_time = sample_timer.Elapsed(); | 533 // been executed (i.e. "soon"). |
220 } | 534 } |
221 | 535 |
222 *elapsed_time = profile_timer.Elapsed(); | 536 // Stop the underlying thread as soon as all immediate tasks are complete. |
223 profile->profile_duration = *elapsed_time; | 537 // Calling Stop() directly would result in deadlock. |
224 native_sampler_->ProfileRecordingStopped(); | 538 StopSoon(); |
225 } | 539 |
226 | 540 // StopSoon will have set the owning sequence (again) so it must be detached |
227 // In an analogous manner to CollectProfile() and samples exceeding the expected | 541 // (again) in order for Stop/Start to be called (again) should more work |
228 // total sampling time, bursts may also exceed the burst_interval. We adopt the | 542 // come in. Holding the |task_runner_lock_| ensures the necessary happens- |
229 // same wait-and-see approach here. | 543 // after with regard to this detach and future Thread API calls. |
230 void StackSamplingProfiler::SamplingThread::CollectProfiles( | 544 DetachFromSequence(); |
231 CallStackProfiles* profiles) { | 545 |
232 if (stop_event_.TimedWait(params_.initial_delay)) | 546 // Clear the task_runner_ variable so the thread will be restarted when |
233 return; | 547 // new work comes in. |
234 | 548 task_runner_ = nullptr; |
235 TimeDelta previous_elapsed_profile_time; | 549 } |
236 for (int i = 0; i < params_.bursts; ++i) { | 550 |
237 if (i != 0) { | 551 bool StackSamplingProfiler::SamplingThread::UpdateNextSampleTime( |
238 // Always wait, even if for 0 seconds, so we can observe a signal on | 552 CollectionContext* collection) { |
239 // stop_event_. | 553 if (++collection->sample < collection->params.samples_per_burst) { |
240 if (stop_event_.TimedWait( | 554 collection->next_sample_time += collection->params.sampling_interval; |
241 std::max(params_.burst_interval - previous_elapsed_profile_time, | 555 return true; |
242 TimeDelta()))) | 556 } |
243 return; | 557 |
244 } | 558 // This will keep a consistent average interval between samples but will |
245 | 559 // result in constant series of acquisitions, thus nearly locking out the |
246 CallStackProfile profile; | 560 // target thread, if the interval is smaller than the time it takes to |
247 bool was_stopped = false; | 561 // actually acquire the sample. Anything sampling that quickly is going |
248 CollectProfile(&profile, &previous_elapsed_profile_time, &was_stopped); | 562 // to be a problem anyway so don't worry about it. |
249 if (!profile.samples.empty()) | 563 if (++collection->burst < collection->params.bursts) { |
250 profiles->push_back(std::move(profile)); | 564 collection->sample = 0; |
251 | 565 collection->next_sample_time += collection->params.burst_interval; |
252 if (was_stopped) | 566 return true; |
253 return; | 567 } |
254 } | 568 |
255 } | 569 return false; |
256 | 570 } |
257 void StackSamplingProfiler::SamplingThread::Stop() { | 571 |
258 stop_event_.Signal(); | 572 void StackSamplingProfiler::SamplingThread::CleanUp() { |
573 // There should be no collections remaining when the thread stops. | |
574 DCHECK(active_collections_.empty()); | |
575 | |
576 // Let the parent clean up. | |
577 Thread::CleanUp(); | |
259 } | 578 } |
260 | 579 |
261 // StackSamplingProfiler ------------------------------------------------------ | 580 // StackSamplingProfiler ------------------------------------------------------ |
262 | 581 |
263 subtle::Atomic32 StackSamplingProfiler::process_milestones_ = 0; | 582 subtle::Atomic32 StackSamplingProfiler::process_milestones_ = 0; |
264 | 583 |
265 StackSamplingProfiler::SamplingParams::SamplingParams() | 584 StackSamplingProfiler::SamplingParams::SamplingParams() |
266 : initial_delay(TimeDelta::FromMilliseconds(0)), | 585 : initial_delay(TimeDelta::FromMilliseconds(0)), |
267 bursts(1), | 586 bursts(1), |
268 burst_interval(TimeDelta::FromMilliseconds(10000)), | 587 burst_interval(TimeDelta::FromMilliseconds(10000)), |
269 samples_per_burst(300), | 588 samples_per_burst(300), |
270 sampling_interval(TimeDelta::FromMilliseconds(100)) { | 589 sampling_interval(TimeDelta::FromMilliseconds(100)) { |
271 } | 590 } |
272 | 591 |
273 StackSamplingProfiler::StackSamplingProfiler( | 592 StackSamplingProfiler::StackSamplingProfiler( |
274 PlatformThreadId thread_id, | 593 PlatformThreadId thread_id, |
275 const SamplingParams& params, | 594 const SamplingParams& params, |
276 const CompletedCallback& callback) | 595 const CompletedCallback& callback) |
277 : StackSamplingProfiler(thread_id, params, callback, nullptr) {} | 596 : StackSamplingProfiler(thread_id, params, callback, nullptr) {} |
278 | 597 |
279 StackSamplingProfiler::StackSamplingProfiler( | 598 StackSamplingProfiler::StackSamplingProfiler( |
280 PlatformThreadId thread_id, | 599 PlatformThreadId thread_id, |
281 const SamplingParams& params, | 600 const SamplingParams& params, |
282 const CompletedCallback& callback, | 601 const CompletedCallback& callback, |
283 NativeStackSamplerTestDelegate* test_delegate) | 602 NativeStackSamplerTestDelegate* test_delegate) |
284 : thread_id_(thread_id), params_(params), completed_callback_(callback), | 603 : thread_id_(thread_id), |
604 params_(params), | |
605 completed_callback_(callback), | |
606 finished_event_(WaitableEvent::ResetPolicy::MANUAL, | |
607 WaitableEvent::InitialState::NOT_SIGNALED), | |
285 test_delegate_(test_delegate) { | 608 test_delegate_(test_delegate) { |
609 native_sampler_ = NativeStackSampler::Create(thread_id_, &RecordAnnotations, | |
610 test_delegate_); | |
286 } | 611 } |
287 | 612 |
288 StackSamplingProfiler::~StackSamplingProfiler() { | 613 StackSamplingProfiler::~StackSamplingProfiler() { |
289 Stop(); | 614 Stop(); |
290 if (!sampling_thread_handle_.is_null()) | 615 finished_event_.Wait(); |
291 PlatformThread::Join(sampling_thread_handle_); | |
292 } | |
293 | |
294 // static | |
295 void StackSamplingProfiler::StartAndRunAsync( | |
296 PlatformThreadId thread_id, | |
297 const SamplingParams& params, | |
298 const CompletedCallback& callback) { | |
299 CHECK(ThreadTaskRunnerHandle::Get()); | |
300 AsyncRunner::Run(thread_id, params, callback); | |
301 } | 616 } |
302 | 617 |
303 void StackSamplingProfiler::Start() { | 618 void StackSamplingProfiler::Start() { |
304 if (completed_callback_.is_null()) | 619 if (completed_callback_.is_null()) |
305 return; | 620 return; |
306 | 621 |
307 std::unique_ptr<NativeStackSampler> native_sampler = | 622 if (!native_sampler_) |
308 NativeStackSampler::Create(thread_id_, &RecordAnnotations, | |
309 test_delegate_); | |
310 if (!native_sampler) | |
311 return; | 623 return; |
312 | 624 |
313 sampling_thread_.reset(new SamplingThread(std::move(native_sampler), params_, | 625 collection_id_ = SamplingThread::GetInstance()->Add( |
314 completed_callback_)); | 626 MakeUnique<SamplingThread::CollectionContext>( |
315 if (!PlatformThread::Create(0, sampling_thread_.get(), | 627 thread_id_, params_, completed_callback_, &finished_event_, |
316 &sampling_thread_handle_)) | 628 std::move(native_sampler_))); |
317 sampling_thread_.reset(); | |
318 } | 629 } |
319 | 630 |
320 void StackSamplingProfiler::Stop() { | 631 void StackSamplingProfiler::Stop() { |
321 if (sampling_thread_) | 632 SamplingThread::GetInstance()->Remove(collection_id_); |
322 sampling_thread_->Stop(); | |
323 } | 633 } |
324 | 634 |
325 // static | 635 // static |
636 void StackSamplingProfiler::Shutdown() { | |
637 SamplingThread::GetInstance()->Shutdown(); | |
638 } | |
639 | |
640 // static | |
641 void StackSamplingProfiler::UndoShutdownForTesting() { | |
642 SamplingThread::GetInstance()->UndoShutdown(); | |
643 } | |
644 | |
645 // static | |
646 bool StackSamplingProfiler::IsSamplingThreadRunningForTesting() { | |
647 return SamplingThread::GetInstance()->IsRunning(); | |
648 } | |
649 | |
650 // static | |
651 void StackSamplingProfiler::SetSamplingThreadIdleShutdownTimeForTesting( | |
652 int shutdown_ms) { | |
653 SamplingThread::GetInstance()->SetIdleShutdownTime(shutdown_ms); | |
654 } | |
655 | |
656 // static | |
657 void StackSamplingProfiler::InitiateSamplingThreadIdleShutdownForTesting() { | |
658 SamplingThread::GetInstance()->ShutdownIfIdle(); | |
659 } | |
660 | |
661 // static | |
326 void StackSamplingProfiler::SetProcessMilestone(int milestone) { | 662 void StackSamplingProfiler::SetProcessMilestone(int milestone) { |
327 DCHECK_LE(0, milestone); | 663 DCHECK_LE(0, milestone); |
328 DCHECK_GT(static_cast<int>(sizeof(process_milestones_) * 8), milestone); | 664 DCHECK_GT(static_cast<int>(sizeof(process_milestones_) * 8), milestone); |
329 DCHECK_EQ(0, subtle::NoBarrier_Load(&process_milestones_) & (1 << milestone)); | 665 DCHECK_EQ(0, subtle::NoBarrier_Load(&process_milestones_) & (1 << milestone)); |
330 ChangeAtomicFlags(&process_milestones_, 1 << milestone, 0); | 666 ChangeAtomicFlags(&process_milestones_, 1 << milestone, 0); |
331 } | 667 } |
332 | 668 |
333 // static | 669 // static |
334 void StackSamplingProfiler::ResetAnnotationsForTesting() { | 670 void StackSamplingProfiler::ResetAnnotationsForTesting() { |
335 subtle::NoBarrier_Store(&process_milestones_, 0u); | 671 subtle::NoBarrier_Store(&process_milestones_, 0u); |
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378 } | 714 } |
379 | 715 |
380 bool operator<(const StackSamplingProfiler::Frame &a, | 716 bool operator<(const StackSamplingProfiler::Frame &a, |
381 const StackSamplingProfiler::Frame &b) { | 717 const StackSamplingProfiler::Frame &b) { |
382 return (a.module_index < b.module_index) || | 718 return (a.module_index < b.module_index) || |
383 (a.module_index == b.module_index && | 719 (a.module_index == b.module_index && |
384 a.instruction_pointer < b.instruction_pointer); | 720 a.instruction_pointer < b.instruction_pointer); |
385 } | 721 } |
386 | 722 |
387 } // namespace base | 723 } // namespace base |
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