1 /*
2 * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "jfr/jni/jfrJavaSupport.hpp"
27 #include "jfr/leakprofiler/leakProfiler.hpp"
28 #include "jfr/leakprofiler/checkpoint/objectSampleCheckpoint.hpp"
29 #include "jfr/leakprofiler/sampling/objectSampler.hpp"
30 #include "jfr/recorder/jfrRecorder.hpp"
31 #include "jfr/recorder/checkpoint/jfrCheckpointManager.hpp"
32 #include "jfr/recorder/checkpoint/jfrMetadataEvent.hpp"
33 #include "jfr/recorder/repository/jfrChunkRotation.hpp"
34 #include "jfr/recorder/repository/jfrChunkWriter.hpp"
35 #include "jfr/recorder/repository/jfrRepository.hpp"
36 #include "jfr/recorder/service/jfrPostBox.hpp"
37 #include "jfr/recorder/service/jfrRecorderService.hpp"
38 #include "jfr/recorder/stacktrace/jfrStackTraceRepository.hpp"
39 #include "jfr/recorder/storage/jfrStorage.hpp"
40 #include "jfr/recorder/storage/jfrStorageControl.hpp"
41 #include "jfr/recorder/stringpool/jfrStringPool.hpp"
42 #include "jfr/utilities/jfrAllocation.hpp"
43 #include "jfr/utilities/jfrTime.hpp"
44 #include "jfr/writers/jfrJavaEventWriter.hpp"
45 #include "jfr/utilities/jfrTypes.hpp"
46 #include "logging/log.hpp"
47 #include "memory/resourceArea.hpp"
48 #include "runtime/atomic.hpp"
49 #include "runtime/handles.inline.hpp"
50 #include "runtime/mutexLocker.inline.hpp"
51 #include "runtime/orderAccess.hpp"
52 #include "runtime/os.hpp"
53 #include "runtime/safepoint.hpp"
54 #include "runtime/thread.inline.hpp"
55 #include "runtime/vmOperations.hpp"
56 #include "runtime/vmThread.hpp"
57
58 // set data iff *dest == NULL
59 static bool try_set(void* const data, void** dest, bool clear) {
60 assert(data != NULL, "invariant");
61 const void* const current = OrderAccess::load_acquire(dest);
62 if (current != NULL) {
63 if (current != data) {
64 // already set
65 return false;
66 }
67 assert(current == data, "invariant");
68 if (!clear) {
69 // recursion disallowed
70 return false;
71 }
72 }
73 return Atomic::cmpxchg(clear ? NULL : data, dest, current) == current;
74 }
75
76 static void* rotation_thread = NULL;
77 static const int rotation_try_limit = 1000;
78 static const int rotation_retry_sleep_millis = 10;
79
80 class RotationLock : public StackObj {
81 private:
82 Thread* const _thread;
83 bool _acquired;
84
85 void log(bool recursion) {
86 assert(!_acquired, "invariant");
87 const char* error_msg = NULL;
88 if (recursion) {
89 error_msg = "Unable to issue rotation due to recursive calls.";
90 }
91 else {
92 error_msg = "Unable to issue rotation due to wait timeout.";
93 }
94 log_info(jfr)( // For user, should not be "jfr, system"
95 "%s", error_msg);
96 }
97 public:
98 RotationLock(Thread* thread) : _thread(thread), _acquired(false) {
99 assert(_thread != NULL, "invariant");
100 if (_thread == rotation_thread) {
101 // recursion not supported
102 log(true);
103 return;
104 }
105
106 // limited to not spin indefinitely
107 for (int i = 0; i < rotation_try_limit; ++i) {
108 if (try_set(_thread, &rotation_thread, false)) {
109 _acquired = true;
110 assert(_thread == rotation_thread, "invariant");
111 return;
112 }
113 if (_thread->is_Java_thread()) {
114 // in order to allow the system to move to a safepoint
115 MutexLocker msg_lock(JfrMsg_lock);
116 JfrMsg_lock->wait(rotation_retry_sleep_millis);
117 }
118 else {
119 os::naked_short_sleep(rotation_retry_sleep_millis);
120 }
121 }
122 log(false);
123 }
124
125 ~RotationLock() {
126 assert(_thread != NULL, "invariant");
127 if (_acquired) {
128 assert(_thread == rotation_thread, "invariant");
129 while (!try_set(_thread, &rotation_thread, true));
130 }
131 }
132 bool not_acquired() const { return !_acquired; }
133 };
134
135 static int64_t write_checkpoint_event_prologue(JfrChunkWriter& cw, u8 type_id) {
136 const int64_t last_cp_offset = cw.last_checkpoint_offset();
137 const int64_t delta_to_last_checkpoint = 0 == last_cp_offset ? 0 : last_cp_offset - cw.current_offset();
138 cw.reserve(sizeof(u4));
139 cw.write<u8>(EVENT_CHECKPOINT);
140 cw.write(JfrTicks::now());
141 cw.write((int64_t)0); // duration
142 cw.write(delta_to_last_checkpoint);
143 cw.write<bool>(false); // flushpoint
144 cw.write((u4)1); // nof types in this checkpoint
145 cw.write(type_id);
146 const int64_t number_of_elements_offset = cw.current_offset();
147 cw.reserve(sizeof(u4));
148 return number_of_elements_offset;
149 }
150
151 template <typename ContentFunctor>
152 class WriteCheckpointEvent : public StackObj {
153 private:
154 JfrChunkWriter& _cw;
155 u8 _type_id;
156 ContentFunctor& _content_functor;
157 public:
158 WriteCheckpointEvent(JfrChunkWriter& cw, u8 type_id, ContentFunctor& functor) :
159 _cw(cw),
160 _type_id(type_id),
161 _content_functor(functor) {
162 assert(_cw.is_valid(), "invariant");
163 }
164 bool process() {
165 // current_cp_offset is also offset for the event size header field
166 const int64_t current_cp_offset = _cw.current_offset();
167 const int64_t num_elements_offset = write_checkpoint_event_prologue(_cw, _type_id);
168 // invocation
169 _content_functor.process();
170 const u4 number_of_elements = (u4)_content_functor.processed();
171 if (number_of_elements == 0) {
172 // nothing to do, rewind writer to start
173 _cw.seek(current_cp_offset);
174 return true;
175 }
176 assert(number_of_elements > 0, "invariant");
177 assert(_cw.current_offset() > num_elements_offset, "invariant");
178 _cw.write_padded_at_offset<u4>(number_of_elements, num_elements_offset);
179 _cw.write_padded_at_offset<u4>((u4)_cw.current_offset() - current_cp_offset, current_cp_offset);
180 // update writer with last checkpoint position
181 _cw.set_last_checkpoint_offset(current_cp_offset);
182 return true;
183 }
184 };
185
186 template <typename Instance, size_t(Instance::*func)()>
187 class ServiceFunctor {
188 private:
189 Instance& _instance;
190 size_t _processed;
191 public:
192 ServiceFunctor(Instance& instance) : _instance(instance), _processed(0) {}
193 bool process() {
194 _processed = (_instance.*func)();
195 return true;
196 }
197 size_t processed() const { return _processed; }
198 };
199
200 template <typename Instance, void(Instance::*func)()>
201 class JfrVMOperation : public VM_Operation {
202 private:
203 Instance& _instance;
204 public:
205 JfrVMOperation(Instance& instance) : _instance(instance) {}
206 void doit() { (_instance.*func)(); }
207 VMOp_Type type() const { return VMOp_JFRCheckpoint; }
208 Mode evaluation_mode() const { return _safepoint; } // default
209 };
210
211 class WriteStackTraceRepository : public StackObj {
212 private:
213 JfrStackTraceRepository& _repo;
214 JfrChunkWriter& _cw;
215 size_t _elements_processed;
216 bool _clear;
217
218 public:
219 WriteStackTraceRepository(JfrStackTraceRepository& repo, JfrChunkWriter& cw, bool clear) :
220 _repo(repo), _cw(cw), _elements_processed(0), _clear(clear) {}
221 bool process() {
222 _elements_processed = _repo.write(_cw, _clear);
223 return true;
224 }
225 size_t processed() const { return _elements_processed; }
226 void reset() { _elements_processed = 0; }
227 };
228
229 static bool recording = false;
230
231 static void set_recording_state(bool is_recording) {
232 OrderAccess::storestore();
233 recording = is_recording;
234 }
235
236 bool JfrRecorderService::is_recording() {
237 return recording;
238 }
239
240 JfrRecorderService::JfrRecorderService() :
241 _checkpoint_manager(JfrCheckpointManager::instance()),
242 _chunkwriter(JfrRepository::chunkwriter()),
243 _repository(JfrRepository::instance()),
244 _stack_trace_repository(JfrStackTraceRepository::instance()),
245 _storage(JfrStorage::instance()),
246 _string_pool(JfrStringPool::instance()) {}
247
248 void JfrRecorderService::start() {
249 RotationLock rl(Thread::current());
250 if (rl.not_acquired()) {
251 return;
252 }
253 log_debug(jfr, system)("Request to START recording");
254 assert(!is_recording(), "invariant");
255 clear();
256 set_recording_state(true);
257 assert(is_recording(), "invariant");
258 open_new_chunk();
259 log_debug(jfr, system)("Recording STARTED");
260 }
261
262 void JfrRecorderService::clear() {
263 ResourceMark rm;
264 HandleMark hm;
265 pre_safepoint_clear();
266 invoke_safepoint_clear();
267 post_safepoint_clear();
268 }
269
270 void JfrRecorderService::pre_safepoint_clear() {
271 _stack_trace_repository.clear();
272 _string_pool.clear();
273 _storage.clear();
274 }
275
276 void JfrRecorderService::invoke_safepoint_clear() {
277 JfrVMOperation<JfrRecorderService, &JfrRecorderService::safepoint_clear> safepoint_task(*this);
278 VMThread::execute(&safepoint_task);
279 }
280
281 //
282 // safepoint clear sequence
283 //
284 // clear stacktrace repository ->
285 // clear string pool ->
286 // clear storage ->
287 // shift epoch ->
288 // update time
289 //
290 void JfrRecorderService::safepoint_clear() {
291 assert(SafepointSynchronize::is_at_safepoint(), "invariant");
292 _stack_trace_repository.clear();
293 _string_pool.clear();
294 _storage.clear();
295 _checkpoint_manager.shift_epoch();
296 _chunkwriter.time_stamp_chunk_now();
297 }
298
299 void JfrRecorderService::post_safepoint_clear() {
300 _checkpoint_manager.clear();
301 }
302
303 static void stop() {
304 assert(JfrRecorderService::is_recording(), "invariant");
305 log_debug(jfr, system)("Recording STOPPED");
306 set_recording_state(false);
307 assert(!JfrRecorderService::is_recording(), "invariant");
308 }
309
310 void JfrRecorderService::rotate(int msgs) {
311 RotationLock rl(Thread::current());
312 if (rl.not_acquired()) {
313 return;
314 }
315 static bool vm_error = false;
316 if (msgs & MSGBIT(MSG_VM_ERROR)) {
317 vm_error = true;
318 prepare_for_vm_error_rotation();
319 }
320 if (!_storage.control().to_disk()) {
321 in_memory_rotation();
322 } else if (vm_error) {
323 vm_error_rotation();
324 } else {
325 chunk_rotation();
326 }
327 if (msgs & (MSGBIT(MSG_STOP))) {
328 stop();
329 }
330 }
331
332 void JfrRecorderService::prepare_for_vm_error_rotation() {
333 if (!_chunkwriter.is_valid()) {
334 open_new_chunk(true);
335 }
336 _checkpoint_manager.register_service_thread(Thread::current());
337 JfrMetadataEvent::lock();
338 }
339
340 void JfrRecorderService::open_new_chunk(bool vm_error) {
341 assert(!_chunkwriter.is_valid(), "invariant");
342 assert(!JfrStream_lock->owned_by_self(), "invariant");
343 JfrChunkRotation::on_rotation();
344 MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
345 if (!_repository.open_chunk(vm_error)) {
346 assert(!_chunkwriter.is_valid(), "invariant");
347 _storage.control().set_to_disk(false);
348 return;
349 }
350 assert(_chunkwriter.is_valid(), "invariant");
351 _storage.control().set_to_disk(true);
352 }
353
354 void JfrRecorderService::in_memory_rotation() {
355 assert(!_chunkwriter.is_valid(), "invariant");
356 // currently running an in-memory recording
357 open_new_chunk();
358 if (_chunkwriter.is_valid()) {
359 // dump all in-memory buffer data to the newly created chunk
360 serialize_storage_from_in_memory_recording();
361 }
362 }
363
364 void JfrRecorderService::serialize_storage_from_in_memory_recording() {
365 assert(!JfrStream_lock->owned_by_self(), "not holding stream lock!");
366 MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
367 _storage.write();
368 }
369
370 void JfrRecorderService::chunk_rotation() {
371 finalize_current_chunk();
372 open_new_chunk();
373 }
374
375 void JfrRecorderService::finalize_current_chunk() {
376 assert(_chunkwriter.is_valid(), "invariant");
377 write();
378 assert(!_chunkwriter.is_valid(), "invariant");
379 }
380
381 void JfrRecorderService::write() {
382 ResourceMark rm;
383 HandleMark hm;
384 pre_safepoint_write();
385 invoke_safepoint_write();
386 post_safepoint_write();
387 }
388
389 typedef ServiceFunctor<JfrStringPool, &JfrStringPool::write> WriteStringPool;
390 typedef ServiceFunctor<JfrStringPool, &JfrStringPool::write_at_safepoint> WriteStringPoolSafepoint;
391 typedef WriteCheckpointEvent<WriteStackTraceRepository> WriteStackTraceCheckpoint;
392 typedef WriteCheckpointEvent<WriteStringPool> WriteStringPoolCheckpoint;
393 typedef WriteCheckpointEvent<WriteStringPoolSafepoint> WriteStringPoolCheckpointSafepoint;
394
395 static void write_stacktrace_checkpoint(JfrStackTraceRepository& stack_trace_repo, JfrChunkWriter& chunkwriter, bool clear) {
396 WriteStackTraceRepository write_stacktrace_repo(stack_trace_repo, chunkwriter, clear);
397 WriteStackTraceCheckpoint write_stack_trace_checkpoint(chunkwriter, TYPE_STACKTRACE, write_stacktrace_repo);
398 write_stack_trace_checkpoint.process();
399 }
400 static void write_stringpool_checkpoint(JfrStringPool& string_pool, JfrChunkWriter& chunkwriter) {
401 WriteStringPool write_string_pool(string_pool);
402 WriteStringPoolCheckpoint write_string_pool_checkpoint(chunkwriter, TYPE_STRING, write_string_pool);
403 write_string_pool_checkpoint.process();
404 }
405
406 static void write_stringpool_checkpoint_safepoint(JfrStringPool& string_pool, JfrChunkWriter& chunkwriter) {
407 WriteStringPoolSafepoint write_string_pool(string_pool);
408 WriteStringPoolCheckpointSafepoint write_string_pool_checkpoint(chunkwriter, TYPE_STRING, write_string_pool);
409 write_string_pool_checkpoint.process();
410 }
411
412 //
413 // pre-safepoint write sequence
414 //
415 // lock stream lock ->
416 // write non-safepoint dependent types ->
417 // write checkpoint epoch transition list->
418 // write stack trace checkpoint ->
419 // write string pool checkpoint ->
420 // write object sample stacktraces ->
421 // write storage ->
422 // release stream lock
423 //
424 void JfrRecorderService::pre_safepoint_write() {
425 MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
426 assert(_chunkwriter.is_valid(), "invariant");
427 _checkpoint_manager.write_types();
428 _checkpoint_manager.write_epoch_transition_mspace();
429 write_stacktrace_checkpoint(_stack_trace_repository, _chunkwriter, false);
430 write_stringpool_checkpoint(_string_pool, _chunkwriter);
431 if (LeakProfiler::is_running()) {
432 // Exclusive access to the object sampler instance.
433 // The sampler is released (unlocked) later in post_safepoint_write.
434 ObjectSampleCheckpoint::on_rotation(ObjectSampler::acquire(), _stack_trace_repository);
435 }
436 _storage.write();
437 }
438
439 void JfrRecorderService::invoke_safepoint_write() {
440 JfrVMOperation<JfrRecorderService, &JfrRecorderService::safepoint_write> safepoint_task(*this);
441 VMThread::execute(&safepoint_task);
442 }
443
444 //
445 // safepoint write sequence
446 //
447 // lock stream lock ->
448 // write stacktrace repository ->
449 // write string pool ->
450 // write safepoint dependent types ->
451 // write storage ->
452 // shift_epoch ->
453 // update time ->
454 // lock metadata descriptor ->
455 // release stream lock
456 //
457 void JfrRecorderService::safepoint_write() {
458 assert(SafepointSynchronize::is_at_safepoint(), "invariant");
459 MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
460 write_stacktrace_checkpoint(_stack_trace_repository, _chunkwriter, true);
461 write_stringpool_checkpoint_safepoint(_string_pool, _chunkwriter);
462 _checkpoint_manager.write_safepoint_types();
463 _storage.write_at_safepoint();
464 _checkpoint_manager.shift_epoch();
465 _chunkwriter.time_stamp_chunk_now();
466 JfrMetadataEvent::lock();
467 }
468
469 static int64_t write_metadata_event(JfrChunkWriter& chunkwriter) {
470 assert(chunkwriter.is_valid(), "invariant");
471 const int64_t metadata_offset = chunkwriter.current_offset();
472 JfrMetadataEvent::write(chunkwriter, metadata_offset);
473 return metadata_offset;
474 }
475
476 //
477 // post-safepoint write sequence
478 //
479 // write type set ->
480 // release object sampler ->
481 // lock stream lock ->
482 // write checkpoints ->
483 // write metadata event ->
484 // write chunk header ->
485 // close chunk fd ->
486 // release stream lock
487 //
488 void JfrRecorderService::post_safepoint_write() {
489 assert(_chunkwriter.is_valid(), "invariant");
490 // During the safepoint tasks just completed, the system transitioned to a new epoch.
491 // Type tagging is epoch relative which entails we are able to write out the
492 // already tagged artifacts for the previous epoch. We can accomplish this concurrently
493 // with threads now tagging artifacts in relation to the new, now updated, epoch and remain outside of a safepoint.
494 _checkpoint_manager.write_type_set();
495 if (LeakProfiler::is_running()) {
496 // The object sampler instance was exclusively acquired and locked in pre_safepoint_write.
497 // Note: There is a dependency on write_type_set() above, ensure the release is subsequent.
498 ObjectSampler::release();
499 }
500 MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
501 // serialize any outstanding checkpoint memory
502 _checkpoint_manager.write();
503 // serialize the metadata descriptor event and close out the chunk
504 _repository.close_chunk(write_metadata_event(_chunkwriter));
505 assert(!_chunkwriter.is_valid(), "invariant");
506 }
507
508 void JfrRecorderService::vm_error_rotation() {
509 if (_chunkwriter.is_valid()) {
510 finalize_current_chunk_on_vm_error();
511 assert(!_chunkwriter.is_valid(), "invariant");
512 _repository.on_vm_error();
513 }
514 }
515
516 void JfrRecorderService::finalize_current_chunk_on_vm_error() {
517 assert(_chunkwriter.is_valid(), "invariant");
518 pre_safepoint_write();
519 // Do not attempt safepoint dependent operations during emergency dump.
520 // Optimistically write tagged artifacts.
521 _checkpoint_manager.shift_epoch();
522 // update time
523 _chunkwriter.time_stamp_chunk_now();
524 post_safepoint_write();
525 assert(!_chunkwriter.is_valid(), "invariant");
526 }
527
528 void JfrRecorderService::process_full_buffers() {
529 if (_chunkwriter.is_valid()) {
530 assert(!JfrStream_lock->owned_by_self(), "invariant");
531 MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
532 _storage.write_full();
533 }
534 }
535
536 void JfrRecorderService::scavenge() {
537 _storage.scavenge();
538 }
539
540 void JfrRecorderService::evaluate_chunk_size_for_rotation() {
541 JfrChunkRotation::evaluate(_chunkwriter);
542 }