1 /*
2 * Copyright (c) 2016, 2018, 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 "memory/resourceArea.hpp"
47 #include "runtime/atomic.hpp"
48 #include "runtime/handles.inline.hpp"
49 #include "runtime/mutexLocker.hpp"
50 #include "runtime/orderAccess.hpp"
51 #include "runtime/os.hpp"
52 #include "runtime/safepoint.hpp"
53 #include "runtime/thread.inline.hpp"
54 #include "runtime/vm_operations.hpp"
55 #include "runtime/vmThread.hpp"
56
57 // set data iff *dest == NULL
58 static bool try_set(void* const data, void** dest, bool clear) {
59 assert(data != NULL, "invariant");
60 void* const current = OrderAccess::load_ptr_acquire(dest);
61 if (current != NULL) {
62 if (current != data) {
63 // already set
64 return false;
65 }
66 assert(current == data, "invariant");
67 if (!clear) {
68 // recursion disallowed
69 return false;
70 }
71 }
72 return Atomic::cmpxchg_ptr(clear ? NULL : data, dest, current) == current;
73 }
74
75 static void* rotation_thread = NULL;
76 static const int rotation_try_limit = 1000;
77 static const int rotation_retry_sleep_millis = 10;
78
79 class RotationLock : public StackObj {
80 private:
81 Thread* const _thread;
82 bool _acquired;
83
84 void log(bool recursion) {
85 assert(!_acquired, "invariant");
86 const char* error_msg = NULL;
87 if (recursion) {
88 error_msg = "Unable to issue rotation due to recursive calls.";
89 }
90 else {
91 error_msg = "Unable to issue rotation due to wait timeout.";
92 }
93 if (LogJFR) tty->print_cr( // For user, should not be "jfr, system"
94 "%s", error_msg);
95 }
96 public:
97 RotationLock(Thread* thread) : _thread(thread), _acquired(false) {
98 assert(_thread != NULL, "invariant");
99 if (_thread == rotation_thread) {
100 // recursion not supported
101 log(true);
102 return;
103 }
104
105 // limited to not spin indefinitely
106 for (int i = 0; i < rotation_try_limit; ++i) {
107 if (try_set(_thread, &rotation_thread, false)) {
108 _acquired = true;
109 assert(_thread == rotation_thread, "invariant");
110 return;
111 }
112 if (_thread->is_Java_thread()) {
113 // in order to allow the system to move to a safepoint
114 MutexLockerEx msg_lock(JfrMsg_lock);
115 JfrMsg_lock->wait(false, rotation_retry_sleep_millis);
116 }
117 else {
118 os::naked_short_sleep(rotation_retry_sleep_millis);
119 }
120 }
121 log(false);
122 }
123
124 ~RotationLock() {
125 assert(_thread != NULL, "invariant");
126 if (_acquired) {
127 assert(_thread == rotation_thread, "invariant");
128 while (!try_set(_thread, &rotation_thread, true));
129 }
130 }
131 bool not_acquired() const { return !_acquired; }
132 };
133
134 static int64_t write_checkpoint_event_prologue(JfrChunkWriter& cw, u8 type_id) {
135 const int64_t prev_cp_offset = cw.previous_checkpoint_offset();
136 const int64_t prev_cp_relative_offset = 0 == prev_cp_offset ? 0 : prev_cp_offset - cw.current_offset();
137 cw.reserve(sizeof(u4));
138 cw.write<u8>(EVENT_CHECKPOINT);
139 cw.write(JfrTicks::now());
140 cw.write((int64_t)0);
141 cw.write(prev_cp_relative_offset); // write previous checkpoint offset delta
142 cw.write<bool>(false); // flushpoint
143 cw.write((u4)1); // nof types in this checkpoint
144 cw.write(type_id);
145 const int64_t number_of_elements_offset = cw.current_offset();
146 cw.reserve(sizeof(u4));
147 return number_of_elements_offset;
148 }
149
150 template <typename ContentFunctor>
151 class WriteCheckpointEvent : public StackObj {
152 private:
153 JfrChunkWriter& _cw;
154 u8 _type_id;
155 ContentFunctor& _content_functor;
156 public:
157 WriteCheckpointEvent(JfrChunkWriter& cw, u8 type_id, ContentFunctor& functor) :
158 _cw(cw),
159 _type_id(type_id),
160 _content_functor(functor) {
161 assert(_cw.is_valid(), "invariant");
162 }
163 bool process() {
164 // current_cp_offset is also offset for the event size header field
165 const int64_t current_cp_offset = _cw.current_offset();
166 const int64_t num_elements_offset = write_checkpoint_event_prologue(_cw, _type_id);
167 // invocation
168 _content_functor.process();
169 const u4 number_of_elements = (u4)_content_functor.processed();
170 if (number_of_elements == 0) {
171 // nothing to do, rewind writer to start
172 _cw.seek(current_cp_offset);
173 return true;
174 }
175 assert(number_of_elements > 0, "invariant");
176 assert(_cw.current_offset() > num_elements_offset, "invariant");
177 _cw.write_padded_at_offset<u4>(number_of_elements, num_elements_offset);
178 _cw.write_padded_at_offset<u4>((u4)_cw.current_offset() - current_cp_offset, current_cp_offset);
179 // update writer with last checkpoint position
180 _cw.set_previous_checkpoint_offset(current_cp_offset);
181 return true;
182 }
183 };
184
185 template <typename Instance, size_t(Instance::*func)()>
186 class ServiceFunctor {
187 private:
188 Instance& _instance;
189 size_t _processed;
190 public:
191 ServiceFunctor(Instance& instance) : _instance(instance), _processed(0) {}
192 bool process() {
193 _processed = (_instance.*func)();
194 return true;
195 }
196 size_t processed() const { return _processed; }
197 };
198
199 template <typename Instance, void(Instance::*func)()>
200 class JfrVMOperation : public VM_Operation {
201 private:
202 Instance& _instance;
203 public:
204 JfrVMOperation(Instance& instance) : _instance(instance) {}
205 void doit() { (_instance.*func)(); }
206 VMOp_Type type() const { return VMOp_JFRCheckpoint; }
207 Mode evaluation_mode() const { return _safepoint; } // default
208 };
209
210 class WriteStackTraceRepository : public StackObj {
211 private:
212 JfrStackTraceRepository& _repo;
213 JfrChunkWriter& _cw;
214 size_t _elements_processed;
215 bool _clear;
216
217 public:
218 WriteStackTraceRepository(JfrStackTraceRepository& repo, JfrChunkWriter& cw, bool clear) :
219 _repo(repo), _cw(cw), _elements_processed(0), _clear(clear) {}
220 bool process() {
221 _elements_processed = _repo.write(_cw, _clear);
222 return true;
223 }
224 size_t processed() const { return _elements_processed; }
225 void reset() { _elements_processed = 0; }
226 };
227
228 static bool recording = false;
229
230 static void set_recording_state(bool is_recording) {
231 OrderAccess::storestore();
232 recording = is_recording;
233 }
234
235 bool JfrRecorderService::is_recording() {
236 return recording;
237 }
238
239 JfrRecorderService::JfrRecorderService() :
240 _checkpoint_manager(JfrCheckpointManager::instance()),
241 _chunkwriter(JfrRepository::chunkwriter()),
242 _repository(JfrRepository::instance()),
243 _storage(JfrStorage::instance()),
244 _stack_trace_repository(JfrStackTraceRepository::instance()),
245 _string_pool(JfrStringPool::instance()) {}
246
247 void JfrRecorderService::start() {
248 RotationLock rl(Thread::current());
249 if (rl.not_acquired()) {
250 return;
251 }
252 if (LogJFR) tty->print_cr("Request to START recording");
253 assert(!is_recording(), "invariant");
254 clear();
255 set_recording_state(true);
256 assert(is_recording(), "invariant");
257 open_new_chunk();
258 if (LogJFR) tty->print_cr("Recording STARTED");
259 }
260
261 void JfrRecorderService::clear() {
262 ResourceMark rm;
263 HandleMark hm;
264 pre_safepoint_clear();
265 invoke_safepoint_clear();
266 post_safepoint_clear();
267 }
268
269 void JfrRecorderService::pre_safepoint_clear() {
270 _stack_trace_repository.clear();
271 _string_pool.clear();
272 _storage.clear();
273 }
274
275 void JfrRecorderService::invoke_safepoint_clear() {
276 JfrVMOperation<JfrRecorderService, &JfrRecorderService::safepoint_clear> safepoint_task(*this);
277 VMThread::execute(&safepoint_task);
278 }
279
280 //
281 // safepoint clear sequence
282 //
283 // clear stacktrace repository ->
284 // clear string pool ->
285 // clear storage ->
286 // shift epoch ->
287 // update time
288 //
289 void JfrRecorderService::safepoint_clear() {
290 assert(SafepointSynchronize::is_at_safepoint(), "invariant");
291 _stack_trace_repository.clear();
292 _string_pool.clear();
293 _storage.clear();
294 _checkpoint_manager.shift_epoch();
295 _chunkwriter.time_stamp_chunk_now();
296 }
297
298 void JfrRecorderService::post_safepoint_clear() {
299 _checkpoint_manager.clear();
300 }
301
302 static void stop() {
303 assert(JfrRecorderService::is_recording(), "invariant");
304 if (LogJFR) tty->print_cr("Recording STOPPED");
305 set_recording_state(false);
306 assert(!JfrRecorderService::is_recording(), "invariant");
307 }
308
309 void JfrRecorderService::rotate(int msgs) {
310 RotationLock rl(Thread::current());
311 if (rl.not_acquired()) {
312 return;
313 }
314 static bool vm_error = false;
315 if (msgs & MSGBIT(MSG_VM_ERROR)) {
316 vm_error = true;
317 prepare_for_vm_error_rotation();
318 }
319 if (msgs & (MSGBIT(MSG_STOP))) {
320 stop();
321 }
322 // action determined by chunkwriter state
323 if (!_chunkwriter.is_valid()) {
324 in_memory_rotation();
325 return;
326 }
327 if (vm_error) {
328 vm_error_rotation();
329 return;
330 }
331 chunk_rotation();
332 }
333
334 void JfrRecorderService::prepare_for_vm_error_rotation() {
335 if (!_chunkwriter.is_valid()) {
336 open_new_chunk(true);
337 }
338 _checkpoint_manager.register_service_thread(Thread::current());
339 JfrMetadataEvent::lock();
340 }
341
342 void JfrRecorderService::open_new_chunk(bool vm_error) {
343 assert(!_chunkwriter.is_valid(), "invariant");
344 assert(!JfrStream_lock->owned_by_self(), "invariant");
345 JfrChunkRotation::on_rotation();
346 MutexLockerEx stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
347 if (!_repository.open_chunk(vm_error)) {
348 assert(!_chunkwriter.is_valid(), "invariant");
349 _storage.control().set_to_disk(false);
350 return;
351 }
352 assert(_chunkwriter.is_valid(), "invariant");
353 _storage.control().set_to_disk(true);
354 }
355
356 void JfrRecorderService::in_memory_rotation() {
357 assert(!_chunkwriter.is_valid(), "invariant");
358 // currently running an in-memory recording
359 open_new_chunk();
360 if (_chunkwriter.is_valid()) {
361 // dump all in-memory buffer data to the newly created chunk
362 serialize_storage_from_in_memory_recording();
363 }
364 }
365
366 void JfrRecorderService::serialize_storage_from_in_memory_recording() {
367 assert(!JfrStream_lock->owned_by_self(), "not holding stream lock!");
368 MutexLockerEx stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
369 _storage.write();
370 }
371
372 void JfrRecorderService::chunk_rotation() {
373 finalize_current_chunk();
374 open_new_chunk();
375 }
376
377 void JfrRecorderService::finalize_current_chunk() {
378 assert(_chunkwriter.is_valid(), "invariant");
379 write();
380 assert(!_chunkwriter.is_valid(), "invariant");
381 }
382
383 void JfrRecorderService::write() {
384 ResourceMark rm;
385 HandleMark hm;
386 pre_safepoint_write();
387 invoke_safepoint_write();
388 post_safepoint_write();
389 }
390
391 typedef ServiceFunctor<JfrStringPool, &JfrStringPool::write> WriteStringPool;
392 typedef ServiceFunctor<JfrStringPool, &JfrStringPool::write_at_safepoint> WriteStringPoolSafepoint;
393 typedef WriteCheckpointEvent<WriteStackTraceRepository> WriteStackTraceCheckpoint;
394 typedef WriteCheckpointEvent<WriteStringPool> WriteStringPoolCheckpoint;
395 typedef WriteCheckpointEvent<WriteStringPoolSafepoint> WriteStringPoolCheckpointSafepoint;
396
397 static void write_stacktrace_checkpoint(JfrStackTraceRepository& stack_trace_repo, JfrChunkWriter& chunkwriter, bool clear) {
398 WriteStackTraceRepository write_stacktrace_repo(stack_trace_repo, chunkwriter, clear);
399 WriteStackTraceCheckpoint write_stack_trace_checkpoint(chunkwriter, TYPE_STACKTRACE, write_stacktrace_repo);
400 write_stack_trace_checkpoint.process();
401 }
402
403 static void write_object_sample_stacktrace(ObjectSampler* sampler, JfrStackTraceRepository& stack_trace_repository) {
404 WriteObjectSampleStacktrace object_sample_stacktrace(sampler, stack_trace_repository);
405 object_sample_stacktrace.process();
406 }
407
408 static void write_stringpool_checkpoint(JfrStringPool& string_pool, JfrChunkWriter& chunkwriter) {
409 WriteStringPool write_string_pool(string_pool);
410 WriteStringPoolCheckpoint write_string_pool_checkpoint(chunkwriter, TYPE_STRING, write_string_pool);
411 write_string_pool_checkpoint.process();
412 }
413
414 static void write_stringpool_checkpoint_safepoint(JfrStringPool& string_pool, JfrChunkWriter& chunkwriter) {
415 WriteStringPoolSafepoint write_string_pool(string_pool);
416 WriteStringPoolCheckpointSafepoint write_string_pool_checkpoint(chunkwriter, TYPE_STRING, write_string_pool);
417 write_string_pool_checkpoint.process();
418 }
419
420 //
421 // pre-safepoint write sequence
422 //
423 // lock stream lock ->
424 // write non-safepoint dependent types ->
425 // write checkpoint epoch transition list->
426 // write stack trace checkpoint ->
427 // write string pool checkpoint ->
428 // write object sample stacktraces ->
429 // write storage ->
430 // release stream lock
431 //
432 void JfrRecorderService::pre_safepoint_write() {
433 MutexLockerEx stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
434 assert(_chunkwriter.is_valid(), "invariant");
435 _checkpoint_manager.write_types();
436 _checkpoint_manager.write_epoch_transition_mspace();
437 write_stacktrace_checkpoint(_stack_trace_repository, _chunkwriter, false);
438 write_stringpool_checkpoint(_string_pool, _chunkwriter);
439 if (LeakProfiler::is_running()) {
440 // Exclusive access to the object sampler instance.
441 // The sampler is released (unlocked) later in post_safepoint_write.
442 ObjectSampler* const sampler = ObjectSampler::acquire();
443 assert(sampler != NULL, "invariant");
444 write_object_sample_stacktrace(sampler, _stack_trace_repository);
445 }
446 _storage.write();
447 }
448
449 void JfrRecorderService::invoke_safepoint_write() {
450 JfrVMOperation<JfrRecorderService, &JfrRecorderService::safepoint_write> safepoint_task(*this);
451 VMThread::execute(&safepoint_task);
452 }
453
454 //
455 // safepoint write sequence
456 //
457 // lock stream lock ->
458 // write stacktrace repository ->
459 // write string pool ->
460 // write safepoint dependent types ->
461 // write storage ->
462 // shift_epoch ->
463 // update time ->
464 // lock metadata descriptor ->
465 // release stream lock
466 //
467 void JfrRecorderService::safepoint_write() {
468 assert(SafepointSynchronize::is_at_safepoint(), "invariant");
469 MutexLockerEx stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
470 write_stacktrace_checkpoint(_stack_trace_repository, _chunkwriter, true);
471 write_stringpool_checkpoint_safepoint(_string_pool, _chunkwriter);
472 _checkpoint_manager.write_safepoint_types();
473 _storage.write_at_safepoint();
474 _checkpoint_manager.shift_epoch();
475 _chunkwriter.time_stamp_chunk_now();
476 JfrMetadataEvent::lock();
477 }
478
479 static int64_t write_metadata_event(JfrChunkWriter& chunkwriter) {
480 assert(chunkwriter.is_valid(), "invariant");
481 const int64_t metadata_offset = chunkwriter.current_offset();
482 JfrMetadataEvent::write(chunkwriter, metadata_offset);
483 return metadata_offset;
484 }
485
486 //
487 // post-safepoint write sequence
488 //
489 // write type set ->
490 // release object sampler ->
491 // lock stream lock ->
492 // write checkpoints ->
493 // write metadata event ->
494 // write chunk header ->
495 // close chunk fd ->
496 // release stream lock
497 //
498 void JfrRecorderService::post_safepoint_write() {
499 assert(_chunkwriter.is_valid(), "invariant");
500 // During the safepoint tasks just completed, the system transitioned to a new epoch.
501 // Type tagging is epoch relative which entails we are able to write out the
502 // already tagged artifacts for the previous epoch. We can accomplish this concurrently
503 // with threads now tagging artifacts in relation to the new, now updated, epoch and remain outside of a safepoint.
504 _checkpoint_manager.write_type_set();
505 if (LeakProfiler::is_running()) {
506 // The object sampler instance was exclusively acquired and locked in pre_safepoint_write.
507 // Note: There is a dependency on write_type_set() above, ensure the release is subsequent.
508 ObjectSampler::release();
509 } MutexLockerEx stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
510 // serialize any outstanding checkpoint memory
511 _checkpoint_manager.write();
512 // serialize the metadata descriptor event and close out the chunk
513 _repository.close_chunk(write_metadata_event(_chunkwriter));
514 assert(!_chunkwriter.is_valid(), "invariant");
515 }
516
517 void JfrRecorderService::vm_error_rotation() {
518 if (_chunkwriter.is_valid()) {
519 finalize_current_chunk_on_vm_error();
520 assert(!_chunkwriter.is_valid(), "invariant");
521 _repository.on_vm_error();
522 }
523 }
524
525 void JfrRecorderService::finalize_current_chunk_on_vm_error() {
526 assert(_chunkwriter.is_valid(), "invariant");
527 pre_safepoint_write();
528 // Do not attempt safepoint dependent operations during emergency dump.
529 // Optimistically write tagged artifacts.
530 _checkpoint_manager.shift_epoch();
531 // update time
532 _chunkwriter.time_stamp_chunk_now();
533 post_safepoint_write();
534 assert(!_chunkwriter.is_valid(), "invariant");
535 }
536
537 void JfrRecorderService::process_full_buffers() {
538 if (_chunkwriter.is_valid()) {
539 assert(!JfrStream_lock->owned_by_self(), "invariant");
540 MutexLockerEx stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
541 _storage.write_full();
542 }
543 }
544
545 void JfrRecorderService::scavenge() {
546 _storage.scavenge();
547 }
548
549 void JfrRecorderService::evaluate_chunk_size_for_rotation() {
550 JfrChunkRotation::evaluate(_chunkwriter);
551 }