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.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
59static 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
76static void* rotation_thread = NULL;
77static const int rotation_try_limit = 1000;
78static const int rotation_retry_sleep_millis = 10;
79
80class 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
135static int64_t write_checkpoint_event_prologue(JfrChunkWriter& cw, u8 type_id) {
136 const int64_t prev_cp_offset = cw.previous_checkpoint_offset();
137 const int64_t prev_cp_relative_offset = 0 == prev_cp_offset ? 0 : prev_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);
142 cw.write(prev_cp_relative_offset); // write previous checkpoint offset delta
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
151template <typename ContentFunctor>
152class 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_previous_checkpoint_offset(current_cp_offset);
182 return true;
183 }
184};
185
186template <typename Instance, size_t(Instance::*func)()>
187class 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
200template <typename Instance, void(Instance::*func)()>
201class 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
211class 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
229static bool recording = false;
230
231static void set_recording_state(bool is_recording) {
232 OrderAccess::storestore();
233 recording = is_recording;
234}
235
236bool JfrRecorderService::is_recording() {
237 return recording;
238}
239
240JfrRecorderService::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
248void 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
262void JfrRecorderService::clear() {
263 ResourceMark rm;
264 HandleMark hm;
265 pre_safepoint_clear();
266 invoke_safepoint_clear();
267 post_safepoint_clear();
268}
269
270void JfrRecorderService::pre_safepoint_clear() {
271 _stack_trace_repository.clear();
272 _string_pool.clear();
273 _storage.clear();
274}
275
276void 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//
290void 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
299void JfrRecorderService::post_safepoint_clear() {
300 _checkpoint_manager.clear();
301}
302
303static 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
310void 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 (msgs & (MSGBIT(MSG_STOP))) {
321 stop();
322 }
323 // action determined by chunkwriter state
324 if (!_chunkwriter.is_valid()) {
325 in_memory_rotation();
326 return;
327 }
328 if (vm_error) {
329 vm_error_rotation();
330 return;
331 }
332 chunk_rotation();
333}
334
335void JfrRecorderService::prepare_for_vm_error_rotation() {
336 if (!_chunkwriter.is_valid()) {
337 open_new_chunk(true);
338 }
339 _checkpoint_manager.register_service_thread(Thread::current());
340 JfrMetadataEvent::lock();
341}
342
343void JfrRecorderService::open_new_chunk(bool vm_error) {
344 assert(!_chunkwriter.is_valid(), "invariant");
345 assert(!JfrStream_lock->owned_by_self(), "invariant");
346 JfrChunkRotation::on_rotation();
347 MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
348 if (!_repository.open_chunk(vm_error)) {
349 assert(!_chunkwriter.is_valid(), "invariant");
350 _storage.control().set_to_disk(false);
351 return;
352 }
353 assert(_chunkwriter.is_valid(), "invariant");
354 _storage.control().set_to_disk(true);
355}
356
357void JfrRecorderService::in_memory_rotation() {
358 assert(!_chunkwriter.is_valid(), "invariant");
359 // currently running an in-memory recording
360 open_new_chunk();
361 if (_chunkwriter.is_valid()) {
362 // dump all in-memory buffer data to the newly created chunk
363 serialize_storage_from_in_memory_recording();
364 }
365}
366
367void JfrRecorderService::serialize_storage_from_in_memory_recording() {
368 assert(!JfrStream_lock->owned_by_self(), "not holding stream lock!");
369 MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
370 _storage.write();
371}
372
373void JfrRecorderService::chunk_rotation() {
374 finalize_current_chunk();
375 open_new_chunk();
376}
377
378void JfrRecorderService::finalize_current_chunk() {
379 assert(_chunkwriter.is_valid(), "invariant");
380 write();
381 assert(!_chunkwriter.is_valid(), "invariant");
382}
383
384void JfrRecorderService::write() {
385 ResourceMark rm;
386 HandleMark hm;
387 pre_safepoint_write();
388 invoke_safepoint_write();
389 post_safepoint_write();
390}
391
392typedef ServiceFunctor<JfrStringPool, &JfrStringPool::write> WriteStringPool;
393typedef ServiceFunctor<JfrStringPool, &JfrStringPool::write_at_safepoint> WriteStringPoolSafepoint;
394typedef WriteCheckpointEvent<WriteStackTraceRepository> WriteStackTraceCheckpoint;
395typedef WriteCheckpointEvent<WriteStringPool> WriteStringPoolCheckpoint;
396typedef WriteCheckpointEvent<WriteStringPoolSafepoint> WriteStringPoolCheckpointSafepoint;
397
398static void write_stacktrace_checkpoint(JfrStackTraceRepository& stack_trace_repo, JfrChunkWriter& chunkwriter, bool clear) {
399 WriteStackTraceRepository write_stacktrace_repo(stack_trace_repo, chunkwriter, clear);
400 WriteStackTraceCheckpoint write_stack_trace_checkpoint(chunkwriter, TYPE_STACKTRACE, write_stacktrace_repo);
401 write_stack_trace_checkpoint.process();
402}
403
404static void write_object_sample_stacktrace(ObjectSampler* sampler, JfrStackTraceRepository& stack_trace_repository) {
405 WriteObjectSampleStacktrace object_sample_stacktrace(sampler, stack_trace_repository);
406 object_sample_stacktrace.process();
407}
408
409static void write_stringpool_checkpoint(JfrStringPool& string_pool, JfrChunkWriter& chunkwriter) {
410 WriteStringPool write_string_pool(string_pool);
411 WriteStringPoolCheckpoint write_string_pool_checkpoint(chunkwriter, TYPE_STRING, write_string_pool);
412 write_string_pool_checkpoint.process();
413}
414
415static void write_stringpool_checkpoint_safepoint(JfrStringPool& string_pool, JfrChunkWriter& chunkwriter) {
416 WriteStringPoolSafepoint write_string_pool(string_pool);
417 WriteStringPoolCheckpointSafepoint write_string_pool_checkpoint(chunkwriter, TYPE_STRING, write_string_pool);
418 write_string_pool_checkpoint.process();
419}
420
421//
422// pre-safepoint write sequence
423//
424// lock stream lock ->
425// write non-safepoint dependent types ->
426// write checkpoint epoch transition list->
427// write stack trace checkpoint ->
428// write string pool checkpoint ->
429// write object sample stacktraces ->
430// write storage ->
431// release stream lock
432//
433void JfrRecorderService::pre_safepoint_write() {
434 MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
435 assert(_chunkwriter.is_valid(), "invariant");
436 _checkpoint_manager.write_types();
437 _checkpoint_manager.write_epoch_transition_mspace();
438 write_stacktrace_checkpoint(_stack_trace_repository, _chunkwriter, false);
439 write_stringpool_checkpoint(_string_pool, _chunkwriter);
440 if (LeakProfiler::is_running()) {
441 // Exclusive access to the object sampler instance.
442 // The sampler is released (unlocked) later in post_safepoint_write.
443 ObjectSampler* const sampler = ObjectSampler::acquire();
444 assert(sampler != NULL, "invariant");
445 write_object_sample_stacktrace(sampler, _stack_trace_repository);
446 }
447 _storage.write();
448}
449
450void JfrRecorderService::invoke_safepoint_write() {
451 JfrVMOperation<JfrRecorderService, &JfrRecorderService::safepoint_write> safepoint_task(*this);
452 VMThread::execute(&safepoint_task);
453}
454
455//
456// safepoint write sequence
457//
458// lock stream lock ->
459// write stacktrace repository ->
460// write string pool ->
461// write safepoint dependent types ->
462// write storage ->
463// shift_epoch ->
464// update time ->
465// lock metadata descriptor ->
466// release stream lock
467//
468void JfrRecorderService::safepoint_write() {
469 assert(SafepointSynchronize::is_at_safepoint(), "invariant");
470 MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
471 write_stacktrace_checkpoint(_stack_trace_repository, _chunkwriter, true);
472 write_stringpool_checkpoint_safepoint(_string_pool, _chunkwriter);
473 _checkpoint_manager.write_safepoint_types();
474 _storage.write_at_safepoint();
475 _checkpoint_manager.shift_epoch();
476 _chunkwriter.time_stamp_chunk_now();
477 JfrMetadataEvent::lock();
478}
479
480static int64_t write_metadata_event(JfrChunkWriter& chunkwriter) {
481 assert(chunkwriter.is_valid(), "invariant");
482 const int64_t metadata_offset = chunkwriter.current_offset();
483 JfrMetadataEvent::write(chunkwriter, metadata_offset);
484 return metadata_offset;
485}
486
487//
488// post-safepoint write sequence
489//
490// write type set ->
491// release object sampler ->
492// lock stream lock ->
493// write checkpoints ->
494// write metadata event ->
495// write chunk header ->
496// close chunk fd ->
497// release stream lock
498//
499void JfrRecorderService::post_safepoint_write() {
500 assert(_chunkwriter.is_valid(), "invariant");
501 // During the safepoint tasks just completed, the system transitioned to a new epoch.
502 // Type tagging is epoch relative which entails we are able to write out the
503 // already tagged artifacts for the previous epoch. We can accomplish this concurrently
504 // with threads now tagging artifacts in relation to the new, now updated, epoch and remain outside of a safepoint.
505 _checkpoint_manager.write_type_set();
506 if (LeakProfiler::is_running()) {
507 // The object sampler instance was exclusively acquired and locked in pre_safepoint_write.
508 // Note: There is a dependency on write_type_set() above, ensure the release is subsequent.
509 ObjectSampler::release();
510 }
511 MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
512 // serialize any outstanding checkpoint memory
513 _checkpoint_manager.write();
514 // serialize the metadata descriptor event and close out the chunk
515 _repository.close_chunk(write_metadata_event(_chunkwriter));
516 assert(!_chunkwriter.is_valid(), "invariant");
517}
518
519void JfrRecorderService::vm_error_rotation() {
520 if (_chunkwriter.is_valid()) {
521 finalize_current_chunk_on_vm_error();
522 assert(!_chunkwriter.is_valid(), "invariant");
523 _repository.on_vm_error();
524 }
525}
526
527void JfrRecorderService::finalize_current_chunk_on_vm_error() {
528 assert(_chunkwriter.is_valid(), "invariant");
529 pre_safepoint_write();
530 // Do not attempt safepoint dependent operations during emergency dump.
531 // Optimistically write tagged artifacts.
532 _checkpoint_manager.shift_epoch();
533 // update time
534 _chunkwriter.time_stamp_chunk_now();
535 post_safepoint_write();
536 assert(!_chunkwriter.is_valid(), "invariant");
537}
538
539void JfrRecorderService::process_full_buffers() {
540 if (_chunkwriter.is_valid()) {
541 assert(!JfrStream_lock->owned_by_self(), "invariant");
542 MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
543 _storage.write_full();
544 }
545}
546
547void JfrRecorderService::scavenge() {
548 _storage.scavenge();
549}
550
551void JfrRecorderService::evaluate_chunk_size_for_rotation() {
552 JfrChunkRotation::evaluate(_chunkwriter);
553}
554