1 /*
2 * Copyright (c) 2012, 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/recorder/jfrRecorder.hpp"
28 #include "jfr/recorder/access/jfrOptionSet.hpp"
29 #include "jfr/recorder/repository/jfrChunkWriter.hpp"
30 #include "jfr/recorder/service/jfrPostBox.hpp"
31 #include "jfr/recorder/storage/jfrMemorySpace.inline.hpp"
32 #include "jfr/recorder/storage/jfrStorage.hpp"
33 #include "jfr/recorder/storage/jfrStorageControl.hpp"
34 #include "jfr/recorder/storage/jfrStorageUtils.inline.hpp"
35 #include "jfr/utilities/jfrIterator.hpp"
36 #include "logging/log.hpp"
37
38 #include "runtime/mutexLocker.hpp"
39 #include "runtime/orderAccess.inline.hpp"
40 #include "runtime/safepoint.hpp"
41 #include "runtime/thread.hpp"
42 #include "trace/tracing.hpp"
43
44 typedef JfrStorage::Buffer* BufferPtr;
45
46 static JfrStorage* _instance = NULL;
47 static JfrStorageControl* _control;
48
49 JfrStorage& JfrStorage::instance() {
50 return *_instance;
51 }
52
53 JfrStorage* JfrStorage::create(JfrChunkWriter& chunkwriter, JfrPostBox& post_box) {
54 assert(_instance == NULL, "invariant");
55 _instance = new JfrStorage(chunkwriter, post_box);
56 return _instance;
57 }
58
59 void JfrStorage::destroy() {
60 if (_instance != NULL) {
61 delete _instance;
62 _instance = NULL;
63 }
64 }
65
66 JfrStorage::JfrStorage(JfrChunkWriter& chunkwriter, JfrPostBox& post_box) :
67 _control(NULL),
68 _global_mspace(NULL),
69 _thread_local_mspace(NULL),
70 _transient_mspace(NULL),
71 _age_mspace(NULL),
72 _chunkwriter(chunkwriter),
73 _post_box(post_box) {}
74
75 JfrStorage::~JfrStorage() {
76 if (_control != NULL) {
77 delete _control;
78 }
79 if (_global_mspace != NULL) {
80 delete _global_mspace;
81 }
82 if (_thread_local_mspace != NULL) {
83 delete _thread_local_mspace;
84 }
85 if (_transient_mspace != NULL) {
86 delete _transient_mspace;
87 }
88 if (_age_mspace != NULL) {
89 delete _age_mspace;
90 }
91 _instance = NULL;
92 }
93
94 static const size_t in_memory_discard_threshold_delta = 2; // start to discard data when the only this number of free buffers are left
95 static const size_t unlimited_mspace_size = 0;
96 static const size_t thread_local_cache_count = 8;
97 static const size_t thread_local_scavenge_threshold = thread_local_cache_count / 2;
98 static const size_t transient_buffer_size_multiplier = 8; // against thread local buffer size
99
100 static JfrStorageMspace* create_mspace(size_t buffer_size, size_t limit, size_t cache_count, JfrStorage* storage_instance) {
101 JfrStorageMspace* mspace = new JfrStorageMspace(buffer_size, limit, cache_count, storage_instance);
102 if (mspace != NULL) {
103 mspace->initialize();
104 }
105 return mspace;
106 }
107
108 bool JfrStorage::initialize() {
109 assert(_control == NULL, "invariant");
110 assert(_global_mspace == NULL, "invariant");
111 assert(_thread_local_mspace == NULL, "invariant");
112 assert(_transient_mspace == NULL, "invariant");
113 assert(_age_mspace == NULL, "invariant");
114
115 const size_t num_global_buffers = (size_t)JfrOptionSet::num_global_buffers();
116 assert(num_global_buffers >= in_memory_discard_threshold_delta, "invariant");
117 const size_t memory_size = (size_t)JfrOptionSet::memory_size();
118 const size_t global_buffer_size = (size_t)JfrOptionSet::global_buffer_size();
119 const size_t thread_buffer_size = (size_t)JfrOptionSet::thread_buffer_size();
120
121 _control = new JfrStorageControl(num_global_buffers, num_global_buffers - in_memory_discard_threshold_delta);
122 if (_control == NULL) {
123 return false;
124 }
125 _global_mspace = create_mspace(global_buffer_size, memory_size, num_global_buffers, this);
126 if (_global_mspace == NULL) {
127 return false;
128 }
129 _thread_local_mspace = create_mspace(thread_buffer_size, unlimited_mspace_size, thread_local_cache_count, this);
130 if (_thread_local_mspace == NULL) {
131 return false;
132 }
133 _transient_mspace = create_mspace(thread_buffer_size * transient_buffer_size_multiplier, unlimited_mspace_size, 0, this);
134 if (_transient_mspace == NULL) {
135 return false;
136 }
137 _age_mspace = new JfrStorageAgeMspace(0 /* no extra size except header */, unlimited_mspace_size, num_global_buffers, this);
138
139 if (_age_mspace == NULL || !_age_mspace->initialize()) {
140 return false;
141 }
142 control().set_scavenge_threshold(thread_local_scavenge_threshold);
143 return true;
144 }
145
146 JfrStorageControl& JfrStorage::control() {
147 return *instance()._control;
148 }
149
150 static void log_allocation_failure(const char* msg, size_t size) {
151 log_warning(jfr)("Unable to allocate " SIZE_FORMAT " bytes of %s.", size, msg);
152 }
153
154 BufferPtr JfrStorage::acquire_thread_local(Thread* thread, size_t size /* 0 */) {
155 BufferPtr buffer = mspace_get_to_full(size, instance()._thread_local_mspace, thread);
156 if (buffer == NULL) {
157 log_allocation_failure("thread local_memory", size);
158 return NULL;
159 }
160 assert(buffer->acquired_by_self(), "invariant");
161 return buffer;
162 }
163
164 BufferPtr JfrStorage::acquire_transient(size_t size, Thread* thread) {
165 BufferPtr buffer = mspace_allocate_transient_lease_to_full(size, instance()._transient_mspace, thread);
166 if (buffer == NULL) {
167 log_allocation_failure("transient memory", size);
168 return NULL;
169 }
170 assert(buffer->acquired_by_self(), "invariant");
171 assert(buffer->transient(), "invariant");
172 assert(buffer->lease(), "invariant");
173 return buffer;
174 }
175
176 static BufferPtr get_lease(size_t size, JfrStorageMspace* mspace, JfrStorage& storage_instance, size_t retry_count, Thread* thread) {
177 assert(size <= mspace->min_elem_size(), "invariant");
178 while (true) {
179 BufferPtr t = mspace_get_free_lease_with_retry(size, mspace, retry_count, thread);
180 if (t == NULL && storage_instance.control().should_discard()) {
181 storage_instance.discard_oldest(thread);
182 continue;
183 }
184 return t;
185 }
186 }
187
188 static BufferPtr get_promotion_buffer(size_t size, JfrStorageMspace* mspace, JfrStorage& storage_instance, size_t retry_count, Thread* thread) {
189 assert(size <= mspace->min_elem_size(), "invariant");
190 while (true) {
191 BufferPtr t = mspace_get_free_with_retry(size, mspace, retry_count, thread);
192 if (t == NULL && storage_instance.control().should_discard()) {
193 storage_instance.discard_oldest(thread);
194 continue;
195 }
196 return t;
197 }
198 }
199
200 static const size_t lease_retry = 10;
201
202 BufferPtr JfrStorage::acquire_large(size_t size, Thread* thread) {
203 JfrStorage& storage_instance = instance();
204 const size_t max_elem_size = storage_instance._global_mspace->min_elem_size(); // min is also max
205 // if not too large and capacity is still available, ask for a lease from the global system
206 if (size < max_elem_size && storage_instance.control().is_global_lease_allowed()) {
207 BufferPtr const buffer = get_lease(size, storage_instance._global_mspace, storage_instance, lease_retry, thread);
208 if (buffer != NULL) {
209 assert(buffer->acquired_by_self(), "invariant");
210 assert(!buffer->transient(), "invariant");
211 assert(buffer->lease(), "invariant");
212 storage_instance.control().increment_leased();
213 return buffer;
214 }
215 }
216 return acquire_transient(size, thread);
217 }
218
219 static void write_data_loss_event(size_t unflushed_size, Thread* thread) {
220 const u8 total_data_loss = thread->trace_data()->add_data_lost(unflushed_size);
221 if (EventDataLoss::is_enabled()) {
222 EventDataLoss dataloss;
223 dataloss.set_amount(unflushed_size);
224 dataloss.set_total(total_data_loss);
225 dataloss.commit();
226 }
227 }
228
229 static void write_data_loss(BufferPtr buffer, Thread* thread) {
230 assert(buffer != NULL, "invariant");
231 const size_t unflushed_size = buffer->unflushed_size();
232 buffer->concurrent_reinitialization();
233 if (unflushed_size == 0) {
234 return;
235 }
236 assert(buffer->empty(), "invariant");
237 write_data_loss_event(unflushed_size, thread);
238 }
239
240 static const size_t promotion_retry = 100;
241
242 bool JfrStorage::flush_regular_buffer(BufferPtr buffer, Thread* thread) {
243 assert(buffer != NULL, "invariant");
244 assert(!buffer->lease(), "invariant");
245 assert(!buffer->transient(), "invariant");
246 const size_t unflushed_size = buffer->unflushed_size();
247 if (unflushed_size == 0) {
248 buffer->concurrent_reinitialization();
249 assert(buffer->empty(), "invariant");
250 return true;
251 }
252 BufferPtr const promotion_buffer = get_promotion_buffer(unflushed_size, _global_mspace, *this, promotion_retry, thread);
253 if (promotion_buffer == NULL) {
254 write_data_loss(buffer, thread);
255 return false;
256 }
257 assert(promotion_buffer->acquired_by_self(), "invariant");
258 assert(promotion_buffer->free_size() >= unflushed_size, "invariant");
259 buffer->concurrent_move_and_reinitialize(promotion_buffer, unflushed_size);
260 assert(buffer->empty(), "invariant");
261 return true;
262 }
263
264 /*
265 * 1. If the buffer was a "lease" from the global system, release back.
266 * 2. If the buffer is transient (temporal dynamically allocated), retire and register full.
267 *
268 * The buffer is effectively invalidated for the thread post-return,
269 * and the caller should take means to ensure that it is not referenced any longer.
270 */
271 void JfrStorage::release_large(BufferPtr buffer, Thread* thread) {
272 assert(buffer != NULL, "invariant");
273 assert(buffer->lease(), "invariant");
274 assert(buffer->acquired_by_self(), "invariant");
275 buffer->clear_lease();
276 if (buffer->transient()) {
277 buffer->set_retired();
278 register_full(buffer, thread);
279 } else {
280 buffer->release();
281 control().decrement_leased();
282 }
283 }
284
285 static JfrAgeNode* new_age_node(BufferPtr buffer, JfrStorageAgeMspace* age_mspace, Thread* thread) {
286 assert(buffer != NULL, "invariant");
287 assert(age_mspace != NULL, "invariant");
288 return mspace_allocate_transient(0, age_mspace, thread);
289 }
290
291 static void log_registration_failure(size_t unflushed_size) {
292 log_warning(jfr)("Unable to register a full buffer of " SIZE_FORMAT " bytes.", unflushed_size);
293 log_debug(jfr, system)("Cleared 1 full buffer of " SIZE_FORMAT " bytes.", unflushed_size);
294 }
295
296 static void handle_registration_failure(BufferPtr buffer) {
297 assert(buffer != NULL, "invariant");
298 assert(buffer->retired(), "invariant");
299 const size_t unflushed_size = buffer->unflushed_size();
300 buffer->reinitialize();
301 log_registration_failure(unflushed_size);
302 }
303
304 static JfrAgeNode* get_free_age_node(JfrStorageAgeMspace* age_mspace, Thread* thread) {
305 assert(JfrBuffer_lock->owned_by_self(), "invariant");
306 return mspace_get_free_with_detach(0, age_mspace, thread);
307 }
308
309 static bool insert_full_age_node(JfrAgeNode* age_node, JfrStorageAgeMspace* age_mspace, Thread* thread) {
310 assert(JfrBuffer_lock->owned_by_self(), "invariant");
311 assert(age_node->retired_buffer()->retired(), "invariant");
312 age_mspace->insert_full_head(age_node);
313 return true;
314 }
315
316 static bool full_buffer_registration(BufferPtr buffer, JfrStorageAgeMspace* age_mspace, JfrStorageControl& control, Thread* thread) {
317 assert(buffer != NULL, "invariant");
318 assert(buffer->retired(), "invariant");
319 assert(age_mspace != NULL, "invariant");
320 MutexLockerEx lock(JfrBuffer_lock, Mutex::_no_safepoint_check_flag);
321 JfrAgeNode* age_node = get_free_age_node(age_mspace, thread);
322 if (age_node == NULL) {
323 age_node = new_age_node(buffer, age_mspace, thread);
324 if (age_node == NULL) {
325 return false;
326 }
327 }
328 assert(age_node->acquired_by_self(), "invariant");
329 assert(age_node != NULL, "invariant");
330 age_node->set_retired_buffer(buffer);
331 return insert_full_age_node(age_node, age_mspace, thread);
332 }
333
334 void JfrStorage::register_full(BufferPtr buffer, Thread* thread) {
335 assert(buffer != NULL, "invariant");
336 assert(buffer->retired(), "invariant");
337 if (!full_buffer_registration(buffer, _age_mspace, control(), thread)) {
338 handle_registration_failure(buffer);
339 buffer->release();
340 }
341 if (control().should_post_buffer_full_message()) {
342 _post_box.post(MSG_FULLBUFFER);
343 }
344 }
345
346 void JfrStorage::lock() {
347 assert(!JfrBuffer_lock->owned_by_self(), "invariant");
348 JfrBuffer_lock->lock_without_safepoint_check();
349 }
350
351 void JfrStorage::unlock() {
352 assert(JfrBuffer_lock->owned_by_self(), "invariant");
353 JfrBuffer_lock->unlock();
354 }
355
356 // don't use buffer on return, it is gone
357 void JfrStorage::release(BufferPtr buffer, Thread* thread) {
358 assert(buffer != NULL, "invariant");
359 assert(!buffer->lease(), "invariant");
360 assert(!buffer->transient(), "invariant");
361 assert(!buffer->retired(), "invariant");
362 if (!buffer->empty()) {
363 if (!flush_regular_buffer(buffer, thread)) {
364 buffer->concurrent_reinitialization();
365 }
366 }
367 assert(buffer->empty(), "invariant");
368 control().increment_dead();
369 buffer->release();
370 buffer->set_retired();
371 }
372
373 void JfrStorage::release_thread_local(BufferPtr buffer, Thread* thread) {
374 assert(buffer != NULL, "invariant");
375 JfrStorage& storage_instance = instance();
376 storage_instance.release(buffer, thread);
377 if (storage_instance.control().should_scavenge()) {
378 storage_instance._post_box.post(MSG_DEADBUFFER);
379 }
380 }
381
382 static void log_discard(size_t count, size_t amount, size_t current) {
383 if (log_is_enabled(Debug, jfr, system)) {
384 assert(count > 0, "invariant");
385 log_debug(jfr, system)("Cleared " SIZE_FORMAT " full buffer(s) of " SIZE_FORMAT" bytes.", count, amount);
386 log_debug(jfr, system)("Current number of full buffers " SIZE_FORMAT "", current);
387 }
388 }
389
390 void JfrStorage::discard_oldest(Thread* thread) {
391 if (JfrBuffer_lock->try_lock()) {
392 if (!control().should_discard()) {
393 // another thread handled it
394 return;
395 }
396 const size_t num_full_pre_discard = control().full_count();
397 size_t num_full_post_discard = 0;
398 size_t discarded_size = 0;
399 while (true) {
400 JfrAgeNode* const oldest_age_node = _age_mspace->full_tail();
401 if (oldest_age_node == NULL) {
402 break;
403 }
404 BufferPtr const buffer = oldest_age_node->retired_buffer();
405 assert(buffer->retired(), "invariant");
406 discarded_size += buffer->unflushed_size();
407 num_full_post_discard = control().decrement_full();
408 if (buffer->transient()) {
409 mspace_release(buffer, _transient_mspace);
410 mspace_release(oldest_age_node, _age_mspace);
411 continue;
412 } else {
413 mspace_release(oldest_age_node, _age_mspace);
414 buffer->reinitialize();
415 buffer->release(); // pusb
416 break;
417 }
418 }
419 JfrBuffer_lock->unlock();
420 const size_t number_of_discards = num_full_pre_discard - num_full_post_discard;
421 if (number_of_discards > 0) {
422 log_discard(number_of_discards, discarded_size, num_full_post_discard);
423 }
424 }
425 }
426
427 #ifdef ASSERT
428 typedef const BufferPtr ConstBufferPtr;
429
430 static void assert_flush_precondition(ConstBufferPtr cur, size_t used, bool native, const Thread* t) {
431 assert(t != NULL, "invariant");
432 assert(cur != NULL, "invariant");
433 assert(cur->pos() + used <= cur->end(), "invariant");
434 assert(native ? t->trace_data()->native_buffer() == cur : t->trace_data()->java_buffer() == cur, "invariant");
435 }
436
437 static void assert_flush_regular_precondition(ConstBufferPtr cur, const u1* const cur_pos, size_t used, size_t req, const Thread* t) {
438 assert(t != NULL, "invariant");
439 assert(t->trace_data()->shelved_buffer() == NULL, "invariant");
440 assert(cur != NULL, "invariant");
441 assert(!cur->lease(), "invariant");
442 assert(cur_pos != NULL, "invariant");
443 assert(req >= used, "invariant");
444 }
445
446 static void assert_provision_large_precondition(ConstBufferPtr cur, size_t used, size_t req, const Thread* t) {
447 assert(cur != NULL, "invariant");
448 assert(t != NULL, "invariant");
449 assert(t->trace_data()->shelved_buffer() != NULL, "invariant");
450 assert(req >= used, "invariant");
451 }
452
453 static void assert_flush_large_precondition(ConstBufferPtr cur, const u1* const cur_pos, size_t used, size_t req, bool native, Thread* t) {
454 assert(t != NULL, "invariant");
455 assert(cur != NULL, "invariant");
456 assert(cur->lease(), "invariant");
457 assert(cur_pos != NULL, "invariant");
458 assert(native ? t->trace_data()->native_buffer() == cur : t->trace_data()->java_buffer() == cur, "invariant");
459 assert(t->trace_data()->shelved_buffer() != NULL, "invariant");
460 assert(req >= used, "invariant");
461 assert(cur != t->trace_data()->shelved_buffer(), "invariant");
462 }
463 #endif // ASSERT
464
465 BufferPtr JfrStorage::flush(BufferPtr cur, size_t used, size_t req, bool native, Thread* t) {
466 debug_only(assert_flush_precondition(cur, used, native, t);)
467 const u1* const cur_pos = cur->pos();
468 req += used;
469 // requested size now encompass the outstanding used size
470 if (cur->lease()) {
471 return instance().flush_large(cur, cur_pos, used, req, native, t);
472 }
473 // "regular" == !lease
474 return instance().flush_regular(cur, cur_pos, used, req, native, t);
475 }
476
477 BufferPtr JfrStorage::flush_regular(BufferPtr cur, const u1* const cur_pos, size_t used, size_t req, bool native, Thread* t) {
478 debug_only(assert_flush_regular_precondition(cur, cur_pos, used, req, t);)
479 // A flush is needed before memcpy since a non-large buffer is thread stable
480 // (thread local). The flush will not modify memory in addresses above pos()
481 // which is where the "used / uncommitted" data resides. It is therefore both
482 // possible and valid to migrate data after the flush. This is however only
483 // the case for stable thread local buffers; it is not the case for large buffers.
484 if (!cur->empty()) {
485 flush_regular_buffer(cur, t);
486 }
487 assert(t->trace_data()->shelved_buffer() == NULL, "invariant");
488 if (cur->free_size() >= req) {
489 // simplest case, no switching of buffers
490 if (used > 0) {
491 memcpy(cur->pos(), (void*)cur_pos, used);
492 }
493 assert(native ? t->trace_data()->native_buffer() == cur : t->trace_data()->java_buffer() == cur, "invariant");
494 return cur;
495 }
496 // Going for a "larger-than-regular" buffer.
497 // Shelve the current buffer to make room for a temporary lease.
498 t->trace_data()->shelve_buffer(cur);
499 return provision_large(cur, cur_pos, used, req, native, t);
500 }
501
502 static BufferPtr store_buffer_to_thread_local(BufferPtr buffer, JfrThreadData* trace_data, bool native) {
503 assert(buffer != NULL, "invariant");
504 if (native) {
505 trace_data->set_native_buffer(buffer);
506 } else {
507 trace_data->set_java_buffer(buffer);
508 }
509 return buffer;
510 }
511
512 static BufferPtr restore_shelved_buffer(bool native, Thread* t) {
513 JfrThreadData* const trace_data = t->trace_data();
514 BufferPtr shelved = trace_data->shelved_buffer();
515 assert(shelved != NULL, "invariant");
516 t->trace_data()->shelve_buffer(NULL);
517 // restore shelved buffer back as primary
518 return store_buffer_to_thread_local(shelved, trace_data, native);
519 }
520
521 BufferPtr JfrStorage::flush_large(BufferPtr cur, const u1* const cur_pos, size_t used, size_t req, bool native, Thread* t) {
522 debug_only(assert_flush_large_precondition(cur, cur_pos, used, req, native, t);)
523 // Can the "regular" buffer (now shelved) accommodate the requested size?
524 BufferPtr shelved = t->trace_data()->shelved_buffer();
525 assert(shelved != NULL, "invariant");
526 if (shelved->free_size() >= req) {
527 if (req > 0) {
528 memcpy(shelved->pos(), (void*)cur_pos, (size_t)used);
529 }
530 // release and invalidate
531 release_large(cur, t);
532 return restore_shelved_buffer(native, t);
533 }
534 // regular too small
535 return provision_large(cur, cur_pos, used, req, native, t);
536 }
537
538 static BufferPtr large_fail(BufferPtr cur, bool native, JfrStorage& storage_instance, Thread* t) {
539 assert(cur != NULL, "invariant");
540 assert(t != NULL, "invariant");
541 if (cur->lease()) {
542 storage_instance.release_large(cur, t);
543 }
544 return restore_shelved_buffer(native, t);
545 }
546
547 // Always returns a non-null buffer.
548 // If accommodating the large request fails, the shelved buffer is returned
549 // even though it might be smaller than the requested size.
550 // Caller needs to ensure if the size was successfully accommodated.
551 BufferPtr JfrStorage::provision_large(BufferPtr cur, const u1* const cur_pos, size_t used, size_t req, bool native, Thread* t) {
552 debug_only(assert_provision_large_precondition(cur, used, req, t);)
553 assert(t->trace_data()->shelved_buffer() != NULL, "invariant");
554 BufferPtr const buffer = acquire_large(req, t);
555 if (buffer == NULL) {
556 // unable to allocate and serve the request
557 return large_fail(cur, native, *this, t);
558 }
559 // ok managed to acquire a "large" buffer for the requested size
560 assert(buffer->free_size() >= req, "invariant");
561 assert(buffer->lease(), "invariant");
562 // transfer outstanding data
563 memcpy(buffer->pos(), (void*)cur_pos, used);
564 if (cur->lease()) {
565 release_large(cur, t);
566 // don't use current anymore, it is gone
567 }
568 return store_buffer_to_thread_local(buffer, t->trace_data(), native);
569 }
570
571 typedef UnBufferedWriteToChunk<JfrBuffer> WriteOperation;
572 typedef MutexedWriteOp<WriteOperation> MutexedWriteOperation;
573 typedef ConcurrentWriteOp<WriteOperation> ConcurrentWriteOperation;
574 typedef ThreadLocalReleaseOp<JfrStorageMspace> ThreadLocalRelease;
575 typedef CompositeOperation<ConcurrentWriteOperation, ThreadLocalRelease> ThreadLocalWriteOperation;
576
577 size_t JfrStorage::write() {
578 const size_t full_size_processed = write_full();
579 WriteOperation wo(_chunkwriter);
580 ConcurrentWriteOperation cwo(wo);
581 ThreadLocalRelease tlr(_thread_local_mspace);
582 ThreadLocalWriteOperation tlwo(&cwo, &tlr);
583 process_full_list(tlwo, _thread_local_mspace);
584 process_free_list(cwo, _global_mspace);
585 return full_size_processed + wo.processed();
586 }
587
588 size_t JfrStorage::write_at_safepoint() {
589 assert(SafepointSynchronize::is_at_safepoint(), "invariant");
590 WriteOperation wo(_chunkwriter);
591 MutexedWriteOperation writer(wo); // mutexed write mode
592 process_full_list(writer, _thread_local_mspace);
593 assert(_transient_mspace->is_free_empty(), "invariant");
594 process_full_list(writer, _transient_mspace);
595 assert(_global_mspace->is_full_empty(), "invariant");
596 process_free_list(writer, _global_mspace);
597 return wo.processed();
598 }
599
600 typedef DiscardOp<DefaultDiscarder<JfrStorage::Buffer> > DiscardOperation;
601 typedef CompositeOperation<DiscardOperation, ThreadLocalRelease> ThreadLocalDiscardOperation;
602 typedef ReleaseOp<JfrStorageMspace> ReleaseOperation;
603 typedef CompositeOperation<MutexedWriteOperation, ReleaseOperation> FullOperation;
604
605 size_t JfrStorage::clear() {
606 const size_t full_size_processed = clear_full();
607 DiscardOperation discarder(concurrent); // concurrent discard mode
608 ThreadLocalRelease tlr(_thread_local_mspace);
609 ThreadLocalDiscardOperation tldo(&discarder, &tlr);
610 process_full_list(tldo, _thread_local_mspace);
611 assert(_transient_mspace->is_free_empty(), "invariant");
612 process_full_list(discarder, _transient_mspace);
613 assert(_global_mspace->is_full_empty(), "invariant");
614 process_free_list(discarder, _global_mspace);
615 return full_size_processed + discarder.processed();
616 }
617
618 static void insert_free_age_nodes(JfrStorageAgeMspace* age_mspace, JfrAgeNode* head, JfrAgeNode* tail, size_t count) {
619 if (tail != NULL) {
620 assert(tail->next() == NULL, "invariant");
621 assert(head != NULL, "invariant");
622 assert(head->prev() == NULL, "invariant");
623 MutexLockerEx buffer_lock(JfrBuffer_lock, Mutex::_no_safepoint_check_flag);
624 age_mspace->insert_free_tail(head, tail, count);
625 }
626 }
627
628 template <typename Processor>
629 static void process_age_list(Processor& processor, JfrStorageAgeMspace* age_mspace, JfrAgeNode* head, size_t count) {
630 assert(age_mspace != NULL, "invariant");
631 assert(head != NULL, "invariant");
632 JfrAgeNode* node = head;
633 JfrAgeNode* last = NULL;
634 while (node != NULL) {
635 last = node;
636 BufferPtr const buffer = node->retired_buffer();
637 assert(buffer != NULL, "invariant");
638 assert(buffer->retired(), "invariant");
639 processor.process(buffer);
640 // at this point, buffer is already live or destroyed
641 node->clear_identity();
642 JfrAgeNode* const next = (JfrAgeNode*)node->next();
643 if (node->transient()) {
644 // detach
645 last = (JfrAgeNode*)last->prev();
646 if (last != NULL) {
647 last->set_next(next);
648 } else {
649 head = next;
650 }
651 if (next != NULL) {
652 next->set_prev(last);
653 }
654 --count;
655 age_mspace->deallocate(node);
656 }
657 node = next;
658 }
659 insert_free_age_nodes(age_mspace, head, last, count);
660 }
661
662 template <typename Processor>
663 static size_t process_full(Processor& processor, JfrStorageControl& control, JfrStorageAgeMspace* age_mspace) {
664 assert(age_mspace != NULL, "invariant");
665 if (age_mspace->is_full_empty()) {
666 // nothing to do
667 return 0;
668 }
669 size_t count;
670 JfrAgeNode* head;;
671 {
672 // fetch age list
673 MutexLockerEx buffer_lock(JfrBuffer_lock, Mutex::_no_safepoint_check_flag);
674 count = age_mspace->full_count();
675 head = age_mspace->clear_full();
676 control.reset_full();
677 }
678 assert(head != NULL, "invariant");
679 process_age_list(processor, age_mspace, head, count);
680 return count;
681 }
682
683 static void log(size_t count, size_t amount, bool clear = false) {
684 if (log_is_enabled(Debug, jfr, system)) {
685 if (count > 0) {
686 log_debug(jfr, system)( "%s " SIZE_FORMAT " full buffer(s) of " SIZE_FORMAT" B of data%s",
687 clear ? "Discarded" : "Wrote", count, amount, clear ? "." : " to chunk.");
688 }
689 }
690 }
691
692 // full writer
693 // Assumption is retired only; exclusive access
694 // MutexedWriter -> ReleaseOp
695 //
696 size_t JfrStorage::write_full() {
697 assert(_chunkwriter.is_valid(), "invariant");
698 WriteOperation wo(_chunkwriter);
699 MutexedWriteOperation writer(wo); // a retired buffer implies mutexed access
700 ReleaseOperation ro(_transient_mspace);
701 FullOperation cmd(&writer, &ro);
702 const size_t count = process_full(cmd, control(), _age_mspace);
703 log(count, writer.processed());
704 return writer.processed();
705 }
706
707 size_t JfrStorage::clear_full() {
708 DiscardOperation discarder(mutexed); // a retired buffer implies mutexed access
709 const size_t count = process_full(discarder, control(), _age_mspace);
710 log(count, discarder.processed(), true);
711 return discarder.processed();
712 }
713
714 static void scavenge_log(size_t count, size_t amount, size_t current) {
715 if (count > 0) {
716 if (log_is_enabled(Debug, jfr, system)) {
717 log_debug(jfr, system)("Released " SIZE_FORMAT " dead buffer(s) of " SIZE_FORMAT" B of data.", count, amount);
718 log_debug(jfr, system)("Current number of dead buffers " SIZE_FORMAT "", current);
719 }
720 }
721 }
722
723 template <typename Mspace>
724 class Scavenger {
725 private:
726 JfrStorageControl& _control;
727 Mspace* _mspace;
728 size_t _count;
729 size_t _amount;
730 public:
731 typedef typename Mspace::Type Type;
732 Scavenger(JfrStorageControl& control, Mspace* mspace) : _control(control), _mspace(mspace), _count(0), _amount(0) {}
733 bool process(Type* t) {
734 if (t->retired()) {
735 assert(!t->transient(), "invariant");
736 assert(!t->lease(), "invariant");
737 assert(t->identity() == NULL, "invariant");
738 assert(t->empty(), "invariant");
739 ++_count;
740 _amount += t->total_size();
741 _control.decrement_dead();
742 t->clear_retired();
743 mspace_release_critical(t, _mspace);
744 }
745 return true;
746 }
747 size_t processed() const { return _count; }
748 size_t amount() const { return _amount; }
749 };
750
751 size_t JfrStorage::scavenge() {
752 if (control().dead_count() > 0) {
753 Scavenger<JfrStorageMspace> scavenger(control(), _thread_local_mspace);
754 process_full_list(scavenger, _thread_local_mspace);
755 scavenge_log(scavenger.processed(), scavenger.amount(), control().dead_count());
756 return scavenger.processed();
757 }
758 return 0;
759 }