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 "classfile/javaClasses.hpp"
27 #include "jfr/recorder/jfrRecorder.hpp"
28 #include "jfr/recorder/checkpoint/jfrCheckpointManager.hpp"
29 #include "jfr/recorder/checkpoint/jfrCheckpointWriter.hpp"
30 #include "jfr/recorder/checkpoint/types/jfrTypeManager.hpp"
31 #include "jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.hpp"
32 #include "jfr/recorder/service/jfrOptionSet.hpp"
33 #include "jfr/recorder/storage/jfrMemorySpace.inline.hpp"
34 #include "jfr/recorder/storage/jfrStorageUtils.inline.hpp"
35 #include "jfr/recorder/repository/jfrChunkWriter.hpp"
36 #include "jfr/utilities/jfrBigEndian.hpp"
37 #include "jfr/utilities/jfrTypes.hpp"
38 #include "memory/resourceArea.hpp"
39 #include "runtime/mutexLocker.hpp"
40 #include "runtime/orderAccess.inline.hpp"
41 #include "runtime/os.hpp"
42 #include "runtime/safepoint.hpp"
43
44 typedef JfrCheckpointManager::Buffer* BufferPtr;
45
46 static JfrCheckpointManager* _instance = NULL;
47
48 JfrCheckpointManager& JfrCheckpointManager::instance() {
49 return *_instance;
50 }
51
52 JfrCheckpointManager* JfrCheckpointManager::create(JfrChunkWriter& cw) {
53 assert(_instance == NULL, "invariant");
54 _instance = new JfrCheckpointManager(cw);
55 return _instance;
56 }
57
58 void JfrCheckpointManager::destroy() {
59 assert(_instance != NULL, "invariant");
60 delete _instance;
61 _instance = NULL;
62 }
63
64 JfrCheckpointManager::JfrCheckpointManager(JfrChunkWriter& cw) :
65 _free_list_mspace(NULL),
66 _epoch_transition_mspace(NULL),
67 _lock(NULL),
68 _service_thread(NULL),
69 _chunkwriter(cw),
70 _checkpoint_epoch_state(JfrTraceIdEpoch::current()) {}
71
72 JfrCheckpointManager::~JfrCheckpointManager() {
73 if (_free_list_mspace != NULL) {
74 delete _free_list_mspace;
75 }
76 if (_epoch_transition_mspace != NULL) {
77 delete _epoch_transition_mspace;
78 }
79 if (_lock != NULL) {
80 delete _lock;
81 }
82 JfrTypeManager::clear();
83 }
84
85 static const size_t unlimited_mspace_size = 0;
86 static const size_t checkpoint_buffer_cache_count = 2;
87 static const size_t checkpoint_buffer_size = 512 * K;
88
89 static JfrCheckpointMspace* create_mspace(size_t buffer_size, size_t limit, size_t cache_count, JfrCheckpointManager* system) {
90 JfrCheckpointMspace* mspace = new JfrCheckpointMspace(buffer_size, limit, cache_count, system);
91 if (mspace != NULL) {
92 mspace->initialize();
93 }
94 return mspace;
95 }
96
97 bool JfrCheckpointManager::initialize() {
98 assert(_free_list_mspace == NULL, "invariant");
99 _free_list_mspace = create_mspace(checkpoint_buffer_size, unlimited_mspace_size, checkpoint_buffer_cache_count, this);
100 if (_free_list_mspace == NULL) {
101 return false;
102 }
103 assert(_epoch_transition_mspace == NULL, "invariant");
104 _epoch_transition_mspace = create_mspace(checkpoint_buffer_size, unlimited_mspace_size, checkpoint_buffer_cache_count, this);
105 if (_epoch_transition_mspace == NULL) {
106 return false;
107 }
108 assert(_lock == NULL, "invariant");
109 _lock = new Mutex(Monitor::leaf - 1, "Checkpoint mutex", Mutex::_allow_vm_block_flag);
110 if (_lock == NULL) {
111 return false;
112 }
113 return JfrTypeManager::initialize();
114 }
115
116 bool JfrCheckpointManager::use_epoch_transition_mspace(const Thread* thread) const {
117 return _service_thread != thread && OrderAccess::load_acquire((u1*)&_checkpoint_epoch_state) != JfrTraceIdEpoch::current();
118 }
119
120 void JfrCheckpointManager::synchronize_epoch() {
121 assert(_checkpoint_epoch_state != JfrTraceIdEpoch::current(), "invariant");
122 OrderAccess::storestore();
123 _checkpoint_epoch_state = JfrTraceIdEpoch::current();
124 }
125
126 void JfrCheckpointManager::shift_epoch() {
127 debug_only(const u1 current_epoch = JfrTraceIdEpoch::current();)
128 JfrTraceIdEpoch::shift_epoch();
129 assert(current_epoch != JfrTraceIdEpoch::current(), "invariant");
130 }
131
132 void JfrCheckpointManager::register_service_thread(const Thread* thread) {
133 _service_thread = thread;
134 }
135
136 void JfrCheckpointManager::register_full(BufferPtr t, Thread* thread) {
137 // nothing here at the moment
138 assert(t != NULL, "invariant");
139 assert(t->acquired_by(thread), "invariant");
140 assert(t->retired(), "invariant");
141 }
142
143 void JfrCheckpointManager::lock() {
144 assert(!_lock->owned_by_self(), "invariant");
145 _lock->lock_without_safepoint_check();
146 }
147
148 void JfrCheckpointManager::unlock() {
149 _lock->unlock();
150 }
151
152 #ifdef ASSERT
153
154 bool JfrCheckpointManager::is_locked() const {
155 return _lock->owned_by_self();
156 }
157
158 static void assert_free_lease(const BufferPtr buffer) {
159 assert(buffer != NULL, "invariant");
160 assert(buffer->acquired_by_self(), "invariant");
161 assert(buffer->lease(), "invariant");
162 }
163
164 static void assert_release(const BufferPtr buffer) {
165 assert(buffer != NULL, "invariant");
166 assert(buffer->lease(), "invariant");
167 assert(buffer->acquired_by_self(), "invariant");
168 }
169
170 #endif // ASSERT
171
172 static BufferPtr lease_free(size_t size, JfrCheckpointMspace* mspace, size_t retry_count, Thread* thread) {
173 static const size_t max_elem_size = mspace->min_elem_size(); // min is max
174 BufferPtr buffer;
175 if (size <= max_elem_size) {
176 BufferPtr buffer = mspace_get_free_lease_with_retry(size, mspace, retry_count, thread);
177 if (buffer != NULL) {
178 DEBUG_ONLY(assert_free_lease(buffer);)
179 return buffer;
180 }
181 }
182 buffer = mspace_allocate_transient_lease_to_free(size, mspace, thread);
183 DEBUG_ONLY(assert_free_lease(buffer);)
184 return buffer;
185 }
186
187 static const size_t lease_retry = 10;
188
189 BufferPtr JfrCheckpointManager::lease_buffer(Thread* thread, size_t size /* 0 */) {
190 JfrCheckpointManager& manager = instance();
191 if (manager.use_epoch_transition_mspace(thread)) {
192 return lease_free(size, manager._epoch_transition_mspace, lease_retry, thread);
193 }
194 return lease_free(size, manager._free_list_mspace, lease_retry, thread);
195 }
196
197 /*
198 * If the buffer was a "lease" from the free list, release back.
199 *
200 * The buffer is effectively invalidated for the thread post-return,
201 * and the caller should take means to ensure that it is not referenced.
202 */
203 static void release(BufferPtr const buffer, Thread* thread) {
204 DEBUG_ONLY(assert_release(buffer);)
205 buffer->clear_lease();
206 buffer->release();
207 }
208
209 BufferPtr JfrCheckpointManager::flush(BufferPtr old, size_t used, size_t requested, Thread* thread) {
210 assert(old != NULL, "invariant");
211 assert(old->lease(), "invariant");
212 if (0 == requested) {
213 // indicates a lease is being returned
214 release(old, thread);
215 return NULL;
216 }
217 // migration of in-flight information
218 BufferPtr const new_buffer = lease_buffer(thread, used + requested);
219 if (new_buffer != NULL) {
220 migrate_outstanding_writes(old, new_buffer, used, requested);
221 }
222 release(old, thread);
223 return new_buffer; // might be NULL
224 }
225
226 // offsets into the JfrCheckpointEntry
227 static const juint starttime_offset = sizeof(jlong);
228 static const juint duration_offset = starttime_offset + sizeof(jlong);
229 static const juint flushpoint_offset = duration_offset + sizeof(jlong);
230 static const juint types_offset = flushpoint_offset + sizeof(juint);
231 static const juint payload_offset = types_offset + sizeof(juint);
232
233 template <typename Return>
234 static Return read_data(const u1* data) {
235 return JfrBigEndian::read<Return>(data);
236 }
237
238 static jlong total_size(const u1* data) {
239 return read_data<jlong>(data);
240 }
241
242 static jlong starttime(const u1* data) {
243 return read_data<jlong>(data + starttime_offset);
244 }
245
246 static jlong duration(const u1* data) {
247 return read_data<jlong>(data + duration_offset);
248 }
249
250 static bool is_flushpoint(const u1* data) {
251 return read_data<juint>(data + flushpoint_offset) == (juint)1;
252 }
253
254 static juint number_of_types(const u1* data) {
255 return read_data<juint>(data + types_offset);
256 }
257
258 static void write_checkpoint_header(JfrChunkWriter& cw, intptr_t offset_prev_cp_event, const u1* data) {
259 cw.reserve(sizeof(u4));
260 cw.write((u8)EVENT_CHECKPOINT);
261 cw.write(starttime(data));
262 cw.write(duration(data));
263 cw.write((jlong)offset_prev_cp_event);
264 cw.write(is_flushpoint(data));
265 cw.write(number_of_types(data));
266 }
267
268 static void write_checkpoint_content(JfrChunkWriter& cw, const u1* data, size_t size) {
269 assert(data != NULL, "invariant");
270 cw.write_unbuffered(data + payload_offset, size);
271 }
272
273 static size_t write_checkpoint_event(JfrChunkWriter& cw, const u1* data) {
274 assert(data != NULL, "invariant");
275 const intptr_t previous_checkpoint_event = cw.previous_checkpoint_offset();
276 const intptr_t event_begin = cw.current_offset();
277 const intptr_t offset_to_previous_checkpoint_event = 0 == previous_checkpoint_event ? 0 : previous_checkpoint_event - event_begin;
278 const jlong total_checkpoint_size = total_size(data);
279 write_checkpoint_header(cw, offset_to_previous_checkpoint_event, data);
280 write_checkpoint_content(cw, data, total_checkpoint_size - sizeof(JfrCheckpointEntry));
281 const jlong checkpoint_event_size = cw.current_offset() - event_begin;
282 cw.write_padded_at_offset<u4>(checkpoint_event_size, event_begin);
283 cw.set_previous_checkpoint_offset(event_begin);
284 return (size_t)total_checkpoint_size;
285 }
286
287 static size_t write_checkpoints(JfrChunkWriter& cw, const u1* data, size_t size) {
288 assert(cw.is_valid(), "invariant");
289 assert(data != NULL, "invariant");
290 assert(size > 0, "invariant");
291 const u1* const limit = data + size;
292 const u1* next_entry = data;
293 size_t processed = 0;
294 while (next_entry < limit) {
295 const size_t checkpoint_size = write_checkpoint_event(cw, next_entry);
296 processed += checkpoint_size;
297 next_entry += checkpoint_size;
298 }
299 assert(next_entry == limit, "invariant");
300 return processed;
301 }
302
303 template <typename T>
304 class CheckpointWriteOp {
305 private:
306 JfrChunkWriter& _writer;
307 size_t _processed;
308 public:
309 typedef T Type;
310 CheckpointWriteOp(JfrChunkWriter& writer) : _writer(writer), _processed(0) {}
311 bool write(Type* t, const u1* data, size_t size) {
312 _processed += write_checkpoints(_writer, data, size);
313 return true;
314 }
315 size_t processed() const { return _processed; }
316 };
317
318 typedef CheckpointWriteOp<JfrCheckpointMspace::Type> WriteOperation;
319 typedef MutexedWriteOp<WriteOperation> MutexedWriteOperation;
320 typedef ReleaseOp<JfrCheckpointMspace> CheckpointReleaseOperation;
321 typedef CompositeOperation<MutexedWriteOperation, CheckpointReleaseOperation> CheckpointWriteOperation;
322
323 static size_t write_mspace_exclusive(JfrCheckpointMspace* mspace, JfrChunkWriter& chunkwriter) {
324 Thread* const thread = Thread::current();
325 WriteOperation wo(chunkwriter);
326 MutexedWriteOperation mwo(wo);
327 CheckpointReleaseOperation cro(mspace, thread, false);
328 CheckpointWriteOperation cpwo(&mwo, &cro);
329 assert(mspace->is_full_empty(), "invariant");
330 process_free_list(cpwo, mspace);
331 return wo.processed();
332 }
333
334 size_t JfrCheckpointManager::write() {
335 const size_t processed = write_mspace_exclusive(_free_list_mspace, _chunkwriter);
336 synchronize_epoch();
337 return processed;
338 }
339
340 size_t JfrCheckpointManager::write_epoch_transition_mspace() {
341 return write_mspace_exclusive(_epoch_transition_mspace, _chunkwriter);
342 }
343
344 typedef DiscardOp<DefaultDiscarder<JfrBuffer> > DiscardOperation;
345 size_t JfrCheckpointManager::clear() {
346 DiscardOperation discarder(mutexed); // mutexed discard mode
347 process_free_list(discarder, _free_list_mspace);
348 process_free_list(discarder, _epoch_transition_mspace);
349 synchronize_epoch();
350 return discarder.processed();
351 }
352
353 size_t JfrCheckpointManager::write_types() {
354 JfrCheckpointWriter writer(false, true, Thread::current());
355 JfrTypeManager::write_types(writer);
356 return writer.used_size();
357 }
358
359 size_t JfrCheckpointManager::write_safepoint_types() {
360 // this is also a "flushpoint"
361 JfrCheckpointWriter writer(true, true, Thread::current());
362 JfrTypeManager::write_safepoint_types(writer);
363 return writer.used_size();
364 }
365
366 void JfrCheckpointManager::write_type_set() {
367 JfrTypeManager::write_type_set();
368 }
369
370 void JfrCheckpointManager::write_type_set_for_unloaded_classes() {
371 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint!");
372 JfrTypeManager::write_type_set_for_unloaded_classes();
373 }
374
375 void JfrCheckpointManager::create_thread_checkpoint(JavaThread* jt) {
376 JfrTypeManager::create_thread_checkpoint(jt);
377 }
378
379 void JfrCheckpointManager::write_thread_checkpoint(JavaThread* jt) {
380 JfrTypeManager::write_thread_checkpoint(jt);
381 }