Sun, 03 Feb 2013 22:28:08 +0400
8002048: Protocol to discovery of manageable Java processes on a network
Summary: Introduce a protocol to discover manageble Java instances across a network subnet, JDP
Reviewed-by: sla, dfuchs
zgu@3900 | 1 | /* |
zgu@3900 | 2 | * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved. |
zgu@3900 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
zgu@3900 | 4 | * |
zgu@3900 | 5 | * This code is free software; you can redistribute it and/or modify it |
zgu@3900 | 6 | * under the terms of the GNU General Public License version 2 only, as |
zgu@3900 | 7 | * published by the Free Software Foundation. |
zgu@3900 | 8 | * |
zgu@3900 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
zgu@3900 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
zgu@3900 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
zgu@3900 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
zgu@3900 | 13 | * accompanied this code). |
zgu@3900 | 14 | * |
zgu@3900 | 15 | * You should have received a copy of the GNU General Public License version |
zgu@3900 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
zgu@3900 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
zgu@3900 | 18 | * |
zgu@3900 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
zgu@3900 | 20 | * or visit www.oracle.com if you need additional information or have any |
zgu@3900 | 21 | * questions. |
zgu@3900 | 22 | * |
zgu@3900 | 23 | */ |
zgu@3900 | 24 | #include "precompiled.hpp" |
zgu@3900 | 25 | |
zgu@4400 | 26 | #include "oops/instanceKlass.hpp" |
zgu@3900 | 27 | #include "runtime/atomic.hpp" |
zgu@3900 | 28 | #include "runtime/interfaceSupport.hpp" |
zgu@3900 | 29 | #include "runtime/mutexLocker.hpp" |
zgu@3900 | 30 | #include "runtime/safepoint.hpp" |
zgu@3900 | 31 | #include "runtime/threadCritical.hpp" |
ctornqvi@4512 | 32 | #include "runtime/vm_operations.hpp" |
zgu@3900 | 33 | #include "services/memPtr.hpp" |
zgu@3900 | 34 | #include "services/memReporter.hpp" |
zgu@3900 | 35 | #include "services/memTracker.hpp" |
zgu@3900 | 36 | #include "utilities/decoder.hpp" |
zgu@3900 | 37 | #include "utilities/globalDefinitions.hpp" |
zgu@3900 | 38 | |
zgu@3900 | 39 | bool NMT_track_callsite = false; |
zgu@3900 | 40 | |
zgu@3900 | 41 | // walk all 'known' threads at NMT sync point, and collect their recorders |
zgu@3900 | 42 | void SyncThreadRecorderClosure::do_thread(Thread* thread) { |
zgu@3900 | 43 | assert(SafepointSynchronize::is_at_safepoint(), "Safepoint required"); |
zgu@3900 | 44 | if (thread->is_Java_thread()) { |
zgu@3900 | 45 | JavaThread* javaThread = (JavaThread*)thread; |
zgu@3900 | 46 | MemRecorder* recorder = javaThread->get_recorder(); |
zgu@3900 | 47 | if (recorder != NULL) { |
zgu@3900 | 48 | MemTracker::enqueue_pending_recorder(recorder); |
zgu@3900 | 49 | javaThread->set_recorder(NULL); |
zgu@3900 | 50 | } |
zgu@3900 | 51 | } |
zgu@3900 | 52 | _thread_count ++; |
zgu@3900 | 53 | } |
zgu@3900 | 54 | |
zgu@3900 | 55 | |
zgu@3900 | 56 | MemRecorder* MemTracker::_global_recorder = NULL; |
zgu@3900 | 57 | MemSnapshot* MemTracker::_snapshot = NULL; |
zgu@3900 | 58 | MemBaseline MemTracker::_baseline; |
zgu@3936 | 59 | Mutex* MemTracker::_query_lock = NULL; |
zgu@3900 | 60 | volatile MemRecorder* MemTracker::_merge_pending_queue = NULL; |
zgu@3900 | 61 | volatile MemRecorder* MemTracker::_pooled_recorders = NULL; |
zgu@3900 | 62 | MemTrackWorker* MemTracker::_worker_thread = NULL; |
zgu@3900 | 63 | int MemTracker::_sync_point_skip_count = 0; |
zgu@3900 | 64 | MemTracker::NMTLevel MemTracker::_tracking_level = MemTracker::NMT_off; |
zgu@3900 | 65 | volatile MemTracker::NMTStates MemTracker::_state = NMT_uninited; |
zgu@3900 | 66 | MemTracker::ShutdownReason MemTracker::_reason = NMT_shutdown_none; |
zgu@3900 | 67 | int MemTracker::_thread_count = 255; |
zgu@3900 | 68 | volatile jint MemTracker::_pooled_recorder_count = 0; |
ctornqvi@4512 | 69 | volatile unsigned long MemTracker::_processing_generation = 0; |
ctornqvi@4512 | 70 | volatile bool MemTracker::_worker_thread_idle = false; |
zgu@3900 | 71 | debug_only(intx MemTracker::_main_thread_tid = 0;) |
zgu@3994 | 72 | NOT_PRODUCT(volatile jint MemTracker::_pending_recorder_count = 0;) |
zgu@3900 | 73 | |
zgu@3900 | 74 | void MemTracker::init_tracking_options(const char* option_line) { |
zgu@3900 | 75 | _tracking_level = NMT_off; |
zgu@4291 | 76 | if (strcmp(option_line, "=summary") == 0) { |
zgu@3900 | 77 | _tracking_level = NMT_summary; |
zgu@4291 | 78 | } else if (strcmp(option_line, "=detail") == 0) { |
zgu@3900 | 79 | _tracking_level = NMT_detail; |
zgu@4291 | 80 | } else if (strcmp(option_line, "=off") != 0) { |
zgu@4291 | 81 | vm_exit_during_initialization("Syntax error, expecting -XX:NativeMemoryTracking=[off|summary|detail]", NULL); |
zgu@3900 | 82 | } |
zgu@3900 | 83 | } |
zgu@3900 | 84 | |
zgu@3900 | 85 | // first phase of bootstrapping, when VM is still in single-threaded mode. |
zgu@3900 | 86 | void MemTracker::bootstrap_single_thread() { |
zgu@3900 | 87 | if (_tracking_level > NMT_off) { |
zgu@3900 | 88 | assert(_state == NMT_uninited, "wrong state"); |
zgu@3900 | 89 | |
zgu@3900 | 90 | // NMT is not supported with UseMallocOnly is on. NMT can NOT |
zgu@3900 | 91 | // handle the amount of malloc data without significantly impacting |
zgu@3900 | 92 | // runtime performance when this flag is on. |
zgu@3900 | 93 | if (UseMallocOnly) { |
zgu@3900 | 94 | shutdown(NMT_use_malloc_only); |
zgu@3900 | 95 | return; |
zgu@3900 | 96 | } |
zgu@3900 | 97 | |
zgu@3936 | 98 | _query_lock = new (std::nothrow) Mutex(Monitor::max_nonleaf, "NMT_queryLock"); |
zgu@3936 | 99 | if (_query_lock == NULL) { |
zgu@3936 | 100 | shutdown(NMT_out_of_memory); |
zgu@3936 | 101 | return; |
zgu@3936 | 102 | } |
zgu@3936 | 103 | |
zgu@3900 | 104 | debug_only(_main_thread_tid = os::current_thread_id();) |
zgu@3900 | 105 | _state = NMT_bootstrapping_single_thread; |
zgu@3900 | 106 | NMT_track_callsite = (_tracking_level == NMT_detail && can_walk_stack()); |
zgu@3900 | 107 | } |
zgu@3900 | 108 | } |
zgu@3900 | 109 | |
zgu@3900 | 110 | // second phase of bootstrapping, when VM is about to or already entered multi-theaded mode. |
zgu@3900 | 111 | void MemTracker::bootstrap_multi_thread() { |
zgu@3900 | 112 | if (_tracking_level > NMT_off && _state == NMT_bootstrapping_single_thread) { |
zgu@3900 | 113 | // create nmt lock for multi-thread execution |
zgu@3900 | 114 | assert(_main_thread_tid == os::current_thread_id(), "wrong thread"); |
zgu@3900 | 115 | _state = NMT_bootstrapping_multi_thread; |
zgu@3900 | 116 | NMT_track_callsite = (_tracking_level == NMT_detail && can_walk_stack()); |
zgu@3900 | 117 | } |
zgu@3900 | 118 | } |
zgu@3900 | 119 | |
zgu@3900 | 120 | // fully start nmt |
zgu@3900 | 121 | void MemTracker::start() { |
zgu@3900 | 122 | // Native memory tracking is off from command line option |
zgu@3900 | 123 | if (_tracking_level == NMT_off || shutdown_in_progress()) return; |
zgu@3900 | 124 | |
zgu@3900 | 125 | assert(_main_thread_tid == os::current_thread_id(), "wrong thread"); |
zgu@3900 | 126 | assert(_state == NMT_bootstrapping_multi_thread, "wrong state"); |
zgu@3900 | 127 | |
zgu@3900 | 128 | _snapshot = new (std::nothrow)MemSnapshot(); |
zgu@3900 | 129 | if (_snapshot != NULL && !_snapshot->out_of_memory()) { |
zgu@3900 | 130 | if (start_worker()) { |
zgu@3900 | 131 | _state = NMT_started; |
zgu@3900 | 132 | NMT_track_callsite = (_tracking_level == NMT_detail && can_walk_stack()); |
zgu@3900 | 133 | return; |
zgu@3900 | 134 | } |
zgu@3900 | 135 | } |
zgu@3900 | 136 | |
zgu@3900 | 137 | // fail to start native memory tracking, shut it down |
zgu@3900 | 138 | shutdown(NMT_initialization); |
zgu@3900 | 139 | } |
zgu@3900 | 140 | |
zgu@3900 | 141 | /** |
zgu@3900 | 142 | * Shutting down native memory tracking. |
zgu@3900 | 143 | * We can not shutdown native memory tracking immediately, so we just |
zgu@3900 | 144 | * setup shutdown pending flag, every native memory tracking component |
zgu@3900 | 145 | * should orderly shut itself down. |
zgu@3900 | 146 | * |
zgu@3900 | 147 | * The shutdown sequences: |
zgu@3900 | 148 | * 1. MemTracker::shutdown() sets MemTracker to shutdown pending state |
zgu@3900 | 149 | * 2. Worker thread calls MemTracker::final_shutdown(), which transites |
zgu@3900 | 150 | * MemTracker to final shutdown state. |
zgu@3900 | 151 | * 3. At sync point, MemTracker does final cleanup, before sets memory |
zgu@3900 | 152 | * tracking level to off to complete shutdown. |
zgu@3900 | 153 | */ |
zgu@3900 | 154 | void MemTracker::shutdown(ShutdownReason reason) { |
zgu@3900 | 155 | if (_tracking_level == NMT_off) return; |
zgu@3900 | 156 | |
zgu@3900 | 157 | if (_state <= NMT_bootstrapping_single_thread) { |
zgu@3900 | 158 | // we still in single thread mode, there is not contention |
zgu@3900 | 159 | _state = NMT_shutdown_pending; |
zgu@3900 | 160 | _reason = reason; |
zgu@3900 | 161 | } else { |
zgu@3900 | 162 | // we want to know who initialized shutdown |
zgu@3900 | 163 | if ((jint)NMT_started == Atomic::cmpxchg((jint)NMT_shutdown_pending, |
zgu@3900 | 164 | (jint*)&_state, (jint)NMT_started)) { |
zgu@3900 | 165 | _reason = reason; |
zgu@3900 | 166 | } |
zgu@3900 | 167 | } |
zgu@3900 | 168 | } |
zgu@3900 | 169 | |
zgu@3900 | 170 | // final phase of shutdown |
zgu@3900 | 171 | void MemTracker::final_shutdown() { |
zgu@3900 | 172 | // delete all pending recorders and pooled recorders |
zgu@3900 | 173 | delete_all_pending_recorders(); |
zgu@3900 | 174 | delete_all_pooled_recorders(); |
zgu@3900 | 175 | |
zgu@3900 | 176 | { |
zgu@3900 | 177 | // shared baseline and snapshot are the only objects needed to |
zgu@3900 | 178 | // create query results |
zgu@3936 | 179 | MutexLockerEx locker(_query_lock, true); |
zgu@3900 | 180 | // cleanup baseline data and snapshot |
zgu@3900 | 181 | _baseline.clear(); |
zgu@3900 | 182 | delete _snapshot; |
zgu@3900 | 183 | _snapshot = NULL; |
zgu@3900 | 184 | } |
zgu@3900 | 185 | |
zgu@3900 | 186 | // shutdown shared decoder instance, since it is only |
zgu@3900 | 187 | // used by native memory tracking so far. |
zgu@3900 | 188 | Decoder::shutdown(); |
zgu@3900 | 189 | |
zgu@3900 | 190 | MemTrackWorker* worker = NULL; |
zgu@3900 | 191 | { |
zgu@3900 | 192 | ThreadCritical tc; |
zgu@3900 | 193 | // can not delete worker inside the thread critical |
zgu@3900 | 194 | if (_worker_thread != NULL && Thread::current() == _worker_thread) { |
zgu@3900 | 195 | worker = _worker_thread; |
zgu@3900 | 196 | _worker_thread = NULL; |
zgu@3900 | 197 | } |
zgu@3900 | 198 | } |
zgu@3900 | 199 | if (worker != NULL) { |
zgu@3900 | 200 | delete worker; |
zgu@3900 | 201 | } |
zgu@3900 | 202 | _state = NMT_final_shutdown; |
zgu@3900 | 203 | } |
zgu@3900 | 204 | |
zgu@3900 | 205 | // delete all pooled recorders |
zgu@3900 | 206 | void MemTracker::delete_all_pooled_recorders() { |
zgu@3900 | 207 | // free all pooled recorders |
zgu@3900 | 208 | volatile MemRecorder* cur_head = _pooled_recorders; |
zgu@3900 | 209 | if (cur_head != NULL) { |
zgu@3900 | 210 | MemRecorder* null_ptr = NULL; |
zgu@3900 | 211 | while (cur_head != NULL && (void*)cur_head != Atomic::cmpxchg_ptr((void*)null_ptr, |
zgu@3900 | 212 | (void*)&_pooled_recorders, (void*)cur_head)) { |
zgu@3900 | 213 | cur_head = _pooled_recorders; |
zgu@3900 | 214 | } |
zgu@3900 | 215 | if (cur_head != NULL) { |
zgu@3900 | 216 | delete cur_head; |
zgu@3900 | 217 | _pooled_recorder_count = 0; |
zgu@3900 | 218 | } |
zgu@3900 | 219 | } |
zgu@3900 | 220 | } |
zgu@3900 | 221 | |
zgu@3900 | 222 | // delete all recorders in pending queue |
zgu@3900 | 223 | void MemTracker::delete_all_pending_recorders() { |
zgu@3900 | 224 | // free all pending recorders |
zgu@3900 | 225 | MemRecorder* pending_head = get_pending_recorders(); |
zgu@3900 | 226 | if (pending_head != NULL) { |
zgu@3900 | 227 | delete pending_head; |
zgu@3900 | 228 | } |
zgu@3900 | 229 | } |
zgu@3900 | 230 | |
zgu@3900 | 231 | /* |
zgu@3900 | 232 | * retrieve per-thread recorder of specified thread. |
zgu@3900 | 233 | * if thread == NULL, it means global recorder |
zgu@3900 | 234 | */ |
zgu@3900 | 235 | MemRecorder* MemTracker::get_thread_recorder(JavaThread* thread) { |
zgu@3900 | 236 | if (shutdown_in_progress()) return NULL; |
zgu@3900 | 237 | |
zgu@3900 | 238 | MemRecorder* rc; |
zgu@3900 | 239 | if (thread == NULL) { |
zgu@3900 | 240 | rc = _global_recorder; |
zgu@3900 | 241 | } else { |
zgu@3900 | 242 | rc = thread->get_recorder(); |
zgu@3900 | 243 | } |
zgu@3900 | 244 | |
zgu@3900 | 245 | if (rc != NULL && rc->is_full()) { |
zgu@3900 | 246 | enqueue_pending_recorder(rc); |
zgu@3900 | 247 | rc = NULL; |
zgu@3900 | 248 | } |
zgu@3900 | 249 | |
zgu@3900 | 250 | if (rc == NULL) { |
zgu@3900 | 251 | rc = get_new_or_pooled_instance(); |
zgu@3900 | 252 | if (thread == NULL) { |
zgu@3900 | 253 | _global_recorder = rc; |
zgu@3900 | 254 | } else { |
zgu@3900 | 255 | thread->set_recorder(rc); |
zgu@3900 | 256 | } |
zgu@3900 | 257 | } |
zgu@3900 | 258 | return rc; |
zgu@3900 | 259 | } |
zgu@3900 | 260 | |
zgu@3900 | 261 | /* |
zgu@3900 | 262 | * get a per-thread recorder from pool, or create a new one if |
zgu@3900 | 263 | * there is not one available. |
zgu@3900 | 264 | */ |
zgu@3900 | 265 | MemRecorder* MemTracker::get_new_or_pooled_instance() { |
zgu@3900 | 266 | MemRecorder* cur_head = const_cast<MemRecorder*> (_pooled_recorders); |
zgu@3900 | 267 | if (cur_head == NULL) { |
zgu@3900 | 268 | MemRecorder* rec = new (std::nothrow)MemRecorder(); |
zgu@3900 | 269 | if (rec == NULL || rec->out_of_memory()) { |
zgu@3900 | 270 | shutdown(NMT_out_of_memory); |
zgu@3900 | 271 | if (rec != NULL) { |
zgu@3900 | 272 | delete rec; |
zgu@3900 | 273 | rec = NULL; |
zgu@3900 | 274 | } |
zgu@3900 | 275 | } |
zgu@3900 | 276 | return rec; |
zgu@3900 | 277 | } else { |
zgu@3900 | 278 | MemRecorder* next_head = cur_head->next(); |
zgu@3900 | 279 | if ((void*)cur_head != Atomic::cmpxchg_ptr((void*)next_head, (void*)&_pooled_recorders, |
zgu@3900 | 280 | (void*)cur_head)) { |
zgu@3900 | 281 | return get_new_or_pooled_instance(); |
zgu@3900 | 282 | } |
zgu@3900 | 283 | cur_head->set_next(NULL); |
zgu@3900 | 284 | Atomic::dec(&_pooled_recorder_count); |
ctornqvi@4512 | 285 | cur_head->set_generation(); |
zgu@3900 | 286 | return cur_head; |
zgu@3900 | 287 | } |
zgu@3900 | 288 | } |
zgu@3900 | 289 | |
zgu@3900 | 290 | /* |
zgu@3900 | 291 | * retrieve all recorders in pending queue, and empty the queue |
zgu@3900 | 292 | */ |
zgu@3900 | 293 | MemRecorder* MemTracker::get_pending_recorders() { |
zgu@3900 | 294 | MemRecorder* cur_head = const_cast<MemRecorder*>(_merge_pending_queue); |
zgu@3900 | 295 | MemRecorder* null_ptr = NULL; |
zgu@3900 | 296 | while ((void*)cur_head != Atomic::cmpxchg_ptr((void*)null_ptr, (void*)&_merge_pending_queue, |
zgu@3900 | 297 | (void*)cur_head)) { |
zgu@3900 | 298 | cur_head = const_cast<MemRecorder*>(_merge_pending_queue); |
zgu@3900 | 299 | } |
zgu@3994 | 300 | NOT_PRODUCT(Atomic::store(0, &_pending_recorder_count)); |
zgu@3900 | 301 | return cur_head; |
zgu@3900 | 302 | } |
zgu@3900 | 303 | |
zgu@3900 | 304 | /* |
zgu@3900 | 305 | * release a recorder to recorder pool. |
zgu@3900 | 306 | */ |
zgu@3900 | 307 | void MemTracker::release_thread_recorder(MemRecorder* rec) { |
zgu@3900 | 308 | assert(rec != NULL, "null recorder"); |
zgu@3900 | 309 | // we don't want to pool too many recorders |
zgu@3900 | 310 | rec->set_next(NULL); |
zgu@3900 | 311 | if (shutdown_in_progress() || _pooled_recorder_count > _thread_count * 2) { |
zgu@3900 | 312 | delete rec; |
zgu@3900 | 313 | return; |
zgu@3900 | 314 | } |
zgu@3900 | 315 | |
zgu@3900 | 316 | rec->clear(); |
zgu@3900 | 317 | MemRecorder* cur_head = const_cast<MemRecorder*>(_pooled_recorders); |
zgu@3900 | 318 | rec->set_next(cur_head); |
zgu@3900 | 319 | while ((void*)cur_head != Atomic::cmpxchg_ptr((void*)rec, (void*)&_pooled_recorders, |
zgu@3900 | 320 | (void*)cur_head)) { |
zgu@3900 | 321 | cur_head = const_cast<MemRecorder*>(_pooled_recorders); |
zgu@3900 | 322 | rec->set_next(cur_head); |
zgu@3900 | 323 | } |
zgu@3900 | 324 | Atomic::inc(&_pooled_recorder_count); |
zgu@3900 | 325 | } |
zgu@3900 | 326 | |
zgu@3900 | 327 | /* |
zgu@3900 | 328 | * This is the most important method in whole nmt implementation. |
zgu@3900 | 329 | * |
zgu@3900 | 330 | * Create a memory record. |
zgu@3900 | 331 | * 1. When nmt is in single-threaded bootstrapping mode, no lock is needed as VM |
zgu@3900 | 332 | * still in single thread mode. |
zgu@3900 | 333 | * 2. For all threads other than JavaThread, ThreadCritical is needed |
zgu@3900 | 334 | * to write to recorders to global recorder. |
zgu@3900 | 335 | * 3. For JavaThreads that are not longer visible by safepoint, also |
zgu@3900 | 336 | * need to take ThreadCritical and records are written to global |
zgu@3900 | 337 | * recorders, since these threads are NOT walked by Threads.do_thread(). |
zgu@3900 | 338 | * 4. JavaThreads that are running in native state, have to transition |
zgu@3900 | 339 | * to VM state before writing to per-thread recorders. |
zgu@3900 | 340 | * 5. JavaThreads that are running in VM state do not need any lock and |
zgu@3900 | 341 | * records are written to per-thread recorders. |
zgu@3900 | 342 | * 6. For a thread has yet to attach VM 'Thread', they need to take |
zgu@3900 | 343 | * ThreadCritical to write to global recorder. |
zgu@3900 | 344 | * |
zgu@3900 | 345 | * Important note: |
zgu@3900 | 346 | * NO LOCK should be taken inside ThreadCritical lock !!! |
zgu@3900 | 347 | */ |
zgu@3900 | 348 | void MemTracker::create_memory_record(address addr, MEMFLAGS flags, |
zgu@3900 | 349 | size_t size, address pc, Thread* thread) { |
zgu@4079 | 350 | assert(addr != NULL, "Sanity check"); |
zgu@3900 | 351 | if (!shutdown_in_progress()) { |
zgu@3900 | 352 | // single thread, we just write records direct to global recorder,' |
zgu@3900 | 353 | // with any lock |
zgu@3900 | 354 | if (_state == NMT_bootstrapping_single_thread) { |
zgu@3900 | 355 | assert(_main_thread_tid == os::current_thread_id(), "wrong thread"); |
zgu@3900 | 356 | thread = NULL; |
zgu@3900 | 357 | } else { |
zgu@3900 | 358 | if (thread == NULL) { |
zgu@3900 | 359 | // don't use Thread::current(), since it is possible that |
zgu@3900 | 360 | // the calling thread has yet to attach to VM 'Thread', |
zgu@3900 | 361 | // which will result assertion failure |
zgu@3900 | 362 | thread = ThreadLocalStorage::thread(); |
zgu@3900 | 363 | } |
zgu@3900 | 364 | } |
zgu@3900 | 365 | |
zgu@3900 | 366 | if (thread != NULL) { |
zgu@3900 | 367 | if (thread->is_Java_thread() && ((JavaThread*)thread)->is_safepoint_visible()) { |
zgu@4193 | 368 | JavaThread* java_thread = (JavaThread*)thread; |
zgu@3935 | 369 | JavaThreadState state = java_thread->thread_state(); |
zgu@3935 | 370 | if (SafepointSynchronize::safepoint_safe(java_thread, state)) { |
zgu@3935 | 371 | // JavaThreads that are safepoint safe, can run through safepoint, |
zgu@3935 | 372 | // so ThreadCritical is needed to ensure no threads at safepoint create |
zgu@3935 | 373 | // new records while the records are being gathered and the sequence number is changing |
zgu@3935 | 374 | ThreadCritical tc; |
zgu@3935 | 375 | create_record_in_recorder(addr, flags, size, pc, java_thread); |
zgu@3900 | 376 | } else { |
zgu@3935 | 377 | create_record_in_recorder(addr, flags, size, pc, java_thread); |
zgu@3900 | 378 | } |
zgu@3900 | 379 | } else { |
zgu@3900 | 380 | // other threads, such as worker and watcher threads, etc. need to |
zgu@3900 | 381 | // take ThreadCritical to write to global recorder |
zgu@3900 | 382 | ThreadCritical tc; |
zgu@3900 | 383 | create_record_in_recorder(addr, flags, size, pc, NULL); |
zgu@3900 | 384 | } |
zgu@3900 | 385 | } else { |
zgu@3900 | 386 | if (_state == NMT_bootstrapping_single_thread) { |
zgu@3900 | 387 | // single thread, no lock needed |
zgu@3900 | 388 | create_record_in_recorder(addr, flags, size, pc, NULL); |
zgu@3900 | 389 | } else { |
zgu@3900 | 390 | // for thread has yet to attach VM 'Thread', we can not use VM mutex. |
zgu@3900 | 391 | // use native thread critical instead |
zgu@3900 | 392 | ThreadCritical tc; |
zgu@3900 | 393 | create_record_in_recorder(addr, flags, size, pc, NULL); |
zgu@3900 | 394 | } |
zgu@3900 | 395 | } |
zgu@3900 | 396 | } |
zgu@3900 | 397 | } |
zgu@3900 | 398 | |
zgu@3900 | 399 | // write a record to proper recorder. No lock can be taken from this method |
zgu@3900 | 400 | // down. |
zgu@3900 | 401 | void MemTracker::create_record_in_recorder(address addr, MEMFLAGS flags, |
zgu@3935 | 402 | size_t size, address pc, JavaThread* thread) { |
zgu@3900 | 403 | |
zgu@3935 | 404 | MemRecorder* rc = get_thread_recorder(thread); |
zgu@3900 | 405 | if (rc != NULL) { |
zgu@3900 | 406 | rc->record(addr, flags, size, pc); |
zgu@3900 | 407 | } |
zgu@3900 | 408 | } |
zgu@3900 | 409 | |
zgu@3900 | 410 | /** |
zgu@3900 | 411 | * enqueue a recorder to pending queue |
zgu@3900 | 412 | */ |
zgu@3900 | 413 | void MemTracker::enqueue_pending_recorder(MemRecorder* rec) { |
zgu@3900 | 414 | assert(rec != NULL, "null recorder"); |
zgu@3900 | 415 | |
zgu@3900 | 416 | // we are shutting down, so just delete it |
zgu@3900 | 417 | if (shutdown_in_progress()) { |
zgu@3900 | 418 | rec->set_next(NULL); |
zgu@3900 | 419 | delete rec; |
zgu@3900 | 420 | return; |
zgu@3900 | 421 | } |
zgu@3900 | 422 | |
zgu@3900 | 423 | MemRecorder* cur_head = const_cast<MemRecorder*>(_merge_pending_queue); |
zgu@3900 | 424 | rec->set_next(cur_head); |
zgu@3900 | 425 | while ((void*)cur_head != Atomic::cmpxchg_ptr((void*)rec, (void*)&_merge_pending_queue, |
zgu@3900 | 426 | (void*)cur_head)) { |
zgu@3900 | 427 | cur_head = const_cast<MemRecorder*>(_merge_pending_queue); |
zgu@3900 | 428 | rec->set_next(cur_head); |
zgu@3900 | 429 | } |
zgu@3994 | 430 | NOT_PRODUCT(Atomic::inc(&_pending_recorder_count);) |
zgu@3900 | 431 | } |
zgu@3900 | 432 | |
zgu@3900 | 433 | /* |
zgu@3900 | 434 | * The method is called at global safepoint |
zgu@3900 | 435 | * during it synchronization process. |
zgu@3900 | 436 | * 1. enqueue all JavaThreads' per-thread recorders |
zgu@3900 | 437 | * 2. enqueue global recorder |
zgu@3900 | 438 | * 3. retrieve all pending recorders |
zgu@3900 | 439 | * 4. reset global sequence number generator |
zgu@3900 | 440 | * 5. call worker's sync |
zgu@3900 | 441 | */ |
zgu@3900 | 442 | #define MAX_SAFEPOINTS_TO_SKIP 128 |
zgu@3900 | 443 | #define SAFE_SEQUENCE_THRESHOLD 30 |
zgu@3900 | 444 | #define HIGH_GENERATION_THRESHOLD 60 |
zgu@3900 | 445 | |
zgu@3900 | 446 | void MemTracker::sync() { |
zgu@3900 | 447 | assert(_tracking_level > NMT_off, "NMT is not enabled"); |
zgu@3900 | 448 | assert(SafepointSynchronize::is_at_safepoint(), "Safepoint required"); |
zgu@3900 | 449 | |
zgu@3900 | 450 | // Some GC tests hit large number of safepoints in short period of time |
zgu@3900 | 451 | // without meaningful activities. We should prevent going to |
zgu@3900 | 452 | // sync point in these cases, which can potentially exhaust generation buffer. |
zgu@3900 | 453 | // Here is the factots to determine if we should go into sync point: |
zgu@3900 | 454 | // 1. not to overflow sequence number |
zgu@3900 | 455 | // 2. if we are in danger to overflow generation buffer |
zgu@3900 | 456 | // 3. how many safepoints we already skipped sync point |
zgu@3900 | 457 | if (_state == NMT_started) { |
zgu@3900 | 458 | // worker thread is not ready, no one can manage generation |
zgu@3900 | 459 | // buffer, so skip this safepoint |
zgu@3900 | 460 | if (_worker_thread == NULL) return; |
zgu@3900 | 461 | |
zgu@3900 | 462 | if (_sync_point_skip_count < MAX_SAFEPOINTS_TO_SKIP) { |
zgu@3900 | 463 | int per_seq_in_use = SequenceGenerator::peek() * 100 / max_jint; |
zgu@3900 | 464 | int per_gen_in_use = _worker_thread->generations_in_use() * 100 / MAX_GENERATIONS; |
zgu@3900 | 465 | if (per_seq_in_use < SAFE_SEQUENCE_THRESHOLD && per_gen_in_use >= HIGH_GENERATION_THRESHOLD) { |
zgu@3900 | 466 | _sync_point_skip_count ++; |
zgu@3900 | 467 | return; |
zgu@3900 | 468 | } |
zgu@3900 | 469 | } |
zgu@3900 | 470 | _sync_point_skip_count = 0; |
zgu@3900 | 471 | { |
zgu@3900 | 472 | // This method is running at safepoint, with ThreadCritical lock, |
zgu@3900 | 473 | // it should guarantee that NMT is fully sync-ed. |
zgu@3900 | 474 | ThreadCritical tc; |
zgu@3935 | 475 | |
zgu@4193 | 476 | SequenceGenerator::reset(); |
zgu@4193 | 477 | |
zgu@3935 | 478 | // walk all JavaThreads to collect recorders |
zgu@3935 | 479 | SyncThreadRecorderClosure stc; |
zgu@3935 | 480 | Threads::threads_do(&stc); |
zgu@3935 | 481 | |
zgu@3935 | 482 | _thread_count = stc.get_thread_count(); |
zgu@3935 | 483 | MemRecorder* pending_recorders = get_pending_recorders(); |
zgu@3935 | 484 | |
zgu@3900 | 485 | if (_global_recorder != NULL) { |
zgu@3900 | 486 | _global_recorder->set_next(pending_recorders); |
zgu@3900 | 487 | pending_recorders = _global_recorder; |
zgu@3900 | 488 | _global_recorder = NULL; |
zgu@3900 | 489 | } |
zgu@3900 | 490 | // check _worker_thread with lock to avoid racing condition |
zgu@3900 | 491 | if (_worker_thread != NULL) { |
zgu@4400 | 492 | _worker_thread->at_sync_point(pending_recorders, InstanceKlass::number_of_instance_classes()); |
zgu@3900 | 493 | } |
zgu@4193 | 494 | |
zgu@4193 | 495 | assert(SequenceGenerator::peek() == 1, "Should not have memory activities during sync-point"); |
zgu@3900 | 496 | } |
zgu@3900 | 497 | } |
zgu@3900 | 498 | |
zgu@3900 | 499 | // now, it is the time to shut whole things off |
zgu@3900 | 500 | if (_state == NMT_final_shutdown) { |
zgu@3900 | 501 | // walk all JavaThreads to delete all recorders |
zgu@3900 | 502 | SyncThreadRecorderClosure stc; |
zgu@3900 | 503 | Threads::threads_do(&stc); |
zgu@3900 | 504 | // delete global recorder |
zgu@3900 | 505 | { |
zgu@3900 | 506 | ThreadCritical tc; |
zgu@3900 | 507 | if (_global_recorder != NULL) { |
zgu@3900 | 508 | delete _global_recorder; |
zgu@3900 | 509 | _global_recorder = NULL; |
zgu@3900 | 510 | } |
zgu@3900 | 511 | } |
zgu@3935 | 512 | MemRecorder* pending_recorders = get_pending_recorders(); |
zgu@3935 | 513 | if (pending_recorders != NULL) { |
zgu@3935 | 514 | delete pending_recorders; |
zgu@3935 | 515 | } |
zgu@3935 | 516 | // try at a later sync point to ensure MemRecorder instance drops to zero to |
zgu@3935 | 517 | // completely shutdown NMT |
zgu@3935 | 518 | if (MemRecorder::_instance_count == 0) { |
zgu@3935 | 519 | _state = NMT_shutdown; |
zgu@3935 | 520 | _tracking_level = NMT_off; |
zgu@3935 | 521 | } |
zgu@3900 | 522 | } |
zgu@3900 | 523 | } |
zgu@3900 | 524 | |
zgu@3900 | 525 | /* |
zgu@3900 | 526 | * Start worker thread. |
zgu@3900 | 527 | */ |
zgu@3900 | 528 | bool MemTracker::start_worker() { |
zgu@3900 | 529 | assert(_worker_thread == NULL, "Just Check"); |
zgu@3900 | 530 | _worker_thread = new (std::nothrow) MemTrackWorker(); |
zgu@3900 | 531 | if (_worker_thread == NULL || _worker_thread->has_error()) { |
zgu@3900 | 532 | shutdown(NMT_initialization); |
zgu@3900 | 533 | return false; |
zgu@3900 | 534 | } |
zgu@3900 | 535 | _worker_thread->start(); |
zgu@3900 | 536 | return true; |
zgu@3900 | 537 | } |
zgu@3900 | 538 | |
zgu@3900 | 539 | /* |
zgu@3900 | 540 | * We need to collect a JavaThread's per-thread recorder |
zgu@3900 | 541 | * before it exits. |
zgu@3900 | 542 | */ |
zgu@3900 | 543 | void MemTracker::thread_exiting(JavaThread* thread) { |
zgu@3900 | 544 | if (is_on()) { |
zgu@3900 | 545 | MemRecorder* rec = thread->get_recorder(); |
zgu@3900 | 546 | if (rec != NULL) { |
zgu@3900 | 547 | enqueue_pending_recorder(rec); |
zgu@3900 | 548 | thread->set_recorder(NULL); |
zgu@3900 | 549 | } |
zgu@3900 | 550 | } |
zgu@3900 | 551 | } |
zgu@3900 | 552 | |
zgu@3900 | 553 | // baseline current memory snapshot |
zgu@3900 | 554 | bool MemTracker::baseline() { |
zgu@3936 | 555 | MutexLockerEx lock(_query_lock, true); |
zgu@3900 | 556 | MemSnapshot* snapshot = get_snapshot(); |
zgu@3900 | 557 | if (snapshot != NULL) { |
zgu@3900 | 558 | return _baseline.baseline(*snapshot, false); |
zgu@3900 | 559 | } |
zgu@3900 | 560 | return false; |
zgu@3900 | 561 | } |
zgu@3900 | 562 | |
zgu@3900 | 563 | // print memory usage from current snapshot |
zgu@3900 | 564 | bool MemTracker::print_memory_usage(BaselineOutputer& out, size_t unit, bool summary_only) { |
zgu@3900 | 565 | MemBaseline baseline; |
zgu@3936 | 566 | MutexLockerEx lock(_query_lock, true); |
zgu@3900 | 567 | MemSnapshot* snapshot = get_snapshot(); |
zgu@3900 | 568 | if (snapshot != NULL && baseline.baseline(*snapshot, summary_only)) { |
zgu@3900 | 569 | BaselineReporter reporter(out, unit); |
zgu@3900 | 570 | reporter.report_baseline(baseline, summary_only); |
zgu@3900 | 571 | return true; |
zgu@3900 | 572 | } |
zgu@3900 | 573 | return false; |
zgu@3900 | 574 | } |
zgu@3900 | 575 | |
ctornqvi@4512 | 576 | // Whitebox API for blocking until the current generation of NMT data has been merged |
ctornqvi@4512 | 577 | bool MemTracker::wbtest_wait_for_data_merge() { |
ctornqvi@4512 | 578 | // NMT can't be shutdown while we're holding _query_lock |
ctornqvi@4512 | 579 | MutexLockerEx lock(_query_lock, true); |
ctornqvi@4512 | 580 | assert(_worker_thread != NULL, "Invalid query"); |
ctornqvi@4512 | 581 | // the generation at query time, so NMT will spin till this generation is processed |
ctornqvi@4512 | 582 | unsigned long generation_at_query_time = SequenceGenerator::current_generation(); |
ctornqvi@4512 | 583 | unsigned long current_processing_generation = _processing_generation; |
ctornqvi@4512 | 584 | // if generation counter overflown |
ctornqvi@4512 | 585 | bool generation_overflown = (generation_at_query_time < current_processing_generation); |
ctornqvi@4512 | 586 | long generations_to_wrap = MAX_UNSIGNED_LONG - current_processing_generation; |
ctornqvi@4512 | 587 | // spin |
ctornqvi@4512 | 588 | while (!shutdown_in_progress()) { |
ctornqvi@4512 | 589 | if (!generation_overflown) { |
ctornqvi@4512 | 590 | if (current_processing_generation > generation_at_query_time) { |
ctornqvi@4512 | 591 | return true; |
ctornqvi@4512 | 592 | } |
ctornqvi@4512 | 593 | } else { |
ctornqvi@4512 | 594 | assert(generations_to_wrap >= 0, "Sanity check"); |
ctornqvi@4512 | 595 | long current_generations_to_wrap = MAX_UNSIGNED_LONG - current_processing_generation; |
ctornqvi@4512 | 596 | assert(current_generations_to_wrap >= 0, "Sanity check"); |
ctornqvi@4512 | 597 | // to overflow an unsigned long should take long time, so to_wrap check should be sufficient |
ctornqvi@4512 | 598 | if (current_generations_to_wrap > generations_to_wrap && |
ctornqvi@4512 | 599 | current_processing_generation > generation_at_query_time) { |
ctornqvi@4512 | 600 | return true; |
ctornqvi@4512 | 601 | } |
ctornqvi@4512 | 602 | } |
ctornqvi@4512 | 603 | |
ctornqvi@4512 | 604 | // if worker thread is idle, but generation is not advancing, that means |
ctornqvi@4512 | 605 | // there is not safepoint to let NMT advance generation, force one. |
ctornqvi@4512 | 606 | if (_worker_thread_idle) { |
ctornqvi@4512 | 607 | VM_ForceSafepoint vfs; |
ctornqvi@4512 | 608 | VMThread::execute(&vfs); |
ctornqvi@4512 | 609 | } |
ctornqvi@4512 | 610 | MemSnapshot* snapshot = get_snapshot(); |
ctornqvi@4512 | 611 | if (snapshot == NULL) { |
ctornqvi@4512 | 612 | return false; |
ctornqvi@4512 | 613 | } |
ctornqvi@4512 | 614 | snapshot->wait(1000); |
ctornqvi@4512 | 615 | current_processing_generation = _processing_generation; |
ctornqvi@4512 | 616 | } |
ctornqvi@4512 | 617 | // We end up here if NMT is shutting down before our data has been merged |
ctornqvi@4512 | 618 | return false; |
ctornqvi@4512 | 619 | } |
ctornqvi@4512 | 620 | |
zgu@3900 | 621 | // compare memory usage between current snapshot and baseline |
zgu@3900 | 622 | bool MemTracker::compare_memory_usage(BaselineOutputer& out, size_t unit, bool summary_only) { |
zgu@3936 | 623 | MutexLockerEx lock(_query_lock, true); |
zgu@3900 | 624 | if (_baseline.baselined()) { |
zgu@3900 | 625 | MemBaseline baseline; |
zgu@3900 | 626 | MemSnapshot* snapshot = get_snapshot(); |
zgu@3900 | 627 | if (snapshot != NULL && baseline.baseline(*snapshot, summary_only)) { |
zgu@3900 | 628 | BaselineReporter reporter(out, unit); |
zgu@3900 | 629 | reporter.diff_baselines(baseline, _baseline, summary_only); |
zgu@3900 | 630 | return true; |
zgu@3900 | 631 | } |
zgu@3900 | 632 | } |
zgu@3900 | 633 | return false; |
zgu@3900 | 634 | } |
zgu@3900 | 635 | |
zgu@3900 | 636 | #ifndef PRODUCT |
zgu@3900 | 637 | void MemTracker::walk_stack(int toSkip, char* buf, int len) { |
zgu@3900 | 638 | int cur_len = 0; |
zgu@3900 | 639 | char tmp[1024]; |
zgu@3900 | 640 | address pc; |
zgu@3900 | 641 | |
zgu@3900 | 642 | while (cur_len < len) { |
zgu@3900 | 643 | pc = os::get_caller_pc(toSkip + 1); |
zgu@3900 | 644 | if (pc != NULL && os::dll_address_to_function_name(pc, tmp, sizeof(tmp), NULL)) { |
zgu@3900 | 645 | jio_snprintf(&buf[cur_len], (len - cur_len), "%s\n", tmp); |
zgu@3900 | 646 | cur_len = (int)strlen(buf); |
zgu@3900 | 647 | } else { |
zgu@3900 | 648 | buf[cur_len] = '\0'; |
zgu@3900 | 649 | break; |
zgu@3900 | 650 | } |
zgu@3900 | 651 | toSkip ++; |
zgu@3900 | 652 | } |
zgu@3900 | 653 | } |
zgu@3900 | 654 | |
zgu@3900 | 655 | void MemTracker::print_tracker_stats(outputStream* st) { |
zgu@3900 | 656 | st->print_cr("\nMemory Tracker Stats:"); |
zgu@3900 | 657 | st->print_cr("\tMax sequence number = %d", SequenceGenerator::max_seq_num()); |
zgu@3900 | 658 | st->print_cr("\tthead count = %d", _thread_count); |
zgu@3900 | 659 | st->print_cr("\tArena instance = %d", Arena::_instance_count); |
zgu@3900 | 660 | st->print_cr("\tpooled recorder count = %d", _pooled_recorder_count); |
zgu@3900 | 661 | st->print_cr("\tqueued recorder count = %d", _pending_recorder_count); |
zgu@3900 | 662 | st->print_cr("\tmemory recorder instance count = %d", MemRecorder::_instance_count); |
zgu@3900 | 663 | if (_worker_thread != NULL) { |
zgu@3900 | 664 | st->print_cr("\tWorker thread:"); |
zgu@3900 | 665 | st->print_cr("\t\tSync point count = %d", _worker_thread->_sync_point_count); |
zgu@3900 | 666 | st->print_cr("\t\tpending recorder count = %d", _worker_thread->count_pending_recorders()); |
zgu@3900 | 667 | st->print_cr("\t\tmerge count = %d", _worker_thread->_merge_count); |
zgu@3900 | 668 | } else { |
zgu@3900 | 669 | st->print_cr("\tWorker thread is not started"); |
zgu@3900 | 670 | } |
zgu@3900 | 671 | st->print_cr(" "); |
zgu@3900 | 672 | |
zgu@3900 | 673 | if (_snapshot != NULL) { |
zgu@3900 | 674 | _snapshot->print_snapshot_stats(st); |
zgu@3900 | 675 | } else { |
zgu@3900 | 676 | st->print_cr("No snapshot"); |
zgu@3900 | 677 | } |
zgu@3900 | 678 | } |
zgu@3900 | 679 | #endif |
zgu@3900 | 680 |