src/ceph/src/common/WorkQueue.cc

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
   7  *
   8  * This is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License version 2.1, as published by the Free Software
  11  * Foundation.  See file COPYING.
  12  *
  13  */
  14
  15 #include "WorkQueue.h"
  16 #include "include/compat.h"
  17 #include "common/errno.h"
  18
  19 #define dout_subsys ceph_subsys_tp
  20 #undef dout_prefix
  21 #define dout_prefix *_dout << name << " "
  22
  23
  24 ThreadPool::ThreadPool(CephContext *cct_, string nm, string tn, int n, const char *option)
  25   : cct(cct_), name(std::move(nm)), thread_name(std::move(tn)),
  26     lockname(name + "::lock"),
  27     _lock(lockname.c_str()),  // this should be safe due to declaration order
  28     _stop(false),
  29     _pause(0),
  30     _draining(0),
  31     ioprio_class(-1),
  32     ioprio_priority(-1),
  33     _num_threads(n),
  34     processing(0)
  35 {
  36   if (option) {
  37     _thread_num_option = option;
  38     // set up conf_keys
  39     _conf_keys = new const char*[2];
  40     _conf_keys[0] = _thread_num_option.c_str();
  41     _conf_keys[1] = NULL;
  42   } else {
  43     _conf_keys = new const char*[1];
  44     _conf_keys[0] = NULL;
  45   }
  46 }
  47
  48 void ThreadPool::TPHandle::suspend_tp_timeout()
  49 {
  50   cct->get_heartbeat_map()->clear_timeout(hb);
  51 }
  52
  53 void ThreadPool::TPHandle::reset_tp_timeout()
  54 {
  55   cct->get_heartbeat_map()->reset_timeout(
  56     hb, grace, suicide_grace);
  57 }
  58
  59 ThreadPool::~ThreadPool()
  60 {
  61   assert(_threads.empty());
  62   delete[] _conf_keys;
  63 }
  64
  65 void ThreadPool::handle_conf_change(const struct md_config_t *conf,
  66                                     const std::set <std::string> &changed)
  67 {
  68   if (changed.count(_thread_num_option)) {
  69     char *buf;
  70     int r = conf->get_val(_thread_num_option.c_str(), &buf, -1);
  71     assert(r >= 0);
  72     int v = atoi(buf);
  73     free(buf);
  74     if (v >= 0) {
  75       _lock.Lock();
  76       _num_threads = v;
  77       start_threads();
  78       _cond.SignalAll();
  79       _lock.Unlock();
  80     }
  81   }
  82 }
  83
  84 void ThreadPool::worker(WorkThread *wt)
  85 {
  86   _lock.Lock();
  87   ldout(cct,10) << "worker start" << dendl;
  88
  89   std::stringstream ss;
  90   ss << name << " thread " << (void *)pthread_self();
  91   heartbeat_handle_d *hb = cct->get_heartbeat_map()->add_worker(ss.str(), pthread_self());
  92
  93   while (!_stop) {
  94
  95     // manage dynamic thread pool
  96     join_old_threads();
  97     if (_threads.size() > _num_threads) {
  98       ldout(cct,1) << " worker shutting down; too many threads (" << _threads.size() << " > " << _num_threads << ")" << dendl;
  99       _threads.erase(wt);
 100       _old_threads.push_back(wt);
 101       break;
 102     }
 103
 104     if (!_pause && !work_queues.empty()) {
 105       WorkQueue_* wq;
 106       int tries = work_queues.size();
 107       bool did = false;
 108       while (tries--) {
 109         next_work_queue %= work_queues.size();
 110         wq = work_queues[next_work_queue++];
 111
 112         void *item = wq->_void_dequeue();
 113         if (item) {
 114           processing++;
 115           ldout(cct,12) << "worker wq " << wq->name << " start processing " << item
 116                         << " (" << processing << " active)" << dendl;
 117           TPHandle tp_handle(cct, hb, wq->timeout_interval, wq->suicide_interval);
 118           tp_handle.reset_tp_timeout();
 119           _lock.Unlock();
 120           wq->_void_process(item, tp_handle);
 121           _lock.Lock();
 122           wq->_void_process_finish(item);
 123           processing--;
 124           ldout(cct,15) << "worker wq " << wq->name << " done processing " << item
 125                         << " (" << processing << " active)" << dendl;
 126           if (_pause || _draining)
 127             _wait_cond.Signal();
 128           did = true;
 129           break;
 130         }
 131       }
 132       if (did)
 133         continue;
 134     }
 135
 136     ldout(cct,20) << "worker waiting" << dendl;
 137     cct->get_heartbeat_map()->reset_timeout(
 138       hb,
 139       cct->_conf->threadpool_default_timeout,
 140       0);
 141     _cond.WaitInterval(_lock,
 142       utime_t(
 143         cct->_conf->threadpool_empty_queue_max_wait, 0));
 144   }
 145   ldout(cct,1) << "worker finish" << dendl;
 146
 147   cct->get_heartbeat_map()->remove_worker(hb);
 148
 149   _lock.Unlock();
 150 }
 151
 152 void ThreadPool::start_threads()
 153 {
 154   assert(_lock.is_locked());
 155   while (_threads.size() < _num_threads) {
 156     WorkThread *wt = new WorkThread(this);
 157     ldout(cct, 10) << "start_threads creating and starting " << wt << dendl;
 158     _threads.insert(wt);
 159
 160     int r = wt->set_ioprio(ioprio_class, ioprio_priority);
 161     if (r < 0)
 162       lderr(cct) << " set_ioprio got " << cpp_strerror(r) << dendl;
 163
 164     wt->create(thread_name.c_str());
 165   }
 166 }
 167
 168 void ThreadPool::join_old_threads()
 169 {
 170   assert(_lock.is_locked());
 171   while (!_old_threads.empty()) {
 172     ldout(cct, 10) << "join_old_threads joining and deleting " << _old_threads.front() << dendl;
 173     _old_threads.front()->join();
 174     delete _old_threads.front();
 175     _old_threads.pop_front();
 176   }
 177 }
 178
 179 void ThreadPool::start()
 180 {
 181   ldout(cct,10) << "start" << dendl;
 182
 183   if (_thread_num_option.length()) {
 184     ldout(cct, 10) << " registering config observer on " << _thread_num_option << dendl;
 185     cct->_conf->add_observer(this);
 186   }
 187
 188   _lock.Lock();
 189   start_threads();
 190   _lock.Unlock();
 191   ldout(cct,15) << "started" << dendl;
 192 }
 193
 194 void ThreadPool::stop(bool clear_after)
 195 {
 196   ldout(cct,10) << "stop" << dendl;
 197
 198   if (_thread_num_option.length()) {
 199     ldout(cct, 10) << " unregistering config observer on " << _thread_num_option << dendl;
 200     cct->_conf->remove_observer(this);
 201   }
 202
 203   _lock.Lock();
 204   _stop = true;
 205   _cond.Signal();
 206   join_old_threads();
 207   _lock.Unlock();
 208   for (set<WorkThread*>::iterator p = _threads.begin();
 209        p != _threads.end();
 210        ++p) {
 211     (*p)->join();
 212     delete *p;
 213   }
 214   _threads.clear();
 215   _lock.Lock();
 216   for (unsigned i=0; i<work_queues.size(); i++)
 217     work_queues[i]->_clear();
 218   _stop = false;
 219   _lock.Unlock();
 220   ldout(cct,15) << "stopped" << dendl;
 221 }
 222
 223 void ThreadPool::pause()
 224 {
 225   ldout(cct,10) << "pause" << dendl;
 226   _lock.Lock();
 227   _pause++;
 228   while (processing)
 229     _wait_cond.Wait(_lock);
 230   _lock.Unlock();
 231   ldout(cct,15) << "paused" << dendl;
 232 }
 233
 234 void ThreadPool::pause_new()
 235 {
 236   ldout(cct,10) << "pause_new" << dendl;
 237   _lock.Lock();
 238   _pause++;
 239   _lock.Unlock();
 240 }
 241
 242 void ThreadPool::unpause()
 243 {
 244   ldout(cct,10) << "unpause" << dendl;
 245   _lock.Lock();
 246   assert(_pause > 0);
 247   _pause--;
 248   _cond.Signal();
 249   _lock.Unlock();
 250 }
 251
 252 void ThreadPool::drain(WorkQueue_* wq)
 253 {
 254   ldout(cct,10) << "drain" << dendl;
 255   _lock.Lock();
 256   _draining++;
 257   while (processing || (wq != NULL && !wq->_empty()))
 258     _wait_cond.Wait(_lock);
 259   _draining--;
 260   _lock.Unlock();
 261 }
 262
 263 void ThreadPool::set_ioprio(int cls, int priority)
 264 {
 265   Mutex::Locker l(_lock);
 266   ioprio_class = cls;
 267   ioprio_priority = priority;
 268   for (set<WorkThread*>::iterator p = _threads.begin();
 269        p != _threads.end();
 270        ++p) {
 271     ldout(cct,10) << __func__
 272                   << " class " << cls << " priority " << priority
 273                   << " pid " << (*p)->get_pid()
 274                   << dendl;
 275     int r = (*p)->set_ioprio(cls, priority);
 276     if (r < 0)
 277       lderr(cct) << " set_ioprio got " << cpp_strerror(r) << dendl;
 278   }
 279 }
 280
 281 ShardedThreadPool::ShardedThreadPool(CephContext *pcct_, string nm, string tn,
 282   uint32_t pnum_threads):
 283   cct(pcct_),
 284   name(std::move(nm)),
 285   thread_name(std::move(tn)),
 286   lockname(name + "::lock"),
 287   shardedpool_lock(lockname.c_str()),
 288   num_threads(pnum_threads),
 289   num_paused(0),
 290   num_drained(0),
 291   wq(NULL) {}
 292
 293 void ShardedThreadPool::shardedthreadpool_worker(uint32_t thread_index)
 294 {
 295   assert(wq != NULL);
 296   ldout(cct,10) << "worker start" << dendl;
 297
 298   std::stringstream ss;
 299   ss << name << " thread " << (void *)pthread_self();
 300   heartbeat_handle_d *hb = cct->get_heartbeat_map()->add_worker(ss.str(), pthread_self());
 301
 302   while (!stop_threads) {
 303     if (pause_threads) {
 304       shardedpool_lock.Lock();
 305       ++num_paused;
 306       wait_cond.Signal();
 307       while (pause_threads) {
 308        cct->get_heartbeat_map()->reset_timeout(
 309                 hb,
 310                 wq->timeout_interval, wq->suicide_interval);
 311        shardedpool_cond.WaitInterval(shardedpool_lock,
 312            utime_t(
 313            cct->_conf->threadpool_empty_queue_max_wait, 0));
 314       }
 315       --num_paused;
 316       shardedpool_lock.Unlock();
 317     }
 318     if (drain_threads) {
 319       shardedpool_lock.Lock();
 320       if (wq->is_shard_empty(thread_index)) {
 321         ++num_drained;
 322         wait_cond.Signal();
 323         while (drain_threads) {
 324           cct->get_heartbeat_map()->reset_timeout(
 325             hb,
 326             wq->timeout_interval, wq->suicide_interval);
 327           shardedpool_cond.WaitInterval(shardedpool_lock,
 328             utime_t(
 329               cct->_conf->threadpool_empty_queue_max_wait, 0));
 330         }
 331         --num_drained;
 332       }
 333       shardedpool_lock.Unlock();
 334     }
 335
 336     cct->get_heartbeat_map()->reset_timeout(
 337       hb,
 338       wq->timeout_interval, wq->suicide_interval);
 339     wq->_process(thread_index, hb);
 340
 341   }
 342
 343   ldout(cct,10) << "sharded worker finish" << dendl;
 344
 345   cct->get_heartbeat_map()->remove_worker(hb);
 346
 347 }
 348
 349 void ShardedThreadPool::start_threads()
 350 {
 351   assert(shardedpool_lock.is_locked());
 352   int32_t thread_index = 0;
 353   while (threads_shardedpool.size() < num_threads) {
 354
 355     WorkThreadSharded *wt = new WorkThreadSharded(this, thread_index);
 356     ldout(cct, 10) << "start_threads creating and starting " << wt << dendl;
 357     threads_shardedpool.push_back(wt);
 358     wt->create(thread_name.c_str());
 359     thread_index++;
 360   }
 361 }
 362
 363 void ShardedThreadPool::start()
 364 {
 365   ldout(cct,10) << "start" << dendl;
 366
 367   shardedpool_lock.Lock();
 368   start_threads();
 369   shardedpool_lock.Unlock();
 370   ldout(cct,15) << "started" << dendl;
 371 }
 372
 373 void ShardedThreadPool::stop()
 374 {
 375   ldout(cct,10) << "stop" << dendl;
 376   stop_threads = true;
 377   assert(wq != NULL);
 378   wq->return_waiting_threads();
 379   for (vector<WorkThreadSharded*>::iterator p = threads_shardedpool.begin();
 380        p != threads_shardedpool.end();
 381        ++p) {
 382     (*p)->join();
 383     delete *p;
 384   }
 385   threads_shardedpool.clear();
 386   ldout(cct,15) << "stopped" << dendl;
 387 }
 388
 389 void ShardedThreadPool::pause()
 390 {
 391   ldout(cct,10) << "pause" << dendl;
 392   shardedpool_lock.Lock();
 393   pause_threads = true;
 394   assert(wq != NULL);
 395   wq->return_waiting_threads();
 396   while (num_threads != num_paused){
 397     wait_cond.Wait(shardedpool_lock);
 398   }
 399   shardedpool_lock.Unlock();
 400   ldout(cct,10) << "paused" << dendl;
 401 }
 402
 403 void ShardedThreadPool::pause_new()
 404 {
 405   ldout(cct,10) << "pause_new" << dendl;
 406   shardedpool_lock.Lock();
 407   pause_threads = true;
 408   assert(wq != NULL);
 409   wq->return_waiting_threads();
 410   shardedpool_lock.Unlock();
 411   ldout(cct,10) << "paused_new" << dendl;
 412 }
 413
 414 void ShardedThreadPool::unpause()
 415 {
 416   ldout(cct,10) << "unpause" << dendl;
 417   shardedpool_lock.Lock();
 418   pause_threads = false;
 419   shardedpool_cond.Signal();
 420   shardedpool_lock.Unlock();
 421   ldout(cct,10) << "unpaused" << dendl;
 422 }
 423
 424 void ShardedThreadPool::drain()
 425 {
 426   ldout(cct,10) << "drain" << dendl;
 427   shardedpool_lock.Lock();
 428   drain_threads = true;
 429   assert(wq != NULL);
 430   wq->return_waiting_threads();
 431   while (num_threads != num_drained) {
 432     wait_cond.Wait(shardedpool_lock);
 433   }
 434   drain_threads = false;
 435   shardedpool_cond.Signal();
 436   shardedpool_lock.Unlock();
 437   ldout(cct,10) << "drained" << dendl;
 438 }
 439