ceph/src/msg/QueueStrategy.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) 2014 CohortFS, LLC
   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 #include <string>
  15 #include "QueueStrategy.h"
  16 #define dout_subsys ceph_subsys_ms
  17 #include "common/debug.h"
  18 #include "common/backport14.h"
  19
  20 QueueStrategy::QueueStrategy(int _n_threads)
  21   : lock("QueueStrategy::lock"),
  22     n_threads(_n_threads),
  23     stop(false),
  24     mqueue(),
  25     disp_threads()
  26 {
  27 }
  28
  29 void QueueStrategy::ds_dispatch(Message *m) {
  30   msgr->ms_fast_preprocess(m);
  31   if (msgr->ms_can_fast_dispatch(m)) {
  32     msgr->ms_fast_dispatch(m);
  33     return;
  34   }
  35   lock.Lock();
  36   mqueue.push_back(*m);
  37   if (disp_threads.size()) {
  38     if (! disp_threads.empty()) {
  39       QSThread *thrd = &disp_threads.front();
  40       disp_threads.pop_front();
  41       thrd->cond.Signal();
  42     }
  43   }
  44   lock.Unlock();
  45 }
  46
  47 void QueueStrategy::entry(QSThread *thrd)
  48 {
  49   Message *m = NULL;
  50   for (;;) {
  51     lock.Lock();
  52     for (;;) {
  53       if (! mqueue.empty()) {
  54         m = &(mqueue.front());
  55         mqueue.pop_front();
  56         break;
  57       }
  58       m = NULL;
  59       if (stop)
  60         break;
  61       disp_threads.push_front(*thrd);
  62       thrd->cond.Wait(lock);
  63     }
  64     lock.Unlock();
  65     if (stop) {
  66         if (!m) break;
  67         m->put();
  68         continue;
  69     }
  70     get_messenger()->ms_deliver_dispatch(m);
  71   }
  72 }
  73
  74 void QueueStrategy::shutdown()
  75 {
  76   QSThread *thrd;
  77   lock.Lock();
  78   stop = true;
  79   while (disp_threads.size()) {
  80     thrd = &(disp_threads.front());
  81     disp_threads.pop_front();
  82     thrd->cond.Signal();
  83   }
  84   lock.Unlock();
  85 }
  86
  87 void QueueStrategy::wait()
  88 {
  89   lock.Lock();
  90   assert(stop);
  91   for (auto& thread : threads) {
  92     lock.Unlock();
  93
  94     // join outside of lock
  95     thread->join();
  96
  97     lock.Lock();
  98   }
  99   lock.Unlock();
 100 }
 101
 102 void QueueStrategy::start()
 103 {
 104   assert(!stop);
 105   lock.Lock();
 106   threads.reserve(n_threads);
 107   for (int ix = 0; ix < n_threads; ++ix) {
 108     string thread_name = "ms_xio_qs_";
 109     thread_name.append(std::to_string(ix));
 110     auto thrd = ceph::make_unique<QSThread>(this);
 111     thrd->create(thread_name.c_str());
 112     threads.emplace_back(std::move(thrd));
 113   }
 114   lock.Unlock();
 115 }