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
  19 QueueStrategy::QueueStrategy(int _n_threads)
  20   : lock("QueueStrategy::lock"),
  21     n_threads(_n_threads),
  22     stop(false),
  23     mqueue(),
  24     disp_threads()
  25 {
  26 }
  27
  28 void QueueStrategy::ds_dispatch(Message *m) {
  29   msgr->ms_fast_preprocess(m);
  30   if (msgr->ms_can_fast_dispatch(m)) {
  31     msgr->ms_fast_dispatch(m);
  32     return;
  33   }
  34   lock.Lock();
  35   mqueue.push_back(*m);
  36   if (disp_threads.size()) {
  37     if (! disp_threads.empty()) {
  38       QSThread *thrd = &disp_threads.front();
  39       disp_threads.pop_front();
  40       thrd->cond.Signal();
  41     }
  42   }
  43   lock.Unlock();
  44 }
  45
  46 void QueueStrategy::entry(QSThread *thrd)
  47 {
  48   Message *m = NULL;
  49   for (;;) {
  50     lock.Lock();
  51     for (;;) {
  52       if (! mqueue.empty()) {
  53         m = &(mqueue.front());
  54         mqueue.pop_front();
  55         break;
  56       }
  57       m = NULL;
  58       if (stop)
  59         break;
  60       disp_threads.push_front(*thrd);
  61       thrd->cond.Wait(lock);
  62     }
  63     lock.Unlock();
  64     if (stop) {
  65         if (!m) break;
  66         m->put();
  67         continue;
  68     }
  69     get_messenger()->ms_deliver_dispatch(m);
  70   }
  71 }
  72
  73 void QueueStrategy::shutdown()
  74 {
  75   QSThread *thrd;
  76   lock.Lock();
  77   stop = true;
  78   while (disp_threads.size()) {
  79     thrd = &(disp_threads.front());
  80     disp_threads.pop_front();
  81     thrd->cond.Signal();
  82   }
  83   lock.Unlock();
  84 }
  85
  86 void QueueStrategy::wait()
  87 {
  88   QSThread *thrd;
  89   lock.Lock();
  90   assert(stop);
  91   while (disp_threads.size()) {
  92     thrd = &(disp_threads.front());
  93     disp_threads.pop_front();
  94     lock.Unlock();
  95
  96     // join outside of lock
  97     thrd->join();
  98
  99     lock.Lock();
 100   }
 101   lock.Unlock();
 102 }
 103
 104 void QueueStrategy::start()
 105 {
 106   QSThread *thrd;
 107   assert(!stop);
 108   lock.Lock();
 109   for (int ix = 0; ix < n_threads; ++ix) {
 110     string thread_name = "ms_xio_qs_";
 111     thread_name.append(std::to_string(ix));
 112     thrd = new QSThread(this);
 113     thrd->create(thread_name.c_str());
 114   }
 115   lock.Unlock();
 116 }