src/lib/job_manager.cc

   1 /*
   2     Copyright (C) 2012 Carl Hetherington <cth@carlh.net>
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 /** @file  src/job_manager.cc
  21  *  @brief A simple scheduler for jobs.
  22  */
  23
  24 #include <iostream>
  25 #include <boost/thread.hpp>
  26 #include "job_manager.h"
  27 #include "job.h"
  28 #include "cross.h"
  29
  30 using std::string;
  31 using std::list;
  32 using std::cout;
  33 using boost::shared_ptr;
  34 using boost::weak_ptr;
  35
  36 JobManager* JobManager::_instance = 0;
  37
  38 JobManager::JobManager ()
  39         : _terminate (false)
  40         , _last_active_jobs (false)
  41         , _scheduler (new boost::thread (boost::bind (&JobManager::scheduler, this)))
  42 {
  43
  44 }
  45
  46 JobManager::~JobManager ()
  47 {
  48         {
  49                 boost::mutex::scoped_lock lm (_mutex);
  50                 _terminate = true;
  51         }
  52
  53         if (_scheduler->joinable ()) {
  54                 _scheduler->join ();
  55         }
  56 }
  57
  58 shared_ptr<Job>
  59 JobManager::add (shared_ptr<Job> j)
  60 {
  61         {
  62                 boost::mutex::scoped_lock lm (_mutex);
  63                 _jobs.push_back (j);
  64         }
  65
  66         emit (boost::bind (boost::ref (JobAdded), weak_ptr<Job> (j)));
  67
  68         return j;
  69 }
  70
  71 list<shared_ptr<Job> >
  72 JobManager::get () const
  73 {
  74         boost::mutex::scoped_lock lm (_mutex);
  75         return _jobs;
  76 }
  77
  78 bool
  79 JobManager::work_to_do () const
  80 {
  81         boost::mutex::scoped_lock lm (_mutex);
  82         list<shared_ptr<Job> >::const_iterator i = _jobs.begin();
  83         while (i != _jobs.end() && (*i)->finished()) {
  84                 ++i;
  85         }
  86
  87         return i != _jobs.end ();
  88 }
  89
  90 bool
  91 JobManager::errors () const
  92 {
  93         boost::mutex::scoped_lock lm (_mutex);
  94         for (list<shared_ptr<Job> >::const_iterator i = _jobs.begin(); i != _jobs.end(); ++i) {
  95                 if ((*i)->finished_in_error ()) {
  96                         return true;
  97                 }
  98         }
  99
 100         return false;
 101 }
 102
 103 void
 104 JobManager::scheduler ()
 105 {
 106         while (true) {
 107
 108                 bool active_jobs = false;
 109
 110                 {
 111                         boost::mutex::scoped_lock lm (_mutex);
 112                         if (_terminate) {
 113                                 return;
 114                         }
 115
 116                         for (list<shared_ptr<Job> >::iterator i = _jobs.begin(); i != _jobs.end(); ++i) {
 117
 118                                 if (!(*i)->finished ()) {
 119                                         active_jobs = true;
 120                                 }
 121
 122                                 if ((*i)->running ()) {
 123                                         /* Something is already happening */
 124                                         break;
 125                                 }
 126
 127                                 if ((*i)->is_new()) {
 128                                         (*i)->start ();
 129
 130                                         /* Only start one job at once */
 131                                         break;
 132                                 }
 133                         }
 134                 }
 135
 136                 if (active_jobs != _last_active_jobs) {
 137                         _last_active_jobs = active_jobs;
 138                         emit (boost::bind (boost::ref (ActiveJobsChanged), active_jobs));
 139                 }
 140
 141                 dcpomatic_sleep (1);
 142         }
 143 }
 144
 145 JobManager *
 146 JobManager::instance ()
 147 {
 148         if (_instance == 0) {
 149                 _instance = new JobManager ();
 150         }
 151
 152         return _instance;
 153 }
 154
 155 void
 156 JobManager::drop ()
 157 {
 158         delete _instance;
 159         _instance = 0;
 160 }