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 #include "ui_signaller.h"
  30
  31 using std::string;
  32 using std::list;
  33 using std::cout;
  34 using boost::shared_ptr;
  35 using boost::weak_ptr;
  36
  37 JobManager* JobManager::_instance = 0;
  38
  39 JobManager::JobManager ()
  40         : _terminate (false)
  41         , _last_active_jobs (false)
  42         , _scheduler (new boost::thread (boost::bind (&JobManager::scheduler, this)))
  43 {
  44
  45 }
  46
  47 JobManager::~JobManager ()
  48 {
  49         {
  50                 boost::mutex::scoped_lock lm (_mutex);
  51                 _terminate = true;
  52         }
  53
  54         if (_scheduler->joinable ()) {
  55                 _scheduler->join ();
  56         }
  57 }
  58
  59 shared_ptr<Job>
  60 JobManager::add (shared_ptr<Job> j)
  61 {
  62         {
  63                 boost::mutex::scoped_lock lm (_mutex);
  64                 _jobs.push_back (j);
  65         }
  66
  67         if (ui_signaller) {
  68                 ui_signaller->emit (boost::bind (boost::ref (JobAdded), weak_ptr<Job> (j)));
  69         }
  70
  71         return j;
  72 }
  73
  74 list<shared_ptr<Job> >
  75 JobManager::get () const
  76 {
  77         boost::mutex::scoped_lock lm (_mutex);
  78         return _jobs;
  79 }
  80
  81 bool
  82 JobManager::work_to_do () const
  83 {
  84         boost::mutex::scoped_lock lm (_mutex);
  85         list<shared_ptr<Job> >::const_iterator i = _jobs.begin();
  86         while (i != _jobs.end() && (*i)->finished()) {
  87                 ++i;
  88         }
  89
  90         return i != _jobs.end ();
  91 }
  92
  93 bool
  94 JobManager::errors () const
  95 {
  96         boost::mutex::scoped_lock lm (_mutex);
  97         for (list<shared_ptr<Job> >::const_iterator i = _jobs.begin(); i != _jobs.end(); ++i) {
  98                 if ((*i)->finished_in_error ()) {
  99                         return true;
 100                 }
 101         }
 102
 103         return false;
 104 }
 105
 106 void
 107 JobManager::scheduler ()
 108 {
 109         while (true) {
 110
 111                 bool active_jobs = false;
 112
 113                 {
 114                         boost::mutex::scoped_lock lm (_mutex);
 115                         if (_terminate) {
 116                                 return;
 117                         }
 118
 119                         for (list<shared_ptr<Job> >::iterator i = _jobs.begin(); i != _jobs.end(); ++i) {
 120
 121                                 if (!(*i)->finished ()) {
 122                                         active_jobs = true;
 123                                 }
 124
 125                                 if ((*i)->running ()) {
 126                                         /* Something is already happening */
 127                                         break;
 128                                 }
 129
 130                                 if ((*i)->is_new()) {
 131                                         (*i)->start ();
 132
 133                                         /* Only start one job at once */
 134                                         break;
 135                                 }
 136                         }
 137                 }
 138
 139                 if (active_jobs != _last_active_jobs) {
 140                         _last_active_jobs = active_jobs;
 141                         if (ui_signaller) {
 142                                 ui_signaller->emit (boost::bind (boost::ref (ActiveJobsChanged), active_jobs));
 143                         }
 144                 }
 145
 146                 dcpomatic_sleep (1);
 147         }
 148 }
 149
 150 JobManager *
 151 JobManager::instance ()
 152 {
 153         if (_instance == 0) {
 154                 _instance = new JobManager ();
 155         }
 156
 157         return _instance;
 158 }
 159
 160 void
 161 JobManager::drop ()
 162 {
 163         delete _instance;
 164         _instance = 0;
 165 }