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         emit (boost::bind (boost::ref (JobAdded), weak_ptr<Job> (j)));
  68
  69         return j;
  70 }
  71
  72 list<shared_ptr<Job> >
  73 JobManager::get () const
  74 {
  75         boost::mutex::scoped_lock lm (_mutex);
  76         return _jobs;
  77 }
  78
  79 bool
  80 JobManager::work_to_do () const
  81 {
  82         boost::mutex::scoped_lock lm (_mutex);
  83         list<shared_ptr<Job> >::const_iterator i = _jobs.begin();
  84         while (i != _jobs.end() && (*i)->finished()) {
  85                 ++i;
  86         }
  87
  88         return i != _jobs.end ();
  89 }
  90
  91 bool
  92 JobManager::errors () const
  93 {
  94         boost::mutex::scoped_lock lm (_mutex);
  95         for (list<shared_ptr<Job> >::const_iterator i = _jobs.begin(); i != _jobs.end(); ++i) {
  96                 if ((*i)->finished_in_error ()) {
  97                         return true;
  98                 }
  99         }
 100
 101         return false;
 102 }
 103
 104 void
 105 JobManager::scheduler ()
 106 {
 107         while (true) {
 108
 109                 bool active_jobs = false;
 110
 111                 {
 112                         boost::mutex::scoped_lock lm (_mutex);
 113                         if (_terminate) {
 114                                 return;
 115                         }
 116
 117                         for (list<shared_ptr<Job> >::iterator i = _jobs.begin(); i != _jobs.end(); ++i) {
 118
 119                                 if (!(*i)->finished ()) {
 120                                         active_jobs = true;
 121                                 }
 122
 123                                 if ((*i)->running ()) {
 124                                         /* Something is already happening */
 125                                         break;
 126                                 }
 127
 128                                 if ((*i)->is_new()) {
 129                                         (*i)->start ();
 130
 131                                         /* Only start one job at once */
 132                                         break;
 133                                 }
 134                         }
 135                 }
 136
 137                 if (active_jobs != _last_active_jobs) {
 138                         _last_active_jobs = active_jobs;
 139                         emit (boost::bind (boost::ref (ActiveJobsChanged), active_jobs));
 140                 }
 141
 142                 dcpomatic_sleep (1);
 143         }
 144 }
 145
 146 JobManager *
 147 JobManager::instance ()
 148 {
 149         if (_instance == 0) {
 150                 _instance = new JobManager ();
 151         }
 152
 153         return _instance;
 154 }
 155
 156 void
 157 JobManager::drop ()
 158 {
 159         delete _instance;
 160         _instance = 0;
 161 }