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         : _last_active_jobs (false)
  41 {
  42         boost::thread (boost::bind (&JobManager::scheduler, this));
  43 }
  44
  45 shared_ptr<Job>
  46 JobManager::add (shared_ptr<Job> j)
  47 {
  48         {
  49                 boost::mutex::scoped_lock lm (_mutex);
  50                 _jobs.push_back (j);
  51         }
  52
  53         if (ui_signaller) {
  54                 ui_signaller->emit (boost::bind (boost::ref (JobAdded), weak_ptr<Job> (j)));
  55         }
  56
  57         return j;
  58 }
  59
  60 list<shared_ptr<Job> >
  61 JobManager::get () const
  62 {
  63         boost::mutex::scoped_lock lm (_mutex);
  64         return _jobs;
  65 }
  66
  67 bool
  68 JobManager::work_to_do () const
  69 {
  70         boost::mutex::scoped_lock lm (_mutex);
  71         list<shared_ptr<Job> >::const_iterator i = _jobs.begin();
  72         while (i != _jobs.end() && (*i)->finished()) {
  73                 ++i;
  74         }
  75
  76         return i != _jobs.end ();
  77 }
  78
  79 bool
  80 JobManager::errors () const
  81 {
  82         boost::mutex::scoped_lock lm (_mutex);
  83         for (list<shared_ptr<Job> >::const_iterator i = _jobs.begin(); i != _jobs.end(); ++i) {
  84                 if ((*i)->finished_in_error ()) {
  85                         return true;
  86                 }
  87         }
  88
  89         return false;
  90 }
  91
  92 void
  93 JobManager::scheduler ()
  94 {
  95         while (1) {
  96
  97                 bool active_jobs = false;
  98
  99                 {
 100                         boost::mutex::scoped_lock lm (_mutex);
 101                         for (list<shared_ptr<Job> >::iterator i = _jobs.begin(); i != _jobs.end(); ++i) {
 102
 103                                 if (!(*i)->finished ()) {
 104                                         active_jobs = true;
 105                                 }
 106
 107                                 if ((*i)->running ()) {
 108                                         /* Something is already happening */
 109                                         break;
 110                                 }
 111
 112                                 if ((*i)->is_new()) {
 113                                         (*i)->start ();
 114
 115                                         /* Only start one job at once */
 116                                         break;
 117                                 }
 118                         }
 119                 }
 120
 121                 if (active_jobs != _last_active_jobs) {
 122                         _last_active_jobs = active_jobs;
 123                         if (ui_signaller) {
 124                                 ui_signaller->emit (boost::bind (boost::ref (ActiveJobsChanged), active_jobs));
 125                         }
 126                 }
 127
 128                 dcpomatic_sleep (1);
 129         }
 130 }
 131
 132 JobManager *
 133 JobManager::instance ()
 134 {
 135         if (_instance == 0) {
 136                 _instance = new JobManager ();
 137         }
 138
 139         return _instance;
 140 }