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