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