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 void
  52 JobManager::add_after (shared_ptr<Job> after, shared_ptr<Job> j)
  53 {
  54         boost::mutex::scoped_lock lm (_mutex);
  55         list<shared_ptr<Job> >::iterator i = find (_jobs.begin(), _jobs.end(), after);
  56         assert (i != _jobs.end ());
  57         ++i;
  58         _jobs.insert (i, j);
  59 }
  60
  61 list<shared_ptr<Job> >
  62 JobManager::get () const
  63 {
  64         boost::mutex::scoped_lock lm (_mutex);
  65         return _jobs;
  66 }
  67
  68 bool
  69 JobManager::work_to_do () const
  70 {
  71         boost::mutex::scoped_lock lm (_mutex);
  72         list<shared_ptr<Job> >::const_iterator i = _jobs.begin();
  73         while (i != _jobs.end() && (*i)->finished()) {
  74                 ++i;
  75         }
  76
  77         return i != _jobs.end ();
  78 }
  79
  80 bool
  81 JobManager::errors () const
  82 {
  83         boost::mutex::scoped_lock lm (_mutex);
  84         for (list<shared_ptr<Job> >::const_iterator i = _jobs.begin(); i != _jobs.end(); ++i) {
  85                 if ((*i)->finished_in_error ()) {
  86                         return true;
  87                 }
  88         }
  89
  90         return false;
  91 }
  92
  93 void
  94 JobManager::scheduler ()
  95 {
  96         while (1) {
  97
  98                 bool active_jobs = false;
  99
 100                 {
 101                         boost::mutex::scoped_lock lm (_mutex);
 102                         for (list<shared_ptr<Job> >::iterator i = _jobs.begin(); i != _jobs.end(); ++i) {
 103
 104                                 if (!(*i)->finished ()) {
 105                                         active_jobs = true;
 106                                 }
 107
 108                                 if ((*i)->running ()) {
 109                                         /* Something is already happening */
 110                                         break;
 111                                 }
 112
 113                                 if ((*i)->is_new()) {
 114                                         (*i)->start ();
 115
 116                                         /* Only start one job at once */
 117                                         break;
 118                                 }
 119                         }
 120                 }
 121
 122                 if (active_jobs != _last_active_jobs) {
 123                         _last_active_jobs = active_jobs;
 124                         if (ui_signaller) {
 125                                 ui_signaller->emit (boost::bind (boost::ref (ActiveJobsChanged), active_jobs));
 126                         }
 127                 }
 128
 129                 dcpomatic_sleep (1);
 130         }
 131 }
 132
 133 JobManager *
 134 JobManager::instance ()
 135 {
 136         if (_instance == 0) {
 137                 _instance = new JobManager ();
 138         }
 139
 140         return _instance;
 141 }