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
  30 using namespace std;
  31 using namespace boost;
  32
  33 JobManager* JobManager::_instance = 0;
  34
  35 JobManager::JobManager ()
  36 {
  37         boost::thread (boost::bind (&JobManager::scheduler, this));
  38 }
  39
  40 shared_ptr<Job>
  41 JobManager::add (shared_ptr<Job> j)
  42 {
  43         boost::mutex::scoped_lock lm (_mutex);
  44         _jobs.push_back (j);
  45         return j;
  46 }
  47
  48 void
  49 JobManager::add_after (shared_ptr<Job> after, shared_ptr<Job> j)
  50 {
  51         boost::mutex::scoped_lock lm (_mutex);
  52         list<shared_ptr<Job> >::iterator i = find (_jobs.begin(), _jobs.end(), after);
  53         assert (i != _jobs.end ());
  54         ++i;
  55         _jobs.insert (i, j);
  56 }
  57
  58 list<shared_ptr<Job> >
  59 JobManager::get () const
  60 {
  61         boost::mutex::scoped_lock lm (_mutex);
  62         return _jobs;
  63 }
  64
  65 bool
  66 JobManager::work_to_do () const
  67 {
  68         boost::mutex::scoped_lock lm (_mutex);
  69         list<shared_ptr<Job> >::const_iterator i = _jobs.begin();
  70         while (i != _jobs.end() && (*i)->finished()) {
  71                 ++i;
  72         }
  73
  74         return i != _jobs.end ();
  75 }
  76
  77 bool
  78 JobManager::errors () const
  79 {
  80         boost::mutex::scoped_lock lm (_mutex);
  81         for (list<shared_ptr<Job> >::const_iterator i = _jobs.begin(); i != _jobs.end(); ++i) {
  82                 if ((*i)->finished_in_error ()) {
  83                         return true;
  84                 }
  85         }
  86
  87         return false;
  88 }
  89
  90
  91 void
  92 JobManager::scheduler ()
  93 {
  94         while (1) {
  95                 {
  96                         boost::mutex::scoped_lock lm (_mutex);
  97                         for (list<shared_ptr<Job> >::iterator i = _jobs.begin(); i != _jobs.end(); ++i) {
  98                                 if ((*i)->running ()) {
  99                                         /* Something is already happening */
 100                                         break;
 101                                 }
 102
 103                                 if ((*i)->is_new()) {
 104                                         shared_ptr<Job> r = (*i)->required ();
 105                                         if (!r || r->finished_ok ()) {
 106                                                 (*i)->start ();
 107
 108                                                 /* Only start one job at once */
 109                                                 break;
 110                                         }
 111                                 }
 112                         }
 113                 }
 114
 115                 dvdomatic_sleep (1);
 116         }
 117 }
 118
 119 JobManager *
 120 JobManager::instance ()
 121 {
 122         if (_instance == 0) {
 123                 _instance = new JobManager ();
 124         }
 125
 126         return _instance;
 127 }