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 std::string;
  31 using std::list;
  32 using boost::shared_ptr;
  33
  34 JobManager* JobManager::_instance = 0;
  35
  36 JobManager::JobManager ()
  37 {
  38         boost::thread (boost::bind (&JobManager::scheduler, this));
  39 }
  40
  41 shared_ptr<Job>
  42 JobManager::add (shared_ptr<Job> j)
  43 {
  44         boost::mutex::scoped_lock lm (_mutex);
  45         _jobs.push_back (j);
  46         return j;
  47 }
  48
  49 void
  50 JobManager::add_after (shared_ptr<Job> after, shared_ptr<Job> j)
  51 {
  52         boost::mutex::scoped_lock lm (_mutex);
  53         list<shared_ptr<Job> >::iterator i = find (_jobs.begin(), _jobs.end(), after);
  54         assert (i != _jobs.end ());
  55         ++i;
  56         _jobs.insert (i, 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
  92 void
  93 JobManager::scheduler ()
  94 {
  95         while (1) {
  96                 {
  97                         boost::mutex::scoped_lock lm (_mutex);
  98                         for (list<shared_ptr<Job> >::iterator i = _jobs.begin(); i != _jobs.end(); ++i) {
  99                                 if ((*i)->running ()) {
 100                                         /* Something is already happening */
 101                                         break;
 102                                 }
 103
 104                                 if ((*i)->is_new()) {
 105                                         shared_ptr<Job> r = (*i)->required ();
 106                                         if (!r || r->finished_ok ()) {
 107                                                 (*i)->start ();
 108
 109                                                 /* Only start one job at once */
 110                                                 break;
 111                                         }
 112                                 }
 113                         }
 114                 }
 115
 116                 dvdomatic_sleep (1);
 117         }
 118 }
 119
 120 JobManager *
 121 JobManager::instance ()
 122 {
 123         if (_instance == 0) {
 124                 _instance = new JobManager ();
 125         }
 126
 127         return _instance;
 128 }