src/linkgraph/linkgraphschedule.h

   1 /* $Id$ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   6  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   8  */
   9
  10 /** @file linkgraphschedule.h Declaration of link graph schedule used for cargo distribution. */
  11
  12 #ifndef LINKGRAPHSCHEDULE_H
  13 #define LINKGRAPHSCHEDULE_H
  14
  15 #include "linkgraph.h"
  16
  17 class LinkGraphJob;
  18
  19 /**
  20  * A handler doing "something" on a link graph component. It must not keep any
  21  * state as it is called concurrently from different threads.
  22  */
  23 class ComponentHandler {
  24 public:
  25         /**
  26          * Destroy the handler. Must be given due to virtual Run.
  27          */
  28         virtual ~ComponentHandler() {}
  29
  30         /**
  31          * Run the handler. A link graph handler must not read or write any data
  32          * outside the given component as that would create a potential desync.
  33          * @param job Link graph component to run the handler on.
  34          */
  35         virtual void Run(LinkGraphJob &job) const = 0;
  36 };
  37
  38 class LinkGraphSchedule {
  39 private:
  40         LinkGraphSchedule();
  41         ~LinkGraphSchedule();
  42         typedef std::list<LinkGraph *> GraphList;
  43         typedef std::list<LinkGraphJob *> JobList;
  44         friend const SaveLoad *GetLinkGraphScheduleDesc();
  45
  46 protected:
  47         ComponentHandler *handlers[6]; ///< Handlers to be run for each job.
  48         GraphList schedule;            ///< Queue for new jobs.
  49         JobList running;               ///< Currently running jobs.
  50
  51 public:
  52         /* This is a tick where not much else is happening, so a small lag might go unnoticed. */
  53         static const uint SPAWN_JOIN_TICK = 21; ///< Tick when jobs are spawned or joined every day.
  54         static LinkGraphSchedule instance;
  55
  56         static void Run(void *j);
  57         static void Clear();
  58
  59         void SpawnNext();
  60         void JoinNext();
  61         void SpawnAll();
  62         void ShiftDates(int interval);
  63
  64         /**
  65          * Queue a link graph for execution.
  66          * @param lg Link graph to be queued.
  67          */
  68         void Queue(LinkGraph *lg)
  69         {
  70                 assert(LinkGraph::Get(lg->index) == lg);
  71                 this->schedule.push_back(lg);
  72         }
  73
  74         /**
  75          * Remove a link graph from the execution queue.
  76          * @param lg Link graph to be removed.
  77          */
  78         void Unqueue(LinkGraph *lg) { this->schedule.remove(lg); }
  79 };
  80
  81 #endif /* LINKGRAPHSCHEDULE_H */