/*
* This file is part of OpenTTD.
* 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.
* 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.
* 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 .
*/
/** @file linkgraphschedule.cpp Definition of link graph schedule used for cargo distribution. */
#include "../stdafx.h"
#include "linkgraphschedule.h"
#include "init.h"
#include "demands.h"
#include "mcf.h"
#include "flowmapper.h"
#include "../framerate_type.h"
#include "../safeguards.h"
/**
* Static instance of LinkGraphSchedule.
* Note: This instance is created on task start.
* Lazy creation on first usage results in a data race between the CDist threads.
*/
/* static */ LinkGraphSchedule LinkGraphSchedule::instance;
/**
* Start the next job in the schedule.
*/
void LinkGraphSchedule::SpawnNext()
{
if (this->schedule.empty()) return;
LinkGraph *next = this->schedule.front();
LinkGraph *first = next;
while (next->Size() < 2) {
this->schedule.splice(this->schedule.end(), this->schedule, this->schedule.begin());
next = this->schedule.front();
if (next == first) return;
}
assert(next == LinkGraph::Get(next->index));
this->schedule.pop_front();
if (LinkGraphJob::CanAllocateItem()) {
LinkGraphJob *job = new LinkGraphJob(*next);
job->SpawnThread();
this->running.push_back(job);
} else {
NOT_REACHED();
}
}
/**
* Join the next finished job, if available.
*/
void LinkGraphSchedule::JoinNext()
{
if (this->running.empty()) return;
LinkGraphJob *next = this->running.front();
if (!next->IsFinished()) return;
this->running.pop_front();
LinkGraphID id = next->LinkGraphIndex();
delete next; // implicitly joins the thread
if (LinkGraph::IsValidID(id)) {
LinkGraph *lg = LinkGraph::Get(id);
this->Unqueue(lg); // Unqueue to avoid double-queueing recycled IDs.
this->Queue(lg);
}
}
/**
* Run all handlers for the given Job.
* @param job Pointer to a link graph job.
*/
/* static */ void LinkGraphSchedule::Run(LinkGraphJob *job)
{
for (uint i = 0; i < lengthof(instance.handlers); ++i) {
instance.handlers[i]->Run(*job);
}
}
/**
* Start all threads in the running list. This is only useful for save/load.
* Usually threads are started when the job is created.
*/
void LinkGraphSchedule::SpawnAll()
{
for (JobList::iterator i = this->running.begin(); i != this->running.end(); ++i) {
(*i)->SpawnThread();
}
}
/**
* Clear all link graphs and jobs from the schedule.
*/
/* static */ void LinkGraphSchedule::Clear()
{
for (JobList::iterator i(instance.running.begin()); i != instance.running.end(); ++i) {
(*i)->JoinThread();
}
instance.running.clear();
instance.schedule.clear();
}
/**
* Shift all dates (join dates and edge annotations) of link graphs and link
* graph jobs by the number of days given.
* @param interval Number of days to be added or subtracted.
*/
void LinkGraphSchedule::ShiftDates(int interval)
{
for (LinkGraph *lg : LinkGraph::Iterate()) lg->ShiftDates(interval);
for (LinkGraphJob *lgj : LinkGraphJob::Iterate()) lgj->ShiftJoinDate(interval);
}
/**
* Create a link graph schedule and initialize its handlers.
*/
LinkGraphSchedule::LinkGraphSchedule()
{
this->handlers[0] = new InitHandler;
this->handlers[1] = new DemandHandler;
this->handlers[2] = new MCFHandler;
this->handlers[3] = new FlowMapper(false);
this->handlers[4] = new MCFHandler;
this->handlers[5] = new FlowMapper(true);
}
/**
* Delete a link graph schedule and its handlers.
*/
LinkGraphSchedule::~LinkGraphSchedule()
{
this->Clear();
for (uint i = 0; i < lengthof(this->handlers); ++i) {
delete this->handlers[i];
}
}
/**
* Spawn or join a link graph job or compress a link graph if any link graph is
* due to do so.
*/
void OnTick_LinkGraph()
{
if (_date_fract != LinkGraphSchedule::SPAWN_JOIN_TICK) return;
Date offset = _date % _settings_game.linkgraph.recalc_interval;
if (offset == 0) {
LinkGraphSchedule::instance.SpawnNext();
} else if (offset == _settings_game.linkgraph.recalc_interval / 2) {
PerformanceMeasurer framerate(PFE_GL_LINKGRAPH);
LinkGraphSchedule::instance.JoinNext();
}
}