summaryrefslogtreecommitdiff
path: root/src/linkgraph/linkgraphschedule.cpp
blob: f056d7cfcd6b7b9358b68c11656153e3eeb02fe8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
/* $Id$ */

/*
 * 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 <http://www.gnu.org/licenses/>.
 */

/** @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"

/**
 * Spawn a thread if possible and run the link graph job in the thread. If
 * that's not possible run the job right now in the current thread.
 * @param job Job to be executed.
 */
void LinkGraphSchedule::SpawnThread(LinkGraphJob *job)
{
	if (!ThreadObject::New(&(LinkGraphSchedule::Run), job, &job->thread)) {
		job->thread = NULL;
		/* Of course this will hang a bit.
		 * On the other hand, if you want to play games which make this hang noticably
		 * on a platform without threads then you'll probably get other problems first.
		 * OK:
		 * If someone comes and tells me that this hangs for him/her, I'll implement a
		 * smaller grained "Step" method for all handlers and add some more ticks where
		 * "Step" is called. No problem in principle.
		 */
		LinkGraphSchedule::Run(job);
	}
}

/**
 * Join the calling thread with the given job's thread if threading is enabled.
 * @param job Job whose execution thread is to be joined.
 */
void LinkGraphSchedule::JoinThread(LinkGraphJob *job)
{
	if (job->thread != NULL) {
		job->thread->Join();
		delete job->thread;
		job->thread = NULL;
	}
}

/**
 * Start the next job in the schedule.
 */
void LinkGraphSchedule::SpawnNext()
{
	if (this->schedule.empty()) return;
	LinkGraph *next = this->schedule.front();
	assert(next == LinkGraph::Get(next->index));
	this->schedule.pop_front();
	if (LinkGraphJob::CanAllocateItem()) {
		LinkGraphJob *job = new LinkGraphJob(*next);
		this->SpawnThread(job);
		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();
	this->JoinThread(next);
	delete next;
	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. This method is tailored to
 * ThreadObject::New.
 * @param j Pointer to a link graph job.
 */
/* static */ void LinkGraphSchedule::Run(void *j)
{
	LinkGraphJob *job = (LinkGraphJob *)j;
	LinkGraphSchedule *schedule = LinkGraphSchedule::Instance();
	for (uint i = 0; i < lengthof(schedule->handlers); ++i) {
		schedule->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) {
		this->SpawnThread(*i);
	}
}

/**
 * Clear all link graphs and jobs from the schedule.
 */
/* static */ void LinkGraphSchedule::Clear()
{
	LinkGraphSchedule *inst = LinkGraphSchedule::Instance();
	for (JobList::iterator i(inst->running.begin()); i != inst->running.end(); ++i) {
		inst->JoinThread(*i);
	}
	inst->running.clear();
	inst->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)
{
	LinkGraph *lg;
	FOR_ALL_LINK_GRAPHS(lg) lg->ShiftDates(interval);
	LinkGraphJob *lgj;
	FOR_ALL_LINK_GRAPH_JOBS(lgj) 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<MCF1stPass>;
	this->handlers[3] = new FlowMapper(false);
	this->handlers[4] = new MCFHandler<MCF2ndPass>;
	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];
	}
}

/**
 * Retrieve the link graph schedule or create it if necessary.
 */
/* static */ LinkGraphSchedule *LinkGraphSchedule::Instance()
{
	static LinkGraphSchedule inst;
	return &inst;
}

/**
 * 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) {
		LinkGraphSchedule::Instance()->JoinNext();
	}
}