OpenTTD
linkgraphjob.cpp
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1 /* $Id: linkgraphjob.cpp 26482 2014-04-23 20:13:33Z rubidium $ */
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 
12 #include "../stdafx.h"
13 #include "../core/pool_func.hpp"
14 #include "../window_func.h"
15 #include "linkgraphjob.h"
16 #include "linkgraphschedule.h"
17 
18 #include "../safeguards.h"
19 
20 /* Initialize the link-graph-job-pool */
23 
24 
31  /* Copying the link graph here also copies its index member.
32  * This is on purpose. */
33  link_graph(orig),
34  settings(_settings_game.linkgraph),
35  thread(NULL),
36  join_date(_date + _settings_game.linkgraph.recalc_time)
37 {
38 }
39 
44 void LinkGraphJob::EraseFlows(NodeID from)
45 {
46  for (NodeID node_id = 0; node_id < this->Size(); ++node_id) {
47  (*this)[node_id].Flows().erase(from);
48  }
49 }
50 
56 {
57  if (!ThreadObject::New(&(LinkGraphSchedule::Run), this, &this->thread)) {
58  this->thread = NULL;
59  /* Of course this will hang a bit.
60  * On the other hand, if you want to play games which make this hang noticably
61  * on a platform without threads then you'll probably get other problems first.
62  * OK:
63  * If someone comes and tells me that this hangs for him/her, I'll implement a
64  * smaller grained "Step" method for all handlers and add some more ticks where
65  * "Step" is called. No problem in principle. */
67  }
68 }
69 
74 {
75  if (this->thread != NULL) {
76  this->thread->Join();
77  delete this->thread;
78  this->thread = NULL;
79  }
80 }
81 
86 {
87  this->JoinThread();
88 
89  /* Don't update stuff from other pools, when everything is being removed.
90  * Accessing other pools may be invalid. */
91  if (CleaningPool()) return;
92 
93  /* Link graph has been merged into another one. */
94  if (!LinkGraph::IsValidID(this->link_graph.index)) return;
95 
96  uint size = this->Size();
97  for (NodeID node_id = 0; node_id < size; ++node_id) {
98  Node from = (*this)[node_id];
99 
100  /* The station can have been deleted. Remove all flows originating from it then. */
101  Station *st = Station::GetIfValid(from.Station());
102  if (st == NULL) {
103  this->EraseFlows(node_id);
104  continue;
105  }
106 
107  /* Link graph merging and station deletion may change around IDs. Make
108  * sure that everything is still consistent or ignore it otherwise. */
109  GoodsEntry &ge = st->goods[this->Cargo()];
110  if (ge.link_graph != this->link_graph.index || ge.node != node_id) {
111  this->EraseFlows(node_id);
112  continue;
113  }
114 
116  FlowStatMap &flows = from.Flows();
117 
118  for (EdgeIterator it(from.Begin()); it != from.End(); ++it) {
119  if (from[it->first].Flow() == 0) continue;
120  StationID to = (*this)[it->first].Station();
121  Station *st2 = Station::GetIfValid(to);
122  if (st2 == NULL || st2->goods[this->Cargo()].link_graph != this->link_graph.index ||
123  st2->goods[this->Cargo()].node != it->first ||
124  (*lg)[node_id][it->first].LastUpdate() == INVALID_DATE) {
125  /* Edge has been removed. Delete flows. */
126  StationIDStack erased = flows.DeleteFlows(to);
127  /* Delete old flows for source stations which have been deleted
128  * from the new flows. This avoids flow cycles between old and
129  * new flows. */
130  while (!erased.IsEmpty()) ge.flows.erase(erased.Pop());
131  } else if ((*lg)[node_id][it->first].LastUnrestrictedUpdate() == INVALID_DATE) {
132  /* Edge is fully restricted. */
133  flows.RestrictFlows(to);
134  }
135  }
136 
137  /* Swap shares and invalidate ones that are completely deleted. Don't
138  * really delete them as we could then end up with unroutable cargo
139  * somewhere. Do delete them and also reroute relevant cargo if
140  * automatic distribution has been turned off for that cargo. */
141  for (FlowStatMap::iterator it(ge.flows.begin()); it != ge.flows.end();) {
142  FlowStatMap::iterator new_it = flows.find(it->first);
143  if (new_it == flows.end()) {
144  if (_settings_game.linkgraph.GetDistributionType(this->Cargo()) != DT_MANUAL) {
145  it->second.Invalidate();
146  ++it;
147  } else {
148  FlowStat shares(INVALID_STATION, 1);
149  it->second.SwapShares(shares);
150  ge.flows.erase(it++);
151  for (FlowStat::SharesMap::const_iterator shares_it(shares.GetShares()->begin());
152  shares_it != shares.GetShares()->end(); ++shares_it) {
153  RerouteCargo(st, this->Cargo(), shares_it->second, st->index);
154  }
155  }
156  } else {
157  it->second.SwapShares(new_it->second);
158  flows.erase(new_it);
159  ++it;
160  }
161  }
162  ge.flows.insert(flows.begin(), flows.end());
163  InvalidateWindowData(WC_STATION_VIEW, st->index, this->Cargo());
164  }
165 }
166 
173 {
174  uint size = this->Size();
175  this->nodes.Resize(size);
176  this->edges.Resize(size, size);
177  for (uint i = 0; i < size; ++i) {
178  this->nodes[i].Init(this->link_graph[i].Supply());
179  EdgeAnnotation *node_edges = this->edges[i];
180  for (uint j = 0; j < size; ++j) {
181  node_edges[j].Init();
182  }
183  }
184 }
185 
190 {
191  this->demand = 0;
192  this->flow = 0;
193  this->unsatisfied_demand = 0;
194 }
195 
202 {
203  this->undelivered_supply = supply;
204  new (&this->flows) FlowStatMap;
205  new (&this->paths) PathList;
206 }
207 
216 void Path::Fork(Path *base, uint cap, int free_cap, uint dist)
217 {
218  this->capacity = min(base->capacity, cap);
219  this->free_capacity = min(base->free_capacity, free_cap);
220  this->distance = base->distance + dist;
221  assert(this->distance > 0);
222  if (this->parent != base) {
223  this->Detach();
224  this->parent = base;
225  this->parent->num_children++;
226  }
227  this->origin = base->origin;
228 }
229 
238 uint Path::AddFlow(uint new_flow, LinkGraphJob &job, uint max_saturation)
239 {
240  if (this->parent != NULL) {
241  LinkGraphJob::Edge edge = job[this->parent->node][this->node];
242  if (max_saturation != UINT_MAX) {
243  uint usable_cap = edge.Capacity() * max_saturation / 100;
244  if (usable_cap > edge.Flow()) {
245  new_flow = min(new_flow, usable_cap - edge.Flow());
246  } else {
247  return 0;
248  }
249  }
250  new_flow = this->parent->AddFlow(new_flow, job, max_saturation);
251  if (this->flow == 0 && new_flow > 0) {
252  job[this->parent->node].Paths().push_front(this);
253  }
254  edge.AddFlow(new_flow);
255  }
256  this->flow += new_flow;
257  return new_flow;
258 }
259 
265 Path::Path(NodeID n, bool source) :
266  distance(source ? 0 : UINT_MAX),
267  capacity(source ? UINT_MAX : 0),
268  free_capacity(source ? INT_MAX : INT_MIN),
269  flow(0), node(n), origin(source ? n : INVALID_NODE),
270  num_children(0), parent(NULL)
271 {}
272