OpenTTD
linkgraphjob.cpp
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1 /* $Id: linkgraphjob.cpp 27178 2015-03-07 18:27:01Z frosch $ */
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 
29 /* static */ Path *Path::invalid_path = new Path(INVALID_NODE, true);
30 
38  /* Copying the link graph here also copies its index member.
39  * This is on purpose. */
40  link_graph(orig),
41  settings(_settings_game.linkgraph),
42  thread(NULL),
43  join_date(_date + _settings_game.linkgraph.recalc_time)
44 {
45 }
46 
51 void LinkGraphJob::EraseFlows(NodeID from)
52 {
53  for (NodeID node_id = 0; node_id < this->Size(); ++node_id) {
54  (*this)[node_id].Flows().erase(from);
55  }
56 }
57 
63 {
64  if (!ThreadObject::New(&(LinkGraphSchedule::Run), this, &this->thread)) {
65  this->thread = NULL;
66  /* Of course this will hang a bit.
67  * On the other hand, if you want to play games which make this hang noticably
68  * on a platform without threads then you'll probably get other problems first.
69  * OK:
70  * If someone comes and tells me that this hangs for him/her, I'll implement a
71  * smaller grained "Step" method for all handlers and add some more ticks where
72  * "Step" is called. No problem in principle. */
74  }
75 }
76 
81 {
82  if (this->thread != NULL) {
83  this->thread->Join();
84  delete this->thread;
85  this->thread = NULL;
86  }
87 }
88 
93 {
94  this->JoinThread();
95 
96  /* Don't update stuff from other pools, when everything is being removed.
97  * Accessing other pools may be invalid. */
98  if (CleaningPool()) return;
99 
100  /* Link graph has been merged into another one. */
101  if (!LinkGraph::IsValidID(this->link_graph.index)) return;
102 
103  uint size = this->Size();
104  for (NodeID node_id = 0; node_id < size; ++node_id) {
105  Node from = (*this)[node_id];
106 
107  /* The station can have been deleted. Remove all flows originating from it then. */
108  Station *st = Station::GetIfValid(from.Station());
109  if (st == NULL) {
110  this->EraseFlows(node_id);
111  continue;
112  }
113 
114  /* Link graph merging and station deletion may change around IDs. Make
115  * sure that everything is still consistent or ignore it otherwise. */
116  GoodsEntry &ge = st->goods[this->Cargo()];
117  if (ge.link_graph != this->link_graph.index || ge.node != node_id) {
118  this->EraseFlows(node_id);
119  continue;
120  }
121 
123  FlowStatMap &flows = from.Flows();
124 
125  for (EdgeIterator it(from.Begin()); it != from.End(); ++it) {
126  if (from[it->first].Flow() == 0) continue;
127  StationID to = (*this)[it->first].Station();
128  Station *st2 = Station::GetIfValid(to);
129  if (st2 == NULL || st2->goods[this->Cargo()].link_graph != this->link_graph.index ||
130  st2->goods[this->Cargo()].node != it->first ||
131  (*lg)[node_id][it->first].LastUpdate() == INVALID_DATE) {
132  /* Edge has been removed. Delete flows. */
133  StationIDStack erased = flows.DeleteFlows(to);
134  /* Delete old flows for source stations which have been deleted
135  * from the new flows. This avoids flow cycles between old and
136  * new flows. */
137  while (!erased.IsEmpty()) ge.flows.erase(erased.Pop());
138  } else if ((*lg)[node_id][it->first].LastUnrestrictedUpdate() == INVALID_DATE) {
139  /* Edge is fully restricted. */
140  flows.RestrictFlows(to);
141  }
142  }
143 
144  /* Swap shares and invalidate ones that are completely deleted. Don't
145  * really delete them as we could then end up with unroutable cargo
146  * somewhere. Do delete them and also reroute relevant cargo if
147  * automatic distribution has been turned off for that cargo. */
148  for (FlowStatMap::iterator it(ge.flows.begin()); it != ge.flows.end();) {
149  FlowStatMap::iterator new_it = flows.find(it->first);
150  if (new_it == flows.end()) {
151  if (_settings_game.linkgraph.GetDistributionType(this->Cargo()) != DT_MANUAL) {
152  it->second.Invalidate();
153  ++it;
154  } else {
155  FlowStat shares(INVALID_STATION, 1);
156  it->second.SwapShares(shares);
157  ge.flows.erase(it++);
158  for (FlowStat::SharesMap::const_iterator shares_it(shares.GetShares()->begin());
159  shares_it != shares.GetShares()->end(); ++shares_it) {
160  RerouteCargo(st, this->Cargo(), shares_it->second, st->index);
161  }
162  }
163  } else {
164  it->second.SwapShares(new_it->second);
165  flows.erase(new_it);
166  ++it;
167  }
168  }
169  ge.flows.insert(flows.begin(), flows.end());
170  InvalidateWindowData(WC_STATION_VIEW, st->index, this->Cargo());
171  }
172 }
173 
180 {
181  uint size = this->Size();
182  this->nodes.Resize(size);
183  this->edges.Resize(size, size);
184  for (uint i = 0; i < size; ++i) {
185  this->nodes[i].Init(this->link_graph[i].Supply());
186  EdgeAnnotation *node_edges = this->edges[i];
187  for (uint j = 0; j < size; ++j) {
188  node_edges[j].Init();
189  }
190  }
191 }
192 
197 {
198  this->demand = 0;
199  this->flow = 0;
200  this->unsatisfied_demand = 0;
201 }
202 
209 {
210  this->undelivered_supply = supply;
211  new (&this->flows) FlowStatMap;
212  new (&this->paths) PathList;
213 }
214 
223 void Path::Fork(Path *base, uint cap, int free_cap, uint dist)
224 {
225  this->capacity = min(base->capacity, cap);
226  this->free_capacity = min(base->free_capacity, free_cap);
227  this->distance = base->distance + dist;
228  assert(this->distance > 0);
229  if (this->parent != base) {
230  this->Detach();
231  this->parent = base;
232  this->parent->num_children++;
233  }
234  this->origin = base->origin;
235 }
236 
245 uint Path::AddFlow(uint new_flow, LinkGraphJob &job, uint max_saturation)
246 {
247  if (this->parent != NULL) {
248  LinkGraphJob::Edge edge = job[this->parent->node][this->node];
249  if (max_saturation != UINT_MAX) {
250  uint usable_cap = edge.Capacity() * max_saturation / 100;
251  if (usable_cap > edge.Flow()) {
252  new_flow = min(new_flow, usable_cap - edge.Flow());
253  } else {
254  return 0;
255  }
256  }
257  new_flow = this->parent->AddFlow(new_flow, job, max_saturation);
258  if (this->flow == 0 && new_flow > 0) {
259  job[this->parent->node].Paths().push_front(this);
260  }
261  edge.AddFlow(new_flow);
262  }
263  this->flow += new_flow;
264  return new_flow;
265 }
266 
272 Path::Path(NodeID n, bool source) :
273  distance(source ? 0 : UINT_MAX),
274  capacity(source ? UINT_MAX : 0),
275  free_capacity(source ? INT_MAX : INT_MIN),
276  flow(0), node(n), origin(source ? n : INVALID_NODE),
277  num_children(0), parent(NULL)
278 {}
279