this repo has no description
dekker.one
1/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2/*
3 * Main authors:
4 * Christian Schulte <schulte@gecode.org>
5 *
6 * Copyright:
7 * Christian Schulte, 2015
8 *
9 * This file is part of Gecode, the generic constraint
10 * development environment:
11 * http://www.gecode.org
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining
14 * a copy of this software and associated documentation files (the
15 * "Software"), to deal in the Software without restriction, including
16 * without limitation the rights to use, copy, modify, merge, publish,
17 * distribute, sublicense, and/or sell copies of the Software, and to
18 * permit persons to whom the Software is furnished to do so, subject to
19 * the following conditions:
20 *
21 * The above copyright notice and this permission notice shall be
22 * included in all copies or substantial portions of the Software.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
28 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
29 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
30 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
31 *
32 */
33
34#include <climits>
35
36namespace Gecode { namespace Search { namespace Seq {
37
38
39 forceinline
40 PortfolioStop::PortfolioStop(Stop* so0)
41 : so(so0) {}
42 forceinline void
43 PortfolioStop::share(SharedStopInfo* ssi0) {
44 ssi = ssi0;
45 }
46
47
48 forceinline
49 Slave::Slave(void)
50 : slave(nullptr), stop(nullptr) {}
51 forceinline void
52 Slave::init(Engine* e, Stop* s) {
53 slave = e; stop = s;
54 }
55 forceinline Space*
56 Slave::next(void) {
57 return slave->next();
58 }
59 forceinline Statistics
60 Slave::statistics(void) const {
61 return slave->statistics();
62 }
63 forceinline bool
64 Slave::stopped(void) const {
65 return slave->stopped();
66 }
67 forceinline void
68 Slave::constrain(const Space& b) {
69 slave->constrain(b);
70 }
71 forceinline
72 Slave::~Slave(void) {
73 delete slave;
74 delete stop;
75 }
76
77
78 template<bool best>
79 forceinline
80 PBS<best>::PBS(Engine** e, Stop** s, unsigned int n,
81 const Statistics& stat0,
82 const Search::Options& opt)
83 : stat(stat0), slice(opt.slice),
84 slaves(heap.alloc<Slave>(n)), n_slaves(n), cur(0),
85 slave_stop(false) {
86 ssi.done = false;
87 ssi.l = opt.slice;
88
89 for (unsigned int i=0U; i<n; i++) {
90 slaves[i].init(e[i],static_cast<PortfolioStop*>(s[i]));
91 static_cast<PortfolioStop*>(s[i])->share(&ssi);
92 }
93 }
94
95 template<bool best>
96 Space*
97 PBS<best>::next(void) {
98 slave_stop = false;
99 unsigned int n_exhausted = 0;
100 while (n_slaves > 0) {
101 if (Space* s = slaves[cur].next()) {
102 // Constrain other slaves
103 if (best) {
104 for (unsigned int i=0U; i<cur; i++)
105 slaves[i].constrain(*s);
106 for (unsigned int i=cur+1; i<n_slaves; i++)
107 slaves[i].constrain(*s);
108 }
109 return s;
110 }
111 if (slaves[cur].stopped()) {
112 if (ssi.done) {
113 cur++; n_exhausted++;
114 } else {
115 slave_stop = true;
116 return nullptr;
117 }
118 } else {
119 // This slave is done, kill it after saving the statistics
120 stat += slaves[cur].statistics();
121 slaves[cur].~Slave();
122 slaves[cur] = slaves[--n_slaves];
123 if (n_slaves == 1)
124 // Disable stoping by seeting a high limit
125 ssi.l = ULONG_MAX;
126 }
127 if (n_exhausted == n_slaves) {
128 n_exhausted = 0;
129 // Increment by one slice
130 ssi.l += slice;
131 }
132 if (cur == n_slaves)
133 cur = 0;
134 }
135 return nullptr;
136 }
137
138 template<bool best>
139 bool
140 PBS<best>::stopped(void) const {
141 return slave_stop;
142 }
143
144 template<bool best>
145 Statistics
146 PBS<best>::statistics(void) const {
147 Statistics s(stat);
148 for (unsigned int i=0U; i<n_slaves; i++)
149 s += slaves[i].statistics();
150 return s;
151 }
152
153 template<bool best>
154 void
155 PBS<best>::constrain(const Space& b) {
156 if (!best)
157 throw NoBest("PBS::constrain");
158 for (unsigned int i=0U; i<n_slaves; i++)
159 slaves[i].constrain(b);
160 }
161
162 template<bool best>
163 PBS<best>::~PBS(void) {
164 for (unsigned int i=0U; i<n_slaves; i++)
165 slaves[i].~Slave();
166 // Note that n_slaves might be different now!
167 heap.rfree(slaves);
168 }
169
170}}}
171
172// STATISTICS: search-seq