Scippy

SCIP

Solving Constraint Integer Programs

bandit.c
Go to the documentation of this file.
1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2 /* */
3 /* This file is part of the program and library */
4 /* SCIP --- Solving Constraint Integer Programs */
5 /* */
6 /* Copyright (C) 2002-2021 Konrad-Zuse-Zentrum */
7 /* fuer Informationstechnik Berlin */
8 /* */
9 /* SCIP is distributed under the terms of the ZIB Academic License. */
10 /* */
11 /* You should have received a copy of the ZIB Academic License */
12 /* along with SCIP; see the file COPYING. If not visit scipopt.org. */
13 /* */
14 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
15 
16 /**@file bandit.c
17  * @ingroup OTHER_CFILES
18  * @brief internal API of bandit algorithms and bandit virtual function tables
19  * @author Gregor Hendel
20  */
21 
22 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
23 
24 #include <assert.h>
25 #include <string.h>
26 #include "scip/bandit.h"
27 #include "scip/pub_bandit.h"
28 #include "scip/struct_bandit.h"
29 #include "scip/struct_set.h"
30 #include "scip/set.h"
31 
32 /** creates and resets bandit algorithm */
34  SCIP_BANDIT** bandit, /**< pointer to bandit algorithm data structure */
35  SCIP_BANDITVTABLE* banditvtable, /**< virtual table for this bandit algorithm */
36  BMS_BLKMEM* blkmem, /**< block memory for parameter settings */
37  BMS_BUFMEM* bufmem, /**< buffer memory */
38  SCIP_Real* priorities, /**< nonnegative priorities for each action, or NULL if not needed */
39  int nactions, /**< the positive number of actions for this bandit */
40  unsigned int initseed, /**< initial seed for random number generation */
41  SCIP_BANDITDATA* banditdata /**< algorithm specific bandit data */
42  )
43 {
44  SCIP_BANDIT* banditptr;
45  assert(bandit != NULL);
46  assert(banditvtable != NULL);
47 
48  /* the number of actions must be positive */
49  if( nactions <= 0 )
50  {
51  SCIPerrorMessage("Cannot create bandit selector with %d <= 0 actions\n", nactions);
52 
53  return SCIP_INVALIDDATA;
54  }
55 
56  SCIP_ALLOC( BMSallocBlockMemory(blkmem, bandit) );
57  assert(*bandit != NULL);
58  banditptr = *bandit;
59  banditptr->vtable = banditvtable;
60  banditptr->data = banditdata;
61  banditptr->nactions = nactions;
62 
63  SCIP_CALL( SCIPrandomCreate(&banditptr->rng, blkmem, initseed) );
64 
65  SCIP_CALL( SCIPbanditReset(bufmem, banditptr, priorities, initseed) );
66 
67  return SCIP_OKAY;
68 }
69 
70 /** calls destructor and frees memory of bandit algorithm */
72  BMS_BLKMEM* blkmem, /**< block memory */
73  SCIP_BANDIT** bandit /**< pointer to bandit algorithm data structure */
74  )
75 {
76  SCIP_BANDIT* banditptr;
77  SCIP_BANDITVTABLE* vtable;
78  assert(bandit != NULL);
79  assert(*bandit != NULL);
80 
81  banditptr = *bandit;
82  vtable = banditptr->vtable;
83  assert(vtable != NULL);
84 
85  /* call bandit specific data destructor */
86  if( vtable->banditfree != NULL )
87  {
88  SCIP_CALL( vtable->banditfree(blkmem, banditptr) );
89  }
90 
91  /* free random number generator */
92  SCIPrandomFree(&banditptr->rng, blkmem);
93 
94  BMSfreeBlockMemory(blkmem, bandit);
95 
96  return SCIP_OKAY;
97 }
98 
99 /** reset the bandit algorithm */
101  BMS_BUFMEM* bufmem, /**< buffer memory */
102  SCIP_BANDIT* bandit, /**< pointer to bandit algorithm data structure */
103  SCIP_Real* priorities, /**< nonnegative priorities for each action, or NULL if not needed */
104  unsigned int seed /**< initial seed for random number generation */
105  )
106 {
107  SCIP_BANDITVTABLE* vtable;
108 
109  assert(bandit != NULL);
110  assert(bufmem != NULL);
111 
112  vtable = bandit->vtable;
113  assert(vtable != NULL);
114  assert(vtable->banditreset != NULL);
115 
116  /* test if the priorities are nonnegative */
117  if( priorities != NULL )
118  {
119  int i;
120 
121  assert(SCIPbanditGetNActions(bandit) > 0);
122 
123  for( i = 0; i < SCIPbanditGetNActions(bandit); ++i )
124  {
125  if( priorities[i] < 0 )
126  {
127  SCIPerrorMessage("Negative priority for action %d\n", i);
128 
129  return SCIP_INVALIDDATA;
130  }
131  }
132  }
133 
134  /* reset the random seed of the bandit algorithm */
135  SCIPrandomSetSeed(bandit->rng, seed);
136 
137  /* call the reset callback of the bandit algorithm */
138  SCIP_CALL( vtable->banditreset(bufmem, bandit, priorities) );
139 
140  return SCIP_OKAY;
141 }
142 
143 /** select the next action */
145  SCIP_BANDIT* bandit, /**< bandit algorithm data structure */
146  int* action /**< pointer to store the selected action */
147  )
148 {
149  assert(bandit != NULL);
150  assert(action != NULL);
151 
152  *action = -1;
153 
154  assert(bandit->vtable->banditselect != NULL);
155 
156  SCIP_CALL( bandit->vtable->banditselect(bandit, action) );
157 
158  assert(*action >= 0);
159  assert(*action < SCIPbanditGetNActions(bandit));
160 
161  return SCIP_OKAY;
162 }
163 
164 /** update the score of the selected action */
166  SCIP_BANDIT* bandit, /**< bandit algorithm data structure */
167  int action, /**< index of action for which the score should be updated */
168  SCIP_Real score /**< observed gain of the i'th action */
169  )
170 {
171  assert(bandit != NULL);
172  assert(0 <= action && action < SCIPbanditGetNActions(bandit));
173  assert(bandit->vtable->banditupdate != NULL);
174 
175  SCIP_CALL( bandit->vtable->banditupdate(bandit, action, score) );
176 
177  return SCIP_OKAY;
178 }
179 
180 /** get data of this bandit algorithm */
182  SCIP_BANDIT* bandit /**< bandit algorithm data structure */
183  )
184 {
185  assert(bandit != NULL);
186 
187  return bandit->data;
188 }
189 
190 /** set the data of this bandit algorithm */
192  SCIP_BANDIT* bandit, /**< bandit algorithm data structure */
193  SCIP_BANDITDATA* banditdata /**< bandit algorihm specific data, or NULL */
194  )
195 {
196  assert(bandit != NULL);
197 
198  bandit->data = banditdata;
199 }
200 
201 /** internal method to create a bandit VTable */
202 static
204  SCIP_BANDITVTABLE** banditvtable, /**< pointer to virtual table for bandit algorithm */
205  const char* name, /**< a name for the algorithm represented by this vtable */
206  SCIP_DECL_BANDITFREE ((*banditfree)), /**< callback to free bandit specific data structures */
207  SCIP_DECL_BANDITSELECT((*banditselect)), /**< selection callback for bandit selector */
208  SCIP_DECL_BANDITUPDATE((*banditupdate)), /**< update callback for bandit algorithms */
209  SCIP_DECL_BANDITRESET ((*banditreset)) /**< update callback for bandit algorithms */
210  )
211 {
212  SCIP_BANDITVTABLE* banditvtableptr;
213 
214  assert(banditvtable != NULL);
215  assert(name != NULL);
216  assert(banditfree != NULL);
217  assert(banditselect != NULL);
218  assert(banditupdate != NULL);
219  assert(banditreset != NULL);
220 
221  /* allocate memory for this virtual function table */
222  SCIP_ALLOC( BMSallocMemory(banditvtable) );
223  BMSclearMemory(*banditvtable);
224 
225  SCIP_ALLOC( BMSduplicateMemoryArray(&(*banditvtable)->name, name, strlen(name)+1) );
226  banditvtableptr = *banditvtable;
227  banditvtableptr->banditfree = banditfree;
228  banditvtableptr->banditselect = banditselect;
229  banditvtableptr->banditupdate = banditupdate;
230  banditvtableptr->banditreset = banditreset;
231 
232  return SCIP_OKAY;
233 }
234 
235 /** create a bandit VTable for bandit algorithm callback functions */
237  SCIP_BANDITVTABLE** banditvtable, /**< pointer to virtual table for bandit algorithm */
238  const char* name, /**< a name for the algorithm represented by this vtable */
239  SCIP_DECL_BANDITFREE ((*banditfree)), /**< callback to free bandit specific data structures */
240  SCIP_DECL_BANDITSELECT((*banditselect)), /**< selection callback for bandit selector */
241  SCIP_DECL_BANDITUPDATE((*banditupdate)), /**< update callback for bandit algorithms */
242  SCIP_DECL_BANDITRESET ((*banditreset)) /**< update callback for bandit algorithms */
243  )
244 {
245  assert(banditvtable != NULL);
246  assert(name != NULL);
247  assert(banditfree != NULL);
248  assert(banditselect != NULL);
249  assert(banditupdate != NULL);
250  assert(banditreset != NULL);
251 
252  SCIP_CALL_FINALLY( doBanditvtableCreate(banditvtable, name, banditfree, banditselect, banditupdate, banditreset),
253  SCIPbanditvtableFree(banditvtable) );
254 
255  return SCIP_OKAY;
256 }
257 
258 
259 /** free a bandit virtual table for bandit algorithm callback functions */
261  SCIP_BANDITVTABLE** banditvtable /**< pointer to virtual table for bandit algorithm */
262  )
263 {
264  assert(banditvtable != NULL);
265  if( *banditvtable == NULL )
266  return;
267 
268  BMSfreeMemoryArrayNull(&(*banditvtable)->name);
269  BMSfreeMemory(banditvtable);
270 }
271 
272 /** return the name of this bandit virtual function table */
274  SCIP_BANDITVTABLE* banditvtable /**< virtual table for bandit algorithm */
275  )
276 {
277  assert(banditvtable != NULL);
278 
279  return banditvtable->name;
280 }
281 
282 
283 /** return the random number generator of a bandit algorithm */
285  SCIP_BANDIT* bandit /**< bandit algorithm data structure */
286  )
287 {
288  assert(bandit != NULL);
289 
290  return bandit->rng;
291 }
292 
293 /** return number of actions of this bandit algorithm */
295  SCIP_BANDIT* bandit /**< bandit algorithm data structure */
296  )
297 {
298  assert(bandit != NULL);
299 
300  return bandit->nactions;
301 }
SCIP_RETCODE SCIPbanditvtableCreate(SCIP_BANDITVTABLE **banditvtable, const char *name, SCIP_DECL_BANDITFREE((*banditfree)), SCIP_DECL_BANDITSELECT((*banditselect)), SCIP_DECL_BANDITUPDATE((*banditupdate)), SCIP_DECL_BANDITRESET((*banditreset)))
Definition: bandit.c:236
#define BMSfreeMemoryArrayNull(ptr)
Definition: memory.h:140
#define SCIP_CALL_FINALLY(x, y)
Definition: def.h:412
internal methods for bandit algorithms
void SCIPbanditvtableFree(SCIP_BANDITVTABLE **banditvtable)
Definition: bandit.c:260
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:54
SCIP_RETCODE SCIPbanditReset(BMS_BUFMEM *bufmem, SCIP_BANDIT *bandit, SCIP_Real *priorities, unsigned int seed)
Definition: bandit.c:100
static SCIP_RETCODE doBanditvtableCreate(SCIP_BANDITVTABLE **banditvtable, const char *name, SCIP_DECL_BANDITFREE((*banditfree)), SCIP_DECL_BANDITSELECT((*banditselect)), SCIP_DECL_BANDITUPDATE((*banditupdate)), SCIP_DECL_BANDITRESET((*banditreset)))
Definition: bandit.c:203
#define BMSfreeMemory(ptr)
Definition: memory.h:137
SCIP_RETCODE SCIPbanditSelect(SCIP_BANDIT *bandit, int *action)
Definition: bandit.c:144
const char * SCIPbanditvtableGetName(SCIP_BANDITVTABLE *banditvtable)
Definition: bandit.c:273
SCIP_BANDITDATA * SCIPbanditGetData(SCIP_BANDIT *bandit)
Definition: bandit.c:181
SCIP_RETCODE SCIPbanditUpdate(SCIP_BANDIT *bandit, int action, SCIP_Real score)
Definition: bandit.c:165
SCIP_RANDNUMGEN * rng
Definition: struct_bandit.h:51
#define SCIPerrorMessage
Definition: pub_message.h:55
data structures for bandit selection algorithms
#define SCIP_DECL_BANDITRESET(x)
Definition: type_bandit.h:73
#define NULL
Definition: lpi_spx1.cpp:155
void SCIPrandomFree(SCIP_RANDNUMGEN **randnumgen, BMS_BLKMEM *blkmem)
Definition: misc.c:9943
void SCIPrandomSetSeed(SCIP_RANDNUMGEN *randnumgen, unsigned int initseed)
Definition: misc.c:9873
internal methods for global SCIP settings
#define SCIP_CALL(x)
Definition: def.h:370
SCIP_RANDNUMGEN * SCIPbanditGetRandnumgen(SCIP_BANDIT *bandit)
Definition: bandit.c:284
void SCIPbanditSetData(SCIP_BANDIT *bandit, SCIP_BANDITDATA *banditdata)
Definition: bandit.c:191
#define BMSduplicateMemoryArray(ptr, source, num)
Definition: memory.h:135
#define BMSfreeBlockMemory(mem, ptr)
Definition: memory.h:456
SCIP_BANDITDATA * data
Definition: struct_bandit.h:53
SCIP_BANDITVTABLE * vtable
Definition: struct_bandit.h:50
public methods for bandit algorithms
SCIP_RETCODE SCIPbanditFree(BMS_BLKMEM *blkmem, SCIP_BANDIT **bandit)
Definition: bandit.c:71
int SCIPbanditGetNActions(SCIP_BANDIT *bandit)
Definition: bandit.c:294
#define BMSclearMemory(ptr)
Definition: memory.h:121
struct SCIP_BanditData SCIP_BANDITDATA
Definition: type_bandit.h:47
#define SCIP_DECL_BANDITFREE(x)
Definition: type_bandit.h:54
const char * name
Definition: struct_bandit.h:40
#define SCIP_Real
Definition: def.h:163
SCIP_RETCODE SCIPrandomCreate(SCIP_RANDNUMGEN **randnumgen, BMS_BLKMEM *blkmem, unsigned int initialseed)
Definition: misc.c:9927
#define BMSallocMemory(ptr)
Definition: memory.h:111
#define SCIP_DECL_BANDITUPDATE(x)
Definition: type_bandit.h:66
#define SCIP_DECL_BANDITSELECT(x)
Definition: type_bandit.h:60
#define BMSallocBlockMemory(mem, ptr)
Definition: memory.h:443
struct BMS_BlkMem BMS_BLKMEM
Definition: memory.h:429
#define SCIP_ALLOC(x)
Definition: def.h:381
datastructures for global SCIP settings
SCIP_RETCODE SCIPbanditCreate(SCIP_BANDIT **bandit, SCIP_BANDITVTABLE *banditvtable, BMS_BLKMEM *blkmem, BMS_BUFMEM *bufmem, SCIP_Real *priorities, int nactions, unsigned int initseed, SCIP_BANDITDATA *banditdata)
Definition: bandit.c:33