ghc/runtime/storage/SMinternal.lh

   1 %
   2 % (c) The AQUA Project, Glasgow University, 1992-1994
   3 %
   4 \begin{code}
   5 #ifndef SMinternals_H
   6 #define SMinternals_H
   7 \end{code}
   8
   9 This stuff needs to be documented.  KH
  10
  11 \begin{code}
  12 /* In the Storage Manager we use the global register mapping */
  13 /* We turn off STG-machine register declarations             */
  14
  15 #if ! (defined(MAIN_REG_MAP) || defined(NULL_REG_MAP) || defined(MARK_REG_MAP) || defined(SCAN_REG_MAP) || defined(SCAV_REG_MAP))
  16 **** please set your REG_MAP ****
  17 #endif
  18
  19 #include "rtsdefs.h"
  20
  21 #ifdef HAVE_SYS_VADVISE_H
  22 #include <sys/vadvise.h>
  23 #endif
  24
  25 extern I_   SM_force_gc;
  26 #define USE_2s  1
  27 #define USE_1s  2
  28
  29 extern I_   SM_word_heap_size; /* all defined in SMinit.lc */
  30 extern I_   SM_alloc_min;
  31 extern StgFloat SM_pc_free_heap;
  32 extern I_   SM_alloc_size;
  33 extern I_   SM_major_gen_size;
  34 /*moved: extern I_   SM_word_stk_size; */
  35 extern FILE    *SM_statsfile;
  36 extern I_   SM_trace;
  37 extern I_   SM_stats_summary;
  38 extern I_   SM_stats_verbose;
  39 extern I_   SM_ring_bell;
  40
  41 extern P_ heap_space;
  42 extern P_ hp_start;
  43
  44 extern void stat_init    PROTO((char *collector, char *c1, char *c2));
  45 extern void stat_startGC PROTO((I_ alloc));
  46 extern void stat_endGC   PROTO((I_ alloc, I_ collect, I_ live, char *comment));
  47 extern void stat_exit    PROTO((I_ alloc));
  48
  49 extern I_ MaxResidency;     /* in words; for stats only */
  50 extern I_ ResidencySamples; /* for stats only */
  51
  52 #define DO_MAX_RESIDENCY(r) /* saves typing */  \
  53     do {                                        \
  54         I_ resid = (r);                         \
  55         ResidencySamples++;                     \
  56         if (resid > MaxResidency) {             \
  57             MaxResidency = resid;               \
  58         }                                       \
  59     } while (0)
  60
  61 extern StgFunPtr _Dummy_entry(STG_NO_ARGS);
  62 extern char *xmalloc PROTO((size_t));
  63
  64 #if defined(_GC_DEBUG)
  65 #define DEBUG_SCAN(str, pos, to, topos) \
  66         if (SM_trace & 2) fprintf(stderr, "%s: 0x%lx, %s 0x%lx\n", str, pos, to, topos)
  67 #define DEBUG_STRING(str) \
  68         if (SM_trace & 2) fprintf(stderr, "%s\n", str)
  69 #else
  70 #define DEBUG_SCAN(str, pos, to, topos)
  71 #define DEBUG_STRING(str)
  72 #endif
  73
  74 /************************ Default HEAP and STACK sizes **********************/
  75
  76 /* A user can change these main defaults with a
  77    "hooks" file equiv to runtime/hooks/SizeHooks.lc.
  78 */
  79
  80 #define DEFAULT_STACKS_SIZE      0x10002  /* 2^16 = 16Kwords = 64Kbytes */
  81
  82 #define DEFAULT_HEAP_SIZE        0x100002 /* 2^20 = 1Mwords = 4Mbytes  */
  83 #define DEFAULT_ALLOC_SIZE       0x4002   /* 2^14 = 16k words = 64k bytes */
  84 #define DEFAULT_PC_FREE          3        /* 3% */
  85
  86 /* I added a couple of extra words above, to be more sure of avoiding
  87     bad effects on direct-mapped caches. (WDP)
  88 */
  89
  90 #define NEXT_SEMI_SPACE(space) ((space + 1) % 2)
  91
  92 /************************ Random stuff **********************/
  93
  94 /* This should be really big */
  95 #define BIG_STRING_LEN           512
  96
  97 /************************** TWO SPACE COPYING (2s) **************************/
  98
  99 #if defined(GC2s)
 100
 101 typedef struct {
 102     P_ base;    /* First word allocatable in semispace */
 103     P_ lim;     /* Last word allocatable in semispace */
 104 } semispaceData;
 105
 106 extern I_ semispace;    /* 0 or 1 -- indexes semispaceInfo */
 107 extern semispaceData semispaceInfo[2];
 108
 109 #endif /* GC2s */
 110
 111
 112 /*********************** SINGLE SPACE COMPACTION (1s) ***********************/
 113
 114 #if defined(GC1s)
 115
 116 typedef struct {
 117     P_ base;  /* First word allocatable in heap */
 118     P_ lim;   /* Last word allocatable in heap */
 119     BitWord *bits;      /* Area for marking bits */
 120     I_ bit_words;       /* Size of marking bit area (in words) */
 121     I_ heap_words;      /* Size of heap area (in words) */
 122 } compactingData;
 123
 124 extern compactingData compactingInfo;
 125
 126 #endif /* GC1s */
 127
 128
 129 /****************************** DUAL MODE (du) ******************************/
 130
 131 #if defined(GCdu)
 132
 133 typedef struct {
 134         I_ mode;
 135         StgFloat resid_to_compact;
 136         StgFloat resid_from_compact;
 137         struct {
 138             P_ base; /* First word allocatable in this mode */
 139             P_ lim;  /* Last word allocatable in this mode */
 140             I_ heap_words; /* Size of area (in words) */
 141             char *name;
 142         } modeinfo[3];
 143         BitWord *bits;      /* Area for marking bits */
 144         I_ bit_words;   /* Size of marking bit area (in words) */
 145 } dualmodeData;
 146
 147 extern dualmodeData dualmodeInfo;
 148
 149 #define DEFAULT_RESID_TO_COMPACT   0.25
 150 #define DEFAULT_RESID_FROM_COMPACT 0.20
 151
 152 #define TWO_SPACE_BOT 0
 153 #define TWO_SPACE_TOP 1
 154 #define COMPACTING    2
 155
 156 #endif /* GCdu */
 157
 158 /*************************** APPELS COLLECTOR (ap) **************************/
 159
 160 #if defined(GCap)
 161
 162 typedef struct {
 163         P_ oldbase;   /* first word allocatable in oldgen */
 164         P_ oldlim;    /* last word allocated in oldgen */
 165         P_ oldlast;   /* oldlim after last major collection */
 166         P_ oldthresh; /* threshold of oldgen occupancy */
 167         P_ oldmax;    /* maximum allocatable in oldgen before heap deemed full */
 168
 169         I_ newfixed;  /* The size of the new generation, if fixed */
 170         I_ newmin;    /* The minimum size of the new generation */
 171         P_ newbase;   /* First word allocatable in newgen top space */
 172         P_ newlim;    /* Last word allocatable in newgen top space */
 173
 174         BitWord *bits;    /* Area for marking bits */
 175
 176         P_ OldCAFlist; /* CAFs promoted to old generation */
 177         I_ OldCAFno;   /* No of CAFs promoted to old generation */
 178         I_ bit_words;  /* Size of marking bit area (in words) */
 179
 180         P_ PromMutables; /* List of recently promoted mutable closures */
 181
 182         I_ semi_space;   /* -F forced 2s collector */
 183         struct {
 184             P_ base;  /* First word allocatable in semispace */
 185             P_ lim;   /* Last word allocatable in semispace */
 186         } space[2];
 187
 188 } appelData;
 189
 190 /* UPDATE INFO - Stored in sm info structure:
 191       Additional info required when updating to keep track of
 192         new generation roots residing in the old generation
 193         (old -> new inter-generation pointers)
 194 */
 195
 196 extern appelData appelInfo;
 197
 198 #endif /* GCap */
 199
 200
 201 /************************ GENERATIONAL COLLECTOR (gn) ***********************/
 202
 203 #if defined(GCgn)
 204
 205 typedef struct {
 206         I_ alloc_words;  /* Size of allocation space */
 207                            /* May be large enough for bit array */
 208         I_ new_words;    /* Size of new generation semi-space */
 209                            /* Must be large enough for bit array */
 210         I_ old_words;    /* Size of old generation */
 211
 212         I_  minor_since_major;
 213                            /* No of minor collections since last major */
 214
 215         P_ allocbase;  /* First word allocatable in oldgen */
 216         P_ alloclim;   /* Last word allocatable in oldgen */
 217
 218         I_ curnew;         /* New gen semi-space currently in use */
 219         struct {
 220          P_ newbase;   /* First word allocatable in newgen semispace */
 221          P_ newlim;    /* Last word allocated in new semi-space */
 222         } newgen[2];
 223
 224         P_ oldbase;    /* First word allocatable in oldgen */
 225         P_ oldend;     /* Last word allocatable in oldgen */
 226         P_ oldwas;     /* Limit of oldgen after last major collection */
 227         P_ oldlim;     /* Last word allocated in oldgen */
 228         P_ oldthresh;  /* Oldgen threshold: less than new_words free */
 229         BitWord *bit_vect; /* Marking bits -- alloc area or old generation */
 230
 231         P_ OldInNew;   /* Old roots pointing to new generation */
 232         I_ OldInNewno; /* No of Old roots pointing to new generation */
 233         P_ NewCAFlist; /* CAFs in new generation */
 234         I_ NewCAFno;   /* No of CAFs in new generation */
 235         P_ OldCAFlist; /* CAFs promoted to old generation */
 236         I_ OldCAFno;   /* No of CAFs promoted to old generation */
 237
 238         P_ PromMutables; /* List of recently promoted mutable closures */
 239
 240         I_ semi_space;  /* -F forced 2s collector */
 241         struct {
 242             P_ base; /* First word allocatable in semispace */
 243             P_ lim;  /* Last word allocatable in semispace */
 244         } space[2];
 245 } genData;
 246
 247 extern genData genInfo;
 248
 249 /* Update INFO - Stored in sm info structure:
 250       Additional info required when updating to keep track of
 251         new generation roots residing in the old generation
 252         (old -> new inter-generation pointers)
 253 */
 254
 255 #endif /* GCap */
 256
 257 /****************************** COPYING ******************************/
 258
 259
 260 #if defined(_INFO_COPYING)
 261
 262 #define EVAC_CODE(infoptr)  ((StgEvacPtr) ((P_)(INFO_RTBL(infoptr)))[COPY_INFO_OFFSET])
 263 #define SCAV_CODE(infoptr)  ((StgScavPtr) ((P_)(INFO_RTBL(infoptr)))[COPY_INFO_OFFSET+1])
 264
 265 extern void Scavenge(STG_NO_ARGS);
 266 extern void  _Scavenge_Forward_Ref(STG_NO_ARGS);
 267
 268 /* Note: any change to FORWARD_ADDRESS should be
 269    reflected in layout of MallocPtrs (includes/SMClosures.lh)
 270 */
 271
 272 #define FORWARD_ADDRESS(closure)  (*(((P_)(closure)) + FIXED_HS))
 273
 274 #define FORWARDREF_ITBL(infolbl,entry,localness,evac_forward)   \
 275 CAT_DECLARE(infolbl,INTERNAL_KIND,"FORWARD_REF","FORWARD_REF")  \
 276 localness W_ infolbl[] = {                                      \
 277         (W_) entry                                              \
 278         ,(W_) INFO_OTHER_TAG                                    \
 279         ,(W_) MK_REP_REF(,evac_forward,)                        \
 280         INCLUDE_PROFILING_INFO(infolbl)                         \
 281         }
 282
 283 P_ _Evacuate_Old_Forward_Ref PROTO((P_));
 284 P_ _Evacuate_New_Forward_Ref PROTO((P_));
 285 P_ _Evacuate_OldRoot_Forward PROTO((P_));
 286 P_ _Evacuate_Forward_Ref PROTO((P_));
 287
 288 MAYBE_DECLARE_RTBL(,_Evacuate_Old_Forward_Ref,)
 289 MAYBE_DECLARE_RTBL(,_Evacuate_New_Forward_Ref,)
 290 MAYBE_DECLARE_RTBL(,_Evacuate_OldRoot_Forward,)
 291 MAYBE_DECLARE_RTBL(,_Evacuate_Forward_Ref,)
 292
 293 #define FORWARDREF_RTBL(evac_forward) \
 294     const W_ MK_REP_LBL(,evac_forward,)[] = { \
 295         INCLUDE_TYPE_INFO(INTERNAL)                             \
 296         INCLUDE_SIZE_INFO(INFO_UNUSED,INFO_UNUSED)              \
 297         INCLUDE_PAR_INFO                                \
 298         INCLUDE_COPYING_INFO(evac_forward,_Scavenge_Forward_Ref)\
 299         INCLUDE_COMPACTING_INFO(INFO_UNUSED,INFO_UNUSED,INFO_UNUSED,INFO_UNUSED) \
 300         }
 301
 302 EXTDATA_RO(Caf_Evac_Upd_info);
 303 extern StgEvacFun _Evacuate_Caf_Evac_Upd;
 304
 305 #define CAF_EVAC_UPD_ITBL(infolbl,entry,localness)              \
 306 CAT_DECLARE(infolbl,INTERNAL_KIND,"CAF_EVAC_UPD","CAF_EVAC_UPD") \
 307 localness W_ infolbl[] = {                                      \
 308         (W_) entry                                              \
 309         ,(W_) INFO_OTHER_TAG                                    \
 310         ,(W_) MK_REP_REF(Caf_Evac_Upd,,)                        \
 311         INCLUDE_PROFILING_INFO(infolbl)                         \
 312         }
 313
 314 MAYBE_DECLARE_RTBL(Caf_Evac_Upd,,)
 315
 316 #define CAF_EVAC_UPD_RTBL() \
 317     const W_ MK_REP_LBL(Caf_Evac_Upd,,)[] = { \
 318         INCLUDE_TYPE_INFO(INTERNAL)                             \
 319         INCLUDE_SIZE_INFO(MIN_UPD_SIZE,INFO_UNUSED)             \
 320         INCLUDE_PAR_INFO                \
 321         INCLUDE_COPYING_INFO(_Evacuate_Caf_Evac_Upd,_Scavenge_Caf) \
 322         INCLUDE_COMPACTING_INFO(INFO_UNUSED,INFO_UNUSED,INFO_UNUSED,INFO_UNUSED) \
 323     }
 324
 325 #define EVACUATE_CLOSURE(closure)      \
 326         (EVAC_CODE(INFO_PTR(closure)))(closure)
 327
 328 #endif /* _INFO_COPYING */
 329
 330
 331 /****************************** MARKING ******************************/
 332
 333 #if defined(_INFO_MARKING)
 334
 335 extern I_ markHeapRoots PROTO((smInfo *sm, P_ cafs1, P_ cafs2,
 336                                 P_ base, P_ lim, BitWord *bit_array));
 337
 338 #define PRMARK_CODE(infoptr) \
 339           (((FP_)(INFO_RTBL(infoptr)))[COMPACTING_INFO_OFFSET+1])
 340
 341 /* Applied to unmarked or marking info pointer */
 342 #define PRRETURN_CODE(infoptr) \
 343           (((FP_)(INFO_RTBL(infoptr)))[COMPACTING_INFO_OFFSET+3])
 344
 345 /* This placed on bottom of PR Marking Stack */
 346
 347 #define DUMMY_PRRETURN_CLOSURE(closure_name, table_name, prreturn_code, dummy_code) \
 348 const W_ table_name[] = {                       \
 349         (W_) dummy_code                         \
 350         ,(W_) INFO_OTHER_TAG                    \
 351         ,(W_) MK_REP_REF(,prreturn_code,)       \
 352         INCLUDE_PROFILING_INFO(Dummy_PrReturn)  \
 353         };                                      \
 354 W_ closure_name = (W_) table_name
 355
 356 EXTFUN(_Dummy_PRReturn_entry);
 357 EXTFUN(_PRMarking_MarkNextRoot);
 358 EXTFUN(_PRMarking_MarkNextCAF);
 359
 360 #ifdef CONCURRENT
 361 EXTFUN(_PRMarking_MarkNextSpark);
 362 #endif
 363
 364 #ifdef PAR
 365 EXTFUN(_PRMarking_MarkNextGA);
 366 MAYBE_DECLARE_RTBL(,_PRMarking_MarkNextGA,)
 367 #else
 368
 369 EXTFUN(_PRMarking_MarkNextAStack);
 370 EXTFUN(_PRMarking_MarkNextBStack);
 371
 372 MAYBE_DECLARE_RTBL(,_PRMarking_MarkNextAStack,)
 373 MAYBE_DECLARE_RTBL(,_PRMarking_MarkNextBStack,)
 374
 375 #endif /* PAR */
 376
 377 #ifdef CONCURRENT
 378 MAYBE_DECLARE_RTBL(,_PRMarking_MarkNextSpark,)
 379 #endif
 380
 381 MAYBE_DECLARE_RTBL(,_PRMarking_MarkNextRoot,)
 382 MAYBE_DECLARE_RTBL(,_PRMarking_MarkNextCAF,)
 383
 384 #define DUMMY_PRRETURN_RTBL(prreturn_code,dummy_code) \
 385     const W_ MK_REP_LBL(,prreturn_code,)[] = {      \
 386         INCLUDE_TYPE_INFO(INTERNAL)                 \
 387         INCLUDE_SIZE_INFO(INFO_UNUSED,INFO_UNUSED)  \
 388         INCLUDE_PAR_INFO   \
 389         INCLUDE_COPYING_INFO(dummy_code,dummy_code) \
 390         INCLUDE_COMPACTING_INFO(dummy_code,dummy_code,dummy_code,prreturn_code) \
 391     }
 392
 393 /* Unused "Code to avoid explicit updating of CAF references" used to live here
 394     (WDP 94/11)
 395 */
 396
 397 #endif /* _INFO_MARKING */
 398
 399
 400 /****************************** COMPACTING ******************************/
 401
 402 #if defined(_INFO_COMPACTING)
 403
 404 #ifndef PAR
 405 P_ Inplace_Compaction PROTO((P_ base, P_ lim,
 406                              P_ scanbase, P_ scablim,
 407                              BitWord *bit_array, I_ bit_array_words,
 408                              StgPtr *MallocPtrList));
 409 #else
 410 P_ Inplace_Compaction PROTO((P_ base, P_ lim,
 411                              P_ scanbase, P_ scablim,
 412                              BitWord *bit_array, I_ bit_array_words));
 413 #endif
 414 /* Applied to marked info pointers */
 415
 416 #define SCAN_LINK_CODE(infoptr) \
 417           ((StgScanPtr) ((P_)(INFO_RTBL(infoptr)))[COMPACTING_INFO_OFFSET])
 418 #define SCAN_MOVE_CODE(infoptr) \
 419           ((StgScanPtr) ((P_)(INFO_RTBL(infoptr)))[COMPACTING_INFO_OFFSET+2])
 420
 421 /*
 422         This fragment tests whether we're in global garbage collection during parallel
 423         evaluation.  If so, then we check the global address of the closure \tr{loc}
 424         and evacuate it in the IMUs if it's a legal global address.
 425 */
 426
 427 #define  LINK_GLOBALADDRESS(loc)
 428
 429 #if defined(GCgn)
 430
 431 extern StgScavFun _Scavenge_OldRoot;               /* Allocated Old -> New root, just skip */
 432 extern StgEvacFun _Evacuate_OldRoot;               /* Should not occur */
 433
 434 extern StgFunPtr  _PRStart_OldRoot(STG_NO_ARGS);   /* Marking old root -- Short circut if points to oldgen */
 435 extern StgScanFun _ScanMove_OldRoot;               /* Scanning old root -- Rebuild old root list */
 436
 437 EXTDATA_RO(OldRoot_info);
 438
 439 #define OLDROOT_ITBL(infolbl,ind_code,localness,entry_localness)\
 440     CAT_DECLARE(infolbl,INTERNAL_KIND,"OLDROOT","OLDROOT")      \
 441     entry_localness(ind_code);                                  \
 442     localness W_ infolbl[] = {                                  \
 443         (W_) ind_code                                           \
 444         ,(W_) INFO_OTHER_TAG                                    \
 445         ,(W_) MK_REP_REF(OldRoot,,)                             \
 446         INCLUDE_PROFILING_INFO(infolbl)                         \
 447         }
 448
 449 MAYBE_DECLARE_RTBL(OldRoot,,)
 450
 451 #define OLDROOT_RTBL()                                                  \
 452     const W_ MK_REP_LBL(OldRoot,,)[] = {                                \
 453         INCLUDE_TYPE_INFO(SPEC_U)                                       \
 454         INCLUDE_SIZE_INFO(2,1)  /* deeply hardwired size/ptrs */        \
 455         INCLUDE_PAR_INFO                        \
 456         INCLUDE_COPYING_INFO(_Evacuate_OldRoot,_Scavenge_OldRoot)       \
 457         SPEC_COMPACTING_INFO(_ScanLink_2_1,_PRStart_OldRoot,_ScanMove_OldRoot,_PRIn_1) \
 458         }
 459
 460 #define LINK_LOCATION_TO_CLOSURE(loc,linklim)                   \
 461           { P_ _temp = (P_) *(loc);                             \
 462           DEBUG_LINK_LOCATION(loc, _temp, linklim);             \
 463           if (DYNAMIC_CLOSURE(_temp) && (_temp <= linklim)) {   \
 464               *((P_)(loc)) = (W_) INFO_PTR(_temp);              \
 465               INFO_PTR(_temp)  = MARK_LOCATION(loc);            \
 466           }}
 467
 468 #else /* ! GCgn */
 469
 470 #define LINK_LOCATION_TO_CLOSURE(loc)           \
 471           { P_ _temp = (P_) *(loc);     \
 472           DEBUG_LINK_LOCATION(loc, _temp);      \
 473           if (DYNAMIC_CLOSURE(_temp)) {         \
 474               *((P_)(loc)) = (W_) INFO_PTR(_temp); \
 475               INFO_PTR(_temp) = MARK_LOCATION(loc);     \
 476           }}
 477
 478 #endif /* ! GCgn */
 479
 480 #if defined(_GC_DEBUG)
 481
 482 #if defined(GCgn)
 483 #define DEBUG_LINK_LOCATION(location, closure, linklim) \
 484     if (SM_trace & 4) {                         \
 485         if (DYNAMIC_CLOSURE(closure) && (closure <= linklim)) \
 486             fprintf(stderr, "  Link Loc: 0x%lx to 0x%lx\n", location, closure); \
 487         else if (! DYNAMIC_CLOSURE(closure))    \
 488              fprintf(stderr, "  Link Loc: 0x%lx to 0x%lx Static Closure -- Not Done\n", location, closure); \
 489         else                                    \
 490              fprintf(stderr, "  Link Loc: 0x%lx to 0x%lx OutOfRange Closure -- Not Done\n", location, closure); \
 491     }
 492 #else /* ! GCgn */
 493 #define DEBUG_LINK_LOCATION(location, closure)  \
 494     if (SM_trace & 4) {                         \
 495         if (DYNAMIC_CLOSURE(closure))           \
 496             fprintf(stderr, "  Link Loc: 0x%lx to 0x%lx\n", location, closure); \
 497         else                                    \
 498             fprintf(stderr, "  Link Loc: 0x%lx to 0x%lx Static Closure -- Not Done\n", location, closure); \
 499     }
 500 #endif /* ! GCgn */
 501
 502 #define DEBUG_UNLINK_LOCATION(location, closure, newlocation)   \
 503     if (SM_trace & 4)                                           \
 504         fprintf(stderr, "  UnLink Loc: 0x%lx, 0x%lx -> 0x%lx\n", location, closure, newlocation)
 505
 506 #define DEBUG_LINK_CAF(caf) \
 507     if (SM_trace & 4)           \
 508         fprintf(stderr, "Caf: 0x%lx  Closure: 0x%lx\n", caf, IND_CLOSURE_PTR(caf))
 509
 510 #define DEBUG_SET_MARK(closure, hp_word) \
 511     if (SM_trace & 8)                    \
 512         fprintf(stderr, "  Set Mark Bit: 0x%lx, word %ld, bit_word %ld, bit %d\n", closure, hp_word, hp_word / BITS_IN(BitWord), hp_word & (BITS_IN(BitWord) - 1))
 513
 514 #else
 515 #if defined(GCgn)
 516 #define DEBUG_LINK_LOCATION(location, closure, linklim)
 517 #else
 518 #define DEBUG_LINK_LOCATION(location, closure)
 519 #endif
 520 #define DEBUG_UNLINK_LOCATION(location, closure, newlocation)
 521 #define DEBUG_LINK_CAF(caf)
 522 #define DEBUG_SET_MARK(closure, hp_word)
 523 #endif
 524
 525 #endif /* _INFO_COMPACTING */
 526
 527 #endif /* SMinternals_H */
 528
 529 \end{code}