rts/Sparks.c

   1 /* ---------------------------------------------------------------------------
   2  *
   3  * (c) The GHC Team, 2000-2006
   4  *
   5  * Sparking support for PARALLEL_HASKELL and THREADED_RTS versions of the RTS.
   6  *
   7  * -------------------------------------------------------------------------*/
   8
   9 #include "PosixSource.h"
  10 #include "Rts.h"
  11 #include "Storage.h"
  12 #include "Schedule.h"
  13 #include "SchedAPI.h"
  14 #include "RtsFlags.h"
  15 #include "RtsUtils.h"
  16 #include "ParTicky.h"
  17 # if defined(PARALLEL_HASKELL)
  18 # include "ParallelRts.h"
  19 # include "GranSimRts.h"   // for GR_...
  20 # elif defined(GRAN)
  21 # include "GranSimRts.h"
  22 # endif
  23 #include "Sparks.h"
  24 #include "Trace.h"
  25
  26 #if defined(THREADED_RTS) || defined(PARALLEL_HASKELL)
  27
  28 static INLINE_ME void bump_hd (StgSparkPool *p)
  29 { p->hd++; if (p->hd == p->lim) p->hd = p->base; }
  30
  31 static INLINE_ME void bump_tl (StgSparkPool *p)
  32 { p->tl++; if (p->tl == p->lim) p->tl = p->base; }
  33
  34 /* -----------------------------------------------------------------------------
  35  *
  36  * Initialising spark pools.
  37  *
  38  * -------------------------------------------------------------------------- */
  39
  40 static void
  41 initSparkPool(StgSparkPool *pool)
  42 {
  43     pool->base = stgMallocBytes(RtsFlags.ParFlags.maxLocalSparks
  44                                 * sizeof(StgClosure *),
  45                                 "initSparkPools");
  46     pool->lim = pool->base + RtsFlags.ParFlags.maxLocalSparks;
  47     pool->hd  = pool->base;
  48     pool->tl  = pool->base;
  49 }
  50
  51 void
  52 initSparkPools( void )
  53 {
  54 #ifdef THREADED_RTS
  55     /* walk over the capabilities, allocating a spark pool for each one */
  56     nat i;
  57     for (i = 0; i < n_capabilities; i++) {
  58         initSparkPool(&capabilities[i].r.rSparks);
  59     }
  60 #else
  61     /* allocate a single spark pool */
  62     initSparkPool(&MainCapability.r.rSparks);
  63 #endif
  64 }
  65
  66 void
  67 freeSparkPool(StgSparkPool *pool) {
  68     stgFree(pool->base);
  69 }
  70
  71 /* -----------------------------------------------------------------------------
  72  *
  73  * findSpark: find a spark on the current Capability that we can fork
  74  * into a thread.
  75  *
  76  * -------------------------------------------------------------------------- */
  77
  78 StgClosure *
  79 findSpark (Capability *cap)
  80 {
  81     StgSparkPool *pool;
  82     StgClosure *spark;
  83
  84     pool = &(cap->r.rSparks);
  85     ASSERT_SPARK_POOL_INVARIANTS(pool);
  86
  87     while (pool->hd != pool->tl) {
  88         spark = *pool->hd;
  89         bump_hd(pool);
  90         if (closure_SHOULD_SPARK(spark)) {
  91 #ifdef GRAN
  92             if (RtsFlags.ParFlags.ParStats.Sparks)
  93                 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
  94                                  GR_STEALING, ((StgTSO *)NULL), spark,
  95                                  0, 0 /* spark_queue_len(ADVISORY_POOL) */);
  96 #endif
  97             return spark;
  98         }
  99     }
 100     // spark pool is now empty
 101     return NULL;
 102 }
 103
 104 /* -----------------------------------------------------------------------------
 105  * Mark all nodes pointed to by sparks in the spark queues (for GC) Does an
 106  * implicit slide i.e. after marking all sparks are at the beginning of the
 107  * spark pool and the spark pool only contains sparkable closures
 108  * -------------------------------------------------------------------------- */
 109
 110 void
 111 markSparkQueue (evac_fn evac)
 112 {
 113     StgClosure **sparkp, **to_sparkp;
 114     nat i, n, pruned_sparks; // stats only
 115     StgSparkPool *pool;
 116     Capability *cap;
 117
 118     PAR_TICKY_MARK_SPARK_QUEUE_START();
 119
 120     n = 0;
 121     pruned_sparks = 0;
 122     for (i = 0; i < n_capabilities; i++) {
 123         cap = &capabilities[i];
 124         pool = &(cap->r.rSparks);
 125
 126         ASSERT_SPARK_POOL_INVARIANTS(pool);
 127
 128 #if defined(PARALLEL_HASKELL)
 129         // stats only
 130         n = 0;
 131         pruned_sparks = 0;
 132 #endif
 133
 134         sparkp = pool->hd;
 135         to_sparkp = pool->hd;
 136         while (sparkp != pool->tl) {
 137             ASSERT(*sparkp!=NULL);
 138             ASSERT(LOOKS_LIKE_CLOSURE_PTR(((StgClosure *)*sparkp)));
 139             // ToDo?: statistics gathering here (also for GUM!)
 140             if (closure_SHOULD_SPARK(*sparkp)) {
 141                 evac(sparkp);
 142                 *to_sparkp++ = *sparkp;
 143                 if (to_sparkp == pool->lim) {
 144                     to_sparkp = pool->base;
 145                 }
 146                 n++;
 147             } else {
 148                 pruned_sparks++;
 149             }
 150             sparkp++;
 151             if (sparkp == pool->lim) {
 152                 sparkp = pool->base;
 153             }
 154         }
 155         pool->tl = to_sparkp;
 156
 157         PAR_TICKY_MARK_SPARK_QUEUE_END(n);
 158
 159 #if defined(PARALLEL_HASKELL)
 160         debugTrace(DEBUG_sched,
 161                    "marked %d sparks and pruned %d sparks on [%x]",
 162                    n, pruned_sparks, mytid);
 163 #else
 164         debugTrace(DEBUG_sched,
 165                    "marked %d sparks and pruned %d sparks",
 166                    n, pruned_sparks);
 167 #endif
 168
 169         debugTrace(DEBUG_sched,
 170                    "new spark queue len=%d; (hd=%p; tl=%p)\n",
 171                    sparkPoolSize(pool), pool->hd, pool->tl);
 172     }
 173 }
 174
 175 /* -----------------------------------------------------------------------------
 176  *
 177  * Turn a spark into a real thread
 178  *
 179  * -------------------------------------------------------------------------- */
 180
 181 void
 182 createSparkThread (Capability *cap, StgClosure *p)
 183 {
 184     StgTSO *tso;
 185
 186     tso = createGenThread (cap, RtsFlags.GcFlags.initialStkSize, p);
 187     appendToRunQueue(cap,tso);
 188 }
 189
 190 /* -----------------------------------------------------------------------------
 191  *
 192  * Create a new spark
 193  *
 194  * -------------------------------------------------------------------------- */
 195
 196 #define DISCARD_NEW
 197
 198 StgInt
 199 newSpark (StgRegTable *reg, StgClosure *p)
 200 {
 201     StgSparkPool *pool = &(reg->rSparks);
 202
 203     ASSERT_SPARK_POOL_INVARIANTS(pool);
 204
 205     if (closure_SHOULD_SPARK(p)) {
 206 #ifdef DISCARD_NEW
 207         StgClosure **new_tl;
 208         new_tl = pool->tl + 1;
 209         if (new_tl == pool->lim) { new_tl = pool->base; }
 210         if (new_tl != pool->hd) {
 211             *pool->tl = p;
 212             pool->tl = new_tl;
 213         } else if (!closure_SHOULD_SPARK(*pool->hd)) {
 214             // if the old closure is not sparkable, discard it and
 215             // keep the new one.  Otherwise, keep the old one.
 216             *pool->tl = p;
 217             bump_hd(pool);
 218         }
 219 #else  /* DISCARD OLD */
 220         *pool->tl = p;
 221         bump_tl(pool);
 222         if (pool->tl == pool->hd) { bump_hd(pool); }
 223 #endif
 224     }
 225
 226     ASSERT_SPARK_POOL_INVARIANTS(pool);
 227     return 1;
 228 }
 229
 230 #else
 231
 232 StgInt
 233 newSpark (StgRegTable *reg STG_UNUSED, StgClosure *p STG_UNUSED)
 234 {
 235     /* nothing */
 236     return 1;
 237 }
 238
 239 #endif /* PARALLEL_HASKELL || THREADED_RTS */
 240
 241
 242 /* -----------------------------------------------------------------------------
 243  *
 244  * GRAN & PARALLEL_HASKELL stuff beyond here.
 245  *
 246  * -------------------------------------------------------------------------- */
 247
 248 #if defined(PARALLEL_HASKELL) || defined(GRAN)
 249
 250 static void slide_spark_pool( StgSparkPool *pool );
 251
 252 rtsBool
 253 add_to_spark_queue( StgClosure *closure, StgSparkPool *pool )
 254 {
 255   if (pool->tl == pool->lim)
 256     slide_spark_pool(pool);
 257
 258   if (closure_SHOULD_SPARK(closure) &&
 259       pool->tl < pool->lim) {
 260     *(pool->tl++) = closure;
 261
 262 #if defined(PARALLEL_HASKELL)
 263     // collect parallel global statistics (currently done together with GC stats)
 264     if (RtsFlags.ParFlags.ParStats.Global &&
 265         RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
 266       // debugBelch("Creating spark for %x @ %11.2f\n", closure, usertime());
 267       globalParStats.tot_sparks_created++;
 268     }
 269 #endif
 270     return rtsTrue;
 271   } else {
 272 #if defined(PARALLEL_HASKELL)
 273     // collect parallel global statistics (currently done together with GC stats)
 274     if (RtsFlags.ParFlags.ParStats.Global &&
 275         RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
 276       //debugBelch("Ignoring spark for %x @ %11.2f\n", closure, usertime());
 277       globalParStats.tot_sparks_ignored++;
 278     }
 279 #endif
 280     return rtsFalse;
 281   }
 282 }
 283
 284 static void
 285 slide_spark_pool( StgSparkPool *pool )
 286 {
 287   StgClosure **sparkp, **to_sparkp;
 288
 289   sparkp = pool->hd;
 290   to_sparkp = pool->base;
 291   while (sparkp < pool->tl) {
 292     ASSERT(to_sparkp<=sparkp);
 293     ASSERT(*sparkp!=NULL);
 294     ASSERT(LOOKS_LIKE_GHC_INFO((*sparkp)->header.info));
 295
 296     if (closure_SHOULD_SPARK(*sparkp)) {
 297       *to_sparkp++ = *sparkp++;
 298     } else {
 299       sparkp++;
 300     }
 301   }
 302   pool->hd = pool->base;
 303   pool->tl = to_sparkp;
 304 }
 305
 306 void
 307 disposeSpark(spark)
 308 StgClosure *spark;
 309 {
 310 #if !defined(THREADED_RTS)
 311   Capability *cap;
 312   StgSparkPool *pool;
 313
 314   cap = &MainRegTable;
 315   pool = &(cap->rSparks);
 316   ASSERT(pool->hd <= pool->tl && pool->tl <= pool->lim);
 317 #endif
 318   ASSERT(spark != (StgClosure *)NULL);
 319   /* Do nothing */
 320 }
 321
 322
 323 #elif defined(GRAN)
 324
 325 /*
 326    Search the spark queue of the proc in event for a spark that's worth
 327    turning into a thread
 328    (was gimme_spark in the old RTS)
 329 */
 330 void
 331 findLocalSpark (rtsEvent *event, rtsBool *found_res, rtsSparkQ *spark_res)
 332 {
 333    PEs proc = event->proc,       /* proc to search for work */
 334        creator = event->creator; /* proc that requested work */
 335    StgClosure* node;
 336    rtsBool found;
 337    rtsSparkQ spark_of_non_local_node = NULL,
 338              spark_of_non_local_node_prev = NULL,
 339              low_priority_spark = NULL,
 340              low_priority_spark_prev = NULL,
 341              spark = NULL, prev = NULL;
 342
 343    /* Choose a spark from the local spark queue */
 344    prev = (rtsSpark*)NULL;
 345    spark = pending_sparks_hds[proc];
 346    found = rtsFalse;
 347
 348    // ToDo: check this code & implement local sparking !! -- HWL
 349    while (!found && spark != (rtsSpark*)NULL)
 350      {
 351        ASSERT((prev!=(rtsSpark*)NULL || spark==pending_sparks_hds[proc]) &&
 352               (prev==(rtsSpark*)NULL || prev->next==spark) &&
 353               (spark->prev==prev));
 354        node = spark->node;
 355        if (!closure_SHOULD_SPARK(node))
 356          {
 357            IF_GRAN_DEBUG(checkSparkQ,
 358                          debugBelch("^^ pruning spark %p (node %p) in gimme_spark",
 359                                spark, node));
 360
 361            if (RtsFlags.GranFlags.GranSimStats.Sparks)
 362              DumpRawGranEvent(proc, (PEs)0, SP_PRUNED,(StgTSO*)NULL,
 363                               spark->node, spark->name, spark_queue_len(proc));
 364
 365            ASSERT(spark != (rtsSpark*)NULL);
 366            ASSERT(SparksAvail>0);
 367            --SparksAvail;
 368
 369            ASSERT(prev==(rtsSpark*)NULL || prev->next==spark);
 370            spark = delete_from_sparkq (spark, proc, rtsTrue);
 371            if (spark != (rtsSpark*)NULL)
 372              prev = spark->prev;
 373            continue;
 374          }
 375        /* -- node should eventually be sparked */
 376        else if (RtsFlags.GranFlags.PreferSparksOfLocalNodes &&
 377                !IS_LOCAL_TO(PROCS(node),CurrentProc))
 378          {
 379            barf("Local sparking not yet implemented");
 380
 381            /* Remember first low priority spark */
 382            if (spark_of_non_local_node==(rtsSpark*)NULL) {
 383              spark_of_non_local_node_prev = prev;
 384              spark_of_non_local_node = spark;
 385               }
 386
 387            if (spark->next == (rtsSpark*)NULL) {
 388              /* ASSERT(spark==SparkQueueTl);  just for testing */
 389              prev = spark_of_non_local_node_prev;
 390              spark = spark_of_non_local_node;
 391              found = rtsTrue;
 392              break;
 393            }
 394
 395 # if defined(GRAN) && defined(GRAN_CHECK)
 396            /* Should never happen; just for testing
 397            if (spark==pending_sparks_tl) {
 398              debugBelch("ReSchedule: Last spark != SparkQueueTl\n");
 399                 stg_exit(EXIT_FAILURE);
 400                 } */
 401 # endif
 402            prev = spark;
 403            spark = spark->next;
 404            ASSERT(SparksAvail>0);
 405            --SparksAvail;
 406            continue;
 407          }
 408        else if ( RtsFlags.GranFlags.DoPrioritySparking ||
 409                  (spark->gran_info >= RtsFlags.GranFlags.SparkPriority2) )
 410          {
 411            if (RtsFlags.GranFlags.DoPrioritySparking)
 412              barf("Priority sparking not yet implemented");
 413
 414            found = rtsTrue;
 415          }
 416 #if 0
 417        else /* only used if SparkPriority2 is defined */
 418          {
 419            /* ToDo: fix the code below and re-integrate it */
 420            /* Remember first low priority spark */
 421            if (low_priority_spark==(rtsSpark*)NULL) {
 422              low_priority_spark_prev = prev;
 423              low_priority_spark = spark;
 424            }
 425
 426            if (spark->next == (rtsSpark*)NULL) {
 427                 /* ASSERT(spark==spark_queue_tl);  just for testing */
 428              prev = low_priority_spark_prev;
 429              spark = low_priority_spark;
 430              found = rtsTrue;       /* take low pri spark => rc is 2  */
 431              break;
 432            }
 433
 434            /* Should never happen; just for testing
 435            if (spark==pending_sparks_tl) {
 436              debugBelch("ReSchedule: Last spark != SparkQueueTl\n");
 437                 stg_exit(EXIT_FAILURE);
 438              break;
 439            } */
 440            prev = spark;
 441            spark = spark->next;
 442
 443            IF_GRAN_DEBUG(pri,
 444                          debugBelch("++ Ignoring spark of priority %u (SparkPriority=%u); node=%p; name=%u\n",
 445                                spark->gran_info, RtsFlags.GranFlags.SparkPriority,
 446                                spark->node, spark->name);)
 447            }
 448 #endif
 449    }  /* while (spark!=NULL && !found) */
 450
 451    *spark_res = spark;
 452    *found_res = found;
 453 }
 454
 455 /*
 456   Turn the spark into a thread.
 457   In GranSim this basically means scheduling a StartThread event for the
 458   node pointed to by the spark at some point in the future.
 459   (was munch_spark in the old RTS)
 460 */
 461 rtsBool
 462 activateSpark (rtsEvent *event, rtsSparkQ spark)
 463 {
 464   PEs proc = event->proc,       /* proc to search for work */
 465       creator = event->creator; /* proc that requested work */
 466   StgTSO* tso;
 467   StgClosure* node;
 468   rtsTime spark_arrival_time;
 469
 470   /*
 471      We've found a node on PE proc requested by PE creator.
 472      If proc==creator we can turn the spark into a thread immediately;
 473      otherwise we schedule a MoveSpark event on the requesting PE
 474   */
 475
 476   /* DaH Qu' yIchen */
 477   if (proc!=creator) {
 478
 479     /* only possible if we simulate GUM style fishing */
 480     ASSERT(RtsFlags.GranFlags.Fishing);
 481
 482     /* Message packing costs for sending a Fish; qeq jabbI'ID */
 483     CurrentTime[proc] += RtsFlags.GranFlags.Costs.mpacktime;
 484
 485     if (RtsFlags.GranFlags.GranSimStats.Sparks)
 486       DumpRawGranEvent(proc, (PEs)0, SP_EXPORTED,
 487                        (StgTSO*)NULL, spark->node,
 488                        spark->name, spark_queue_len(proc));
 489
 490     /* time of the spark arrival on the remote PE */
 491     spark_arrival_time = CurrentTime[proc] + RtsFlags.GranFlags.Costs.latency;
 492
 493     new_event(creator, proc, spark_arrival_time,
 494               MoveSpark,
 495               (StgTSO*)NULL, spark->node, spark);
 496
 497     CurrentTime[proc] += RtsFlags.GranFlags.Costs.mtidytime;
 498
 499   } else { /* proc==creator i.e. turn the spark into a thread */
 500
 501     if ( RtsFlags.GranFlags.GranSimStats.Global &&
 502          spark->gran_info < RtsFlags.GranFlags.SparkPriority2 ) {
 503
 504       globalGranStats.tot_low_pri_sparks++;
 505       IF_GRAN_DEBUG(pri,
 506                     debugBelch("++ No high priority spark available; low priority (%u) spark chosen: node=%p; name=%u\n",
 507                           spark->gran_info,
 508                           spark->node, spark->name));
 509     }
 510
 511     CurrentTime[proc] += RtsFlags.GranFlags.Costs.threadcreatetime;
 512
 513     node = spark->node;
 514
 515 # if 0
 516     /* ToDo: fix the GC interface and move to StartThread handling-- HWL */
 517     if (GARBAGE COLLECTION IS NECESSARY) {
 518       /* Some kind of backoff needed here in case there's too little heap */
 519 #  if defined(GRAN_CHECK) && defined(GRAN)
 520       if (RtsFlags.GcFlags.giveStats)
 521         fprintf(RtsFlags.GcFlags.statsFile,"***** vIS Qu' chen veQ boSwI'; spark=%p, node=%p;  name=%u\n",
 522                 /* (found==2 ? "no hi pri spark" : "hi pri spark"), */
 523                 spark, node, spark->name);
 524 #  endif
 525       new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc]+1,
 526                   FindWork,
 527                   (StgTSO*)NULL, (StgClosure*)NULL, (rtsSpark*)NULL);
 528       barf("//// activateSpark: out of heap ; ToDo: call GarbageCollect()");
 529       GarbageCollect(GetRoots, rtsFalse);
 530       // HWL old: ReallyPerformThreadGC(TSO_HS+TSO_CTS_SIZE,rtsFalse);
 531       // HWL old: SAVE_Hp -= TSO_HS+TSO_CTS_SIZE;
 532       spark = NULL;
 533       return; /* was: continue; */ /* to the next event, eventually */
 534     }
 535 # endif
 536
 537     if (RtsFlags.GranFlags.GranSimStats.Sparks)
 538       DumpRawGranEvent(CurrentProc,(PEs)0,SP_USED,(StgTSO*)NULL,
 539                        spark->node, spark->name,
 540                        spark_queue_len(CurrentProc));
 541
 542     new_event(proc, proc, CurrentTime[proc],
 543               StartThread,
 544               END_TSO_QUEUE, node, spark); // (rtsSpark*)NULL);
 545
 546     procStatus[proc] = Starting;
 547   }
 548 }
 549
 550 /* -------------------------------------------------------------------------
 551    This is the main point where handling granularity information comes into
 552    play.
 553    ------------------------------------------------------------------------- */
 554
 555 #define MAX_RAND_PRI    100
 556
 557 /*
 558    Granularity info transformers.
 559    Applied to the GRAN_INFO field of a spark.
 560 */
 561 STATIC_INLINE nat  ID(nat x) { return(x); };
 562 STATIC_INLINE nat  INV(nat x) { return(-x); };
 563 STATIC_INLINE nat  IGNORE(nat x) { return (0); };
 564 STATIC_INLINE nat  RAND(nat x) { return ((random() % MAX_RAND_PRI) + 1); }
 565
 566 /* NB: size_info and par_info are currently unused (what a shame!) -- HWL */
 567 rtsSpark *
 568 newSpark(node,name,gran_info,size_info,par_info,local)
 569 StgClosure *node;
 570 nat name, gran_info, size_info, par_info, local;
 571 {
 572   nat pri;
 573   rtsSpark *newspark;
 574
 575   pri = RtsFlags.GranFlags.RandomPriorities ? RAND(gran_info) :
 576         RtsFlags.GranFlags.InversePriorities ? INV(gran_info) :
 577         RtsFlags.GranFlags.IgnorePriorities ? IGNORE(gran_info) :
 578                            ID(gran_info);
 579
 580   if ( RtsFlags.GranFlags.SparkPriority!=0 &&
 581        pri<RtsFlags.GranFlags.SparkPriority ) {
 582     IF_GRAN_DEBUG(pri,
 583       debugBelch(",, NewSpark: Ignoring spark of priority %u (SparkPriority=%u); node=%#x; name=%u\n",
 584               pri, RtsFlags.GranFlags.SparkPriority, node, name));
 585     return ((rtsSpark*)NULL);
 586   }
 587
 588   newspark = (rtsSpark*) stgMallocBytes(sizeof(rtsSpark), "NewSpark");
 589   newspark->prev = newspark->next = (rtsSpark*)NULL;
 590   newspark->node = node;
 591   newspark->name = (name==1) ? CurrentTSO->gran.sparkname : name;
 592   newspark->gran_info = pri;
 593   newspark->global = !local;      /* Check that with parAt, parAtAbs !!*/
 594
 595   if (RtsFlags.GranFlags.GranSimStats.Global) {
 596     globalGranStats.tot_sparks_created++;
 597     globalGranStats.sparks_created_on_PE[CurrentProc]++;
 598   }
 599
 600   return(newspark);
 601 }
 602
 603 void
 604 disposeSpark(spark)
 605 rtsSpark *spark;
 606 {
 607   ASSERT(spark!=NULL);
 608   stgFree(spark);
 609 }
 610
 611 void
 612 disposeSparkQ(spark)
 613 rtsSparkQ spark;
 614 {
 615   if (spark==NULL)
 616     return;
 617
 618   disposeSparkQ(spark->next);
 619
 620 # ifdef GRAN_CHECK
 621   if (SparksAvail < 0) {
 622     debugBelch("disposeSparkQ: SparksAvail<0 after disposing sparkq @ %p\n", &spark);
 623     print_spark(spark);
 624   }
 625 # endif
 626
 627   stgFree(spark);
 628 }
 629
 630 /*
 631    With PrioritySparking add_to_spark_queue performs an insert sort to keep
 632    the spark queue sorted. Otherwise the spark is just added to the end of
 633    the queue.
 634 */
 635
 636 void
 637 add_to_spark_queue(spark)
 638 rtsSpark *spark;
 639 {
 640   rtsSpark *prev = NULL, *next = NULL;
 641   nat count = 0;
 642   rtsBool found = rtsFalse;
 643
 644   if ( spark == (rtsSpark *)NULL ) {
 645     return;
 646   }
 647
 648   if (RtsFlags.GranFlags.DoPrioritySparking && (spark->gran_info != 0) ) {
 649     /* Priority sparking is enabled i.e. spark queues must be sorted */
 650
 651     for (prev = NULL, next = pending_sparks_hd, count=0;
 652          (next != NULL) &&
 653          !(found = (spark->gran_info >= next->gran_info));
 654          prev = next, next = next->next, count++)
 655      {}
 656
 657   } else {   /* 'utQo' */
 658     /* Priority sparking is disabled */
 659
 660     found = rtsFalse;   /* to add it at the end */
 661
 662   }
 663
 664   if (found) {
 665     /* next points to the first spark with a gran_info smaller than that
 666        of spark; therefore, add spark before next into the spark queue */
 667     spark->next = next;
 668     if ( next == NULL ) {
 669       pending_sparks_tl = spark;
 670     } else {
 671       next->prev = spark;
 672     }
 673     spark->prev = prev;
 674     if ( prev == NULL ) {
 675       pending_sparks_hd = spark;
 676     } else {
 677       prev->next = spark;
 678     }
 679   } else {  /* (RtsFlags.GranFlags.DoPrioritySparking && !found) || !DoPrioritySparking */
 680     /* add the spark at the end of the spark queue */
 681     spark->next = NULL;
 682     spark->prev = pending_sparks_tl;
 683     if (pending_sparks_hd == NULL)
 684       pending_sparks_hd = spark;
 685     else
 686       pending_sparks_tl->next = spark;
 687     pending_sparks_tl = spark;
 688   }
 689   ++SparksAvail;
 690
 691   /* add costs for search in priority sparking */
 692   if (RtsFlags.GranFlags.DoPrioritySparking) {
 693     CurrentTime[CurrentProc] += count * RtsFlags.GranFlags.Costs.pri_spark_overhead;
 694   }
 695
 696   IF_GRAN_DEBUG(checkSparkQ,
 697                 debugBelch("++ Spark stats after adding spark %p (node %p) to queue on PE %d",
 698                       spark, spark->node, CurrentProc);
 699                 print_sparkq_stats());
 700
 701 #  if defined(GRAN_CHECK)
 702   if (RtsFlags.GranFlags.Debug.checkSparkQ) {
 703     for (prev = NULL, next =  pending_sparks_hd;
 704          (next != NULL);
 705          prev = next, next = next->next)
 706       {}
 707     if ( (prev!=NULL) && (prev!=pending_sparks_tl) )
 708       debugBelch("SparkQ inconsistency after adding spark %p: (PE %u) pending_sparks_tl (%p) not end of queue (%p)\n",
 709               spark,CurrentProc,
 710               pending_sparks_tl, prev);
 711   }
 712 #  endif
 713
 714 #  if defined(GRAN_CHECK)
 715   /* Check if the sparkq is still sorted. Just for testing, really!  */
 716   if ( RtsFlags.GranFlags.Debug.checkSparkQ &&
 717        RtsFlags.GranFlags.Debug.pri ) {
 718     rtsBool sorted = rtsTrue;
 719     rtsSpark *prev, *next;
 720
 721     if (pending_sparks_hd == NULL ||
 722         pending_sparks_hd->next == NULL ) {
 723       /* just 1 elem => ok */
 724     } else {
 725       for (prev = pending_sparks_hd,
 726            next = pending_sparks_hd->next;
 727            (next != NULL) ;
 728            prev = next, next = next->next) {
 729         sorted = sorted &&
 730                  (prev->gran_info >= next->gran_info);
 731       }
 732     }
 733     if (!sorted) {
 734       debugBelch("ghuH: SPARKQ on PE %d is not sorted:\n",
 735               CurrentProc);
 736       print_sparkq(CurrentProc);
 737     }
 738   }
 739 #  endif
 740 }
 741
 742 nat
 743 spark_queue_len(proc)
 744 PEs proc;
 745 {
 746  rtsSpark *prev, *spark;                     /* prev only for testing !! */
 747  nat len;
 748
 749  for (len = 0, prev = NULL, spark = pending_sparks_hds[proc];
 750       spark != NULL;
 751       len++, prev = spark, spark = spark->next)
 752    {}
 753
 754 #  if defined(GRAN_CHECK)
 755   if ( RtsFlags.GranFlags.Debug.checkSparkQ )
 756     if ( (prev!=NULL) && (prev!=pending_sparks_tls[proc]) )
 757       debugBelch("ERROR in spark_queue_len: (PE %u) pending_sparks_tl (%p) not end of queue (%p)\n",
 758               proc, pending_sparks_tls[proc], prev);
 759 #  endif
 760
 761  return (len);
 762 }
 763
 764 /*
 765    Take spark out of the spark queue on PE p and nuke the spark. Adjusts
 766    hd and tl pointers of the spark queue. Returns a pointer to the next
 767    spark in the queue.
 768 */
 769 rtsSpark *
 770 delete_from_sparkq (spark, p, dispose_too)     /* unlink and dispose spark */
 771 rtsSpark *spark;
 772 PEs p;
 773 rtsBool dispose_too;
 774 {
 775   rtsSpark *new_spark;
 776
 777   if (spark==NULL)
 778     barf("delete_from_sparkq: trying to delete NULL spark\n");
 779
 780 #  if defined(GRAN_CHECK)
 781   if ( RtsFlags.GranFlags.Debug.checkSparkQ ) {
 782     debugBelch("## |%p:%p| (%p)<-spark=%p->(%p) <-(%p)\n",
 783             pending_sparks_hd, pending_sparks_tl,
 784             spark->prev, spark, spark->next,
 785             (spark->next==NULL ? 0 : spark->next->prev));
 786   }
 787 #  endif
 788
 789   if (spark->prev==NULL) {
 790     /* spark is first spark of queue => adjust hd pointer */
 791     ASSERT(pending_sparks_hds[p]==spark);
 792     pending_sparks_hds[p] = spark->next;
 793   } else {
 794     spark->prev->next = spark->next;
 795   }
 796   if (spark->next==NULL) {
 797     ASSERT(pending_sparks_tls[p]==spark);
 798     /* spark is first spark of queue => adjust tl pointer */
 799     pending_sparks_tls[p] = spark->prev;
 800   } else {
 801     spark->next->prev = spark->prev;
 802   }
 803   new_spark = spark->next;
 804
 805 #  if defined(GRAN_CHECK)
 806   if ( RtsFlags.GranFlags.Debug.checkSparkQ ) {
 807     debugBelch("## |%p:%p| (%p)<-spark=%p->(%p) <-(%p); spark=%p will be deleted NOW \n",
 808             pending_sparks_hd, pending_sparks_tl,
 809             spark->prev, spark, spark->next,
 810             (spark->next==NULL ? 0 : spark->next->prev), spark);
 811   }
 812 #  endif
 813
 814   if (dispose_too)
 815     disposeSpark(spark);
 816
 817   return new_spark;
 818 }
 819
 820 /* Mark all nodes pointed to by sparks in the spark queues (for GC) */
 821 void
 822 markSparkQueue(void)
 823 {
 824   StgClosure *MarkRoot(StgClosure *root); // prototype
 825   PEs p;
 826   rtsSpark *sp;
 827
 828   for (p=0; p<RtsFlags.GranFlags.proc; p++)
 829     for (sp=pending_sparks_hds[p]; sp!=NULL; sp=sp->next) {
 830       ASSERT(sp->node!=NULL);
 831       ASSERT(LOOKS_LIKE_GHC_INFO(sp->node->header.info));
 832       // ToDo?: statistics gathering here (also for GUM!)
 833       sp->node = (StgClosure *)MarkRoot(sp->node);
 834     }
 835
 836   IF_DEBUG(gc,
 837            debugBelch("markSparkQueue: spark statistics at start of GC:");
 838            print_sparkq_stats());
 839 }
 840
 841 void
 842 print_spark(spark)
 843 rtsSpark *spark;
 844 {
 845   char str[16];
 846
 847   if (spark==NULL) {
 848     debugBelch("Spark: NIL\n");
 849     return;
 850   } else {
 851     sprintf(str,
 852             ((spark->node==NULL) ? "______" : "%#6lx"),
 853             stgCast(StgPtr,spark->node));
 854
 855     debugBelch("Spark: Node %8s, Name %#6x, Global %5s, Creator %5x, Prev %6p, Next %6p\n",
 856             str, spark->name,
 857             ((spark->global)==rtsTrue?"True":"False"), spark->creator,
 858             spark->prev, spark->next);
 859   }
 860 }
 861
 862 void
 863 print_sparkq(proc)
 864 PEs proc;
 865 // rtsSpark *hd;
 866 {
 867   rtsSpark *x = pending_sparks_hds[proc];
 868
 869   debugBelch("Spark Queue of PE %d with root at %p:\n", proc, x);
 870   for (; x!=(rtsSpark*)NULL; x=x->next) {
 871     print_spark(x);
 872   }
 873 }
 874
 875 /*
 876    Print a statistics of all spark queues.
 877 */
 878 void
 879 print_sparkq_stats(void)
 880 {
 881   PEs p;
 882
 883   debugBelch("SparkQs: [");
 884   for (p=0; p<RtsFlags.GranFlags.proc; p++)
 885     debugBelch(", PE %d: %d", p, spark_queue_len(p));
 886   debugBelch("\n");
 887 }
 888
 889 #endif