1 /* -----------------------------------------------------------------------------
3 * (c) The GHC Team, 2001
8 * ---------------------------------------------------------------------------*/
12 // Turn off inlining when debugging - it obfuscates things
21 #include "RetainerProfile.h"
22 #include "RetainerSet.h"
28 #include "Profiling.h"
34 Note: what to change in order to plug-in a new retainer profiling scheme?
35 (1) type retainer in ../includes/StgRetainerProf.h
36 (2) retainer function R(), i.e., getRetainerFrom()
37 (3) the two hashing functions, hashKeySingleton() and hashKeyAddElement(),
38 in RetainerSet.h, if needed.
39 (4) printRetainer() and printRetainerSetShort() in RetainerSet.c.
42 /* -----------------------------------------------------------------------------
44 * -------------------------------------------------------------------------- */
46 static nat retainerGeneration; // generation
48 static nat numObjectVisited; // total number of objects visited
49 static nat timesAnyObjectVisited; // number of times any objects are visited
52 The rs field in the profile header of any object points to its retainer
53 set in an indirect way: if flip is 0, it points to the retainer set;
54 if flip is 1, it points to the next byte after the retainer set (even
55 for NULL pointers). Therefore, with flip 1, (rs ^ 1) is the actual
56 pointer. See retainerSetOf().
59 StgWord flip = 0; // flip bit
60 // must be 0 if DEBUG_RETAINER is on (for static closures)
62 #define setRetainerSetToNull(c) \
63 (c)->header.prof.hp.rs = (RetainerSet *)((StgWord)NULL | flip)
65 static void retainStack(StgClosure *, retainer, StgPtr, StgPtr);
66 static void retainClosure(StgClosure *, StgClosure *, retainer);
68 static void belongToHeap(StgPtr p);
73 cStackSize records how many times retainStack() has been invoked recursively,
74 that is, the number of activation records for retainStack() on the C stack.
75 maxCStackSize records its max value.
77 cStackSize <= maxCStackSize
79 static nat cStackSize, maxCStackSize;
81 static nat sumOfNewCost; // sum of the cost of each object, computed
82 // when the object is first visited
83 static nat sumOfNewCostExtra; // for those objects not visited during
84 // retainer profiling, e.g., MUT_VAR
85 static nat costArray[N_CLOSURE_TYPES];
87 nat sumOfCostLinear; // sum of the costs of all object, computed
88 // when linearly traversing the heap after
90 nat costArrayLinear[N_CLOSURE_TYPES];
93 /* -----------------------------------------------------------------------------
94 * Retainer stack - header
96 * Although the retainer stack implementation could be separated *
97 * from the retainer profiling engine, there does not seem to be
98 * any advantage in doing that; retainer stack is an integral part
99 * of retainer profiling engine and cannot be use elsewhere at
101 * -------------------------------------------------------------------------- */
111 // fixed layout or layout specified by a field in the closure
116 // See StgClosureInfo in InfoTables.h
117 #if SIZEOF_VOID_P == 8
154 firstStack points to the first block group.
155 currentStack points to the block group currently being used.
156 currentStack->free == stackLimit.
157 stackTop points to the topmost byte in the stack of currentStack.
158 Unless the whole stack is empty, stackTop must point to the topmost
159 object (or byte) in the whole stack. Thus, it is only when the whole stack
160 is empty that stackTop == stackLimit (not during the execution of push()
162 stackBottom == currentStack->start.
163 stackLimit == currentStack->start + BLOCK_SIZE_W * currentStack->blocks.
165 When a current stack becomes empty, stackTop is set to point to
166 the topmost element on the previous block group so as to satisfy
167 the invariants described above.
169 static bdescr *firstStack = NULL;
170 static bdescr *currentStack;
171 static stackElement *stackBottom, *stackTop, *stackLimit;
174 currentStackBoundary is used to mark the current stack chunk.
175 If stackTop == currentStackBoundary, it means that the current stack chunk
176 is empty. It is the responsibility of the user to keep currentStackBoundary
177 valid all the time if it is to be employed.
179 static stackElement *currentStackBoundary;
182 stackSize records the current size of the stack.
183 maxStackSize records its high water mark.
185 stackSize <= maxStackSize
187 stackSize is just an estimate measure of the depth of the graph. The reason
188 is that some heap objects have only a single child and may not result
189 in a new element being pushed onto the stack. Therefore, at the end of
190 retainer profiling, maxStackSize + maxCStackSize is some value no greater
191 than the actual depth of the graph.
193 #ifdef DEBUG_RETAINER
194 static int stackSize, maxStackSize;
197 // number of blocks allocated for one stack
198 #define BLOCKS_IN_STACK 1
200 /* -----------------------------------------------------------------------------
201 * Add a new block group to the stack.
203 * currentStack->link == s.
204 * -------------------------------------------------------------------------- */
206 newStackBlock( bdescr *bd )
209 stackTop = (stackElement *)(bd->start + BLOCK_SIZE_W * bd->blocks);
210 stackBottom = (stackElement *)bd->start;
211 stackLimit = (stackElement *)stackTop;
212 bd->free = (StgPtr)stackLimit;
215 /* -----------------------------------------------------------------------------
216 * Return to the previous block group.
218 * s->link == currentStack.
219 * -------------------------------------------------------------------------- */
221 returnToOldStack( bdescr *bd )
224 stackTop = (stackElement *)bd->free;
225 stackBottom = (stackElement *)bd->start;
226 stackLimit = (stackElement *)(bd->start + BLOCK_SIZE_W * bd->blocks);
227 bd->free = (StgPtr)stackLimit;
230 /* -----------------------------------------------------------------------------
231 * Initializes the traverse stack.
232 * -------------------------------------------------------------------------- */
234 initializeTraverseStack( void )
236 if (firstStack != NULL) {
237 freeChain(firstStack);
240 firstStack = allocGroup(BLOCKS_IN_STACK);
241 firstStack->link = NULL;
242 firstStack->u.back = NULL;
244 newStackBlock(firstStack);
247 /* -----------------------------------------------------------------------------
248 * Frees all the block groups in the traverse stack.
251 * -------------------------------------------------------------------------- */
253 closeTraverseStack( void )
255 freeChain(firstStack);
259 /* -----------------------------------------------------------------------------
260 * Returns rtsTrue if the whole stack is empty.
261 * -------------------------------------------------------------------------- */
262 static INLINE rtsBool
263 isEmptyRetainerStack( void )
265 return (firstStack == currentStack) && stackTop == stackLimit;
268 /* -----------------------------------------------------------------------------
269 * Returns size of stack
270 * -------------------------------------------------------------------------- */
273 retainerStackBlocks( void )
278 for (bd = firstStack; bd != NULL; bd = bd->link)
285 /* -----------------------------------------------------------------------------
286 * Returns rtsTrue if stackTop is at the stack boundary of the current stack,
287 * i.e., if the current stack chunk is empty.
288 * -------------------------------------------------------------------------- */
289 static INLINE rtsBool
292 return stackTop == currentStackBoundary;
295 /* -----------------------------------------------------------------------------
296 * Initializes *info from ptrs and payload.
298 * payload[] begins with ptrs pointers followed by non-pointers.
299 * -------------------------------------------------------------------------- */
301 init_ptrs( stackPos *info, nat ptrs, StgPtr payload )
303 info->type = posTypePtrs;
304 info->next.ptrs.pos = 0;
305 info->next.ptrs.ptrs = ptrs;
306 info->next.ptrs.payload = payload;
309 /* -----------------------------------------------------------------------------
310 * Find the next object from *info.
311 * -------------------------------------------------------------------------- */
312 static INLINE StgClosure *
313 find_ptrs( stackPos *info )
315 if (info->next.ptrs.pos < info->next.ptrs.ptrs) {
316 return (StgClosure *)info->next.ptrs.payload[info->next.ptrs.pos++];
322 /* -----------------------------------------------------------------------------
323 * Initializes *info from SRT information stored in *infoTable.
324 * -------------------------------------------------------------------------- */
326 init_srt_fun( stackPos *info, StgFunInfoTable *infoTable )
328 if (infoTable->i.srt_bitmap == (StgHalfWord)(-1)) {
329 info->type = posTypeLargeSRT;
330 info->next.large_srt.srt = (StgLargeSRT *)GET_FUN_SRT(infoTable);
331 info->next.large_srt.offset = 0;
333 info->type = posTypeSRT;
334 info->next.srt.srt = (StgClosure **)GET_FUN_SRT(infoTable);
335 info->next.srt.srt_bitmap = infoTable->i.srt_bitmap;
340 init_srt_thunk( stackPos *info, StgThunkInfoTable *infoTable )
342 if (infoTable->i.srt_bitmap == (StgHalfWord)(-1)) {
343 info->type = posTypeLargeSRT;
344 info->next.large_srt.srt = (StgLargeSRT *)GET_SRT(infoTable);
345 info->next.large_srt.offset = 0;
347 info->type = posTypeSRT;
348 info->next.srt.srt = (StgClosure **)GET_SRT(infoTable);
349 info->next.srt.srt_bitmap = infoTable->i.srt_bitmap;
353 /* -----------------------------------------------------------------------------
354 * Find the next object from *info.
355 * -------------------------------------------------------------------------- */
356 static INLINE StgClosure *
357 find_srt( stackPos *info )
362 if (info->type == posTypeSRT) {
364 bitmap = info->next.srt.srt_bitmap;
365 while (bitmap != 0) {
366 if ((bitmap & 1) != 0) {
367 #if defined(__PIC__) && defined(mingw32_TARGET_OS)
368 if ((unsigned long)(*(info->next.srt.srt)) & 0x1)
369 c = (* (StgClosure **)((unsigned long)*(info->next.srt.srt)) & ~0x1);
371 c = *(info->next.srt.srt);
373 c = *(info->next.srt.srt);
375 bitmap = bitmap >> 1;
376 info->next.srt.srt++;
377 info->next.srt.srt_bitmap = bitmap;
380 bitmap = bitmap >> 1;
381 info->next.srt.srt++;
383 // bitmap is now zero...
388 nat i = info->next.large_srt.offset;
391 // Follow the pattern from GC.c:scavenge_large_srt_bitmap().
392 bitmap = info->next.large_srt.srt->l.bitmap[i / BITS_IN(W_)];
393 bitmap = bitmap >> (i % BITS_IN(StgWord));
394 while (i < info->next.large_srt.srt->l.size) {
395 if ((bitmap & 1) != 0) {
396 c = ((StgClosure **)info->next.large_srt.srt->srt)[i];
398 info->next.large_srt.offset = i;
402 if (i % BITS_IN(W_) == 0) {
403 bitmap = info->next.large_srt.srt->l.bitmap[i / BITS_IN(W_)];
405 bitmap = bitmap >> 1;
408 // reached the end of this bitmap.
409 info->next.large_srt.offset = i;
414 /* -----------------------------------------------------------------------------
415 * push() pushes a stackElement representing the next child of *c
416 * onto the traverse stack. If *c has no child, *first_child is set
417 * to NULL and nothing is pushed onto the stack. If *c has only one
418 * child, *c_chlid is set to that child and nothing is pushed onto
419 * the stack. If *c has more than two children, *first_child is set
420 * to the first child and a stackElement representing the second
421 * child is pushed onto the stack.
424 * *c_child_r is the most recent retainer of *c's children.
425 * *c is not any of TSO, AP, PAP, AP_STACK, which means that
426 * there cannot be any stack objects.
427 * Note: SRTs are considered to be children as well.
428 * -------------------------------------------------------------------------- */
430 push( StgClosure *c, retainer c_child_r, StgClosure **first_child )
433 bdescr *nbd; // Next Block Descriptor
435 #ifdef DEBUG_RETAINER
436 // debugBelch("push(): stackTop = 0x%x, currentStackBoundary = 0x%x\n", stackTop, currentStackBoundary);
439 ASSERT(get_itbl(c)->type != TSO);
440 ASSERT(get_itbl(c)->type != AP_STACK);
447 se.c_child_r = c_child_r;
450 switch (get_itbl(c)->type) {
460 // one child (fixed), no SRT
463 *first_child = ((StgMutVar *)c)->var;
466 *first_child = ((StgSelector *)c)->selectee;
469 case IND_OLDGEN_PERM:
471 *first_child = ((StgInd *)c)->indirectee;
475 *first_child = c->payload[0];
478 // For CONSTR_2_0 and MVAR, we use se.info.step to record the position
479 // of the next child. We do not write a separate initialization code.
480 // Also we do not have to initialize info.type;
482 // two children (fixed), no SRT
483 // need to push a stackElement, but nothing to store in se.info
485 *first_child = c->payload[0]; // return the first pointer
486 // se.info.type = posTypeStep;
487 // se.info.next.step = 2; // 2 = second
490 // three children (fixed), no SRT
491 // need to push a stackElement
494 // head must be TSO and the head of a linked list of TSOs.
495 // Shoule it be a child? Seems to be yes.
496 *first_child = (StgClosure *)((StgMVar *)c)->head;
497 // se.info.type = posTypeStep;
498 se.info.next.step = 2; // 2 = second
501 // three children (fixed), no SRT
503 *first_child = ((StgWeak *)c)->key;
504 // se.info.type = posTypeStep;
505 se.info.next.step = 2;
508 // layout.payload.ptrs, no SRT
513 init_ptrs(&se.info, get_itbl(c)->layout.payload.ptrs,
515 *first_child = find_ptrs(&se.info);
516 if (*first_child == NULL)
520 // StgMutArrPtr.ptrs, no SRT
521 case MUT_ARR_PTRS_CLEAN:
522 case MUT_ARR_PTRS_DIRTY:
523 case MUT_ARR_PTRS_FROZEN:
524 case MUT_ARR_PTRS_FROZEN0:
525 init_ptrs(&se.info, ((StgMutArrPtrs *)c)->ptrs,
526 (StgPtr)(((StgMutArrPtrs *)c)->payload));
527 *first_child = find_ptrs(&se.info);
528 if (*first_child == NULL)
532 // layout.payload.ptrs, SRT
533 case FUN: // *c is a heap object.
535 init_ptrs(&se.info, get_itbl(c)->layout.payload.ptrs, (StgPtr)c->payload);
536 *first_child = find_ptrs(&se.info);
537 if (*first_child == NULL)
538 // no child from ptrs, so check SRT
544 init_ptrs(&se.info, get_itbl(c)->layout.payload.ptrs,
545 (StgPtr)((StgThunk *)c)->payload);
546 *first_child = find_ptrs(&se.info);
547 if (*first_child == NULL)
548 // no child from ptrs, so check SRT
552 // 1 fixed child, SRT
555 *first_child = c->payload[0];
556 ASSERT(*first_child != NULL);
557 init_srt_fun(&se.info, get_fun_itbl(c));
562 *first_child = ((StgThunk *)c)->payload[0];
563 ASSERT(*first_child != NULL);
564 init_srt_thunk(&se.info, get_thunk_itbl(c));
567 case FUN_STATIC: // *c is a heap object.
568 ASSERT(get_itbl(c)->srt_bitmap != 0);
572 init_srt_fun(&se.info, get_fun_itbl(c));
573 *first_child = find_srt(&se.info);
574 if (*first_child == NULL)
580 ASSERT(get_itbl(c)->srt_bitmap != 0);
584 init_srt_thunk(&se.info, get_thunk_itbl(c));
585 *first_child = find_srt(&se.info);
586 if (*first_child == NULL)
590 case TVAR_WATCH_QUEUE:
591 *first_child = (StgClosure *)((StgTVarWatchQueue *)c)->closure;
592 se.info.next.step = 2; // 2 = second
595 *first_child = (StgClosure *)((StgTVar *)c)->current_value;
598 *first_child = (StgClosure *)((StgTRecHeader *)c)->enclosing_trec;
601 *first_child = (StgClosure *)((StgTRecChunk *)c)->prev_chunk;
602 se.info.next.step = 0; // entry no.
611 case CONSTR_NOCAF_STATIC:
629 barf("Invalid object *c in push()");
633 if (stackTop - 1 < stackBottom) {
634 #ifdef DEBUG_RETAINER
635 // debugBelch("push() to the next stack.\n");
637 // currentStack->free is updated when the active stack is switched
638 // to the next stack.
639 currentStack->free = (StgPtr)stackTop;
641 if (currentStack->link == NULL) {
642 nbd = allocGroup(BLOCKS_IN_STACK);
644 nbd->u.back = currentStack;
645 currentStack->link = nbd;
647 nbd = currentStack->link;
652 // adjust stackTop (acutal push)
654 // If the size of stackElement was huge, we would better replace the
655 // following statement by either a memcpy() call or a switch statement
656 // on the type of the element. Currently, the size of stackElement is
657 // small enough (5 words) that this direct assignment seems to be enough.
659 // ToDo: The line below leads to the warning:
660 // warning: 'se.info.type' may be used uninitialized in this function
661 // This is caused by the fact that there are execution paths through the
662 // large switch statement above where some cases do not initialize this
663 // field. Is this really harmless? Can we avoid the warning?
666 #ifdef DEBUG_RETAINER
668 if (stackSize > maxStackSize) maxStackSize = stackSize;
669 // ASSERT(stackSize >= 0);
670 // debugBelch("stackSize = %d\n", stackSize);
674 /* -----------------------------------------------------------------------------
675 * popOff() and popOffReal(): Pop a stackElement off the traverse stack.
677 * stackTop cannot be equal to stackLimit unless the whole stack is
678 * empty, in which case popOff() is not allowed.
680 * You can think of popOffReal() as a part of popOff() which is
681 * executed at the end of popOff() in necessary. Since popOff() is
682 * likely to be executed quite often while popOffReal() is not, we
683 * separate popOffReal() from popOff(), which is declared as an
684 * INLINE function (for the sake of execution speed). popOffReal()
685 * is called only within popOff() and nowhere else.
686 * -------------------------------------------------------------------------- */
690 bdescr *pbd; // Previous Block Descriptor
692 #ifdef DEBUG_RETAINER
693 // debugBelch("pop() to the previous stack.\n");
696 ASSERT(stackTop + 1 == stackLimit);
697 ASSERT(stackBottom == (stackElement *)currentStack->start);
699 if (firstStack == currentStack) {
700 // The stack is completely empty.
702 ASSERT(stackTop == stackLimit);
703 #ifdef DEBUG_RETAINER
705 if (stackSize > maxStackSize) maxStackSize = stackSize;
707 ASSERT(stackSize >= 0);
708 debugBelch("stackSize = %d\n", stackSize);
714 // currentStack->free is updated when the active stack is switched back
715 // to the previous stack.
716 currentStack->free = (StgPtr)stackLimit;
718 // find the previous block descriptor
719 pbd = currentStack->u.back;
722 returnToOldStack(pbd);
724 #ifdef DEBUG_RETAINER
726 if (stackSize > maxStackSize) maxStackSize = stackSize;
728 ASSERT(stackSize >= 0);
729 debugBelch("stackSize = %d\n", stackSize);
736 #ifdef DEBUG_RETAINER
737 // debugBelch("\tpopOff(): stackTop = 0x%x, currentStackBoundary = 0x%x\n", stackTop, currentStackBoundary);
740 ASSERT(stackTop != stackLimit);
741 ASSERT(!isEmptyRetainerStack());
743 // <= (instead of <) is wrong!
744 if (stackTop + 1 < stackLimit) {
746 #ifdef DEBUG_RETAINER
748 if (stackSize > maxStackSize) maxStackSize = stackSize;
750 ASSERT(stackSize >= 0);
751 debugBelch("stackSize = %d\n", stackSize);
760 /* -----------------------------------------------------------------------------
761 * Finds the next object to be considered for retainer profiling and store
763 * Test if the topmost stack element indicates that more objects are left,
764 * and if so, retrieve the first object and store its pointer to *c. Also,
765 * set *cp and *r appropriately, both of which are stored in the stack element.
766 * The topmost stack element then is overwritten so as for it to now denote
768 * If the topmost stack element indicates no more objects are left, pop
769 * off the stack element until either an object can be retrieved or
770 * the current stack chunk becomes empty, indicated by rtsTrue returned by
771 * isOnBoundary(), in which case *c is set to NULL.
773 * It is okay to call this function even when the current stack chunk
775 * -------------------------------------------------------------------------- */
777 pop( StgClosure **c, StgClosure **cp, retainer *r )
781 #ifdef DEBUG_RETAINER
782 // debugBelch("pop(): stackTop = 0x%x, currentStackBoundary = 0x%x\n", stackTop, currentStackBoundary);
786 if (isOnBoundary()) { // if the current stack chunk is depleted
793 switch (get_itbl(se->c)->type) {
794 // two children (fixed), no SRT
795 // nothing in se.info
797 *c = se->c->payload[1];
803 // three children (fixed), no SRT
804 // need to push a stackElement
807 if (se->info.next.step == 2) {
808 *c = (StgClosure *)((StgMVar *)se->c)->tail;
809 se->info.next.step++; // move to the next step
812 *c = ((StgMVar *)se->c)->value;
819 // three children (fixed), no SRT
821 if (se->info.next.step == 2) {
822 *c = ((StgWeak *)se->c)->value;
823 se->info.next.step++;
826 *c = ((StgWeak *)se->c)->finalizer;
833 case TVAR_WATCH_QUEUE:
834 if (se->info.next.step == 2) {
835 *c = (StgClosure *)((StgTVarWatchQueue *)se->c)->next_queue_entry;
836 se->info.next.step++; // move to the next step
839 *c = (StgClosure *)((StgTVarWatchQueue *)se->c)->prev_queue_entry;
847 *c = (StgClosure *)((StgTVar *)se->c)->first_watch_queue_entry;
854 *c = (StgClosure *)((StgTRecHeader *)se->c)->current_chunk;
861 // These are pretty complicated: we have N entries, each
862 // of which contains 3 fields that we want to follow. So
863 // we divide the step counter: the 2 low bits indicate
864 // which field, and the rest of the bits indicate the
865 // entry number (starting from zero).
867 nat entry_no = se->info.next.step >> 2;
868 nat field_no = se->info.next.step & 3;
869 if (entry_no == ((StgTRecChunk *)se->c)->next_entry_idx) {
874 entry = &((StgTRecChunk *)se->c)->entries[entry_no];
876 *c = (StgClosure *)entry->tvar;
877 } else if (field_no == 1) {
878 *c = entry->expected_value;
880 *c = entry->new_value;
884 se->info.next.step++;
892 // StgMutArrPtr.ptrs, no SRT
893 case MUT_ARR_PTRS_CLEAN:
894 case MUT_ARR_PTRS_DIRTY:
895 case MUT_ARR_PTRS_FROZEN:
896 case MUT_ARR_PTRS_FROZEN0:
897 *c = find_ptrs(&se->info);
906 // layout.payload.ptrs, SRT
907 case FUN: // always a heap object
909 if (se->info.type == posTypePtrs) {
910 *c = find_ptrs(&se->info);
916 init_srt_fun(&se->info, get_fun_itbl(se->c));
922 if (se->info.type == posTypePtrs) {
923 *c = find_ptrs(&se->info);
929 init_srt_thunk(&se->info, get_thunk_itbl(se->c));
945 *c = find_srt(&se->info);
954 // no child (fixed), no SRT
960 // one child (fixed), no SRT
965 case IND_OLDGEN_PERM:
974 case CONSTR_NOCAF_STATIC:
992 barf("Invalid object *c in pop()");
998 /* -----------------------------------------------------------------------------
999 * RETAINER PROFILING ENGINE
1000 * -------------------------------------------------------------------------- */
1003 initRetainerProfiling( void )
1005 initializeAllRetainerSet();
1006 retainerGeneration = 0;
1009 /* -----------------------------------------------------------------------------
1010 * This function must be called before f-closing prof_file.
1011 * -------------------------------------------------------------------------- */
1013 endRetainerProfiling( void )
1015 #ifdef SECOND_APPROACH
1016 outputAllRetainerSet(prof_file);
1020 /* -----------------------------------------------------------------------------
1021 * Returns the actual pointer to the retainer set of the closure *c.
1022 * It may adjust RSET(c) subject to flip.
1024 * RSET(c) is initialized to NULL if its current value does not
1027 * Even though this function has side effects, they CAN be ignored because
1028 * subsequent calls to retainerSetOf() always result in the same return value
1029 * and retainerSetOf() is the only way to retrieve retainerSet of a given
1031 * We have to perform an XOR (^) operation each time a closure is examined.
1032 * The reason is that we do not know when a closure is visited last.
1033 * -------------------------------------------------------------------------- */
1035 maybeInitRetainerSet( StgClosure *c )
1037 if (!isRetainerSetFieldValid(c)) {
1038 setRetainerSetToNull(c);
1042 /* -----------------------------------------------------------------------------
1043 * Returns rtsTrue if *c is a retainer.
1044 * -------------------------------------------------------------------------- */
1045 static INLINE rtsBool
1046 isRetainer( StgClosure *c )
1048 switch (get_itbl(c)->type) {
1052 // TSOs MUST be retainers: they constitute the set of roots.
1060 case MUT_ARR_PTRS_CLEAN:
1061 case MUT_ARR_PTRS_DIRTY:
1062 case MUT_ARR_PTRS_FROZEN:
1063 case MUT_ARR_PTRS_FROZEN0:
1065 // thunks are retainers.
1072 case THUNK_SELECTOR:
1076 // Static thunks, or CAFS, are obviously retainers.
1079 // WEAK objects are roots; there is separate code in which traversing
1080 // begins from WEAK objects.
1083 // Since the other mutvar-type things are retainers, seems
1084 // like the right thing to do:
1106 // partial applications
1113 case IND_OLDGEN_PERM:
1123 case TVAR_WATCH_QUEUE:
1131 // IND_STATIC cannot be *c, *cp, *r in the retainer profiling loop.
1133 // CONSTR_NOCAF_STATIC
1134 // cannot be *c, *cp, *r in the retainer profiling loop.
1135 case CONSTR_NOCAF_STATIC:
1136 // Stack objects are invalid because they are never treated as
1137 // legal objects during retainer profiling.
1152 case INVALID_OBJECT:
1154 barf("Invalid object in isRetainer(): %d", get_itbl(c)->type);
1159 /* -----------------------------------------------------------------------------
1160 * Returns the retainer function value for the closure *c, i.e., R(*c).
1161 * This function does NOT return the retainer(s) of *c.
1163 * *c must be a retainer.
1165 * Depending on the definition of this function, the maintenance of retainer
1166 * sets can be made easier. If most retainer sets are likely to be created
1167 * again across garbage collections, refreshAllRetainerSet() in
1168 * RetainerSet.c can simply do nothing.
1169 * If this is not the case, we can free all the retainer sets and
1170 * re-initialize the hash table.
1171 * See refreshAllRetainerSet() in RetainerSet.c.
1172 * -------------------------------------------------------------------------- */
1173 static INLINE retainer
1174 getRetainerFrom( StgClosure *c )
1176 ASSERT(isRetainer(c));
1178 #if defined(RETAINER_SCHEME_INFO)
1179 // Retainer scheme 1: retainer = info table
1181 #elif defined(RETAINER_SCHEME_CCS)
1182 // Retainer scheme 2: retainer = cost centre stack
1183 return c->header.prof.ccs;
1184 #elif defined(RETAINER_SCHEME_CC)
1185 // Retainer scheme 3: retainer = cost centre
1186 return c->header.prof.ccs->cc;
1190 /* -----------------------------------------------------------------------------
1191 * Associates the retainer set *s with the closure *c, that is, *s becomes
1192 * the retainer set of *c.
1196 * -------------------------------------------------------------------------- */
1198 associate( StgClosure *c, RetainerSet *s )
1200 // StgWord has the same size as pointers, so the following type
1202 RSET(c) = (RetainerSet *)((StgWord)s | flip);
1205 /* -----------------------------------------------------------------------------
1206 Call retainClosure for each of the closures covered by a large bitmap.
1207 -------------------------------------------------------------------------- */
1210 retain_large_bitmap (StgPtr p, StgLargeBitmap *large_bitmap, nat size,
1211 StgClosure *c, retainer c_child_r)
1217 bitmap = large_bitmap->bitmap[b];
1218 for (i = 0; i < size; ) {
1219 if ((bitmap & 1) == 0) {
1220 retainClosure((StgClosure *)*p, c, c_child_r);
1224 if (i % BITS_IN(W_) == 0) {
1226 bitmap = large_bitmap->bitmap[b];
1228 bitmap = bitmap >> 1;
1233 static INLINE StgPtr
1234 retain_small_bitmap (StgPtr p, nat size, StgWord bitmap,
1235 StgClosure *c, retainer c_child_r)
1238 if ((bitmap & 1) == 0) {
1239 retainClosure((StgClosure *)*p, c, c_child_r);
1242 bitmap = bitmap >> 1;
1248 /* -----------------------------------------------------------------------------
1249 * Call retainClosure for each of the closures in an SRT.
1250 * ------------------------------------------------------------------------- */
1253 retain_large_srt_bitmap (StgLargeSRT *srt, StgClosure *c, retainer c_child_r)
1260 p = (StgClosure **)srt->srt;
1262 bitmap = srt->l.bitmap[b];
1263 for (i = 0; i < size; ) {
1264 if ((bitmap & 1) != 0) {
1265 retainClosure((StgClosure *)*p, c, c_child_r);
1269 if (i % BITS_IN(W_) == 0) {
1271 bitmap = srt->l.bitmap[b];
1273 bitmap = bitmap >> 1;
1279 retainSRT (StgClosure **srt, nat srt_bitmap, StgClosure *c, retainer c_child_r)
1284 bitmap = srt_bitmap;
1287 if (bitmap == (StgHalfWord)(-1)) {
1288 retain_large_srt_bitmap( (StgLargeSRT *)srt, c, c_child_r );
1292 while (bitmap != 0) {
1293 if ((bitmap & 1) != 0) {
1294 #ifdef ENABLE_WIN32_DLL_SUPPORT
1295 if ( (unsigned long)(*srt) & 0x1 ) {
1296 retainClosure(*stgCast(StgClosure**,(stgCast(unsigned long, *srt) & ~0x1)),
1299 retainClosure(*srt,c,c_child_r);
1302 retainClosure(*srt,c,c_child_r);
1306 bitmap = bitmap >> 1;
1310 /* -----------------------------------------------------------------------------
1311 * Process all the objects in the stack chunk from stackStart to stackEnd
1312 * with *c and *c_child_r being their parent and their most recent retainer,
1313 * respectively. Treat stackOptionalFun as another child of *c if it is
1316 * *c is one of the following: TSO, AP_STACK.
1317 * If *c is TSO, c == c_child_r.
1318 * stackStart < stackEnd.
1319 * RSET(c) and RSET(c_child_r) are valid, i.e., their
1320 * interpretation conforms to the current value of flip (even when they
1321 * are interpreted to be NULL).
1322 * If *c is TSO, its state is not any of ThreadRelocated, ThreadComplete,
1323 * or ThreadKilled, which means that its stack is ready to process.
1325 * This code was almost plagiarzied from GC.c! For each pointer,
1326 * retainClosure() is invoked instead of evacuate().
1327 * -------------------------------------------------------------------------- */
1329 retainStack( StgClosure *c, retainer c_child_r,
1330 StgPtr stackStart, StgPtr stackEnd )
1332 stackElement *oldStackBoundary;
1334 StgRetInfoTable *info;
1338 #ifdef DEBUG_RETAINER
1340 if (cStackSize > maxCStackSize) maxCStackSize = cStackSize;
1344 Each invocation of retainStack() creates a new virtual
1345 stack. Since all such stacks share a single common stack, we
1346 record the current currentStackBoundary, which will be restored
1349 oldStackBoundary = currentStackBoundary;
1350 currentStackBoundary = stackTop;
1352 #ifdef DEBUG_RETAINER
1353 // debugBelch("retainStack() called: oldStackBoundary = 0x%x, currentStackBoundary = 0x%x\n", oldStackBoundary, currentStackBoundary);
1356 ASSERT(get_itbl(c)->type != TSO ||
1357 (((StgTSO *)c)->what_next != ThreadRelocated &&
1358 ((StgTSO *)c)->what_next != ThreadComplete &&
1359 ((StgTSO *)c)->what_next != ThreadKilled));
1362 while (p < stackEnd) {
1363 info = get_ret_itbl((StgClosure *)p);
1365 switch(info->i.type) {
1368 retainClosure(((StgUpdateFrame *)p)->updatee, c, c_child_r);
1369 p += sizeofW(StgUpdateFrame);
1374 case CATCH_STM_FRAME:
1375 case CATCH_RETRY_FRAME:
1376 case ATOMICALLY_FRAME:
1378 bitmap = BITMAP_BITS(info->i.layout.bitmap);
1379 size = BITMAP_SIZE(info->i.layout.bitmap);
1381 p = retain_small_bitmap(p, size, bitmap, c, c_child_r);
1384 retainSRT((StgClosure **)GET_SRT(info), info->i.srt_bitmap, c, c_child_r);
1391 retainClosure((StgClosure *)*p, c, c_child_r);
1394 size = BCO_BITMAP_SIZE(bco);
1395 retain_large_bitmap(p, BCO_BITMAP(bco), size, c, c_child_r);
1400 // large bitmap (> 32 entries, or > 64 on a 64-bit machine)
1402 size = GET_LARGE_BITMAP(&info->i)->size;
1404 retain_large_bitmap(p, GET_LARGE_BITMAP(&info->i),
1405 size, c, c_child_r);
1407 // and don't forget to follow the SRT
1410 // Dynamic bitmap: the mask is stored on the stack
1413 dyn = ((StgRetDyn *)p)->liveness;
1415 // traverse the bitmap first
1416 bitmap = RET_DYN_LIVENESS(dyn);
1417 p = (P_)&((StgRetDyn *)p)->payload[0];
1418 size = RET_DYN_BITMAP_SIZE;
1419 p = retain_small_bitmap(p, size, bitmap, c, c_child_r);
1421 // skip over the non-ptr words
1422 p += RET_DYN_NONPTRS(dyn) + RET_DYN_NONPTR_REGS_SIZE;
1424 // follow the ptr words
1425 for (size = RET_DYN_PTRS(dyn); size > 0; size--) {
1426 retainClosure((StgClosure *)*p, c, c_child_r);
1433 StgRetFun *ret_fun = (StgRetFun *)p;
1434 StgFunInfoTable *fun_info;
1436 retainClosure(ret_fun->fun, c, c_child_r);
1437 fun_info = get_fun_itbl(UNTAG_CLOSURE(ret_fun->fun));
1439 p = (P_)&ret_fun->payload;
1440 switch (fun_info->f.fun_type) {
1442 bitmap = BITMAP_BITS(fun_info->f.b.bitmap);
1443 size = BITMAP_SIZE(fun_info->f.b.bitmap);
1444 p = retain_small_bitmap(p, size, bitmap, c, c_child_r);
1447 size = GET_FUN_LARGE_BITMAP(fun_info)->size;
1448 retain_large_bitmap(p, GET_FUN_LARGE_BITMAP(fun_info),
1449 size, c, c_child_r);
1453 bitmap = BITMAP_BITS(stg_arg_bitmaps[fun_info->f.fun_type]);
1454 size = BITMAP_SIZE(stg_arg_bitmaps[fun_info->f.fun_type]);
1455 p = retain_small_bitmap(p, size, bitmap, c, c_child_r);
1462 barf("Invalid object found in retainStack(): %d",
1463 (int)(info->i.type));
1467 // restore currentStackBoundary
1468 currentStackBoundary = oldStackBoundary;
1469 #ifdef DEBUG_RETAINER
1470 // debugBelch("retainStack() finished: currentStackBoundary = 0x%x\n", currentStackBoundary);
1473 #ifdef DEBUG_RETAINER
1478 /* ----------------------------------------------------------------------------
1479 * Call retainClosure for each of the children of a PAP/AP
1480 * ------------------------------------------------------------------------- */
1482 static INLINE StgPtr
1483 retain_PAP_payload (StgClosure *pap, /* NOT tagged */
1484 retainer c_child_r, /* NOT tagged */
1485 StgClosure *fun, /* tagged */
1486 StgClosure** payload, StgWord n_args)
1490 StgFunInfoTable *fun_info;
1492 retainClosure(fun, pap, c_child_r);
1493 fun = UNTAG_CLOSURE(fun);
1494 fun_info = get_fun_itbl(fun);
1495 ASSERT(fun_info->i.type != PAP);
1497 p = (StgPtr)payload;
1499 switch (fun_info->f.fun_type) {
1501 bitmap = BITMAP_BITS(fun_info->f.b.bitmap);
1502 p = retain_small_bitmap(p, n_args, bitmap,
1506 retain_large_bitmap(p, GET_FUN_LARGE_BITMAP(fun_info),
1507 n_args, pap, c_child_r);
1511 retain_large_bitmap((StgPtr)payload, BCO_BITMAP(fun),
1512 n_args, pap, c_child_r);
1516 bitmap = BITMAP_BITS(stg_arg_bitmaps[fun_info->f.fun_type]);
1517 p = retain_small_bitmap(p, n_args, bitmap, pap, c_child_r);
1523 /* -----------------------------------------------------------------------------
1524 * Compute the retainer set of *c0 and all its desecents by traversing.
1525 * *cp0 is the parent of *c0, and *r0 is the most recent retainer of *c0.
1527 * c0 = cp0 = r0 holds only for root objects.
1528 * RSET(cp0) and RSET(r0) are valid, i.e., their
1529 * interpretation conforms to the current value of flip (even when they
1530 * are interpreted to be NULL).
1531 * However, RSET(c0) may be corrupt, i.e., it may not conform to
1532 * the current value of flip. If it does not, during the execution
1533 * of this function, RSET(c0) must be initialized as well as all
1536 * stackTop must be the same at the beginning and the exit of this function.
1537 * *c0 can be TSO (as well as AP_STACK).
1538 * -------------------------------------------------------------------------- */
1540 retainClosure( StgClosure *c0, StgClosure *cp0, retainer r0 )
1542 // c = Current closure (possibly tagged)
1543 // cp = Current closure's Parent (NOT tagged)
1544 // r = current closures' most recent Retainer (NOT tagged)
1545 // c_child_r = current closure's children's most recent retainer
1546 // first_child = first child of c
1547 StgClosure *c, *cp, *first_child;
1548 RetainerSet *s, *retainerSetOfc;
1549 retainer r, c_child_r;
1552 #ifdef DEBUG_RETAINER
1553 // StgPtr oldStackTop;
1556 #ifdef DEBUG_RETAINER
1557 // oldStackTop = stackTop;
1558 // debugBelch("retainClosure() called: c0 = 0x%x, cp0 = 0x%x, r0 = 0x%x\n", c0, cp0, r0);
1561 // (c, cp, r) = (c0, cp0, r0)
1568 //debugBelch("loop");
1569 // pop to (c, cp, r);
1573 #ifdef DEBUG_RETAINER
1574 // debugBelch("retainClosure() ends: oldStackTop = 0x%x, stackTop = 0x%x\n", oldStackTop, stackTop);
1579 //debugBelch("inner_loop");
1582 c = UNTAG_CLOSURE(c);
1584 // c = current closure under consideration,
1585 // cp = current closure's parent,
1586 // r = current closure's most recent retainer
1588 // Loop invariants (on the meaning of c, cp, r, and their retainer sets):
1589 // RSET(cp) and RSET(r) are valid.
1590 // RSET(c) is valid only if c has been visited before.
1592 // Loop invariants (on the relation between c, cp, and r)
1593 // if cp is not a retainer, r belongs to RSET(cp).
1594 // if cp is a retainer, r == cp.
1596 typeOfc = get_itbl(c)->type;
1598 #ifdef DEBUG_RETAINER
1601 case CONSTR_NOCAF_STATIC:
1607 if (retainerSetOf(c) == NULL) { // first visit?
1608 costArray[typeOfc] += cost(c);
1609 sumOfNewCost += cost(c);
1618 if (((StgTSO *)c)->what_next == ThreadComplete ||
1619 ((StgTSO *)c)->what_next == ThreadKilled) {
1620 #ifdef DEBUG_RETAINER
1621 debugBelch("ThreadComplete or ThreadKilled encountered in retainClosure()\n");
1625 if (((StgTSO *)c)->what_next == ThreadRelocated) {
1626 #ifdef DEBUG_RETAINER
1627 debugBelch("ThreadRelocated encountered in retainClosure()\n");
1629 c = (StgClosure *)((StgTSO *)c)->_link;
1635 // We just skip IND_STATIC, so its retainer set is never computed.
1636 c = ((StgIndStatic *)c)->indirectee;
1638 // static objects with no pointers out, so goto loop.
1639 case CONSTR_NOCAF_STATIC:
1640 // It is not just enough not to compute the retainer set for *c; it is
1641 // mandatory because CONSTR_NOCAF_STATIC are not reachable from
1642 // scavenged_static_objects, the list from which is assumed to traverse
1643 // all static objects after major garbage collections.
1647 if (get_itbl(c)->srt_bitmap == 0) {
1648 // No need to compute the retainer set; no dynamic objects
1649 // are reachable from *c.
1651 // Static objects: if we traverse all the live closures,
1652 // including static closures, during each heap census then
1653 // we will observe that some static closures appear and
1654 // disappear. eg. a closure may contain a pointer to a
1655 // static function 'f' which is not otherwise reachable
1656 // (it doesn't indirectly point to any CAFs, so it doesn't
1657 // appear in any SRTs), so we would find 'f' during
1658 // traversal. However on the next sweep there may be no
1659 // closures pointing to 'f'.
1661 // We must therefore ignore static closures whose SRT is
1662 // empty, because these are exactly the closures that may
1663 // "appear". A closure with a non-empty SRT, and which is
1664 // still required, will always be reachable.
1666 // But what about CONSTR_STATIC? Surely these may be able
1667 // to appear, and they don't have SRTs, so we can't
1668 // check. So for now, we're calling
1669 // resetStaticObjectForRetainerProfiling() from the
1670 // garbage collector to reset the retainer sets in all the
1671 // reachable static objects.
1678 // The above objects are ignored in computing the average number of times
1679 // an object is visited.
1680 timesAnyObjectVisited++;
1682 // If this is the first visit to c, initialize its retainer set.
1683 maybeInitRetainerSet(c);
1684 retainerSetOfc = retainerSetOf(c);
1687 // isRetainer(cp) == rtsTrue => s == NULL
1688 // isRetainer(cp) == rtsFalse => s == cp.retainer
1692 s = retainerSetOf(cp);
1694 // (c, cp, r, s) is available.
1696 // (c, cp, r, s, R_r) is available, so compute the retainer set for *c.
1697 if (retainerSetOfc == NULL) {
1698 // This is the first visit to *c.
1702 associate(c, singleton(r));
1704 // s is actually the retainer set of *c!
1707 // compute c_child_r
1708 c_child_r = isRetainer(c) ? getRetainerFrom(c) : r;
1710 // This is not the first visit to *c.
1711 if (isMember(r, retainerSetOfc))
1712 goto loop; // no need to process child
1715 associate(c, addElement(r, retainerSetOfc));
1717 // s is not NULL and cp is not a retainer. This means that
1718 // each time *cp is visited, so is *c. Thus, if s has
1719 // exactly one more element in its retainer set than c, s
1720 // is also the new retainer set for *c.
1721 if (s->num == retainerSetOfc->num + 1) {
1724 // Otherwise, just add R_r to the current retainer set of *c.
1726 associate(c, addElement(r, retainerSetOfc));
1731 goto loop; // no need to process child
1733 // compute c_child_r
1737 // now, RSET() of all of *c, *cp, and *r is valid.
1738 // (c, c_child_r) are available.
1742 // Special case closures: we process these all in one go rather
1743 // than attempting to save the current position, because doing so
1747 retainStack(c, c_child_r,
1749 ((StgTSO *)c)->stack + ((StgTSO *)c)->stack_size);
1754 StgPAP *pap = (StgPAP *)c;
1755 retain_PAP_payload(c, c_child_r, pap->fun, pap->payload, pap->n_args);
1761 StgAP *ap = (StgAP *)c;
1762 retain_PAP_payload(c, c_child_r, ap->fun, ap->payload, ap->n_args);
1767 retainClosure(((StgAP_STACK *)c)->fun, c, c_child_r);
1768 retainStack(c, c_child_r,
1769 (StgPtr)((StgAP_STACK *)c)->payload,
1770 (StgPtr)((StgAP_STACK *)c)->payload +
1771 ((StgAP_STACK *)c)->size);
1775 push(c, c_child_r, &first_child);
1777 // If first_child is null, c has no child.
1778 // If first_child is not null, the top stack element points to the next
1779 // object. push() may or may not push a stackElement on the stack.
1780 if (first_child == NULL)
1783 // (c, cp, r) = (first_child, c, c_child_r)
1790 /* -----------------------------------------------------------------------------
1791 * Compute the retainer set for every object reachable from *tl.
1792 * -------------------------------------------------------------------------- */
1794 retainRoot(void *user STG_UNUSED, StgClosure **tl)
1798 // We no longer assume that only TSOs and WEAKs are roots; any closure can
1801 ASSERT(isEmptyRetainerStack());
1802 currentStackBoundary = stackTop;
1804 c = UNTAG_CLOSURE(*tl);
1805 if (c != &stg_END_TSO_QUEUE_closure && isRetainer(c)) {
1806 retainClosure(c, c, getRetainerFrom(c));
1808 retainClosure(c, c, CCS_SYSTEM);
1811 // NOT TRUE: ASSERT(isMember(getRetainerFrom(*tl), retainerSetOf(*tl)));
1812 // *tl might be a TSO which is ThreadComplete, in which
1813 // case we ignore it for the purposes of retainer profiling.
1816 /* -----------------------------------------------------------------------------
1817 * Compute the retainer set for each of the objects in the heap.
1818 * -------------------------------------------------------------------------- */
1820 computeRetainerSet( void )
1827 #ifdef DEBUG_RETAINER
1828 RetainerSet tmpRetainerSet;
1831 markCapabilities(retainRoot, NULL); // for scheduler roots
1833 // This function is called after a major GC, when key, value, and finalizer
1834 // all are guaranteed to be valid, or reachable.
1836 // The following code assumes that WEAK objects are considered to be roots
1837 // for retainer profilng.
1838 for (weak = weak_ptr_list; weak != NULL; weak = weak->link)
1839 // retainRoot((StgClosure *)weak);
1840 retainRoot(NULL, (StgClosure **)&weak);
1842 // Consider roots from the stable ptr table.
1843 markStablePtrTable(retainRoot, NULL);
1845 // The following code resets the rs field of each unvisited mutable
1846 // object (computing sumOfNewCostExtra and updating costArray[] when
1847 // debugging retainer profiler).
1848 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
1849 // NOT TRUE: even G0 has a block on its mutable list
1850 // ASSERT(g != 0 || (generations[g].mut_list == NULL));
1852 // Traversing through mut_list is necessary
1853 // because we can find MUT_VAR objects which have not been
1854 // visited during retainer profiling.
1855 for (bd = generations[g].mut_list; bd != NULL; bd = bd->link) {
1856 for (ml = bd->start; ml < bd->free; ml++) {
1858 maybeInitRetainerSet((StgClosure *)*ml);
1859 rtl = retainerSetOf((StgClosure *)*ml);
1861 #ifdef DEBUG_RETAINER
1863 // first visit to *ml
1864 // This is a violation of the interface rule!
1865 RSET(ml) = (RetainerSet *)((StgWord)(&tmpRetainerSet) | flip);
1867 switch (get_itbl((StgClosure *)ml)->type) {
1871 case CONSTR_NOCAF_STATIC:
1875 barf("Invalid object in computeRetainerSet(): %d", get_itbl((StgClosure*)ml)->type);
1879 costArray[get_itbl((StgClosure *)ml)->type] += cost((StgClosure *)ml);
1880 sumOfNewCostExtra += cost((StgClosure *)ml);
1890 /* -----------------------------------------------------------------------------
1891 * Traverse all static objects for which we compute retainer sets,
1892 * and reset their rs fields to NULL, which is accomplished by
1893 * invoking maybeInitRetainerSet(). This function must be called
1894 * before zeroing all objects reachable from scavenged_static_objects
1895 * in the case of major gabage collections. See GarbageCollect() in
1898 * The mut_once_list of the oldest generation must also be traversed?
1899 * Why? Because if the evacuation of an object pointed to by a static
1900 * indirection object fails, it is put back to the mut_once_list of
1901 * the oldest generation.
1902 * However, this is not necessary because any static indirection objects
1903 * are just traversed through to reach dynamic objects. In other words,
1904 * they are not taken into consideration in computing retainer sets.
1905 * -------------------------------------------------------------------------- */
1907 resetStaticObjectForRetainerProfiling( StgClosure *static_objects )
1909 #ifdef DEBUG_RETAINER
1914 #ifdef DEBUG_RETAINER
1918 while (p != END_OF_STATIC_LIST) {
1919 #ifdef DEBUG_RETAINER
1922 switch (get_itbl(p)->type) {
1924 // Since we do not compute the retainer set of any
1925 // IND_STATIC object, we don't have to reset its retainer
1927 p = (StgClosure*)*IND_STATIC_LINK(p);
1930 maybeInitRetainerSet(p);
1931 p = (StgClosure*)*THUNK_STATIC_LINK(p);
1934 maybeInitRetainerSet(p);
1935 p = (StgClosure*)*FUN_STATIC_LINK(p);
1938 maybeInitRetainerSet(p);
1939 p = (StgClosure*)*STATIC_LINK(get_itbl(p), p);
1942 barf("resetStaticObjectForRetainerProfiling: %p (%s)",
1943 p, get_itbl(p)->type);
1947 #ifdef DEBUG_RETAINER
1948 // debugBelch("count in scavenged_static_objects = %d\n", count);
1952 /* -----------------------------------------------------------------------------
1953 * Perform retainer profiling.
1954 * N is the oldest generation being profilied, where the generations are
1955 * numbered starting at 0.
1958 * This function should be called only immediately after major garbage
1960 * ------------------------------------------------------------------------- */
1962 retainerProfile(void)
1964 #ifdef DEBUG_RETAINER
1966 nat totalHeapSize; // total raw heap size (computed by linear scanning)
1969 #ifdef DEBUG_RETAINER
1970 debugBelch(" < retainerProfile() invoked : %d>\n", retainerGeneration);
1975 // We haven't flipped the bit yet.
1976 #ifdef DEBUG_RETAINER
1977 debugBelch("Before traversing:\n");
1978 sumOfCostLinear = 0;
1979 for (i = 0;i < N_CLOSURE_TYPES; i++)
1980 costArrayLinear[i] = 0;
1981 totalHeapSize = checkHeapSanityForRetainerProfiling();
1983 debugBelch("\tsumOfCostLinear = %d, totalHeapSize = %d\n", sumOfCostLinear, totalHeapSize);
1985 debugBelch("costArrayLinear[] = ");
1986 for (i = 0;i < N_CLOSURE_TYPES; i++)
1987 debugBelch("[%u:%u] ", i, costArrayLinear[i]);
1991 ASSERT(sumOfCostLinear == totalHeapSize);
1994 #define pcostArrayLinear(index) \
1995 if (costArrayLinear[index] > 0) \
1996 debugBelch("costArrayLinear[" #index "] = %u\n", costArrayLinear[index])
1997 pcostArrayLinear(THUNK_STATIC);
1998 pcostArrayLinear(FUN_STATIC);
1999 pcostArrayLinear(CONSTR_STATIC);
2000 pcostArrayLinear(CONSTR_NOCAF_STATIC);
2004 // Now we flips flip.
2007 #ifdef DEBUG_RETAINER
2013 numObjectVisited = 0;
2014 timesAnyObjectVisited = 0;
2016 #ifdef DEBUG_RETAINER
2017 debugBelch("During traversing:\n");
2019 sumOfNewCostExtra = 0;
2020 for (i = 0;i < N_CLOSURE_TYPES; i++)
2025 We initialize the traverse stack each time the retainer profiling is
2026 performed (because the traverse stack size varies on each retainer profiling
2027 and this operation is not costly anyhow). However, we just refresh the
2030 initializeTraverseStack();
2031 #ifdef DEBUG_RETAINER
2032 initializeAllRetainerSet();
2034 refreshAllRetainerSet();
2036 computeRetainerSet();
2038 #ifdef DEBUG_RETAINER
2039 debugBelch("After traversing:\n");
2040 sumOfCostLinear = 0;
2041 for (i = 0;i < N_CLOSURE_TYPES; i++)
2042 costArrayLinear[i] = 0;
2043 totalHeapSize = checkHeapSanityForRetainerProfiling();
2045 debugBelch("\tsumOfCostLinear = %d, totalHeapSize = %d\n", sumOfCostLinear, totalHeapSize);
2046 ASSERT(sumOfCostLinear == totalHeapSize);
2048 // now, compare the two results
2051 costArray[] must be exactly the same as costArrayLinear[].
2053 1) Dead weak pointers, whose type is CONSTR. These objects are not
2054 reachable from any roots.
2056 debugBelch("Comparison:\n");
2057 debugBelch("\tcostArrayLinear[] (must be empty) = ");
2058 for (i = 0;i < N_CLOSURE_TYPES; i++)
2059 if (costArray[i] != costArrayLinear[i])
2060 // nothing should be printed except MUT_VAR after major GCs
2061 debugBelch("[%u:%u] ", i, costArrayLinear[i]);
2064 debugBelch("\tsumOfNewCost = %u\n", sumOfNewCost);
2065 debugBelch("\tsumOfNewCostExtra = %u\n", sumOfNewCostExtra);
2066 debugBelch("\tcostArray[] (must be empty) = ");
2067 for (i = 0;i < N_CLOSURE_TYPES; i++)
2068 if (costArray[i] != costArrayLinear[i])
2069 // nothing should be printed except MUT_VAR after major GCs
2070 debugBelch("[%u:%u] ", i, costArray[i]);
2073 // only for major garbage collection
2074 ASSERT(sumOfNewCost + sumOfNewCostExtra == sumOfCostLinear);
2078 closeTraverseStack();
2079 #ifdef DEBUG_RETAINER
2080 closeAllRetainerSet();
2082 // Note that there is no post-processing for the retainer sets.
2084 retainerGeneration++;
2087 retainerGeneration - 1, // retainerGeneration has just been incremented!
2088 #ifdef DEBUG_RETAINER
2089 maxCStackSize, maxStackSize,
2091 (double)timesAnyObjectVisited / numObjectVisited);
2094 /* -----------------------------------------------------------------------------
2096 * -------------------------------------------------------------------------- */
2098 #ifdef DEBUG_RETAINER
2100 #define LOOKS_LIKE_PTR(r) ((LOOKS_LIKE_STATIC_CLOSURE(r) || \
2101 ((HEAP_ALLOCED(r) && ((Bdescr((P_)r)->flags & BF_FREE) == 0)))) && \
2102 ((StgWord)(*(StgPtr)r)!=0xaaaaaaaa))
2105 sanityCheckHeapClosure( StgClosure *c )
2109 ASSERT(LOOKS_LIKE_GHC_INFO(c->header.info));
2110 ASSERT(!closure_STATIC(c));
2111 ASSERT(LOOKS_LIKE_PTR(c));
2113 if ((((StgWord)RSET(c) & 1) ^ flip) != 0) {
2114 if (get_itbl(c)->type == CONSTR &&
2115 !strcmp(GET_PROF_TYPE(get_itbl(c)), "DEAD_WEAK") &&
2116 !strcmp(GET_PROF_DESC(get_itbl(c)), "DEAD_WEAK")) {
2117 debugBelch("\tUnvisited dead weak pointer object found: c = %p\n", c);
2118 costArray[get_itbl(c)->type] += cost(c);
2119 sumOfNewCost += cost(c);
2122 "Unvisited object: flip = %d, c = %p(%d, %s, %s), rs = %p\n",
2123 flip, c, get_itbl(c)->type,
2124 get_itbl(c)->prof.closure_type, GET_PROF_DESC(get_itbl(c)),
2127 // debugBelch("sanityCheckHeapClosure) S: flip = %d, c = %p(%d), rs = %p\n", flip, c, get_itbl(c)->type, RSET(c));
2130 return closure_sizeW(c);
2134 heapCheck( bdescr *bd )
2137 static nat costSum, size;
2140 while (bd != NULL) {
2142 while (p < bd->free) {
2143 size = sanityCheckHeapClosure((StgClosure *)p);
2144 sumOfCostLinear += size;
2145 costArrayLinear[get_itbl((StgClosure *)p)->type] += size;
2147 // no need for slop check; I think slops are not used currently.
2149 ASSERT(p == bd->free);
2150 costSum += bd->free - bd->start;
2158 smallObjectPoolCheck(void)
2162 static nat costSum, size;
2172 while (p < alloc_Hp) {
2173 size = sanityCheckHeapClosure((StgClosure *)p);
2174 sumOfCostLinear += size;
2175 costArrayLinear[get_itbl((StgClosure *)p)->type] += size;
2178 ASSERT(p == alloc_Hp);
2179 costSum += alloc_Hp - bd->start;
2182 while (bd != NULL) {
2184 while (p < bd->free) {
2185 size = sanityCheckHeapClosure((StgClosure *)p);
2186 sumOfCostLinear += size;
2187 costArrayLinear[get_itbl((StgClosure *)p)->type] += size;
2190 ASSERT(p == bd->free);
2191 costSum += bd->free - bd->start;
2199 chainCheck(bdescr *bd)
2204 while (bd != NULL) {
2205 // bd->free - bd->start is not an accurate measurement of the
2206 // object size. Actually it is always zero, so we compute its
2208 size = sanityCheckHeapClosure((StgClosure *)bd->start);
2209 sumOfCostLinear += size;
2210 costArrayLinear[get_itbl((StgClosure *)bd->start)->type] += size;
2219 checkHeapSanityForRetainerProfiling( void )
2224 debugBelch("START: sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2225 if (RtsFlags.GcFlags.generations == 1) {
2226 costSum += heapCheck(g0s0->to_blocks);
2227 debugBelch("heapCheck: sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2228 costSum += chainCheck(g0s0->large_objects);
2229 debugBelch("chainCheck: sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2231 for (g = 0; g < RtsFlags.GcFlags.generations; g++)
2232 for (s = 0; s < generations[g].n_steps; s++) {
2234 After all live objects have been scavenged, the garbage
2235 collector may create some objects in
2236 scheduleFinalizers(). These objects are created throught
2237 allocate(), so the small object pool or the large object
2238 pool of the g0s0 may not be empty.
2240 if (g == 0 && s == 0) {
2241 costSum += smallObjectPoolCheck();
2242 debugBelch("smallObjectPoolCheck(): sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2243 costSum += chainCheck(generations[g].steps[s].large_objects);
2244 debugBelch("chainCheck(): sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2246 costSum += heapCheck(generations[g].steps[s].blocks);
2247 debugBelch("heapCheck(): sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2248 costSum += chainCheck(generations[g].steps[s].large_objects);
2249 debugBelch("chainCheck(): sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2258 findPointer(StgPtr p)
2264 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
2265 for (s = 0; s < generations[g].n_steps; s++) {
2266 // if (g == 0 && s == 0) continue;
2267 bd = generations[g].steps[s].blocks;
2268 for (; bd; bd = bd->link) {
2269 for (q = bd->start; q < bd->free; q++) {
2270 if (*q == (StgWord)p) {
2272 while (!LOOKS_LIKE_GHC_INFO(*r)) r--;
2273 debugBelch("Found in gen[%d], step[%d]: q = %p, r = %p\n", g, s, q, r);
2278 bd = generations[g].steps[s].large_objects;
2279 for (; bd; bd = bd->link) {
2280 e = bd->start + cost((StgClosure *)bd->start);
2281 for (q = bd->start; q < e; q++) {
2282 if (*q == (StgWord)p) {
2284 while (*r == 0 || !LOOKS_LIKE_GHC_INFO(*r)) r--;
2285 debugBelch("Found in gen[%d], large_objects: %p\n", g, r);
2295 belongToHeap(StgPtr p)
2300 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
2301 for (s = 0; s < generations[g].n_steps; s++) {
2302 // if (g == 0 && s == 0) continue;
2303 bd = generations[g].steps[s].blocks;
2304 for (; bd; bd = bd->link) {
2305 if (bd->start <= p && p < bd->free) {
2306 debugBelch("Belongs to gen[%d], step[%d]", g, s);
2310 bd = generations[g].steps[s].large_objects;
2311 for (; bd; bd = bd->link) {
2312 if (bd->start <= p && p < bd->start + getHeapClosureSize((StgClosure *)bd->start)) {
2313 debugBelch("Found in gen[%d], large_objects: %p\n", g, bd->start);
2320 #endif /* DEBUG_RETAINER */
2322 #endif /* PROFILING */