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"
29 #include "Profiling.h"
31 #include "BlockAlloc.h"
36 Note: what to change in order to plug-in a new retainer profiling scheme?
37 (1) type retainer in ../includes/StgRetainerProf.h
38 (2) retainer function R(), i.e., getRetainerFrom()
39 (3) the two hashing functions, hashKeySingleton() and hashKeyAddElement(),
40 in RetainerSet.h, if needed.
41 (4) printRetainer() and printRetainerSetShort() in RetainerSet.c.
44 /* -----------------------------------------------------------------------------
46 * -------------------------------------------------------------------------- */
48 static nat retainerGeneration; // generation
50 static nat numObjectVisited; // total number of objects visited
51 static nat timesAnyObjectVisited; // number of times any objects are visited
54 The rs field in the profile header of any object points to its retainer
55 set in an indirect way: if flip is 0, it points to the retainer set;
56 if flip is 1, it points to the next byte after the retainer set (even
57 for NULL pointers). Therefore, with flip 1, (rs ^ 1) is the actual
58 pointer. See retainerSetOf().
61 StgWord flip = 0; // flip bit
62 // must be 0 if DEBUG_RETAINER is on (for static closures)
64 #define setRetainerSetToNull(c) \
65 (c)->header.prof.hp.rs = (RetainerSet *)((StgWord)NULL | flip)
67 static void retainStack(StgClosure *, retainer, StgPtr, StgPtr);
68 static void retainClosure(StgClosure *, StgClosure *, retainer);
70 static void belongToHeap(StgPtr p);
75 cStackSize records how many times retainStack() has been invoked recursively,
76 that is, the number of activation records for retainStack() on the C stack.
77 maxCStackSize records its max value.
79 cStackSize <= maxCStackSize
81 static nat cStackSize, maxCStackSize;
83 static nat sumOfNewCost; // sum of the cost of each object, computed
84 // when the object is first visited
85 static nat sumOfNewCostExtra; // for those objects not visited during
86 // retainer profiling, e.g., MUT_VAR
87 static nat costArray[N_CLOSURE_TYPES];
89 nat sumOfCostLinear; // sum of the costs of all object, computed
90 // when linearly traversing the heap after
92 nat costArrayLinear[N_CLOSURE_TYPES];
95 /* -----------------------------------------------------------------------------
96 * Retainer stack - header
98 * Although the retainer stack implementation could be separated *
99 * from the retainer profiling engine, there does not seem to be
100 * any advantage in doing that; retainer stack is an integral part
101 * of retainer profiling engine and cannot be use elsewhere at
103 * -------------------------------------------------------------------------- */
113 // fixed layout or layout specified by a field in the closure
118 // See StgClosureInfo in InfoTables.h
119 #if SIZEOF_VOID_P == 8
156 firstStack points to the first block group.
157 currentStack points to the block group currently being used.
158 currentStack->free == stackLimit.
159 stackTop points to the topmost byte in the stack of currentStack.
160 Unless the whole stack is empty, stackTop must point to the topmost
161 object (or byte) in the whole stack. Thus, it is only when the whole stack
162 is empty that stackTop == stackLimit (not during the execution of push()
164 stackBottom == currentStack->start.
165 stackLimit == currentStack->start + BLOCK_SIZE_W * currentStack->blocks.
167 When a current stack becomes empty, stackTop is set to point to
168 the topmost element on the previous block group so as to satisfy
169 the invariants described above.
171 static bdescr *firstStack = NULL;
172 static bdescr *currentStack;
173 static stackElement *stackBottom, *stackTop, *stackLimit;
176 currentStackBoundary is used to mark the current stack chunk.
177 If stackTop == currentStackBoundary, it means that the current stack chunk
178 is empty. It is the responsibility of the user to keep currentStackBoundary
179 valid all the time if it is to be employed.
181 static stackElement *currentStackBoundary;
184 stackSize records the current size of the stack.
185 maxStackSize records its high water mark.
187 stackSize <= maxStackSize
189 stackSize is just an estimate measure of the depth of the graph. The reason
190 is that some heap objects have only a single child and may not result
191 in a new element being pushed onto the stack. Therefore, at the end of
192 retainer profiling, maxStackSize + maxCStackSize is some value no greater
193 than the actual depth of the graph.
195 #ifdef DEBUG_RETAINER
196 static int stackSize, maxStackSize;
199 // number of blocks allocated for one stack
200 #define BLOCKS_IN_STACK 1
202 /* -----------------------------------------------------------------------------
203 * Add a new block group to the stack.
205 * currentStack->link == s.
206 * -------------------------------------------------------------------------- */
208 newStackBlock( bdescr *bd )
211 stackTop = (stackElement *)(bd->start + BLOCK_SIZE_W * bd->blocks);
212 stackBottom = (stackElement *)bd->start;
213 stackLimit = (stackElement *)stackTop;
214 bd->free = (StgPtr)stackLimit;
217 /* -----------------------------------------------------------------------------
218 * Return to the previous block group.
220 * s->link == currentStack.
221 * -------------------------------------------------------------------------- */
223 returnToOldStack( bdescr *bd )
226 stackTop = (stackElement *)bd->free;
227 stackBottom = (stackElement *)bd->start;
228 stackLimit = (stackElement *)(bd->start + BLOCK_SIZE_W * bd->blocks);
229 bd->free = (StgPtr)stackLimit;
232 /* -----------------------------------------------------------------------------
233 * Initializes the traverse stack.
234 * -------------------------------------------------------------------------- */
236 initializeTraverseStack( void )
238 if (firstStack != NULL) {
239 freeChain(firstStack);
242 firstStack = allocGroup(BLOCKS_IN_STACK);
243 firstStack->link = NULL;
244 firstStack->u.back = NULL;
246 newStackBlock(firstStack);
249 /* -----------------------------------------------------------------------------
250 * Frees all the block groups in the traverse stack.
253 * -------------------------------------------------------------------------- */
255 closeTraverseStack( void )
257 freeChain(firstStack);
261 /* -----------------------------------------------------------------------------
262 * Returns rtsTrue if the whole stack is empty.
263 * -------------------------------------------------------------------------- */
264 static INLINE rtsBool
265 isEmptyRetainerStack( void )
267 return (firstStack == currentStack) && stackTop == stackLimit;
270 /* -----------------------------------------------------------------------------
271 * Returns size of stack
272 * -------------------------------------------------------------------------- */
275 retainerStackBlocks( void )
280 for (bd = firstStack; bd != NULL; bd = bd->link)
287 /* -----------------------------------------------------------------------------
288 * Returns rtsTrue if stackTop is at the stack boundary of the current stack,
289 * i.e., if the current stack chunk is empty.
290 * -------------------------------------------------------------------------- */
291 static INLINE rtsBool
294 return stackTop == currentStackBoundary;
297 /* -----------------------------------------------------------------------------
298 * Initializes *info from ptrs and payload.
300 * payload[] begins with ptrs pointers followed by non-pointers.
301 * -------------------------------------------------------------------------- */
303 init_ptrs( stackPos *info, nat ptrs, StgPtr payload )
305 info->type = posTypePtrs;
306 info->next.ptrs.pos = 0;
307 info->next.ptrs.ptrs = ptrs;
308 info->next.ptrs.payload = payload;
311 /* -----------------------------------------------------------------------------
312 * Find the next object from *info.
313 * -------------------------------------------------------------------------- */
314 static INLINE StgClosure *
315 find_ptrs( stackPos *info )
317 if (info->next.ptrs.pos < info->next.ptrs.ptrs) {
318 return (StgClosure *)info->next.ptrs.payload[info->next.ptrs.pos++];
324 /* -----------------------------------------------------------------------------
325 * Initializes *info from SRT information stored in *infoTable.
326 * -------------------------------------------------------------------------- */
328 init_srt_fun( stackPos *info, StgFunInfoTable *infoTable )
330 if (infoTable->i.srt_bitmap == (StgHalfWord)(-1)) {
331 info->type = posTypeLargeSRT;
332 info->next.large_srt.srt = (StgLargeSRT *)GET_FUN_SRT(infoTable);
333 info->next.large_srt.offset = 0;
335 info->type = posTypeSRT;
336 info->next.srt.srt = (StgClosure **)GET_FUN_SRT(infoTable);
337 info->next.srt.srt_bitmap = infoTable->i.srt_bitmap;
342 init_srt_thunk( stackPos *info, StgThunkInfoTable *infoTable )
344 if (infoTable->i.srt_bitmap == (StgHalfWord)(-1)) {
345 info->type = posTypeLargeSRT;
346 info->next.large_srt.srt = (StgLargeSRT *)GET_SRT(infoTable);
347 info->next.large_srt.offset = 0;
349 info->type = posTypeSRT;
350 info->next.srt.srt = (StgClosure **)GET_SRT(infoTable);
351 info->next.srt.srt_bitmap = infoTable->i.srt_bitmap;
355 /* -----------------------------------------------------------------------------
356 * Find the next object from *info.
357 * -------------------------------------------------------------------------- */
358 static INLINE StgClosure *
359 find_srt( stackPos *info )
364 if (info->type == posTypeSRT) {
366 bitmap = info->next.srt.srt_bitmap;
367 while (bitmap != 0) {
368 if ((bitmap & 1) != 0) {
369 #ifdef ENABLE_WIN32_DLL_SUPPORT
371 if ((unsigned long)(*(info->next.srt.srt)) & 0x1)
372 c = (* (StgClosure **)((unsigned long)*(info->next.srt.srt)) & ~0x1);
374 c = *(info->next.srt.srt);
376 c = *(info->next.srt.srt);
378 bitmap = bitmap >> 1;
379 info->next.srt.srt++;
380 info->next.srt.srt_bitmap = bitmap;
383 bitmap = bitmap >> 1;
384 info->next.srt.srt++;
386 // bitmap is now zero...
391 nat i = info->next.large_srt.offset;
394 // Follow the pattern from GC.c:scavenge_large_srt_bitmap().
395 bitmap = info->next.large_srt.srt->l.bitmap[i / BITS_IN(W_)];
396 bitmap = bitmap >> (i % BITS_IN(StgWord));
397 while (i < info->next.large_srt.srt->l.size) {
398 if ((bitmap & 1) != 0) {
399 c = ((StgClosure **)info->next.large_srt.srt->srt)[i];
401 info->next.large_srt.offset = i;
405 if (i % BITS_IN(W_) == 0) {
406 bitmap = info->next.large_srt.srt->l.bitmap[i / BITS_IN(W_)];
408 bitmap = bitmap >> 1;
411 // reached the end of this bitmap.
412 info->next.large_srt.offset = i;
417 /* -----------------------------------------------------------------------------
418 * push() pushes a stackElement representing the next child of *c
419 * onto the traverse stack. If *c has no child, *first_child is set
420 * to NULL and nothing is pushed onto the stack. If *c has only one
421 * child, *c_chlid is set to that child and nothing is pushed onto
422 * the stack. If *c has more than two children, *first_child is set
423 * to the first child and a stackElement representing the second
424 * child is pushed onto the stack.
427 * *c_child_r is the most recent retainer of *c's children.
428 * *c is not any of TSO, AP, PAP, AP_STACK, which means that
429 * there cannot be any stack objects.
430 * Note: SRTs are considered to be children as well.
431 * -------------------------------------------------------------------------- */
433 push( StgClosure *c, retainer c_child_r, StgClosure **first_child )
436 bdescr *nbd; // Next Block Descriptor
438 #ifdef DEBUG_RETAINER
439 // debugBelch("push(): stackTop = 0x%x, currentStackBoundary = 0x%x\n", stackTop, currentStackBoundary);
442 ASSERT(get_itbl(c)->type != TSO);
443 ASSERT(get_itbl(c)->type != AP_STACK);
450 se.c_child_r = c_child_r;
453 switch (get_itbl(c)->type) {
460 case SE_CAF_BLACKHOLE:
465 // one child (fixed), no SRT
468 *first_child = ((StgMutVar *)c)->var;
471 *first_child = ((StgSelector *)c)->selectee;
474 case IND_OLDGEN_PERM:
476 *first_child = ((StgInd *)c)->indirectee;
480 *first_child = c->payload[0];
483 // For CONSTR_2_0 and MVAR, we use se.info.step to record the position
484 // of the next child. We do not write a separate initialization code.
485 // Also we do not have to initialize info.type;
487 // two children (fixed), no SRT
488 // need to push a stackElement, but nothing to store in se.info
490 *first_child = c->payload[0]; // return the first pointer
491 // se.info.type = posTypeStep;
492 // se.info.next.step = 2; // 2 = second
495 // three children (fixed), no SRT
496 // need to push a stackElement
498 // head must be TSO and the head of a linked list of TSOs.
499 // Shoule it be a child? Seems to be yes.
500 *first_child = (StgClosure *)((StgMVar *)c)->head;
501 // se.info.type = posTypeStep;
502 se.info.next.step = 2; // 2 = second
505 // three children (fixed), no SRT
507 *first_child = ((StgWeak *)c)->key;
508 // se.info.type = posTypeStep;
509 se.info.next.step = 2;
512 // layout.payload.ptrs, no SRT
517 init_ptrs(&se.info, get_itbl(c)->layout.payload.ptrs,
519 *first_child = find_ptrs(&se.info);
520 if (*first_child == NULL)
524 // StgMutArrPtr.ptrs, no SRT
525 case MUT_ARR_PTRS_CLEAN:
526 case MUT_ARR_PTRS_DIRTY:
527 case MUT_ARR_PTRS_FROZEN:
528 case MUT_ARR_PTRS_FROZEN0:
529 init_ptrs(&se.info, ((StgMutArrPtrs *)c)->ptrs,
530 (StgPtr)(((StgMutArrPtrs *)c)->payload));
531 *first_child = find_ptrs(&se.info);
532 if (*first_child == NULL)
536 // layout.payload.ptrs, SRT
537 case FUN: // *c is a heap object.
539 init_ptrs(&se.info, get_itbl(c)->layout.payload.ptrs, (StgPtr)c->payload);
540 *first_child = find_ptrs(&se.info);
541 if (*first_child == NULL)
542 // no child from ptrs, so check SRT
548 init_ptrs(&se.info, get_itbl(c)->layout.payload.ptrs,
549 (StgPtr)((StgThunk *)c)->payload);
550 *first_child = find_ptrs(&se.info);
551 if (*first_child == NULL)
552 // no child from ptrs, so check SRT
556 // 1 fixed child, SRT
559 *first_child = c->payload[0];
560 ASSERT(*first_child != NULL);
561 init_srt_fun(&se.info, get_fun_itbl(c));
566 *first_child = ((StgThunk *)c)->payload[0];
567 ASSERT(*first_child != NULL);
568 init_srt_thunk(&se.info, get_thunk_itbl(c));
571 case FUN_STATIC: // *c is a heap object.
572 ASSERT(get_itbl(c)->srt_bitmap != 0);
576 init_srt_fun(&se.info, get_fun_itbl(c));
577 *first_child = find_srt(&se.info);
578 if (*first_child == NULL)
584 ASSERT(get_itbl(c)->srt_bitmap != 0);
588 init_srt_thunk(&se.info, get_thunk_itbl(c));
589 *first_child = find_srt(&se.info);
590 if (*first_child == NULL)
594 case TVAR_WAIT_QUEUE:
595 *first_child = (StgClosure *)((StgTVarWaitQueue *)c)->waiting_tso;
596 se.info.next.step = 2; // 2 = second
599 *first_child = (StgClosure *)((StgTVar *)c)->current_value;
602 *first_child = (StgClosure *)((StgTRecHeader *)c)->enclosing_trec;
605 *first_child = (StgClosure *)((StgTRecChunk *)c)->prev_chunk;
606 se.info.next.step = 0; // entry no.
616 case CONSTR_CHARLIKE:
617 case CONSTR_NOCAF_STATIC:
638 barf("Invalid object *c in push()");
642 if (stackTop - 1 < stackBottom) {
643 #ifdef DEBUG_RETAINER
644 // debugBelch("push() to the next stack.\n");
646 // currentStack->free is updated when the active stack is switched
647 // to the next stack.
648 currentStack->free = (StgPtr)stackTop;
650 if (currentStack->link == NULL) {
651 nbd = allocGroup(BLOCKS_IN_STACK);
653 nbd->u.back = currentStack;
654 currentStack->link = nbd;
656 nbd = currentStack->link;
661 // adjust stackTop (acutal push)
663 // If the size of stackElement was huge, we would better replace the
664 // following statement by either a memcpy() call or a switch statement
665 // on the type of the element. Currently, the size of stackElement is
666 // small enough (5 words) that this direct assignment seems to be enough.
669 #ifdef DEBUG_RETAINER
671 if (stackSize > maxStackSize) maxStackSize = stackSize;
672 // ASSERT(stackSize >= 0);
673 // debugBelch("stackSize = %d\n", stackSize);
677 /* -----------------------------------------------------------------------------
678 * popOff() and popOffReal(): Pop a stackElement off the traverse stack.
680 * stackTop cannot be equal to stackLimit unless the whole stack is
681 * empty, in which case popOff() is not allowed.
683 * You can think of popOffReal() as a part of popOff() which is
684 * executed at the end of popOff() in necessary. Since popOff() is
685 * likely to be executed quite often while popOffReal() is not, we
686 * separate popOffReal() from popOff(), which is declared as an
687 * INLINE function (for the sake of execution speed). popOffReal()
688 * is called only within popOff() and nowhere else.
689 * -------------------------------------------------------------------------- */
693 bdescr *pbd; // Previous Block Descriptor
695 #ifdef DEBUG_RETAINER
696 // debugBelch("pop() to the previous stack.\n");
699 ASSERT(stackTop + 1 == stackLimit);
700 ASSERT(stackBottom == (stackElement *)currentStack->start);
702 if (firstStack == currentStack) {
703 // The stack is completely empty.
705 ASSERT(stackTop == stackLimit);
706 #ifdef DEBUG_RETAINER
708 if (stackSize > maxStackSize) maxStackSize = stackSize;
710 ASSERT(stackSize >= 0);
711 debugBelch("stackSize = %d\n", stackSize);
717 // currentStack->free is updated when the active stack is switched back
718 // to the previous stack.
719 currentStack->free = (StgPtr)stackLimit;
721 // find the previous block descriptor
722 pbd = currentStack->u.back;
725 returnToOldStack(pbd);
727 #ifdef DEBUG_RETAINER
729 if (stackSize > maxStackSize) maxStackSize = stackSize;
731 ASSERT(stackSize >= 0);
732 debugBelch("stackSize = %d\n", stackSize);
739 #ifdef DEBUG_RETAINER
740 // debugBelch("\tpopOff(): stackTop = 0x%x, currentStackBoundary = 0x%x\n", stackTop, currentStackBoundary);
743 ASSERT(stackTop != stackLimit);
744 ASSERT(!isEmptyRetainerStack());
746 // <= (instead of <) is wrong!
747 if (stackTop + 1 < stackLimit) {
749 #ifdef DEBUG_RETAINER
751 if (stackSize > maxStackSize) maxStackSize = stackSize;
753 ASSERT(stackSize >= 0);
754 debugBelch("stackSize = %d\n", stackSize);
763 /* -----------------------------------------------------------------------------
764 * Finds the next object to be considered for retainer profiling and store
766 * Test if the topmost stack element indicates that more objects are left,
767 * and if so, retrieve the first object and store its pointer to *c. Also,
768 * set *cp and *r appropriately, both of which are stored in the stack element.
769 * The topmost stack element then is overwritten so as for it to now denote
771 * If the topmost stack element indicates no more objects are left, pop
772 * off the stack element until either an object can be retrieved or
773 * the current stack chunk becomes empty, indicated by rtsTrue returned by
774 * isOnBoundary(), in which case *c is set to NULL.
776 * It is okay to call this function even when the current stack chunk
778 * -------------------------------------------------------------------------- */
780 pop( StgClosure **c, StgClosure **cp, retainer *r )
784 #ifdef DEBUG_RETAINER
785 // debugBelch("pop(): stackTop = 0x%x, currentStackBoundary = 0x%x\n", stackTop, currentStackBoundary);
789 if (isOnBoundary()) { // if the current stack chunk is depleted
796 switch (get_itbl(se->c)->type) {
797 // two children (fixed), no SRT
798 // nothing in se.info
800 *c = se->c->payload[1];
806 // three children (fixed), no SRT
807 // need to push a stackElement
809 if (se->info.next.step == 2) {
810 *c = (StgClosure *)((StgMVar *)se->c)->tail;
811 se->info.next.step++; // move to the next step
814 *c = ((StgMVar *)se->c)->value;
821 // three children (fixed), no SRT
823 if (se->info.next.step == 2) {
824 *c = ((StgWeak *)se->c)->value;
825 se->info.next.step++;
828 *c = ((StgWeak *)se->c)->finalizer;
835 case TVAR_WAIT_QUEUE:
836 if (se->info.next.step == 2) {
837 *c = (StgClosure *)((StgTVarWaitQueue *)se->c)->next_queue_entry;
838 se->info.next.step++; // move to the next step
841 *c = (StgClosure *)((StgTVarWaitQueue *)se->c)->prev_queue_entry;
849 *c = (StgClosure *)((StgTVar *)se->c)->first_wait_queue_entry;
856 *c = (StgClosure *)((StgTRecHeader *)se->c)->current_chunk;
863 // These are pretty complicated: we have N entries, each
864 // of which contains 3 fields that we want to follow. So
865 // we divide the step counter: the 2 low bits indicate
866 // which field, and the rest of the bits indicate the
867 // entry number (starting from zero).
868 nat entry_no = se->info.next.step >> 2;
869 nat field_no = se->info.next.step & 3;
870 if (entry_no == ((StgTRecChunk *)se->c)->next_entry_idx) {
875 TRecEntry *entry = &((StgTRecChunk *)se->c)->entries[entry_no];
877 *c = (StgClosure *)entry->tvar;
878 } else if (field_no == 1) {
879 *c = entry->expected_value;
881 *c = entry->new_value;
885 se->info.next.step++;
893 // StgMutArrPtr.ptrs, no SRT
894 case MUT_ARR_PTRS_CLEAN:
895 case MUT_ARR_PTRS_DIRTY:
896 case MUT_ARR_PTRS_FROZEN:
897 case MUT_ARR_PTRS_FROZEN0:
898 *c = find_ptrs(&se->info);
907 // layout.payload.ptrs, SRT
908 case FUN: // always a heap object
910 if (se->info.type == posTypePtrs) {
911 *c = find_ptrs(&se->info);
917 init_srt_fun(&se->info, get_fun_itbl(se->c));
923 if (se->info.type == posTypePtrs) {
924 *c = find_ptrs(&se->info);
930 init_srt_thunk(&se->info, get_thunk_itbl(se->c));
946 *c = find_srt(&se->info);
955 // no child (fixed), no SRT
961 case SE_CAF_BLACKHOLE:
963 // one child (fixed), no SRT
968 case IND_OLDGEN_PERM:
978 case CONSTR_CHARLIKE:
979 case CONSTR_NOCAF_STATIC:
1000 barf("Invalid object *c in pop()");
1006 /* -----------------------------------------------------------------------------
1007 * RETAINER PROFILING ENGINE
1008 * -------------------------------------------------------------------------- */
1011 initRetainerProfiling( void )
1013 initializeAllRetainerSet();
1014 retainerGeneration = 0;
1017 /* -----------------------------------------------------------------------------
1018 * This function must be called before f-closing prof_file.
1019 * -------------------------------------------------------------------------- */
1021 endRetainerProfiling( void )
1023 #ifdef SECOND_APPROACH
1024 outputAllRetainerSet(prof_file);
1028 /* -----------------------------------------------------------------------------
1029 * Returns the actual pointer to the retainer set of the closure *c.
1030 * It may adjust RSET(c) subject to flip.
1032 * RSET(c) is initialized to NULL if its current value does not
1035 * Even though this function has side effects, they CAN be ignored because
1036 * subsequent calls to retainerSetOf() always result in the same return value
1037 * and retainerSetOf() is the only way to retrieve retainerSet of a given
1039 * We have to perform an XOR (^) operation each time a closure is examined.
1040 * The reason is that we do not know when a closure is visited last.
1041 * -------------------------------------------------------------------------- */
1043 maybeInitRetainerSet( StgClosure *c )
1045 if (!isRetainerSetFieldValid(c)) {
1046 setRetainerSetToNull(c);
1050 /* -----------------------------------------------------------------------------
1051 * Returns rtsTrue if *c is a retainer.
1052 * -------------------------------------------------------------------------- */
1053 static INLINE rtsBool
1054 isRetainer( StgClosure *c )
1056 switch (get_itbl(c)->type) {
1060 // TSOs MUST be retainers: they constitute the set of roots.
1067 case MUT_ARR_PTRS_CLEAN:
1068 case MUT_ARR_PTRS_DIRTY:
1069 case MUT_ARR_PTRS_FROZEN:
1070 case MUT_ARR_PTRS_FROZEN0:
1072 // thunks are retainers.
1079 case THUNK_SELECTOR:
1083 // Static thunks, or CAFS, are obviously retainers.
1086 // WEAK objects are roots; there is separate code in which traversing
1087 // begins from WEAK objects.
1090 // Since the other mutvar-type things are retainers, seems
1091 // like the right thing to do:
1113 // partial applications
1119 case SE_CAF_BLACKHOLE:
1122 case IND_OLDGEN_PERM:
1132 case TVAR_WAIT_QUEUE:
1140 // IND_STATIC cannot be *c, *cp, *r in the retainer profiling loop.
1142 // CONSTR_INTLIKE, CONSTR_CHARLIKE, and CONSTR_NOCAF_STATIC
1143 // cannot be *c, *cp, *r in the retainer profiling loop.
1144 case CONSTR_INTLIKE:
1145 case CONSTR_CHARLIKE:
1146 case CONSTR_NOCAF_STATIC:
1147 // Stack objects are invalid because they are never treated as
1148 // legal objects during retainer profiling.
1166 case INVALID_OBJECT:
1168 barf("Invalid object in isRetainer(): %d", get_itbl(c)->type);
1173 /* -----------------------------------------------------------------------------
1174 * Returns the retainer function value for the closure *c, i.e., R(*c).
1175 * This function does NOT return the retainer(s) of *c.
1177 * *c must be a retainer.
1179 * Depending on the definition of this function, the maintenance of retainer
1180 * sets can be made easier. If most retainer sets are likely to be created
1181 * again across garbage collections, refreshAllRetainerSet() in
1182 * RetainerSet.c can simply do nothing.
1183 * If this is not the case, we can free all the retainer sets and
1184 * re-initialize the hash table.
1185 * See refreshAllRetainerSet() in RetainerSet.c.
1186 * -------------------------------------------------------------------------- */
1187 static INLINE retainer
1188 getRetainerFrom( StgClosure *c )
1190 ASSERT(isRetainer(c));
1192 #if defined(RETAINER_SCHEME_INFO)
1193 // Retainer scheme 1: retainer = info table
1195 #elif defined(RETAINER_SCHEME_CCS)
1196 // Retainer scheme 2: retainer = cost centre stack
1197 return c->header.prof.ccs;
1198 #elif defined(RETAINER_SCHEME_CC)
1199 // Retainer scheme 3: retainer = cost centre
1200 return c->header.prof.ccs->cc;
1204 /* -----------------------------------------------------------------------------
1205 * Associates the retainer set *s with the closure *c, that is, *s becomes
1206 * the retainer set of *c.
1210 * -------------------------------------------------------------------------- */
1212 associate( StgClosure *c, RetainerSet *s )
1214 // StgWord has the same size as pointers, so the following type
1216 RSET(c) = (RetainerSet *)((StgWord)s | flip);
1219 /* -----------------------------------------------------------------------------
1220 Call retainClosure for each of the closures covered by a large bitmap.
1221 -------------------------------------------------------------------------- */
1224 retain_large_bitmap (StgPtr p, StgLargeBitmap *large_bitmap, nat size,
1225 StgClosure *c, retainer c_child_r)
1231 bitmap = large_bitmap->bitmap[b];
1232 for (i = 0; i < size; ) {
1233 if ((bitmap & 1) == 0) {
1234 retainClosure((StgClosure *)*p, c, c_child_r);
1238 if (i % BITS_IN(W_) == 0) {
1240 bitmap = large_bitmap->bitmap[b];
1242 bitmap = bitmap >> 1;
1247 static INLINE StgPtr
1248 retain_small_bitmap (StgPtr p, nat size, StgWord bitmap,
1249 StgClosure *c, retainer c_child_r)
1252 if ((bitmap & 1) == 0) {
1253 retainClosure((StgClosure *)*p, c, c_child_r);
1256 bitmap = bitmap >> 1;
1262 /* -----------------------------------------------------------------------------
1263 * Call retainClosure for each of the closures in an SRT.
1264 * ------------------------------------------------------------------------- */
1267 retain_large_srt_bitmap (StgLargeSRT *srt, StgClosure *c, retainer c_child_r)
1274 p = (StgClosure **)srt->srt;
1276 bitmap = srt->l.bitmap[b];
1277 for (i = 0; i < size; ) {
1278 if ((bitmap & 1) != 0) {
1279 retainClosure((StgClosure *)*p, c, c_child_r);
1283 if (i % BITS_IN(W_) == 0) {
1285 bitmap = srt->l.bitmap[b];
1287 bitmap = bitmap >> 1;
1293 retainSRT (StgClosure **srt, nat srt_bitmap, StgClosure *c, retainer c_child_r)
1298 bitmap = srt_bitmap;
1301 if (bitmap == (StgHalfWord)(-1)) {
1302 retain_large_srt_bitmap( (StgLargeSRT *)srt, c, c_child_r );
1306 while (bitmap != 0) {
1307 if ((bitmap & 1) != 0) {
1308 #ifdef ENABLE_WIN32_DLL_SUPPORT
1309 if ( (unsigned long)(*srt) & 0x1 ) {
1310 retainClosure(*stgCast(StgClosure**,(stgCast(unsigned long, *srt) & ~0x1)),
1313 retainClosure(*srt,c,c_child_r);
1316 retainClosure(*srt,c,c_child_r);
1320 bitmap = bitmap >> 1;
1324 /* -----------------------------------------------------------------------------
1325 * Process all the objects in the stack chunk from stackStart to stackEnd
1326 * with *c and *c_child_r being their parent and their most recent retainer,
1327 * respectively. Treat stackOptionalFun as another child of *c if it is
1330 * *c is one of the following: TSO, AP_STACK.
1331 * If *c is TSO, c == c_child_r.
1332 * stackStart < stackEnd.
1333 * RSET(c) and RSET(c_child_r) are valid, i.e., their
1334 * interpretation conforms to the current value of flip (even when they
1335 * are interpreted to be NULL).
1336 * If *c is TSO, its state is not any of ThreadRelocated, ThreadComplete,
1337 * or ThreadKilled, which means that its stack is ready to process.
1339 * This code was almost plagiarzied from GC.c! For each pointer,
1340 * retainClosure() is invoked instead of evacuate().
1341 * -------------------------------------------------------------------------- */
1343 retainStack( StgClosure *c, retainer c_child_r,
1344 StgPtr stackStart, StgPtr stackEnd )
1346 stackElement *oldStackBoundary;
1348 StgRetInfoTable *info;
1352 #ifdef DEBUG_RETAINER
1354 if (cStackSize > maxCStackSize) maxCStackSize = cStackSize;
1358 Each invocation of retainStack() creates a new virtual
1359 stack. Since all such stacks share a single common stack, we
1360 record the current currentStackBoundary, which will be restored
1363 oldStackBoundary = currentStackBoundary;
1364 currentStackBoundary = stackTop;
1366 #ifdef DEBUG_RETAINER
1367 // debugBelch("retainStack() called: oldStackBoundary = 0x%x, currentStackBoundary = 0x%x\n", oldStackBoundary, currentStackBoundary);
1370 ASSERT(get_itbl(c)->type != TSO ||
1371 (((StgTSO *)c)->what_next != ThreadRelocated &&
1372 ((StgTSO *)c)->what_next != ThreadComplete &&
1373 ((StgTSO *)c)->what_next != ThreadKilled));
1376 while (p < stackEnd) {
1377 info = get_ret_itbl((StgClosure *)p);
1379 switch(info->i.type) {
1382 retainClosure(((StgUpdateFrame *)p)->updatee, c, c_child_r);
1383 p += sizeofW(StgUpdateFrame);
1388 case CATCH_STM_FRAME:
1389 case CATCH_RETRY_FRAME:
1390 case ATOMICALLY_FRAME:
1393 bitmap = BITMAP_BITS(info->i.layout.bitmap);
1394 size = BITMAP_SIZE(info->i.layout.bitmap);
1396 p = retain_small_bitmap(p, size, bitmap, c, c_child_r);
1399 retainSRT((StgClosure **)GET_SRT(info), info->i.srt_bitmap, c, c_child_r);
1406 retainClosure((StgClosure *)*p, c, c_child_r);
1409 size = BCO_BITMAP_SIZE(bco);
1410 retain_large_bitmap(p, BCO_BITMAP(bco), size, c, c_child_r);
1415 // large bitmap (> 32 entries, or > 64 on a 64-bit machine)
1418 size = GET_LARGE_BITMAP(&info->i)->size;
1420 retain_large_bitmap(p, GET_LARGE_BITMAP(&info->i),
1421 size, c, c_child_r);
1423 // and don't forget to follow the SRT
1426 // Dynamic bitmap: the mask is stored on the stack
1429 dyn = ((StgRetDyn *)p)->liveness;
1431 // traverse the bitmap first
1432 bitmap = RET_DYN_LIVENESS(dyn);
1433 p = (P_)&((StgRetDyn *)p)->payload[0];
1434 size = RET_DYN_BITMAP_SIZE;
1435 p = retain_small_bitmap(p, size, bitmap, c, c_child_r);
1437 // skip over the non-ptr words
1438 p += RET_DYN_NONPTRS(dyn) + RET_DYN_NONPTR_REGS_SIZE;
1440 // follow the ptr words
1441 for (size = RET_DYN_PTRS(dyn); size > 0; size--) {
1442 retainClosure((StgClosure *)*p, c, c_child_r);
1449 StgRetFun *ret_fun = (StgRetFun *)p;
1450 StgFunInfoTable *fun_info;
1452 retainClosure(ret_fun->fun, c, c_child_r);
1453 fun_info = get_fun_itbl(ret_fun->fun);
1455 p = (P_)&ret_fun->payload;
1456 switch (fun_info->f.fun_type) {
1458 bitmap = BITMAP_BITS(fun_info->f.b.bitmap);
1459 size = BITMAP_SIZE(fun_info->f.b.bitmap);
1460 p = retain_small_bitmap(p, size, bitmap, c, c_child_r);
1463 size = GET_FUN_LARGE_BITMAP(fun_info)->size;
1464 retain_large_bitmap(p, GET_FUN_LARGE_BITMAP(fun_info),
1465 size, c, c_child_r);
1469 bitmap = BITMAP_BITS(stg_arg_bitmaps[fun_info->f.fun_type]);
1470 size = BITMAP_SIZE(stg_arg_bitmaps[fun_info->f.fun_type]);
1471 p = retain_small_bitmap(p, size, bitmap, c, c_child_r);
1478 barf("Invalid object found in retainStack(): %d",
1479 (int)(info->i.type));
1483 // restore currentStackBoundary
1484 currentStackBoundary = oldStackBoundary;
1485 #ifdef DEBUG_RETAINER
1486 // debugBelch("retainStack() finished: currentStackBoundary = 0x%x\n", currentStackBoundary);
1489 #ifdef DEBUG_RETAINER
1494 /* ----------------------------------------------------------------------------
1495 * Call retainClosure for each of the children of a PAP/AP
1496 * ------------------------------------------------------------------------- */
1498 static INLINE StgPtr
1499 retain_PAP_payload (StgClosure *pap, retainer c_child_r, StgClosure *fun,
1500 StgClosure** payload, StgWord n_args)
1504 StgFunInfoTable *fun_info;
1506 retainClosure(fun, pap, c_child_r);
1507 fun_info = get_fun_itbl(fun);
1508 ASSERT(fun_info->i.type != PAP);
1510 p = (StgPtr)payload;
1512 switch (fun_info->f.fun_type) {
1514 bitmap = BITMAP_BITS(fun_info->f.b.bitmap);
1515 p = retain_small_bitmap(p, n_args, bitmap,
1519 retain_large_bitmap(p, GET_FUN_LARGE_BITMAP(fun_info),
1520 n_args, pap, c_child_r);
1524 retain_large_bitmap((StgPtr)payload, BCO_BITMAP(fun),
1525 n_args, pap, c_child_r);
1529 bitmap = BITMAP_BITS(stg_arg_bitmaps[fun_info->f.fun_type]);
1530 p = retain_small_bitmap(p, n_args, bitmap, pap, c_child_r);
1536 /* -----------------------------------------------------------------------------
1537 * Compute the retainer set of *c0 and all its desecents by traversing.
1538 * *cp0 is the parent of *c0, and *r0 is the most recent retainer of *c0.
1540 * c0 = cp0 = r0 holds only for root objects.
1541 * RSET(cp0) and RSET(r0) are valid, i.e., their
1542 * interpretation conforms to the current value of flip (even when they
1543 * are interpreted to be NULL).
1544 * However, RSET(c0) may be corrupt, i.e., it may not conform to
1545 * the current value of flip. If it does not, during the execution
1546 * of this function, RSET(c0) must be initialized as well as all
1549 * stackTop must be the same at the beginning and the exit of this function.
1550 * *c0 can be TSO (as well as AP_STACK).
1551 * -------------------------------------------------------------------------- */
1553 retainClosure( StgClosure *c0, StgClosure *cp0, retainer r0 )
1555 // c = Current closure
1556 // cp = Current closure's Parent
1557 // r = current closures' most recent Retainer
1558 // c_child_r = current closure's children's most recent retainer
1559 // first_child = first child of c
1560 StgClosure *c, *cp, *first_child;
1561 RetainerSet *s, *retainerSetOfc;
1562 retainer r, c_child_r;
1565 #ifdef DEBUG_RETAINER
1566 // StgPtr oldStackTop;
1569 #ifdef DEBUG_RETAINER
1570 // oldStackTop = stackTop;
1571 // debugBelch("retainClosure() called: c0 = 0x%x, cp0 = 0x%x, r0 = 0x%x\n", c0, cp0, r0);
1574 // (c, cp, r) = (c0, cp0, r0)
1581 //debugBelch("loop");
1582 // pop to (c, cp, r);
1586 #ifdef DEBUG_RETAINER
1587 // debugBelch("retainClosure() ends: oldStackTop = 0x%x, stackTop = 0x%x\n", oldStackTop, stackTop);
1592 //debugBelch("inner_loop");
1595 // c = current closure under consideration,
1596 // cp = current closure's parent,
1597 // r = current closure's most recent retainer
1599 // Loop invariants (on the meaning of c, cp, r, and their retainer sets):
1600 // RSET(cp) and RSET(r) are valid.
1601 // RSET(c) is valid only if c has been visited before.
1603 // Loop invariants (on the relation between c, cp, and r)
1604 // if cp is not a retainer, r belongs to RSET(cp).
1605 // if cp is a retainer, r == cp.
1607 typeOfc = get_itbl(c)->type;
1609 #ifdef DEBUG_RETAINER
1612 case CONSTR_INTLIKE:
1613 case CONSTR_CHARLIKE:
1614 case CONSTR_NOCAF_STATIC:
1620 if (retainerSetOf(c) == NULL) { // first visit?
1621 costArray[typeOfc] += cost(c);
1622 sumOfNewCost += cost(c);
1631 if (((StgTSO *)c)->what_next == ThreadComplete ||
1632 ((StgTSO *)c)->what_next == ThreadKilled) {
1633 #ifdef DEBUG_RETAINER
1634 debugBelch("ThreadComplete or ThreadKilled encountered in retainClosure()\n");
1638 if (((StgTSO *)c)->what_next == ThreadRelocated) {
1639 #ifdef DEBUG_RETAINER
1640 debugBelch("ThreadRelocated encountered in retainClosure()\n");
1642 c = (StgClosure *)((StgTSO *)c)->link;
1648 // We just skip IND_STATIC, so its retainer set is never computed.
1649 c = ((StgIndStatic *)c)->indirectee;
1651 case CONSTR_INTLIKE:
1652 case CONSTR_CHARLIKE:
1653 // static objects with no pointers out, so goto loop.
1654 case CONSTR_NOCAF_STATIC:
1655 // It is not just enough not to compute the retainer set for *c; it is
1656 // mandatory because CONSTR_NOCAF_STATIC are not reachable from
1657 // scavenged_static_objects, the list from which is assumed to traverse
1658 // all static objects after major garbage collections.
1662 if (get_itbl(c)->srt_bitmap == 0) {
1663 // No need to compute the retainer set; no dynamic objects
1664 // are reachable from *c.
1666 // Static objects: if we traverse all the live closures,
1667 // including static closures, during each heap census then
1668 // we will observe that some static closures appear and
1669 // disappear. eg. a closure may contain a pointer to a
1670 // static function 'f' which is not otherwise reachable
1671 // (it doesn't indirectly point to any CAFs, so it doesn't
1672 // appear in any SRTs), so we would find 'f' during
1673 // traversal. However on the next sweep there may be no
1674 // closures pointing to 'f'.
1676 // We must therefore ignore static closures whose SRT is
1677 // empty, because these are exactly the closures that may
1678 // "appear". A closure with a non-empty SRT, and which is
1679 // still required, will always be reachable.
1681 // But what about CONSTR_STATIC? Surely these may be able
1682 // to appear, and they don't have SRTs, so we can't
1683 // check. So for now, we're calling
1684 // resetStaticObjectForRetainerProfiling() from the
1685 // garbage collector to reset the retainer sets in all the
1686 // reachable static objects.
1693 // The above objects are ignored in computing the average number of times
1694 // an object is visited.
1695 timesAnyObjectVisited++;
1697 // If this is the first visit to c, initialize its retainer set.
1698 maybeInitRetainerSet(c);
1699 retainerSetOfc = retainerSetOf(c);
1702 // isRetainer(cp) == rtsTrue => s == NULL
1703 // isRetainer(cp) == rtsFalse => s == cp.retainer
1707 s = retainerSetOf(cp);
1709 // (c, cp, r, s) is available.
1711 // (c, cp, r, s, R_r) is available, so compute the retainer set for *c.
1712 if (retainerSetOfc == NULL) {
1713 // This is the first visit to *c.
1717 associate(c, singleton(r));
1719 // s is actually the retainer set of *c!
1722 // compute c_child_r
1723 c_child_r = isRetainer(c) ? getRetainerFrom(c) : r;
1725 // This is not the first visit to *c.
1726 if (isMember(r, retainerSetOfc))
1727 goto loop; // no need to process child
1730 associate(c, addElement(r, retainerSetOfc));
1732 // s is not NULL and cp is not a retainer. This means that
1733 // each time *cp is visited, so is *c. Thus, if s has
1734 // exactly one more element in its retainer set than c, s
1735 // is also the new retainer set for *c.
1736 if (s->num == retainerSetOfc->num + 1) {
1739 // Otherwise, just add R_r to the current retainer set of *c.
1741 associate(c, addElement(r, retainerSetOfc));
1746 goto loop; // no need to process child
1748 // compute c_child_r
1752 // now, RSET() of all of *c, *cp, and *r is valid.
1753 // (c, c_child_r) are available.
1757 // Special case closures: we process these all in one go rather
1758 // than attempting to save the current position, because doing so
1762 retainStack(c, c_child_r,
1764 ((StgTSO *)c)->stack + ((StgTSO *)c)->stack_size);
1769 StgPAP *pap = (StgPAP *)c;
1770 retain_PAP_payload(c, c_child_r, pap->fun, pap->payload, pap->n_args);
1776 StgAP *ap = (StgAP *)c;
1777 retain_PAP_payload(c, c_child_r, ap->fun, ap->payload, ap->n_args);
1782 retainClosure(((StgAP_STACK *)c)->fun, c, c_child_r);
1783 retainStack(c, c_child_r,
1784 (StgPtr)((StgAP_STACK *)c)->payload,
1785 (StgPtr)((StgAP_STACK *)c)->payload +
1786 ((StgAP_STACK *)c)->size);
1790 push(c, c_child_r, &first_child);
1792 // If first_child is null, c has no child.
1793 // If first_child is not null, the top stack element points to the next
1794 // object. push() may or may not push a stackElement on the stack.
1795 if (first_child == NULL)
1798 // (c, cp, r) = (first_child, c, c_child_r)
1805 /* -----------------------------------------------------------------------------
1806 * Compute the retainer set for every object reachable from *tl.
1807 * -------------------------------------------------------------------------- */
1809 retainRoot( StgClosure **tl )
1811 // We no longer assume that only TSOs and WEAKs are roots; any closure can
1814 ASSERT(isEmptyRetainerStack());
1815 currentStackBoundary = stackTop;
1817 if (*tl != &stg_END_TSO_QUEUE_closure && isRetainer(*tl)) {
1818 retainClosure(*tl, *tl, getRetainerFrom(*tl));
1820 retainClosure(*tl, *tl, CCS_SYSTEM);
1823 // NOT TRUE: ASSERT(isMember(getRetainerFrom(*tl), retainerSetOf(*tl)));
1824 // *tl might be a TSO which is ThreadComplete, in which
1825 // case we ignore it for the purposes of retainer profiling.
1828 /* -----------------------------------------------------------------------------
1829 * Compute the retainer set for each of the objects in the heap.
1830 * -------------------------------------------------------------------------- */
1832 computeRetainerSet( void )
1839 #ifdef DEBUG_RETAINER
1840 RetainerSet tmpRetainerSet;
1843 GetRoots(retainRoot); // for scheduler roots
1845 // This function is called after a major GC, when key, value, and finalizer
1846 // all are guaranteed to be valid, or reachable.
1848 // The following code assumes that WEAK objects are considered to be roots
1849 // for retainer profilng.
1850 for (weak = weak_ptr_list; weak != NULL; weak = weak->link)
1851 // retainRoot((StgClosure *)weak);
1852 retainRoot((StgClosure **)&weak);
1854 // Consider roots from the stable ptr table.
1855 markStablePtrTable(retainRoot);
1857 // The following code resets the rs field of each unvisited mutable
1858 // object (computing sumOfNewCostExtra and updating costArray[] when
1859 // debugging retainer profiler).
1860 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
1861 // NOT TRUE: even G0 has a block on its mutable list
1862 // ASSERT(g != 0 || (generations[g].mut_list == NULL));
1864 // Traversing through mut_list is necessary
1865 // because we can find MUT_VAR objects which have not been
1866 // visited during retainer profiling.
1867 for (bd = generations[g].mut_list; bd != NULL; bd = bd->link) {
1868 for (ml = bd->start; ml < bd->free; ml++) {
1870 maybeInitRetainerSet((StgClosure *)*ml);
1871 rtl = retainerSetOf((StgClosure *)*ml);
1873 #ifdef DEBUG_RETAINER
1875 // first visit to *ml
1876 // This is a violation of the interface rule!
1877 RSET(ml) = (RetainerSet *)((StgWord)(&tmpRetainerSet) | flip);
1879 switch (get_itbl((StgClosure *)ml)->type) {
1883 case CONSTR_INTLIKE:
1884 case CONSTR_CHARLIKE:
1885 case CONSTR_NOCAF_STATIC:
1889 barf("Invalid object in computeRetainerSet(): %d", get_itbl((StgClosure*)ml)->type);
1893 costArray[get_itbl((StgClosure *)ml)->type] += cost((StgClosure *)ml);
1894 sumOfNewCostExtra += cost((StgClosure *)ml);
1904 /* -----------------------------------------------------------------------------
1905 * Traverse all static objects for which we compute retainer sets,
1906 * and reset their rs fields to NULL, which is accomplished by
1907 * invoking maybeInitRetainerSet(). This function must be called
1908 * before zeroing all objects reachable from scavenged_static_objects
1909 * in the case of major gabage collections. See GarbageCollect() in
1912 * The mut_once_list of the oldest generation must also be traversed?
1913 * Why? Because if the evacuation of an object pointed to by a static
1914 * indirection object fails, it is put back to the mut_once_list of
1915 * the oldest generation.
1916 * However, this is not necessary because any static indirection objects
1917 * are just traversed through to reach dynamic objects. In other words,
1918 * they are not taken into consideration in computing retainer sets.
1919 * -------------------------------------------------------------------------- */
1921 resetStaticObjectForRetainerProfiling( void )
1923 #ifdef DEBUG_RETAINER
1928 #ifdef DEBUG_RETAINER
1931 p = scavenged_static_objects;
1932 while (p != END_OF_STATIC_LIST) {
1933 #ifdef DEBUG_RETAINER
1936 switch (get_itbl(p)->type) {
1938 // Since we do not compute the retainer set of any
1939 // IND_STATIC object, we don't have to reset its retainer
1941 p = (StgClosure*)*IND_STATIC_LINK(p);
1944 maybeInitRetainerSet(p);
1945 p = (StgClosure*)*THUNK_STATIC_LINK(p);
1948 maybeInitRetainerSet(p);
1949 p = (StgClosure*)*FUN_STATIC_LINK(p);
1952 maybeInitRetainerSet(p);
1953 p = (StgClosure*)*STATIC_LINK(get_itbl(p), p);
1956 barf("resetStaticObjectForRetainerProfiling: %p (%s)",
1957 p, get_itbl(p)->type);
1961 #ifdef DEBUG_RETAINER
1962 // debugBelch("count in scavenged_static_objects = %d\n", count);
1966 /* -----------------------------------------------------------------------------
1967 * Perform retainer profiling.
1968 * N is the oldest generation being profilied, where the generations are
1969 * numbered starting at 0.
1972 * This function should be called only immediately after major garbage
1974 * ------------------------------------------------------------------------- */
1976 retainerProfile(void)
1978 #ifdef DEBUG_RETAINER
1980 nat totalHeapSize; // total raw heap size (computed by linear scanning)
1983 #ifdef DEBUG_RETAINER
1984 debugBelch(" < retainerProfile() invoked : %d>\n", retainerGeneration);
1989 // We haven't flipped the bit yet.
1990 #ifdef DEBUG_RETAINER
1991 debugBelch("Before traversing:\n");
1992 sumOfCostLinear = 0;
1993 for (i = 0;i < N_CLOSURE_TYPES; i++)
1994 costArrayLinear[i] = 0;
1995 totalHeapSize = checkHeapSanityForRetainerProfiling();
1997 debugBelch("\tsumOfCostLinear = %d, totalHeapSize = %d\n", sumOfCostLinear, totalHeapSize);
1999 debugBelch("costArrayLinear[] = ");
2000 for (i = 0;i < N_CLOSURE_TYPES; i++)
2001 debugBelch("[%u:%u] ", i, costArrayLinear[i]);
2005 ASSERT(sumOfCostLinear == totalHeapSize);
2008 #define pcostArrayLinear(index) \
2009 if (costArrayLinear[index] > 0) \
2010 debugBelch("costArrayLinear[" #index "] = %u\n", costArrayLinear[index])
2011 pcostArrayLinear(THUNK_STATIC);
2012 pcostArrayLinear(FUN_STATIC);
2013 pcostArrayLinear(CONSTR_STATIC);
2014 pcostArrayLinear(CONSTR_NOCAF_STATIC);
2015 pcostArrayLinear(CONSTR_INTLIKE);
2016 pcostArrayLinear(CONSTR_CHARLIKE);
2020 // Now we flips flip.
2023 #ifdef DEBUG_RETAINER
2029 numObjectVisited = 0;
2030 timesAnyObjectVisited = 0;
2032 #ifdef DEBUG_RETAINER
2033 debugBelch("During traversing:\n");
2035 sumOfNewCostExtra = 0;
2036 for (i = 0;i < N_CLOSURE_TYPES; i++)
2041 We initialize the traverse stack each time the retainer profiling is
2042 performed (because the traverse stack size varies on each retainer profiling
2043 and this operation is not costly anyhow). However, we just refresh the
2046 initializeTraverseStack();
2047 #ifdef DEBUG_RETAINER
2048 initializeAllRetainerSet();
2050 refreshAllRetainerSet();
2052 computeRetainerSet();
2054 #ifdef DEBUG_RETAINER
2055 debugBelch("After traversing:\n");
2056 sumOfCostLinear = 0;
2057 for (i = 0;i < N_CLOSURE_TYPES; i++)
2058 costArrayLinear[i] = 0;
2059 totalHeapSize = checkHeapSanityForRetainerProfiling();
2061 debugBelch("\tsumOfCostLinear = %d, totalHeapSize = %d\n", sumOfCostLinear, totalHeapSize);
2062 ASSERT(sumOfCostLinear == totalHeapSize);
2064 // now, compare the two results
2067 costArray[] must be exactly the same as costArrayLinear[].
2069 1) Dead weak pointers, whose type is CONSTR. These objects are not
2070 reachable from any roots.
2072 debugBelch("Comparison:\n");
2073 debugBelch("\tcostArrayLinear[] (must be empty) = ");
2074 for (i = 0;i < N_CLOSURE_TYPES; i++)
2075 if (costArray[i] != costArrayLinear[i])
2076 // nothing should be printed except MUT_VAR after major GCs
2077 debugBelch("[%u:%u] ", i, costArrayLinear[i]);
2080 debugBelch("\tsumOfNewCost = %u\n", sumOfNewCost);
2081 debugBelch("\tsumOfNewCostExtra = %u\n", sumOfNewCostExtra);
2082 debugBelch("\tcostArray[] (must be empty) = ");
2083 for (i = 0;i < N_CLOSURE_TYPES; i++)
2084 if (costArray[i] != costArrayLinear[i])
2085 // nothing should be printed except MUT_VAR after major GCs
2086 debugBelch("[%u:%u] ", i, costArray[i]);
2089 // only for major garbage collection
2090 ASSERT(sumOfNewCost + sumOfNewCostExtra == sumOfCostLinear);
2094 closeTraverseStack();
2095 #ifdef DEBUG_RETAINER
2096 closeAllRetainerSet();
2098 // Note that there is no post-processing for the retainer sets.
2100 retainerGeneration++;
2103 retainerGeneration - 1, // retainerGeneration has just been incremented!
2104 #ifdef DEBUG_RETAINER
2105 maxCStackSize, maxStackSize,
2107 (double)timesAnyObjectVisited / numObjectVisited);
2110 /* -----------------------------------------------------------------------------
2112 * -------------------------------------------------------------------------- */
2114 #ifdef DEBUG_RETAINER
2116 #define LOOKS_LIKE_PTR(r) ((LOOKS_LIKE_STATIC_CLOSURE(r) || \
2117 ((HEAP_ALLOCED(r) && ((Bdescr((P_)r)->flags & BF_FREE) == 0)))) && \
2118 ((StgWord)(*(StgPtr)r)!=0xaaaaaaaa))
2121 sanityCheckHeapClosure( StgClosure *c )
2125 ASSERT(LOOKS_LIKE_GHC_INFO(c->header.info));
2126 ASSERT(!closure_STATIC(c));
2127 ASSERT(LOOKS_LIKE_PTR(c));
2129 if ((((StgWord)RSET(c) & 1) ^ flip) != 0) {
2130 if (get_itbl(c)->type == CONSTR &&
2131 !strcmp(get_itbl(c)->prof.closure_type, "DEAD_WEAK") &&
2132 !strcmp(get_itbl(c)->prof.closure_desc, "DEAD_WEAK")) {
2133 debugBelch("\tUnvisited dead weak pointer object found: c = %p\n", c);
2134 costArray[get_itbl(c)->type] += cost(c);
2135 sumOfNewCost += cost(c);
2138 "Unvisited object: flip = %d, c = %p(%d, %s, %s), rs = %p\n",
2139 flip, c, get_itbl(c)->type,
2140 get_itbl(c)->prof.closure_type, get_itbl(c)->prof.closure_desc,
2143 // debugBelch("sanityCheckHeapClosure) S: flip = %d, c = %p(%d), rs = %p\n", flip, c, get_itbl(c)->type, RSET(c));
2146 return closure_sizeW(c);
2150 heapCheck( bdescr *bd )
2153 static nat costSum, size;
2156 while (bd != NULL) {
2158 while (p < bd->free) {
2159 size = sanityCheckHeapClosure((StgClosure *)p);
2160 sumOfCostLinear += size;
2161 costArrayLinear[get_itbl((StgClosure *)p)->type] += size;
2163 // no need for slop check; I think slops are not used currently.
2165 ASSERT(p == bd->free);
2166 costSum += bd->free - bd->start;
2174 smallObjectPoolCheck(void)
2178 static nat costSum, size;
2180 bd = small_alloc_list;
2188 while (p < alloc_Hp) {
2189 size = sanityCheckHeapClosure((StgClosure *)p);
2190 sumOfCostLinear += size;
2191 costArrayLinear[get_itbl((StgClosure *)p)->type] += size;
2194 ASSERT(p == alloc_Hp);
2195 costSum += alloc_Hp - bd->start;
2198 while (bd != NULL) {
2200 while (p < bd->free) {
2201 size = sanityCheckHeapClosure((StgClosure *)p);
2202 sumOfCostLinear += size;
2203 costArrayLinear[get_itbl((StgClosure *)p)->type] += size;
2206 ASSERT(p == bd->free);
2207 costSum += bd->free - bd->start;
2215 chainCheck(bdescr *bd)
2220 while (bd != NULL) {
2221 // bd->free - bd->start is not an accurate measurement of the
2222 // object size. Actually it is always zero, so we compute its
2224 size = sanityCheckHeapClosure((StgClosure *)bd->start);
2225 sumOfCostLinear += size;
2226 costArrayLinear[get_itbl((StgClosure *)bd->start)->type] += size;
2235 checkHeapSanityForRetainerProfiling( void )
2240 debugBelch("START: sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2241 if (RtsFlags.GcFlags.generations == 1) {
2242 costSum += heapCheck(g0s0->to_blocks);
2243 debugBelch("heapCheck: sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2244 costSum += chainCheck(g0s0->large_objects);
2245 debugBelch("chainCheck: sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2247 for (g = 0; g < RtsFlags.GcFlags.generations; g++)
2248 for (s = 0; s < generations[g].n_steps; s++) {
2250 After all live objects have been scavenged, the garbage
2251 collector may create some objects in
2252 scheduleFinalizers(). These objects are created throught
2253 allocate(), so the small object pool or the large object
2254 pool of the g0s0 may not be empty.
2256 if (g == 0 && s == 0) {
2257 costSum += smallObjectPoolCheck();
2258 debugBelch("smallObjectPoolCheck(): sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2259 costSum += chainCheck(generations[g].steps[s].large_objects);
2260 debugBelch("chainCheck(): sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2262 costSum += heapCheck(generations[g].steps[s].blocks);
2263 debugBelch("heapCheck(): sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2264 costSum += chainCheck(generations[g].steps[s].large_objects);
2265 debugBelch("chainCheck(): sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2274 findPointer(StgPtr p)
2280 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
2281 for (s = 0; s < generations[g].n_steps; s++) {
2282 // if (g == 0 && s == 0) continue;
2283 bd = generations[g].steps[s].blocks;
2284 for (; bd; bd = bd->link) {
2285 for (q = bd->start; q < bd->free; q++) {
2286 if (*q == (StgWord)p) {
2288 while (!LOOKS_LIKE_GHC_INFO(*r)) r--;
2289 debugBelch("Found in gen[%d], step[%d]: q = %p, r = %p\n", g, s, q, r);
2294 bd = generations[g].steps[s].large_objects;
2295 for (; bd; bd = bd->link) {
2296 e = bd->start + cost((StgClosure *)bd->start);
2297 for (q = bd->start; q < e; q++) {
2298 if (*q == (StgWord)p) {
2300 while (*r == 0 || !LOOKS_LIKE_GHC_INFO(*r)) r--;
2301 debugBelch("Found in gen[%d], large_objects: %p\n", g, r);
2311 belongToHeap(StgPtr p)
2316 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
2317 for (s = 0; s < generations[g].n_steps; s++) {
2318 // if (g == 0 && s == 0) continue;
2319 bd = generations[g].steps[s].blocks;
2320 for (; bd; bd = bd->link) {
2321 if (bd->start <= p && p < bd->free) {
2322 debugBelch("Belongs to gen[%d], step[%d]", g, s);
2326 bd = generations[g].steps[s].large_objects;
2327 for (; bd; bd = bd->link) {
2328 if (bd->start <= p && p < bd->start + getHeapClosureSize((StgClosure *)bd->start)) {
2329 debugBelch("Found in gen[%d], large_objects: %p\n", g, bd->start);
2336 #endif /* DEBUG_RETAINER */
2338 #endif /* PROFILING */