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)
601 case CONSTR_CHARLIKE:
602 case CONSTR_NOCAF_STATIC:
623 barf("Invalid object *c in push()");
627 if (stackTop - 1 < stackBottom) {
628 #ifdef DEBUG_RETAINER
629 // debugBelch("push() to the next stack.\n");
631 // currentStack->free is updated when the active stack is switched
632 // to the next stack.
633 currentStack->free = (StgPtr)stackTop;
635 if (currentStack->link == NULL) {
636 nbd = allocGroup(BLOCKS_IN_STACK);
638 nbd->u.back = currentStack;
639 currentStack->link = nbd;
641 nbd = currentStack->link;
646 // adjust stackTop (acutal push)
648 // If the size of stackElement was huge, we would better replace the
649 // following statement by either a memcpy() call or a switch statement
650 // on the type of the element. Currently, the size of stackElement is
651 // small enough (5 words) that this direct assignment seems to be enough.
654 #ifdef DEBUG_RETAINER
656 if (stackSize > maxStackSize) maxStackSize = stackSize;
657 // ASSERT(stackSize >= 0);
658 // debugBelch("stackSize = %d\n", stackSize);
662 /* -----------------------------------------------------------------------------
663 * popOff() and popOffReal(): Pop a stackElement off the traverse stack.
665 * stackTop cannot be equal to stackLimit unless the whole stack is
666 * empty, in which case popOff() is not allowed.
668 * You can think of popOffReal() as a part of popOff() which is
669 * executed at the end of popOff() in necessary. Since popOff() is
670 * likely to be executed quite often while popOffReal() is not, we
671 * separate popOffReal() from popOff(), which is declared as an
672 * INLINE function (for the sake of execution speed). popOffReal()
673 * is called only within popOff() and nowhere else.
674 * -------------------------------------------------------------------------- */
678 bdescr *pbd; // Previous Block Descriptor
680 #ifdef DEBUG_RETAINER
681 // debugBelch("pop() to the previous stack.\n");
684 ASSERT(stackTop + 1 == stackLimit);
685 ASSERT(stackBottom == (stackElement *)currentStack->start);
687 if (firstStack == currentStack) {
688 // The stack is completely empty.
690 ASSERT(stackTop == stackLimit);
691 #ifdef DEBUG_RETAINER
693 if (stackSize > maxStackSize) maxStackSize = stackSize;
695 ASSERT(stackSize >= 0);
696 debugBelch("stackSize = %d\n", stackSize);
702 // currentStack->free is updated when the active stack is switched back
703 // to the previous stack.
704 currentStack->free = (StgPtr)stackLimit;
706 // find the previous block descriptor
707 pbd = currentStack->u.back;
710 returnToOldStack(pbd);
712 #ifdef DEBUG_RETAINER
714 if (stackSize > maxStackSize) maxStackSize = stackSize;
716 ASSERT(stackSize >= 0);
717 debugBelch("stackSize = %d\n", stackSize);
724 #ifdef DEBUG_RETAINER
725 // debugBelch("\tpopOff(): stackTop = 0x%x, currentStackBoundary = 0x%x\n", stackTop, currentStackBoundary);
728 ASSERT(stackTop != stackLimit);
729 ASSERT(!isEmptyRetainerStack());
731 // <= (instead of <) is wrong!
732 if (stackTop + 1 < stackLimit) {
734 #ifdef DEBUG_RETAINER
736 if (stackSize > maxStackSize) maxStackSize = stackSize;
738 ASSERT(stackSize >= 0);
739 debugBelch("stackSize = %d\n", stackSize);
748 /* -----------------------------------------------------------------------------
749 * Finds the next object to be considered for retainer profiling and store
751 * Test if the topmost stack element indicates that more objects are left,
752 * and if so, retrieve the first object and store its pointer to *c. Also,
753 * set *cp and *r appropriately, both of which are stored in the stack element.
754 * The topmost stack element then is overwritten so as for it to now denote
756 * If the topmost stack element indicates no more objects are left, pop
757 * off the stack element until either an object can be retrieved or
758 * the current stack chunk becomes empty, indicated by rtsTrue returned by
759 * isOnBoundary(), in which case *c is set to NULL.
761 * It is okay to call this function even when the current stack chunk
763 * -------------------------------------------------------------------------- */
765 pop( StgClosure **c, StgClosure **cp, retainer *r )
769 #ifdef DEBUG_RETAINER
770 // debugBelch("pop(): stackTop = 0x%x, currentStackBoundary = 0x%x\n", stackTop, currentStackBoundary);
774 if (isOnBoundary()) { // if the current stack chunk is depleted
781 switch (get_itbl(se->c)->type) {
782 // two children (fixed), no SRT
783 // nothing in se.info
785 *c = se->c->payload[1];
791 // three children (fixed), no SRT
792 // need to push a stackElement
794 if (se->info.next.step == 2) {
795 *c = (StgClosure *)((StgMVar *)se->c)->tail;
796 se->info.next.step++; // move to the next step
799 *c = ((StgMVar *)se->c)->value;
806 // three children (fixed), no SRT
808 if (se->info.next.step == 2) {
809 *c = ((StgWeak *)se->c)->value;
810 se->info.next.step++;
813 *c = ((StgWeak *)se->c)->finalizer;
824 // StgMutArrPtr.ptrs, no SRT
825 case MUT_ARR_PTRS_CLEAN:
826 case MUT_ARR_PTRS_DIRTY:
827 case MUT_ARR_PTRS_FROZEN:
828 case MUT_ARR_PTRS_FROZEN0:
829 *c = find_ptrs(&se->info);
838 // layout.payload.ptrs, SRT
839 case FUN: // always a heap object
841 if (se->info.type == posTypePtrs) {
842 *c = find_ptrs(&se->info);
848 init_srt_fun(&se->info, get_fun_itbl(se->c));
854 if (se->info.type == posTypePtrs) {
855 *c = find_ptrs(&se->info);
861 init_srt_thunk(&se->info, get_thunk_itbl(se->c));
877 *c = find_srt(&se->info);
886 // no child (fixed), no SRT
892 case SE_CAF_BLACKHOLE:
894 // one child (fixed), no SRT
899 case IND_OLDGEN_PERM:
909 case CONSTR_CHARLIKE:
910 case CONSTR_NOCAF_STATIC:
931 barf("Invalid object *c in pop()");
937 /* -----------------------------------------------------------------------------
938 * RETAINER PROFILING ENGINE
939 * -------------------------------------------------------------------------- */
942 initRetainerProfiling( void )
944 initializeAllRetainerSet();
945 retainerGeneration = 0;
948 /* -----------------------------------------------------------------------------
949 * This function must be called before f-closing prof_file.
950 * -------------------------------------------------------------------------- */
952 endRetainerProfiling( void )
954 #ifdef SECOND_APPROACH
955 outputAllRetainerSet(prof_file);
959 /* -----------------------------------------------------------------------------
960 * Returns the actual pointer to the retainer set of the closure *c.
961 * It may adjust RSET(c) subject to flip.
963 * RSET(c) is initialized to NULL if its current value does not
966 * Even though this function has side effects, they CAN be ignored because
967 * subsequent calls to retainerSetOf() always result in the same return value
968 * and retainerSetOf() is the only way to retrieve retainerSet of a given
970 * We have to perform an XOR (^) operation each time a closure is examined.
971 * The reason is that we do not know when a closure is visited last.
972 * -------------------------------------------------------------------------- */
974 maybeInitRetainerSet( StgClosure *c )
976 if (!isRetainerSetFieldValid(c)) {
977 setRetainerSetToNull(c);
981 /* -----------------------------------------------------------------------------
982 * Returns rtsTrue if *c is a retainer.
983 * -------------------------------------------------------------------------- */
984 static INLINE rtsBool
985 isRetainer( StgClosure *c )
987 switch (get_itbl(c)->type) {
991 // TSOs MUST be retainers: they constitute the set of roots.
998 case MUT_ARR_PTRS_CLEAN:
999 case MUT_ARR_PTRS_DIRTY:
1000 case MUT_ARR_PTRS_FROZEN:
1001 case MUT_ARR_PTRS_FROZEN0:
1003 // thunks are retainers.
1010 case THUNK_SELECTOR:
1014 // Static thunks, or CAFS, are obviously retainers.
1017 // WEAK objects are roots; there is separate code in which traversing
1018 // begins from WEAK objects.
1040 // partial applications
1046 case SE_CAF_BLACKHOLE:
1049 case IND_OLDGEN_PERM:
1063 // IND_STATIC cannot be *c, *cp, *r in the retainer profiling loop.
1065 // CONSTR_INTLIKE, CONSTR_CHARLIKE, and CONSTR_NOCAF_STATIC
1066 // cannot be *c, *cp, *r in the retainer profiling loop.
1067 case CONSTR_INTLIKE:
1068 case CONSTR_CHARLIKE:
1069 case CONSTR_NOCAF_STATIC:
1070 // Stack objects are invalid because they are never treated as
1071 // legal objects during retainer profiling.
1089 case INVALID_OBJECT:
1091 barf("Invalid object in isRetainer(): %d", get_itbl(c)->type);
1096 /* -----------------------------------------------------------------------------
1097 * Returns the retainer function value for the closure *c, i.e., R(*c).
1098 * This function does NOT return the retainer(s) of *c.
1100 * *c must be a retainer.
1102 * Depending on the definition of this function, the maintenance of retainer
1103 * sets can be made easier. If most retainer sets are likely to be created
1104 * again across garbage collections, refreshAllRetainerSet() in
1105 * RetainerSet.c can simply do nothing.
1106 * If this is not the case, we can free all the retainer sets and
1107 * re-initialize the hash table.
1108 * See refreshAllRetainerSet() in RetainerSet.c.
1109 * -------------------------------------------------------------------------- */
1110 static INLINE retainer
1111 getRetainerFrom( StgClosure *c )
1113 ASSERT(isRetainer(c));
1115 #if defined(RETAINER_SCHEME_INFO)
1116 // Retainer scheme 1: retainer = info table
1118 #elif defined(RETAINER_SCHEME_CCS)
1119 // Retainer scheme 2: retainer = cost centre stack
1120 return c->header.prof.ccs;
1121 #elif defined(RETAINER_SCHEME_CC)
1122 // Retainer scheme 3: retainer = cost centre
1123 return c->header.prof.ccs->cc;
1127 /* -----------------------------------------------------------------------------
1128 * Associates the retainer set *s with the closure *c, that is, *s becomes
1129 * the retainer set of *c.
1133 * -------------------------------------------------------------------------- */
1135 associate( StgClosure *c, RetainerSet *s )
1137 // StgWord has the same size as pointers, so the following type
1139 RSET(c) = (RetainerSet *)((StgWord)s | flip);
1142 /* -----------------------------------------------------------------------------
1143 Call retainClosure for each of the closures covered by a large bitmap.
1144 -------------------------------------------------------------------------- */
1147 retain_large_bitmap (StgPtr p, StgLargeBitmap *large_bitmap, nat size,
1148 StgClosure *c, retainer c_child_r)
1154 bitmap = large_bitmap->bitmap[b];
1155 for (i = 0; i < size; ) {
1156 if ((bitmap & 1) == 0) {
1157 retainClosure((StgClosure *)*p, c, c_child_r);
1161 if (i % BITS_IN(W_) == 0) {
1163 bitmap = large_bitmap->bitmap[b];
1165 bitmap = bitmap >> 1;
1170 static INLINE StgPtr
1171 retain_small_bitmap (StgPtr p, nat size, StgWord bitmap,
1172 StgClosure *c, retainer c_child_r)
1175 if ((bitmap & 1) == 0) {
1176 retainClosure((StgClosure *)*p, c, c_child_r);
1179 bitmap = bitmap >> 1;
1185 /* -----------------------------------------------------------------------------
1186 * Call retainClosure for each of the closures in an SRT.
1187 * ------------------------------------------------------------------------- */
1190 retain_large_srt_bitmap (StgLargeSRT *srt, StgClosure *c, retainer c_child_r)
1197 p = (StgClosure **)srt->srt;
1199 bitmap = srt->l.bitmap[b];
1200 for (i = 0; i < size; ) {
1201 if ((bitmap & 1) != 0) {
1202 retainClosure((StgClosure *)*p, c, c_child_r);
1206 if (i % BITS_IN(W_) == 0) {
1208 bitmap = srt->l.bitmap[b];
1210 bitmap = bitmap >> 1;
1216 retainSRT (StgClosure **srt, nat srt_bitmap, StgClosure *c, retainer c_child_r)
1221 bitmap = srt_bitmap;
1224 if (bitmap == (StgHalfWord)(-1)) {
1225 retain_large_srt_bitmap( (StgLargeSRT *)srt, c, c_child_r );
1229 while (bitmap != 0) {
1230 if ((bitmap & 1) != 0) {
1231 #ifdef ENABLE_WIN32_DLL_SUPPORT
1232 if ( (unsigned long)(*srt) & 0x1 ) {
1233 retainClosure(*stgCast(StgClosure**,(stgCast(unsigned long, *srt) & ~0x1)),
1236 retainClosure(*srt,c,c_child_r);
1239 retainClosure(*srt,c,c_child_r);
1243 bitmap = bitmap >> 1;
1247 /* -----------------------------------------------------------------------------
1248 * Process all the objects in the stack chunk from stackStart to stackEnd
1249 * with *c and *c_child_r being their parent and their most recent retainer,
1250 * respectively. Treat stackOptionalFun as another child of *c if it is
1253 * *c is one of the following: TSO, AP_STACK.
1254 * If *c is TSO, c == c_child_r.
1255 * stackStart < stackEnd.
1256 * RSET(c) and RSET(c_child_r) are valid, i.e., their
1257 * interpretation conforms to the current value of flip (even when they
1258 * are interpreted to be NULL).
1259 * If *c is TSO, its state is not any of ThreadRelocated, ThreadComplete,
1260 * or ThreadKilled, which means that its stack is ready to process.
1262 * This code was almost plagiarzied from GC.c! For each pointer,
1263 * retainClosure() is invoked instead of evacuate().
1264 * -------------------------------------------------------------------------- */
1266 retainStack( StgClosure *c, retainer c_child_r,
1267 StgPtr stackStart, StgPtr stackEnd )
1269 stackElement *oldStackBoundary;
1271 StgRetInfoTable *info;
1275 #ifdef DEBUG_RETAINER
1277 if (cStackSize > maxCStackSize) maxCStackSize = cStackSize;
1281 Each invocation of retainStack() creates a new virtual
1282 stack. Since all such stacks share a single common stack, we
1283 record the current currentStackBoundary, which will be restored
1286 oldStackBoundary = currentStackBoundary;
1287 currentStackBoundary = stackTop;
1289 #ifdef DEBUG_RETAINER
1290 // debugBelch("retainStack() called: oldStackBoundary = 0x%x, currentStackBoundary = 0x%x\n", oldStackBoundary, currentStackBoundary);
1293 ASSERT(get_itbl(c)->type != TSO ||
1294 (((StgTSO *)c)->what_next != ThreadRelocated &&
1295 ((StgTSO *)c)->what_next != ThreadComplete &&
1296 ((StgTSO *)c)->what_next != ThreadKilled));
1299 while (p < stackEnd) {
1300 info = get_ret_itbl((StgClosure *)p);
1302 switch(info->i.type) {
1305 retainClosure(((StgUpdateFrame *)p)->updatee, c, c_child_r);
1306 p += sizeofW(StgUpdateFrame);
1313 bitmap = BITMAP_BITS(info->i.layout.bitmap);
1314 size = BITMAP_SIZE(info->i.layout.bitmap);
1316 p = retain_small_bitmap(p, size, bitmap, c, c_child_r);
1319 retainSRT((StgClosure **)GET_SRT(info), info->i.srt_bitmap, c, c_child_r);
1326 retainClosure((StgClosure *)*p, c, c_child_r);
1329 size = BCO_BITMAP_SIZE(bco);
1330 retain_large_bitmap(p, BCO_BITMAP(bco), size, c, c_child_r);
1335 // large bitmap (> 32 entries, or > 64 on a 64-bit machine)
1338 size = GET_LARGE_BITMAP(&info->i)->size;
1340 retain_large_bitmap(p, GET_LARGE_BITMAP(&info->i),
1341 size, c, c_child_r);
1343 // and don't forget to follow the SRT
1346 // Dynamic bitmap: the mask is stored on the stack
1349 dyn = ((StgRetDyn *)p)->liveness;
1351 // traverse the bitmap first
1352 bitmap = RET_DYN_LIVENESS(dyn);
1353 p = (P_)&((StgRetDyn *)p)->payload[0];
1354 size = RET_DYN_BITMAP_SIZE;
1355 p = retain_small_bitmap(p, size, bitmap, c, c_child_r);
1357 // skip over the non-ptr words
1358 p += RET_DYN_NONPTRS(dyn) + RET_DYN_NONPTR_REGS_SIZE;
1360 // follow the ptr words
1361 for (size = RET_DYN_PTRS(dyn); size > 0; size--) {
1362 retainClosure((StgClosure *)*p, c, c_child_r);
1369 StgRetFun *ret_fun = (StgRetFun *)p;
1370 StgFunInfoTable *fun_info;
1372 retainClosure(ret_fun->fun, c, c_child_r);
1373 fun_info = get_fun_itbl(ret_fun->fun);
1375 p = (P_)&ret_fun->payload;
1376 switch (fun_info->f.fun_type) {
1378 bitmap = BITMAP_BITS(fun_info->f.b.bitmap);
1379 size = BITMAP_SIZE(fun_info->f.b.bitmap);
1380 p = retain_small_bitmap(p, size, bitmap, c, c_child_r);
1383 size = GET_FUN_LARGE_BITMAP(fun_info)->size;
1384 retain_large_bitmap(p, GET_FUN_LARGE_BITMAP(fun_info),
1385 size, c, c_child_r);
1389 bitmap = BITMAP_BITS(stg_arg_bitmaps[fun_info->f.fun_type]);
1390 size = BITMAP_SIZE(stg_arg_bitmaps[fun_info->f.fun_type]);
1391 p = retain_small_bitmap(p, size, bitmap, c, c_child_r);
1398 barf("Invalid object found in retainStack(): %d",
1399 (int)(info->i.type));
1403 // restore currentStackBoundary
1404 currentStackBoundary = oldStackBoundary;
1405 #ifdef DEBUG_RETAINER
1406 // debugBelch("retainStack() finished: currentStackBoundary = 0x%x\n", currentStackBoundary);
1409 #ifdef DEBUG_RETAINER
1414 /* ----------------------------------------------------------------------------
1415 * Call retainClosure for each of the children of a PAP/AP
1416 * ------------------------------------------------------------------------- */
1418 static INLINE StgPtr
1419 retain_PAP_payload (StgClosure *pap, retainer c_child_r, StgClosure *fun,
1420 StgClosure** payload, StgWord n_args)
1424 StgFunInfoTable *fun_info;
1426 retainClosure(fun, pap, c_child_r);
1427 fun_info = get_fun_itbl(fun);
1428 ASSERT(fun_info->i.type != PAP);
1430 p = (StgPtr)payload;
1432 switch (fun_info->f.fun_type) {
1434 bitmap = BITMAP_BITS(fun_info->f.b.bitmap);
1435 p = retain_small_bitmap(p, n_args, bitmap,
1439 retain_large_bitmap(p, GET_FUN_LARGE_BITMAP(fun_info),
1440 n_args, pap, c_child_r);
1444 retain_large_bitmap((StgPtr)payload, BCO_BITMAP(fun),
1445 n_args, pap, c_child_r);
1449 bitmap = BITMAP_BITS(stg_arg_bitmaps[fun_info->f.fun_type]);
1450 p = retain_small_bitmap(p, n_args, bitmap, pap, c_child_r);
1456 /* -----------------------------------------------------------------------------
1457 * Compute the retainer set of *c0 and all its desecents by traversing.
1458 * *cp0 is the parent of *c0, and *r0 is the most recent retainer of *c0.
1460 * c0 = cp0 = r0 holds only for root objects.
1461 * RSET(cp0) and RSET(r0) are valid, i.e., their
1462 * interpretation conforms to the current value of flip (even when they
1463 * are interpreted to be NULL).
1464 * However, RSET(c0) may be corrupt, i.e., it may not conform to
1465 * the current value of flip. If it does not, during the execution
1466 * of this function, RSET(c0) must be initialized as well as all
1469 * stackTop must be the same at the beginning and the exit of this function.
1470 * *c0 can be TSO (as well as AP_STACK).
1471 * -------------------------------------------------------------------------- */
1473 retainClosure( StgClosure *c0, StgClosure *cp0, retainer r0 )
1475 // c = Current closure
1476 // cp = Current closure's Parent
1477 // r = current closures' most recent Retainer
1478 // c_child_r = current closure's children's most recent retainer
1479 // first_child = first child of c
1480 StgClosure *c, *cp, *first_child;
1481 RetainerSet *s, *retainerSetOfc;
1482 retainer r, c_child_r;
1485 #ifdef DEBUG_RETAINER
1486 // StgPtr oldStackTop;
1489 #ifdef DEBUG_RETAINER
1490 // oldStackTop = stackTop;
1491 // debugBelch("retainClosure() called: c0 = 0x%x, cp0 = 0x%x, r0 = 0x%x\n", c0, cp0, r0);
1494 // (c, cp, r) = (c0, cp0, r0)
1501 //debugBelch("loop");
1502 // pop to (c, cp, r);
1506 #ifdef DEBUG_RETAINER
1507 // debugBelch("retainClosure() ends: oldStackTop = 0x%x, stackTop = 0x%x\n", oldStackTop, stackTop);
1512 //debugBelch("inner_loop");
1515 // c = current closure under consideration,
1516 // cp = current closure's parent,
1517 // r = current closure's most recent retainer
1519 // Loop invariants (on the meaning of c, cp, r, and their retainer sets):
1520 // RSET(cp) and RSET(r) are valid.
1521 // RSET(c) is valid only if c has been visited before.
1523 // Loop invariants (on the relation between c, cp, and r)
1524 // if cp is not a retainer, r belongs to RSET(cp).
1525 // if cp is a retainer, r == cp.
1527 typeOfc = get_itbl(c)->type;
1529 #ifdef DEBUG_RETAINER
1532 case CONSTR_INTLIKE:
1533 case CONSTR_CHARLIKE:
1534 case CONSTR_NOCAF_STATIC:
1540 if (retainerSetOf(c) == NULL) { // first visit?
1541 costArray[typeOfc] += cost(c);
1542 sumOfNewCost += cost(c);
1551 if (((StgTSO *)c)->what_next == ThreadComplete ||
1552 ((StgTSO *)c)->what_next == ThreadKilled) {
1553 #ifdef DEBUG_RETAINER
1554 debugBelch("ThreadComplete or ThreadKilled encountered in retainClosure()\n");
1558 if (((StgTSO *)c)->what_next == ThreadRelocated) {
1559 #ifdef DEBUG_RETAINER
1560 debugBelch("ThreadRelocated encountered in retainClosure()\n");
1562 c = (StgClosure *)((StgTSO *)c)->link;
1568 // We just skip IND_STATIC, so its retainer set is never computed.
1569 c = ((StgIndStatic *)c)->indirectee;
1571 case CONSTR_INTLIKE:
1572 case CONSTR_CHARLIKE:
1573 // static objects with no pointers out, so goto loop.
1574 case CONSTR_NOCAF_STATIC:
1575 // It is not just enough not to compute the retainer set for *c; it is
1576 // mandatory because CONSTR_NOCAF_STATIC are not reachable from
1577 // scavenged_static_objects, the list from which is assumed to traverse
1578 // all static objects after major garbage collections.
1582 if (get_itbl(c)->srt_bitmap == 0) {
1583 // No need to compute the retainer set; no dynamic objects
1584 // are reachable from *c.
1586 // Static objects: if we traverse all the live closures,
1587 // including static closures, during each heap census then
1588 // we will observe that some static closures appear and
1589 // disappear. eg. a closure may contain a pointer to a
1590 // static function 'f' which is not otherwise reachable
1591 // (it doesn't indirectly point to any CAFs, so it doesn't
1592 // appear in any SRTs), so we would find 'f' during
1593 // traversal. However on the next sweep there may be no
1594 // closures pointing to 'f'.
1596 // We must therefore ignore static closures whose SRT is
1597 // empty, because these are exactly the closures that may
1598 // "appear". A closure with a non-empty SRT, and which is
1599 // still required, will always be reachable.
1601 // But what about CONSTR_STATIC? Surely these may be able
1602 // to appear, and they don't have SRTs, so we can't
1603 // check. So for now, we're calling
1604 // resetStaticObjectForRetainerProfiling() from the
1605 // garbage collector to reset the retainer sets in all the
1606 // reachable static objects.
1613 // The above objects are ignored in computing the average number of times
1614 // an object is visited.
1615 timesAnyObjectVisited++;
1617 // If this is the first visit to c, initialize its retainer set.
1618 maybeInitRetainerSet(c);
1619 retainerSetOfc = retainerSetOf(c);
1622 // isRetainer(cp) == rtsTrue => s == NULL
1623 // isRetainer(cp) == rtsFalse => s == cp.retainer
1627 s = retainerSetOf(cp);
1629 // (c, cp, r, s) is available.
1631 // (c, cp, r, s, R_r) is available, so compute the retainer set for *c.
1632 if (retainerSetOfc == NULL) {
1633 // This is the first visit to *c.
1637 associate(c, singleton(r));
1639 // s is actually the retainer set of *c!
1642 // compute c_child_r
1643 c_child_r = isRetainer(c) ? getRetainerFrom(c) : r;
1645 // This is not the first visit to *c.
1646 if (isMember(r, retainerSetOfc))
1647 goto loop; // no need to process child
1650 associate(c, addElement(r, retainerSetOfc));
1652 // s is not NULL and cp is not a retainer. This means that
1653 // each time *cp is visited, so is *c. Thus, if s has
1654 // exactly one more element in its retainer set than c, s
1655 // is also the new retainer set for *c.
1656 if (s->num == retainerSetOfc->num + 1) {
1659 // Otherwise, just add R_r to the current retainer set of *c.
1661 associate(c, addElement(r, retainerSetOfc));
1666 goto loop; // no need to process child
1668 // compute c_child_r
1672 // now, RSET() of all of *c, *cp, and *r is valid.
1673 // (c, c_child_r) are available.
1677 // Special case closures: we process these all in one go rather
1678 // than attempting to save the current position, because doing so
1682 retainStack(c, c_child_r,
1684 ((StgTSO *)c)->stack + ((StgTSO *)c)->stack_size);
1689 StgPAP *pap = (StgPAP *)c;
1690 retain_PAP_payload(c, c_child_r, pap->fun, pap->payload, pap->n_args);
1696 StgAP *ap = (StgAP *)c;
1697 retain_PAP_payload(c, c_child_r, ap->fun, ap->payload, ap->n_args);
1702 retainClosure(((StgAP_STACK *)c)->fun, c, c_child_r);
1703 retainStack(c, c_child_r,
1704 (StgPtr)((StgAP_STACK *)c)->payload,
1705 (StgPtr)((StgAP_STACK *)c)->payload +
1706 ((StgAP_STACK *)c)->size);
1710 push(c, c_child_r, &first_child);
1712 // If first_child is null, c has no child.
1713 // If first_child is not null, the top stack element points to the next
1714 // object. push() may or may not push a stackElement on the stack.
1715 if (first_child == NULL)
1718 // (c, cp, r) = (first_child, c, c_child_r)
1725 /* -----------------------------------------------------------------------------
1726 * Compute the retainer set for every object reachable from *tl.
1727 * -------------------------------------------------------------------------- */
1729 retainRoot( StgClosure **tl )
1731 // We no longer assume that only TSOs and WEAKs are roots; any closure can
1734 ASSERT(isEmptyRetainerStack());
1735 currentStackBoundary = stackTop;
1737 if (isRetainer(*tl)) {
1738 retainClosure(*tl, *tl, getRetainerFrom(*tl));
1740 retainClosure(*tl, *tl, CCS_SYSTEM);
1743 // NOT TRUE: ASSERT(isMember(getRetainerFrom(*tl), retainerSetOf(*tl)));
1744 // *tl might be a TSO which is ThreadComplete, in which
1745 // case we ignore it for the purposes of retainer profiling.
1748 /* -----------------------------------------------------------------------------
1749 * Compute the retainer set for each of the objects in the heap.
1750 * -------------------------------------------------------------------------- */
1752 computeRetainerSet( void )
1759 #ifdef DEBUG_RETAINER
1760 RetainerSet tmpRetainerSet;
1763 GetRoots(retainRoot); // for scheduler roots
1765 // This function is called after a major GC, when key, value, and finalizer
1766 // all are guaranteed to be valid, or reachable.
1768 // The following code assumes that WEAK objects are considered to be roots
1769 // for retainer profilng.
1770 for (weak = weak_ptr_list; weak != NULL; weak = weak->link)
1771 // retainRoot((StgClosure *)weak);
1772 retainRoot((StgClosure **)&weak);
1774 // Consider roots from the stable ptr table.
1775 markStablePtrTable(retainRoot);
1777 // The following code resets the rs field of each unvisited mutable
1778 // object (computing sumOfNewCostExtra and updating costArray[] when
1779 // debugging retainer profiler).
1780 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
1781 ASSERT(g != 0 || (generations[g].mut_list == NULL));
1783 // Traversing through mut_list is necessary
1784 // because we can find MUT_VAR objects which have not been
1785 // visited during retainer profiling.
1786 for (bd = generations[g].mut_list; bd != NULL; bd = bd->link) {
1787 for (ml = bd->start; ml < bd->free; ml++) {
1789 maybeInitRetainerSet((StgClosure *)*ml);
1790 rtl = retainerSetOf((StgClosure *)*ml);
1792 #ifdef DEBUG_RETAINER
1794 // first visit to *ml
1795 // This is a violation of the interface rule!
1796 RSET(ml) = (RetainerSet *)((StgWord)(&tmpRetainerSet) | flip);
1798 switch (get_itbl((StgClosure *)ml)->type) {
1802 case CONSTR_INTLIKE:
1803 case CONSTR_CHARLIKE:
1804 case CONSTR_NOCAF_STATIC:
1808 barf("Invalid object in computeRetainerSet(): %d", get_itbl((StgClosure*)ml)->type);
1812 costArray[get_itbl((StgClosure *)ml)->type] += cost((StgClosure *)ml);
1813 sumOfNewCostExtra += cost((StgClosure *)ml);
1823 /* -----------------------------------------------------------------------------
1824 * Traverse all static objects for which we compute retainer sets,
1825 * and reset their rs fields to NULL, which is accomplished by
1826 * invoking maybeInitRetainerSet(). This function must be called
1827 * before zeroing all objects reachable from scavenged_static_objects
1828 * in the case of major gabage collections. See GarbageCollect() in
1831 * The mut_once_list of the oldest generation must also be traversed?
1832 * Why? Because if the evacuation of an object pointed to by a static
1833 * indirection object fails, it is put back to the mut_once_list of
1834 * the oldest generation.
1835 * However, this is not necessary because any static indirection objects
1836 * are just traversed through to reach dynamic objects. In other words,
1837 * they are not taken into consideration in computing retainer sets.
1838 * -------------------------------------------------------------------------- */
1840 resetStaticObjectForRetainerProfiling( void )
1842 #ifdef DEBUG_RETAINER
1847 #ifdef DEBUG_RETAINER
1850 p = scavenged_static_objects;
1851 while (p != END_OF_STATIC_LIST) {
1852 #ifdef DEBUG_RETAINER
1855 switch (get_itbl(p)->type) {
1857 // Since we do not compute the retainer set of any
1858 // IND_STATIC object, we don't have to reset its retainer
1860 p = (StgClosure*)*IND_STATIC_LINK(p);
1863 maybeInitRetainerSet(p);
1864 p = (StgClosure*)*THUNK_STATIC_LINK(p);
1867 maybeInitRetainerSet(p);
1868 p = (StgClosure*)*FUN_STATIC_LINK(p);
1871 maybeInitRetainerSet(p);
1872 p = (StgClosure*)*STATIC_LINK(get_itbl(p), p);
1875 barf("resetStaticObjectForRetainerProfiling: %p (%s)",
1876 p, get_itbl(p)->type);
1880 #ifdef DEBUG_RETAINER
1881 // debugBelch("count in scavenged_static_objects = %d\n", count);
1885 /* -----------------------------------------------------------------------------
1886 * Perform retainer profiling.
1887 * N is the oldest generation being profilied, where the generations are
1888 * numbered starting at 0.
1891 * This function should be called only immediately after major garbage
1893 * ------------------------------------------------------------------------- */
1895 retainerProfile(void)
1897 #ifdef DEBUG_RETAINER
1899 nat totalHeapSize; // total raw heap size (computed by linear scanning)
1902 #ifdef DEBUG_RETAINER
1903 debugBelch(" < retainerProfile() invoked : %d>\n", retainerGeneration);
1908 // We haven't flipped the bit yet.
1909 #ifdef DEBUG_RETAINER
1910 debugBelch("Before traversing:\n");
1911 sumOfCostLinear = 0;
1912 for (i = 0;i < N_CLOSURE_TYPES; i++)
1913 costArrayLinear[i] = 0;
1914 totalHeapSize = checkHeapSanityForRetainerProfiling();
1916 debugBelch("\tsumOfCostLinear = %d, totalHeapSize = %d\n", sumOfCostLinear, totalHeapSize);
1918 debugBelch("costArrayLinear[] = ");
1919 for (i = 0;i < N_CLOSURE_TYPES; i++)
1920 debugBelch("[%u:%u] ", i, costArrayLinear[i]);
1924 ASSERT(sumOfCostLinear == totalHeapSize);
1927 #define pcostArrayLinear(index) \
1928 if (costArrayLinear[index] > 0) \
1929 debugBelch("costArrayLinear[" #index "] = %u\n", costArrayLinear[index])
1930 pcostArrayLinear(THUNK_STATIC);
1931 pcostArrayLinear(FUN_STATIC);
1932 pcostArrayLinear(CONSTR_STATIC);
1933 pcostArrayLinear(CONSTR_NOCAF_STATIC);
1934 pcostArrayLinear(CONSTR_INTLIKE);
1935 pcostArrayLinear(CONSTR_CHARLIKE);
1939 // Now we flips flip.
1942 #ifdef DEBUG_RETAINER
1948 numObjectVisited = 0;
1949 timesAnyObjectVisited = 0;
1951 #ifdef DEBUG_RETAINER
1952 debugBelch("During traversing:\n");
1954 sumOfNewCostExtra = 0;
1955 for (i = 0;i < N_CLOSURE_TYPES; i++)
1960 We initialize the traverse stack each time the retainer profiling is
1961 performed (because the traverse stack size varies on each retainer profiling
1962 and this operation is not costly anyhow). However, we just refresh the
1965 initializeTraverseStack();
1966 #ifdef DEBUG_RETAINER
1967 initializeAllRetainerSet();
1969 refreshAllRetainerSet();
1971 computeRetainerSet();
1973 #ifdef DEBUG_RETAINER
1974 debugBelch("After traversing:\n");
1975 sumOfCostLinear = 0;
1976 for (i = 0;i < N_CLOSURE_TYPES; i++)
1977 costArrayLinear[i] = 0;
1978 totalHeapSize = checkHeapSanityForRetainerProfiling();
1980 debugBelch("\tsumOfCostLinear = %d, totalHeapSize = %d\n", sumOfCostLinear, totalHeapSize);
1981 ASSERT(sumOfCostLinear == totalHeapSize);
1983 // now, compare the two results
1986 costArray[] must be exactly the same as costArrayLinear[].
1988 1) Dead weak pointers, whose type is CONSTR. These objects are not
1989 reachable from any roots.
1991 debugBelch("Comparison:\n");
1992 debugBelch("\tcostArrayLinear[] (must be empty) = ");
1993 for (i = 0;i < N_CLOSURE_TYPES; i++)
1994 if (costArray[i] != costArrayLinear[i])
1995 // nothing should be printed except MUT_VAR after major GCs
1996 debugBelch("[%u:%u] ", i, costArrayLinear[i]);
1999 debugBelch("\tsumOfNewCost = %u\n", sumOfNewCost);
2000 debugBelch("\tsumOfNewCostExtra = %u\n", sumOfNewCostExtra);
2001 debugBelch("\tcostArray[] (must be empty) = ");
2002 for (i = 0;i < N_CLOSURE_TYPES; i++)
2003 if (costArray[i] != costArrayLinear[i])
2004 // nothing should be printed except MUT_VAR after major GCs
2005 debugBelch("[%u:%u] ", i, costArray[i]);
2008 // only for major garbage collection
2009 ASSERT(sumOfNewCost + sumOfNewCostExtra == sumOfCostLinear);
2013 closeTraverseStack();
2014 #ifdef DEBUG_RETAINER
2015 closeAllRetainerSet();
2017 // Note that there is no post-processing for the retainer sets.
2019 retainerGeneration++;
2022 retainerGeneration - 1, // retainerGeneration has just been incremented!
2023 #ifdef DEBUG_RETAINER
2024 maxCStackSize, maxStackSize,
2026 (double)timesAnyObjectVisited / numObjectVisited);
2029 /* -----------------------------------------------------------------------------
2031 * -------------------------------------------------------------------------- */
2033 #ifdef DEBUG_RETAINER
2035 #define LOOKS_LIKE_PTR(r) ((LOOKS_LIKE_STATIC_CLOSURE(r) || \
2036 ((HEAP_ALLOCED(r) && ((Bdescr((P_)r)->flags & BF_FREE) == 0)))) && \
2037 ((StgWord)(*(StgPtr)r)!=0xaaaaaaaa))
2040 sanityCheckHeapClosure( StgClosure *c )
2044 ASSERT(LOOKS_LIKE_GHC_INFO(c->header.info));
2045 ASSERT(!closure_STATIC(c));
2046 ASSERT(LOOKS_LIKE_PTR(c));
2048 if ((((StgWord)RSET(c) & 1) ^ flip) != 0) {
2049 if (get_itbl(c)->type == CONSTR &&
2050 !strcmp(get_itbl(c)->prof.closure_type, "DEAD_WEAK") &&
2051 !strcmp(get_itbl(c)->prof.closure_desc, "DEAD_WEAK")) {
2052 debugBelch("\tUnvisited dead weak pointer object found: c = %p\n", c);
2053 costArray[get_itbl(c)->type] += cost(c);
2054 sumOfNewCost += cost(c);
2057 "Unvisited object: flip = %d, c = %p(%d, %s, %s), rs = %p\n",
2058 flip, c, get_itbl(c)->type,
2059 get_itbl(c)->prof.closure_type, get_itbl(c)->prof.closure_desc,
2062 // debugBelch("sanityCheckHeapClosure) S: flip = %d, c = %p(%d), rs = %p\n", flip, c, get_itbl(c)->type, RSET(c));
2065 return closure_sizeW(c);
2069 heapCheck( bdescr *bd )
2072 static nat costSum, size;
2075 while (bd != NULL) {
2077 while (p < bd->free) {
2078 size = sanityCheckHeapClosure((StgClosure *)p);
2079 sumOfCostLinear += size;
2080 costArrayLinear[get_itbl((StgClosure *)p)->type] += size;
2082 // no need for slop check; I think slops are not used currently.
2084 ASSERT(p == bd->free);
2085 costSum += bd->free - bd->start;
2093 smallObjectPoolCheck(void)
2097 static nat costSum, size;
2099 bd = small_alloc_list;
2107 while (p < alloc_Hp) {
2108 size = sanityCheckHeapClosure((StgClosure *)p);
2109 sumOfCostLinear += size;
2110 costArrayLinear[get_itbl((StgClosure *)p)->type] += size;
2113 ASSERT(p == alloc_Hp);
2114 costSum += alloc_Hp - bd->start;
2117 while (bd != NULL) {
2119 while (p < bd->free) {
2120 size = sanityCheckHeapClosure((StgClosure *)p);
2121 sumOfCostLinear += size;
2122 costArrayLinear[get_itbl((StgClosure *)p)->type] += size;
2125 ASSERT(p == bd->free);
2126 costSum += bd->free - bd->start;
2134 chainCheck(bdescr *bd)
2139 while (bd != NULL) {
2140 // bd->free - bd->start is not an accurate measurement of the
2141 // object size. Actually it is always zero, so we compute its
2143 size = sanityCheckHeapClosure((StgClosure *)bd->start);
2144 sumOfCostLinear += size;
2145 costArrayLinear[get_itbl((StgClosure *)bd->start)->type] += size;
2154 checkHeapSanityForRetainerProfiling( void )
2159 debugBelch("START: sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2160 if (RtsFlags.GcFlags.generations == 1) {
2161 costSum += heapCheck(g0s0->to_blocks);
2162 debugBelch("heapCheck: sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2163 costSum += chainCheck(g0s0->large_objects);
2164 debugBelch("chainCheck: sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2166 for (g = 0; g < RtsFlags.GcFlags.generations; g++)
2167 for (s = 0; s < generations[g].n_steps; s++) {
2169 After all live objects have been scavenged, the garbage
2170 collector may create some objects in
2171 scheduleFinalizers(). These objects are created throught
2172 allocate(), so the small object pool or the large object
2173 pool of the g0s0 may not be empty.
2175 if (g == 0 && s == 0) {
2176 costSum += smallObjectPoolCheck();
2177 debugBelch("smallObjectPoolCheck(): sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2178 costSum += chainCheck(generations[g].steps[s].large_objects);
2179 debugBelch("chainCheck(): sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2181 costSum += heapCheck(generations[g].steps[s].blocks);
2182 debugBelch("heapCheck(): sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2183 costSum += chainCheck(generations[g].steps[s].large_objects);
2184 debugBelch("chainCheck(): sumOfCostLinear = %d, costSum = %d\n", sumOfCostLinear, costSum);
2193 findPointer(StgPtr p)
2199 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
2200 for (s = 0; s < generations[g].n_steps; s++) {
2201 // if (g == 0 && s == 0) continue;
2202 bd = generations[g].steps[s].blocks;
2203 for (; bd; bd = bd->link) {
2204 for (q = bd->start; q < bd->free; q++) {
2205 if (*q == (StgWord)p) {
2207 while (!LOOKS_LIKE_GHC_INFO(*r)) r--;
2208 debugBelch("Found in gen[%d], step[%d]: q = %p, r = %p\n", g, s, q, r);
2213 bd = generations[g].steps[s].large_objects;
2214 for (; bd; bd = bd->link) {
2215 e = bd->start + cost((StgClosure *)bd->start);
2216 for (q = bd->start; q < e; q++) {
2217 if (*q == (StgWord)p) {
2219 while (*r == 0 || !LOOKS_LIKE_GHC_INFO(*r)) r--;
2220 debugBelch("Found in gen[%d], large_objects: %p\n", g, r);
2230 belongToHeap(StgPtr p)
2235 for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
2236 for (s = 0; s < generations[g].n_steps; s++) {
2237 // if (g == 0 && s == 0) continue;
2238 bd = generations[g].steps[s].blocks;
2239 for (; bd; bd = bd->link) {
2240 if (bd->start <= p && p < bd->free) {
2241 debugBelch("Belongs to gen[%d], step[%d]", g, s);
2245 bd = generations[g].steps[s].large_objects;
2246 for (; bd; bd = bd->link) {
2247 if (bd->start <= p && p < bd->start + getHeapClosureSize((StgClosure *)bd->start)) {
2248 debugBelch("Found in gen[%d], large_objects: %p\n", g, bd->start);
2255 #endif /* DEBUG_RETAINER */
2257 #endif /* PROFILING */