--- /dev/null
+/* -----------------------------------------------------------------------------
+ *
+ * (c) The GHC Team 2001
+ *
+ * Compacting garbage collector
+ *
+ * ---------------------------------------------------------------------------*/
+
+#include "PosixSource.h"
+#include "Rts.h"
+#include "RtsUtils.h"
+#include "RtsFlags.h"
+#include "OSThreads.h"
+#include "Storage.h"
+#include "BlockAlloc.h"
+#include "MBlock.h"
+#include "GCCompact.h"
+#include "Schedule.h"
+#include "Apply.h"
+
+// Turn off inlining when debugging - it obfuscates things
+#ifdef DEBUG
+# undef STATIC_INLINE
+# define STATIC_INLINE static
+#endif
+
+/* -----------------------------------------------------------------------------
+ Threading / unthreading pointers.
+
+ The basic idea here is to chain together all the fields pointing at
+ a particular object, with the root of the chain in the object's
+ info table field. The original contents of the info pointer goes
+ at the end of the chain.
+
+ Adding a new field to the chain is a matter of swapping the
+ contents of the field with the contents of the object's info table
+ field.
+
+ To unthread the chain, we walk down it updating all the fields on
+ the chain with the new location of the object. We stop when we
+ reach the info pointer at the end.
+
+ We use a trick to identify the info pointer: when swapping pointers
+ for threading, we set the low bit of the original pointer, with the
+ result that all the pointers in the chain have their low bits set
+ except for the info pointer.
+ -------------------------------------------------------------------------- */
+
+STATIC_INLINE void
+thread( StgPtr p )
+{
+ StgPtr q = (StgPtr)*p;
+ bdescr *bd;
+
+ // It doesn't look like a closure at the moment, because the info
+ // ptr is possibly threaded:
+ // ASSERT(LOOKS_LIKE_CLOSURE_PTR(q));
+
+ if (HEAP_ALLOCED(q)) {
+ bd = Bdescr(q);
+ // a handy way to discover whether the ptr is into the
+ // compacted area of the old gen, is that the EVACUATED flag
+ // is zero (it's non-zero for all the other areas of live
+ // memory).
+ if ((bd->flags & BF_EVACUATED) == 0) {
+ *p = (StgWord)*q;
+ *q = (StgWord)p + 1; // set the low bit
+ }
+ }
+}
+
+STATIC_INLINE void
+unthread( StgPtr p, StgPtr free )
+{
+ StgWord q = *p, r;
+
+ while ((q & 1) != 0) {
+ q -= 1; // unset the low bit again
+ r = *((StgPtr)q);
+ *((StgPtr)q) = (StgWord)free;
+ q = r;
+ }
+ *p = q;
+}
+
+STATIC_INLINE StgInfoTable *
+get_threaded_info( StgPtr p )
+{
+ StgPtr q = (P_)GET_INFO((StgClosure *)p);
+
+ while (((StgWord)q & 1) != 0) {
+ q = (P_)*((StgPtr)((StgWord)q-1));
+ }
+
+ ASSERT(LOOKS_LIKE_INFO_PTR(q));
+ return INFO_PTR_TO_STRUCT((StgInfoTable *)q);
+}
+
+// A word-aligned memmove will be faster for small objects than libc's or gcc's.
+// Remember, the two regions *might* overlap, but: to <= from.
+STATIC_INLINE void
+move(StgPtr to, StgPtr from, nat size)
+{
+ for(; size > 0; --size) {
+ *to++ = *from++;
+ }
+}
+
+static void
+thread_static( StgClosure* p )
+{
+ const StgInfoTable *info;
+
+ // keep going until we've threaded all the objects on the linked
+ // list...
+ while (p != END_OF_STATIC_LIST) {
+
+ info = get_itbl(p);
+ switch (info->type) {
+
+ case IND_STATIC:
+ thread((StgPtr)&((StgInd *)p)->indirectee);
+ p = *IND_STATIC_LINK(p);
+ continue;
+
+ case THUNK_STATIC:
+ p = *THUNK_STATIC_LINK(p);
+ continue;
+ case FUN_STATIC:
+ p = *FUN_STATIC_LINK(p);
+ continue;
+ case CONSTR_STATIC:
+ p = *STATIC_LINK(info,p);
+ continue;
+
+ default:
+ barf("thread_static: strange closure %d", (int)(info->type));
+ }
+
+ }
+}
+
+STATIC_INLINE void
+thread_large_bitmap( StgPtr p, StgLargeBitmap *large_bitmap, nat size )
+{
+ nat i, b;
+ StgWord bitmap;
+
+ b = 0;
+ bitmap = large_bitmap->bitmap[b];
+ for (i = 0; i < size; ) {
+ if ((bitmap & 1) == 0) {
+ thread(p);
+ }
+ i++;
+ p++;
+ if (i % BITS_IN(W_) == 0) {
+ b++;
+ bitmap = large_bitmap->bitmap[b];
+ } else {
+ bitmap = bitmap >> 1;
+ }
+ }
+}
+
+STATIC_INLINE StgPtr
+thread_arg_block (StgFunInfoTable *fun_info, StgClosure **args)
+{
+ StgPtr p;
+ StgWord bitmap;
+ nat size;
+
+ p = (StgPtr)args;
+ switch (fun_info->f.fun_type) {
+ case ARG_GEN:
+ bitmap = BITMAP_BITS(fun_info->f.b.bitmap);
+ size = BITMAP_SIZE(fun_info->f.b.bitmap);
+ goto small_bitmap;
+ case ARG_GEN_BIG:
+ size = GET_FUN_LARGE_BITMAP(fun_info)->size;
+ thread_large_bitmap(p, GET_FUN_LARGE_BITMAP(fun_info), size);
+ p += size;
+ break;
+ default:
+ bitmap = BITMAP_BITS(stg_arg_bitmaps[fun_info->f.fun_type]);
+ size = BITMAP_SIZE(stg_arg_bitmaps[fun_info->f.fun_type]);
+ small_bitmap:
+ while (size > 0) {
+ if ((bitmap & 1) == 0) {
+ thread(p);
+ }
+ p++;
+ bitmap = bitmap >> 1;
+ size--;
+ }
+ break;
+ }
+ return p;
+}
+
+static void
+thread_stack(StgPtr p, StgPtr stack_end)
+{
+ const StgRetInfoTable* info;
+ StgWord bitmap;
+ nat size;
+
+ // highly similar to scavenge_stack, but we do pointer threading here.
+
+ while (p < stack_end) {
+
+ // *p must be the info pointer of an activation
+ // record. All activation records have 'bitmap' style layout
+ // info.
+ //
+ info = get_ret_itbl((StgClosure *)p);
+
+ switch (info->i.type) {
+
+ // Dynamic bitmap: the mask is stored on the stack
+ case RET_DYN:
+ {
+ StgWord dyn;
+ dyn = ((StgRetDyn *)p)->liveness;
+
+ // traverse the bitmap first
+ bitmap = RET_DYN_LIVENESS(dyn);
+ p = (P_)&((StgRetDyn *)p)->payload[0];
+ size = RET_DYN_BITMAP_SIZE;
+ while (size > 0) {
+ if ((bitmap & 1) == 0) {
+ thread(p);
+ }
+ p++;
+ bitmap = bitmap >> 1;
+ size--;
+ }
+
+ // skip over the non-ptr words
+ p += RET_DYN_NONPTRS(dyn) + RET_DYN_NONPTR_REGS_SIZE;
+
+ // follow the ptr words
+ for (size = RET_DYN_PTRS(dyn); size > 0; size--) {
+ thread(p);
+ p++;
+ }
+ continue;
+ }
+
+ // small bitmap (<= 32 entries, or 64 on a 64-bit machine)
+ case CATCH_RETRY_FRAME:
+ case CATCH_STM_FRAME:
+ case ATOMICALLY_FRAME:
+ case UPDATE_FRAME:
+ case STOP_FRAME:
+ case CATCH_FRAME:
+ case RET_SMALL:
+ case RET_VEC_SMALL:
+ bitmap = BITMAP_BITS(info->i.layout.bitmap);
+ size = BITMAP_SIZE(info->i.layout.bitmap);
+ p++;
+ // NOTE: the payload starts immediately after the info-ptr, we
+ // don't have an StgHeader in the same sense as a heap closure.
+ while (size > 0) {
+ if ((bitmap & 1) == 0) {
+ thread(p);
+ }
+ p++;
+ bitmap = bitmap >> 1;
+ size--;
+ }
+ continue;
+
+ case RET_BCO: {
+ StgBCO *bco;
+ nat size;
+
+ p++;
+ bco = (StgBCO *)*p;
+ thread(p);
+ p++;
+ size = BCO_BITMAP_SIZE(bco);
+ thread_large_bitmap(p, BCO_BITMAP(bco), size);
+ p += size;
+ continue;
+ }
+
+ // large bitmap (> 32 entries, or 64 on a 64-bit machine)
+ case RET_BIG:
+ case RET_VEC_BIG:
+ p++;
+ size = GET_LARGE_BITMAP(&info->i)->size;
+ thread_large_bitmap(p, GET_LARGE_BITMAP(&info->i), size);
+ p += size;
+ continue;
+
+ case RET_FUN:
+ {
+ StgRetFun *ret_fun = (StgRetFun *)p;
+ StgFunInfoTable *fun_info;
+
+ fun_info = itbl_to_fun_itbl(
+ get_threaded_info((StgPtr)ret_fun->fun));
+ // *before* threading it!
+ thread((StgPtr)&ret_fun->fun);
+ p = thread_arg_block(fun_info, ret_fun->payload);
+ continue;
+ }
+
+ default:
+ barf("thread_stack: weird activation record found on stack: %d",
+ (int)(info->i.type));
+ }
+ }
+}
+
+STATIC_INLINE StgPtr
+thread_PAP_payload (StgClosure *fun, StgClosure **payload, StgWord size)
+{
+ StgPtr p;
+ StgWord bitmap;
+ StgFunInfoTable *fun_info;
+
+ fun_info = itbl_to_fun_itbl(get_threaded_info((StgPtr)fun));
+ ASSERT(fun_info->i.type != PAP);
+
+ p = (StgPtr)payload;
+
+ switch (fun_info->f.fun_type) {
+ case ARG_GEN:
+ bitmap = BITMAP_BITS(fun_info->f.b.bitmap);
+ goto small_bitmap;
+ case ARG_GEN_BIG:
+ thread_large_bitmap(p, GET_FUN_LARGE_BITMAP(fun_info), size);
+ p += size;
+ break;
+ case ARG_BCO:
+ thread_large_bitmap((StgPtr)payload, BCO_BITMAP(fun), size);
+ p += size;
+ break;
+ default:
+ bitmap = BITMAP_BITS(stg_arg_bitmaps[fun_info->f.fun_type]);
+ small_bitmap:
+ while (size > 0) {
+ if ((bitmap & 1) == 0) {
+ thread(p);
+ }
+ p++;
+ bitmap = bitmap >> 1;
+ size--;
+ }
+ break;
+ }
+
+ return p;
+}
+
+STATIC_INLINE StgPtr
+thread_PAP (StgPAP *pap)
+{
+ StgPtr p;
+ p = thread_PAP_payload(pap->fun, pap->payload, pap->n_args);
+ thread((StgPtr)&pap->fun);
+ return p;
+}
+
+STATIC_INLINE StgPtr
+thread_AP (StgAP *ap)
+{
+ StgPtr p;
+ p = thread_PAP_payload(ap->fun, ap->payload, ap->n_args);
+ thread((StgPtr)&ap->fun);
+ return p;
+}
+
+STATIC_INLINE StgPtr
+thread_AP_STACK (StgAP_STACK *ap)
+{
+ thread((StgPtr)&ap->fun);
+ thread_stack((P_)ap->payload, (P_)ap->payload + ap->size);
+ return (P_)ap + sizeofW(StgAP_STACK) + ap->size;
+}
+
+static StgPtr
+thread_TSO (StgTSO *tso)
+{
+ thread((StgPtr)&tso->link);
+ thread((StgPtr)&tso->global_link);
+
+ if ( tso->why_blocked == BlockedOnMVar
+ || tso->why_blocked == BlockedOnBlackHole
+ || tso->why_blocked == BlockedOnException
+#if defined(PAR)
+ || tso->why_blocked == BlockedOnGA
+ || tso->why_blocked == BlockedOnGA_NoSend
+#endif
+ ) {
+ thread((StgPtr)&tso->block_info.closure);
+ }
+ if ( tso->blocked_exceptions != NULL ) {
+ thread((StgPtr)&tso->blocked_exceptions);
+ }
+
+ thread((StgPtr)&tso->trec);
+
+ thread_stack(tso->sp, &(tso->stack[tso->stack_size]));
+ return (StgPtr)tso + tso_sizeW(tso);
+}
+
+
+static void
+update_fwd_large( bdescr *bd )
+{
+ StgPtr p;
+ const StgInfoTable* info;
+
+ for (; bd != NULL; bd = bd->link) {
+
+ p = bd->start;
+ info = get_itbl((StgClosure *)p);
+
+ switch (info->type) {
+
+ case ARR_WORDS:
+ // nothing to follow
+ continue;
+
+ case MUT_ARR_PTRS_CLEAN:
+ case MUT_ARR_PTRS_DIRTY:
+ case MUT_ARR_PTRS_FROZEN:
+ case MUT_ARR_PTRS_FROZEN0:
+ // follow everything
+ {
+ StgPtr next;
+
+ next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
+ for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
+ thread(p);
+ }
+ continue;
+ }
+
+ case TSO:
+ thread_TSO((StgTSO *)p);
+ continue;
+
+ case AP_STACK:
+ thread_AP_STACK((StgAP_STACK *)p);
+ continue;
+
+ case PAP:
+ thread_PAP((StgPAP *)p);
+ continue;
+
+ case TREC_CHUNK:
+ {
+ StgWord i;
+ StgTRecChunk *tc = (StgTRecChunk *)p;
+ TRecEntry *e = &(tc -> entries[0]);
+ thread((StgPtr)&tc->prev_chunk);
+ for (i = 0; i < tc -> next_entry_idx; i ++, e++ ) {
+ thread((StgPtr)&e->tvar);
+ thread((StgPtr)&e->expected_value);
+ thread((StgPtr)&e->new_value);
+ }
+ continue;
+ }
+
+ default:
+ barf("update_fwd_large: unknown/strange object %d", (int)(info->type));
+ }
+ }
+}
+
+STATIC_INLINE StgPtr
+thread_obj (StgInfoTable *info, StgPtr p)
+{
+ switch (info->type) {
+ case THUNK_0_1:
+ return p + sizeofW(StgThunk) + 1;
+
+ case FUN_0_1:
+ case CONSTR_0_1:
+ return p + sizeofW(StgHeader) + 1;
+
+ case FUN_1_0:
+ case CONSTR_1_0:
+ thread((StgPtr)&((StgClosure *)p)->payload[0]);
+ return p + sizeofW(StgHeader) + 1;
+
+ case THUNK_1_0:
+ thread((StgPtr)&((StgThunk *)p)->payload[0]);
+ return p + sizeofW(StgThunk) + 1;
+
+ case THUNK_0_2:
+ return p + sizeofW(StgThunk) + 2;
+
+ case FUN_0_2:
+ case CONSTR_0_2:
+ return p + sizeofW(StgHeader) + 2;
+
+ case THUNK_1_1:
+ thread((StgPtr)&((StgThunk *)p)->payload[0]);
+ return p + sizeofW(StgThunk) + 2;
+
+ case FUN_1_1:
+ case CONSTR_1_1:
+ thread((StgPtr)&((StgClosure *)p)->payload[0]);
+ return p + sizeofW(StgHeader) + 2;
+
+ case THUNK_2_0:
+ thread((StgPtr)&((StgThunk *)p)->payload[0]);
+ thread((StgPtr)&((StgThunk *)p)->payload[1]);
+ return p + sizeofW(StgThunk) + 2;
+
+ case FUN_2_0:
+ case CONSTR_2_0:
+ thread((StgPtr)&((StgClosure *)p)->payload[0]);
+ thread((StgPtr)&((StgClosure *)p)->payload[1]);
+ return p + sizeofW(StgHeader) + 2;
+
+ case BCO: {
+ StgBCO *bco = (StgBCO *)p;
+ thread((StgPtr)&bco->instrs);
+ thread((StgPtr)&bco->literals);
+ thread((StgPtr)&bco->ptrs);
+ thread((StgPtr)&bco->itbls);
+ return p + bco_sizeW(bco);
+ }
+
+ case THUNK:
+ {
+ StgPtr end;
+
+ end = (P_)((StgThunk *)p)->payload +
+ info->layout.payload.ptrs;
+ for (p = (P_)((StgThunk *)p)->payload; p < end; p++) {
+ thread(p);
+ }
+ return p + info->layout.payload.nptrs;
+ }
+
+ case FUN:
+ case CONSTR:
+ case STABLE_NAME:
+ case IND_PERM:
+ case MUT_VAR_CLEAN:
+ case MUT_VAR_DIRTY:
+ case CAF_BLACKHOLE:
+ case SE_CAF_BLACKHOLE:
+ case SE_BLACKHOLE:
+ case BLACKHOLE:
+ {
+ StgPtr end;
+
+ end = (P_)((StgClosure *)p)->payload +
+ info->layout.payload.ptrs;
+ for (p = (P_)((StgClosure *)p)->payload; p < end; p++) {
+ thread(p);
+ }
+ return p + info->layout.payload.nptrs;
+ }
+
+ case WEAK:
+ {
+ StgWeak *w = (StgWeak *)p;
+ thread((StgPtr)&w->key);
+ thread((StgPtr)&w->value);
+ thread((StgPtr)&w->finalizer);
+ if (w->link != NULL) {
+ thread((StgPtr)&w->link);
+ }
+ return p + sizeofW(StgWeak);
+ }
+
+ case MVAR:
+ {
+ StgMVar *mvar = (StgMVar *)p;
+ thread((StgPtr)&mvar->head);
+ thread((StgPtr)&mvar->tail);
+ thread((StgPtr)&mvar->value);
+ return p + sizeofW(StgMVar);
+ }
+
+ case IND_OLDGEN:
+ case IND_OLDGEN_PERM:
+ thread((StgPtr)&((StgInd *)p)->indirectee);
+ return p + sizeofW(StgInd);
+
+ case THUNK_SELECTOR:
+ {
+ StgSelector *s = (StgSelector *)p;
+ thread((StgPtr)&s->selectee);
+ return p + THUNK_SELECTOR_sizeW();
+ }
+
+ case AP_STACK:
+ return thread_AP_STACK((StgAP_STACK *)p);
+
+ case PAP:
+ return thread_PAP((StgPAP *)p);
+
+ case AP:
+ return thread_AP((StgAP *)p);
+
+ case ARR_WORDS:
+ return p + arr_words_sizeW((StgArrWords *)p);
+
+ case MUT_ARR_PTRS_CLEAN:
+ case MUT_ARR_PTRS_DIRTY:
+ case MUT_ARR_PTRS_FROZEN:
+ case MUT_ARR_PTRS_FROZEN0:
+ // follow everything
+ {
+ StgPtr next;
+
+ next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
+ for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
+ thread(p);
+ }
+ return p;
+ }
+
+ case TSO:
+ return thread_TSO((StgTSO *)p);
+
+ case TVAR_WAIT_QUEUE:
+ {
+ StgTVarWaitQueue *wq = (StgTVarWaitQueue *)p;
+ thread((StgPtr)&wq->waiting_tso);
+ thread((StgPtr)&wq->next_queue_entry);
+ thread((StgPtr)&wq->prev_queue_entry);
+ return p + sizeofW(StgTVarWaitQueue);
+ }
+
+ case TVAR:
+ {
+ StgTVar *tvar = (StgTVar *)p;
+ thread((StgPtr)&tvar->current_value);
+ thread((StgPtr)&tvar->first_wait_queue_entry);
+ return p + sizeofW(StgTVar);
+ }
+
+ case TREC_HEADER:
+ {
+ StgTRecHeader *trec = (StgTRecHeader *)p;
+ thread((StgPtr)&trec->enclosing_trec);
+ thread((StgPtr)&trec->current_chunk);
+ return p + sizeofW(StgTRecHeader);
+ }
+
+ case TREC_CHUNK:
+ {
+ StgWord i;
+ StgTRecChunk *tc = (StgTRecChunk *)p;
+ TRecEntry *e = &(tc -> entries[0]);
+ thread((StgPtr)&tc->prev_chunk);
+ for (i = 0; i < tc -> next_entry_idx; i ++, e++ ) {
+ thread((StgPtr)&e->tvar);
+ thread((StgPtr)&e->expected_value);
+ thread((StgPtr)&e->new_value);
+ }
+ return p + sizeofW(StgTRecChunk);
+ }
+
+ default:
+ barf("update_fwd: unknown/strange object %d", (int)(info->type));
+ return NULL;
+ }
+}
+
+static void
+update_fwd( bdescr *blocks )
+{
+ StgPtr p;
+ bdescr *bd;
+ StgInfoTable *info;
+
+ bd = blocks;
+
+#if defined(PAR)
+ barf("update_fwd: ToDo");
+#endif
+
+ // cycle through all the blocks in the step
+ for (; bd != NULL; bd = bd->link) {
+ p = bd->start;
+
+ // linearly scan the objects in this block
+ while (p < bd->free) {
+ ASSERT(LOOKS_LIKE_CLOSURE_PTR(p));
+ info = get_itbl((StgClosure *)p);
+ p = thread_obj(info, p);
+ }
+ }
+}
+
+static void
+update_fwd_compact( bdescr *blocks )
+{
+ StgPtr p, q, free;
+#if 0
+ StgWord m;
+#endif
+ bdescr *bd, *free_bd;
+ StgInfoTable *info;
+ nat size;
+
+ bd = blocks;
+ free_bd = blocks;
+ free = free_bd->start;
+
+#if defined(PAR)
+ barf("update_fwd: ToDo");
+#endif
+
+ // cycle through all the blocks in the step
+ for (; bd != NULL; bd = bd->link) {
+ p = bd->start;
+
+ while (p < bd->free ) {
+
+ while ( p < bd->free && !is_marked(p,bd) ) {
+ p++;
+ }
+ if (p >= bd->free) {
+ break;
+ }
+
+#if 0
+ next:
+ m = * ((StgPtr)bd->u.bitmap + ((p - bd->start) / (BITS_IN(StgWord))));
+ m >>= ((p - bd->start) & (BITS_IN(StgWord) - 1));
+
+ while ( p < bd->free ) {
+
+ if ((m & 1) == 0) {
+ m >>= 1;
+ p++;
+ if (((StgWord)p & (sizeof(W_) * BITS_IN(StgWord))) == 0) {
+ goto next;
+ } else {
+ continue;
+ }
+ }
+#endif
+
+ // Problem: we need to know the destination for this cell
+ // in order to unthread its info pointer. But we can't
+ // know the destination without the size, because we may
+ // spill into the next block. So we have to run down the
+ // threaded list and get the info ptr first.
+ info = get_threaded_info(p);
+
+ q = p;
+
+ p = thread_obj(info, p);
+
+ size = p - q;
+ if (free + size > free_bd->start + BLOCK_SIZE_W) {
+ // unset the next bit in the bitmap to indicate that
+ // this object needs to be pushed into the next
+ // block. This saves us having to run down the
+ // threaded info pointer list twice during the next pass.
+ unmark(q+1,bd);
+ free_bd = free_bd->link;
+ free = free_bd->start;
+ } else {
+ ASSERT(is_marked(q+1,bd));
+ }
+
+ unthread(q,free);
+ free += size;
+#if 0
+ goto next;
+#endif
+ }
+ }
+}
+
+static nat
+update_bkwd_compact( step *stp )
+{
+ StgPtr p, free;
+#if 0
+ StgWord m;
+#endif
+ bdescr *bd, *free_bd;
+ StgInfoTable *info;
+ nat size, free_blocks;
+
+ bd = free_bd = stp->old_blocks;
+ free = free_bd->start;
+ free_blocks = 1;
+
+#if defined(PAR)
+ barf("update_bkwd: ToDo");
+#endif
+
+ // cycle through all the blocks in the step
+ for (; bd != NULL; bd = bd->link) {
+ p = bd->start;
+
+ while (p < bd->free ) {
+
+ while ( p < bd->free && !is_marked(p,bd) ) {
+ p++;
+ }
+ if (p >= bd->free) {
+ break;
+ }
+
+#if 0
+ next:
+ m = * ((StgPtr)bd->u.bitmap + ((p - bd->start) / (BITS_IN(StgWord))));
+ m >>= ((p - bd->start) & (BITS_IN(StgWord) - 1));
+
+ while ( p < bd->free ) {
+
+ if ((m & 1) == 0) {
+ m >>= 1;
+ p++;
+ if (((StgWord)p & (sizeof(W_) * BITS_IN(StgWord))) == 0) {
+ goto next;
+ } else {
+ continue;
+ }
+ }
+#endif
+
+ if (!is_marked(p+1,bd)) {
+ // don't forget to update the free ptr in the block desc.
+ free_bd->free = free;
+ free_bd = free_bd->link;
+ free = free_bd->start;
+ free_blocks++;
+ }
+
+ unthread(p,free);
+ ASSERT(LOOKS_LIKE_INFO_PTR(((StgClosure *)p)->header.info));
+ info = get_itbl((StgClosure *)p);
+ size = closure_sizeW_((StgClosure *)p,info);
+
+ if (free != p) {
+ move(free,p,size);
+ }
+
+ // relocate TSOs
+ if (info->type == TSO) {
+ move_TSO((StgTSO *)p, (StgTSO *)free);
+ }
+
+ free += size;
+ p += size;
+#if 0
+ goto next;
+#endif
+ }
+ }
+
+ // free the remaining blocks and count what's left.
+ free_bd->free = free;
+ if (free_bd->link != NULL) {
+ freeChain(free_bd->link);
+ free_bd->link = NULL;
+ }
+
+ return free_blocks;
+}
+
+void
+compact( void (*get_roots)(evac_fn) )
+{
+ nat g, s, blocks;
+ step *stp;
+
+ // 1. thread the roots
+ get_roots((evac_fn)thread);
+
+ // the weak pointer lists...
+ if (weak_ptr_list != NULL) {
+ thread((StgPtr)(void *)&weak_ptr_list);
+ }
+ if (old_weak_ptr_list != NULL) {
+ thread((StgPtr)(void *)&old_weak_ptr_list); // tmp
+ }
+
+ // mutable lists
+ for (g = 1; g < RtsFlags.GcFlags.generations; g++) {
+ bdescr *bd;
+ StgPtr p;
+ for (bd = generations[g].mut_list; bd != NULL; bd = bd->link) {
+ for (p = bd->start; p < bd->free; p++) {
+ thread(p);
+ }
+ }
+ }
+
+ // the global thread list
+ thread((StgPtr)(void *)&all_threads);
+
+ // any threads resurrected during this GC
+ thread((StgPtr)(void *)&resurrected_threads);
+
+ // the task list
+ {
+ Task *task;
+ for (task = all_tasks; task != NULL; task = task->all_link) {
+ if (task->tso) {
+ thread((StgPtr)&task->tso);
+ }
+ }
+ }
+
+ // the static objects
+ thread_static(scavenged_static_objects);
+
+ // the stable pointer table
+ threadStablePtrTable((evac_fn)thread);
+
+ // the CAF list (used by GHCi)
+ markCAFs((evac_fn)thread);
+
+ // 2. update forward ptrs
+ for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
+ for (s = 0; s < generations[g].n_steps; s++) {
+ if (g==0 && s ==0) continue;
+ stp = &generations[g].steps[s];
+ IF_DEBUG(gc, debugBelch("update_fwd: %d.%d\n", stp->gen->no, stp->no););
+
+ update_fwd(stp->blocks);
+ update_fwd_large(stp->scavenged_large_objects);
+ if (g == RtsFlags.GcFlags.generations-1 && stp->old_blocks != NULL) {
+ IF_DEBUG(gc, debugBelch("update_fwd: %d.%d (compact)\n", stp->gen->no, stp->no););
+ update_fwd_compact(stp->old_blocks);
+ }
+ }
+ }
+
+ // 3. update backward ptrs
+ stp = &oldest_gen->steps[0];
+ if (stp->old_blocks != NULL) {
+ blocks = update_bkwd_compact(stp);
+ IF_DEBUG(gc, debugBelch("update_bkwd: %d.%d (compact, old: %d blocks, now %d blocks)\n",
+ stp->gen->no, stp->no,
+ stp->n_old_blocks, blocks););
+ stp->n_old_blocks = blocks;
+ }
+}
projects / ghc-hetmet.git / blobdiff