+ while (bd != step->hp_bd || p < step->hp) {
+
+ /* If we're at the end of this block, move on to the next block */
+ if (bd != step->hp_bd && p == bd->free) {
+ bd = bd->link;
+ p = bd->start;
+ continue;
+ }
+
+ q = p; /* save ptr to object */
+
+ ASSERT(p && (LOOKS_LIKE_GHC_INFO(GET_INFO((StgClosure *)p))
+ || IS_HUGS_CONSTR_INFO(GET_INFO((StgClosure *)p))));
+
+ info = get_itbl((StgClosure *)p);
+ switch (info -> type) {
+
+ case BCO:
+ {
+ StgBCO* bco = stgCast(StgBCO*,p);
+ nat i;
+ for (i = 0; i < bco->n_ptrs; i++) {
+ bcoConstCPtr(bco,i) = evacuate(bcoConstCPtr(bco,i));
+ }
+ p += bco_sizeW(bco);
+ break;
+ }
+
+ case MVAR:
+ /* treat MVars specially, because we don't want to evacuate the
+ * mut_link field in the middle of the closure.
+ */
+ {
+ StgMVar *mvar = ((StgMVar *)p);
+ evac_gen = 0;
+ (StgClosure *)mvar->head = evacuate((StgClosure *)mvar->head);
+ (StgClosure *)mvar->tail = evacuate((StgClosure *)mvar->tail);
+ (StgClosure *)mvar->value = evacuate((StgClosure *)mvar->value);
+ p += sizeofW(StgMVar);
+ evac_gen = saved_evac_gen;
+ break;
+ }
+
+ case THUNK_2_0:
+ case FUN_2_0:
+ scavenge_srt(info);
+ case CONSTR_2_0:
+ ((StgClosure *)p)->payload[1] = evacuate(((StgClosure *)p)->payload[1]);
+ ((StgClosure *)p)->payload[0] = evacuate(((StgClosure *)p)->payload[0]);
+ p += sizeofW(StgHeader) + 2;
+ break;
+
+ case THUNK_1_0:
+ scavenge_srt(info);
+ ((StgClosure *)p)->payload[0] = evacuate(((StgClosure *)p)->payload[0]);
+ p += sizeofW(StgHeader) + 2; /* MIN_UPD_SIZE */
+ break;
+
+ case FUN_1_0:
+ scavenge_srt(info);
+ case CONSTR_1_0:
+ ((StgClosure *)p)->payload[0] = evacuate(((StgClosure *)p)->payload[0]);
+ p += sizeofW(StgHeader) + 1;
+ break;
+
+ case THUNK_0_1:
+ scavenge_srt(info);
+ p += sizeofW(StgHeader) + 2; /* MIN_UPD_SIZE */
+ break;
+
+ case FUN_0_1:
+ scavenge_srt(info);
+ case CONSTR_0_1:
+ p += sizeofW(StgHeader) + 1;
+ break;
+
+ case THUNK_0_2:
+ case FUN_0_2:
+ scavenge_srt(info);
+ case CONSTR_0_2:
+ p += sizeofW(StgHeader) + 2;
+ break;
+
+ case THUNK_1_1:
+ case FUN_1_1:
+ scavenge_srt(info);
+ case CONSTR_1_1:
+ ((StgClosure *)p)->payload[0] = evacuate(((StgClosure *)p)->payload[0]);
+ p += sizeofW(StgHeader) + 2;
+ break;
+
+ case FUN:
+ case THUNK:
+ scavenge_srt(info);
+ /* fall through */
+
+ case CONSTR:
+ case WEAK:
+ case FOREIGN:
+ case STABLE_NAME:
+ {
+ StgPtr end;
+
+ end = (P_)((StgClosure *)p)->payload + info->layout.payload.ptrs;
+ for (p = (P_)((StgClosure *)p)->payload; p < end; p++) {
+ (StgClosure *)*p = evacuate((StgClosure *)*p);
+ }
+ p += info->layout.payload.nptrs;
+ break;
+ }
+
+ case IND_PERM:
+ if (step->gen->no != 0) {
+ SET_INFO(((StgClosure *)p), &IND_OLDGEN_PERM_info);
+ }
+ /* fall through */
+ case IND_OLDGEN_PERM:
+ ((StgIndOldGen *)p)->indirectee =
+ evacuate(((StgIndOldGen *)p)->indirectee);
+ if (failed_to_evac) {
+ failed_to_evac = rtsFalse;
+ recordOldToNewPtrs((StgMutClosure *)p);
+ }
+ p += sizeofW(StgIndOldGen);
+ break;
+
+ case CAF_UNENTERED:
+ {
+ StgCAF *caf = (StgCAF *)p;
+
+ caf->body = evacuate(caf->body);
+ if (failed_to_evac) {
+ failed_to_evac = rtsFalse;
+ recordOldToNewPtrs((StgMutClosure *)p);
+ } else {
+ caf->mut_link = NULL;
+ }
+ p += sizeofW(StgCAF);
+ break;
+ }
+
+ case CAF_ENTERED:
+ {
+ StgCAF *caf = (StgCAF *)p;
+
+ caf->body = evacuate(caf->body);
+ caf->value = evacuate(caf->value);
+ if (failed_to_evac) {
+ failed_to_evac = rtsFalse;
+ recordOldToNewPtrs((StgMutClosure *)p);
+ } else {
+ caf->mut_link = NULL;
+ }
+ p += sizeofW(StgCAF);
+ break;
+ }
+
+ case MUT_VAR:
+ /* ignore MUT_CONSs */
+ if (((StgMutVar *)p)->header.info != &MUT_CONS_info) {
+ evac_gen = 0;
+ ((StgMutVar *)p)->var = evacuate(((StgMutVar *)p)->var);
+ evac_gen = saved_evac_gen;
+ }
+ p += sizeofW(StgMutVar);
+ break;
+
+ case CAF_BLACKHOLE:
+ case SE_CAF_BLACKHOLE:
+ case SE_BLACKHOLE:
+ case BLACKHOLE:
+ p += BLACKHOLE_sizeW();
+ break;
+
+ case BLACKHOLE_BQ:
+ {
+ StgBlockingQueue *bh = (StgBlockingQueue *)p;
+ (StgClosure *)bh->blocking_queue =
+ evacuate((StgClosure *)bh->blocking_queue);
+ if (failed_to_evac) {
+ failed_to_evac = rtsFalse;
+ recordMutable((StgMutClosure *)bh);
+ }
+ p += BLACKHOLE_sizeW();
+ break;
+ }
+
+ case THUNK_SELECTOR:
+ {
+ StgSelector *s = (StgSelector *)p;
+ s->selectee = evacuate(s->selectee);
+ p += THUNK_SELECTOR_sizeW();
+ break;
+ }
+
+ case IND:
+ case IND_OLDGEN:
+ barf("scavenge:IND???\n");
+
+ case CONSTR_INTLIKE:
+ case CONSTR_CHARLIKE:
+ case CONSTR_STATIC:
+ case CONSTR_NOCAF_STATIC:
+ case THUNK_STATIC:
+ case FUN_STATIC:
+ case IND_STATIC:
+ /* Shouldn't see a static object here. */
+ barf("scavenge: STATIC object\n");
+
+ case RET_BCO:
+ case RET_SMALL:
+ case RET_VEC_SMALL:
+ case RET_BIG:
+ case RET_VEC_BIG:
+ case RET_DYN:
+ case UPDATE_FRAME:
+ case STOP_FRAME:
+ case CATCH_FRAME:
+ case SEQ_FRAME:
+ /* Shouldn't see stack frames here. */
+ barf("scavenge: stack frame\n");
+
+ case AP_UPD: /* same as PAPs */
+ case PAP:
+ /* Treat a PAP just like a section of stack, not forgetting to
+ * evacuate the function pointer too...
+ */
+ {
+ StgPAP* pap = stgCast(StgPAP*,p);
+
+ pap->fun = evacuate(pap->fun);
+ scavenge_stack((P_)pap->payload, (P_)pap->payload + pap->n_args);
+ p += pap_sizeW(pap);
+ break;
+ }
+
+ case ARR_WORDS:
+ /* nothing to follow */
+ p += arr_words_sizeW(stgCast(StgArrWords*,p));
+ break;
+
+ case MUT_ARR_PTRS:
+ /* follow everything */
+ {
+ StgPtr next;
+
+ evac_gen = 0; /* repeatedly mutable */
+ next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
+ for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
+ (StgClosure *)*p = evacuate((StgClosure *)*p);
+ }
+ evac_gen = saved_evac_gen;
+ break;
+ }
+
+ case MUT_ARR_PTRS_FROZEN:
+ /* follow everything */
+ {
+ StgPtr start = p, next;
+
+ next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
+ for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
+ (StgClosure *)*p = evacuate((StgClosure *)*p);
+ }
+ if (failed_to_evac) {
+ /* we can do this easier... */
+ recordMutable((StgMutClosure *)start);
+ failed_to_evac = rtsFalse;
+ }
+ break;
+ }
+
+ case TSO:
+ {
+ StgTSO *tso;
+
+ tso = (StgTSO *)p;
+ evac_gen = 0;
+ /* chase the link field for any TSOs on the same queue */
+ (StgClosure *)tso->link = evacuate((StgClosure *)tso->link);
+ if ( tso->why_blocked == BlockedOnMVar
+ || tso->why_blocked == BlockedOnBlackHole) {
+ tso->block_info.closure = evacuate(tso->block_info.closure);
+ }
+ /* scavenge this thread's stack */
+ scavenge_stack(tso->sp, &(tso->stack[tso->stack_size]));
+ evac_gen = saved_evac_gen;
+ p += tso_sizeW(tso);
+ break;
+ }
+
+ case BLOCKED_FETCH:
+ case FETCH_ME:
+ case EVACUATED:
+ barf("scavenge: unimplemented/strange closure type\n");
+
+ default:
+ barf("scavenge");
+ }
+
+ /* If we didn't manage to promote all the objects pointed to by
+ * the current object, then we have to designate this object as
+ * mutable (because it contains old-to-new generation pointers).
+ */
+ if (failed_to_evac) {
+ mkMutCons((StgClosure *)q, &generations[evac_gen]);
+ failed_to_evac = rtsFalse;
+ }
+ }
+
+ step->scan_bd = bd;
+ step->scan = p;
+}
+
+/* -----------------------------------------------------------------------------
+ Scavenge one object.
+
+ This is used for objects that are temporarily marked as mutable
+ because they contain old-to-new generation pointers. Only certain
+ objects can have this property.
+ -------------------------------------------------------------------------- */
+static rtsBool
+scavenge_one(StgClosure *p)
+{
+ const StgInfoTable *info;
+ rtsBool no_luck;
+
+ ASSERT(p && (LOOKS_LIKE_GHC_INFO(GET_INFO(p))
+ || IS_HUGS_CONSTR_INFO(GET_INFO(p))));
+
+ info = get_itbl(p);
+
+ switch (info -> type) {
+
+ case FUN:
+ case FUN_1_0: /* hardly worth specialising these guys */
+ case FUN_0_1:
+ case FUN_1_1:
+ case FUN_0_2:
+ case FUN_2_0:
+ case THUNK:
+ case THUNK_1_0:
+ case THUNK_0_1:
+ case THUNK_1_1:
+ case THUNK_0_2:
+ case THUNK_2_0:
+ case CONSTR:
+ case CONSTR_1_0:
+ case CONSTR_0_1:
+ case CONSTR_1_1:
+ case CONSTR_0_2:
+ case CONSTR_2_0:
+ case WEAK:
+ case FOREIGN:
+ case IND_PERM:
+ case IND_OLDGEN_PERM:
+ case CAF_UNENTERED:
+ {
+ StgPtr q, end;
+
+ end = (P_)p->payload + info->layout.payload.ptrs;
+ for (q = (P_)p->payload; q < end; q++) {
+ (StgClosure *)*q = evacuate((StgClosure *)*q);
+ }
+ break;
+ }
+
+ case CAF_BLACKHOLE:
+ case SE_CAF_BLACKHOLE:
+ case SE_BLACKHOLE:
+ case BLACKHOLE:
+ break;
+
+ case THUNK_SELECTOR:
+ {
+ StgSelector *s = (StgSelector *)p;
+ s->selectee = evacuate(s->selectee);
+ break;
+ }
+
+ case AP_UPD: /* same as PAPs */
+ case PAP:
+ /* Treat a PAP just like a section of stack, not forgetting to
+ * evacuate the function pointer too...
+ */
+ {
+ StgPAP* pap = (StgPAP *)p;
+
+ pap->fun = evacuate(pap->fun);
+ scavenge_stack((P_)pap->payload, (P_)pap->payload + pap->n_args);
+ break;
+ }
+
+ case IND_OLDGEN:
+ /* This might happen if for instance a MUT_CONS was pointing to a
+ * THUNK which has since been updated. The IND_OLDGEN will
+ * be on the mutable list anyway, so we don't need to do anything
+ * here.
+ */
+ break;
+
+ default:
+ barf("scavenge_one: strange object");
+ }
+
+ no_luck = failed_to_evac;
+ failed_to_evac = rtsFalse;
+ return (no_luck);
+}
+
+
+/* -----------------------------------------------------------------------------
+ Scavenging mutable lists.
+
+ We treat the mutable list of each generation > N (i.e. all the
+ generations older than the one being collected) as roots. We also
+ remove non-mutable objects from the mutable list at this point.
+ -------------------------------------------------------------------------- */
+
+static void
+scavenge_mut_once_list(generation *gen)
+{
+ const StgInfoTable *info;
+ StgMutClosure *p, *next, *new_list;