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authorBen Gamari <ben@smart-cactus.org>2019-05-21 21:07:17 -0400
committerBen Gamari <ben@smart-cactus.org>2019-10-22 12:18:39 -0400
commit3bc172a41c43ebe3d81caf4d75f10cfb48218006 (patch)
tree199706db815ae42bb1111a76a952f1621bcd6ba5 /rts
parentb967e470d806656b0f751d40884ae7edfeaa534c (diff)
downloadhaskell-3bc172a41c43ebe3d81caf4d75f10cfb48218006.tar.gz
NonMoving: Clean mut_list
Diffstat (limited to 'rts')
-rw-r--r--rts/sm/NonMovingSweep.c122
1 files changed, 121 insertions, 1 deletions
diff --git a/rts/sm/NonMovingSweep.c b/rts/sm/NonMovingSweep.c
index 0236ef82e9..7af5508afc 100644
--- a/rts/sm/NonMovingSweep.c
+++ b/rts/sm/NonMovingSweep.c
@@ -153,6 +153,126 @@ GNUC_ATTR_HOT void nonmovingSweep(void)
}
}
+/* Must a closure remain on the mutable list?
+ *
+ * A closure must remain if any of the following applies:
+ *
+ * 1. it contains references to a younger generation
+ * 2. it's a mutable closure (e.g. mutable array or MUT_PRIM)
+ */
+static bool is_closure_clean(StgClosure *p)
+{
+ const StgInfoTable *info = get_itbl(p);
+
+#define CLEAN(ptr) (!HEAP_ALLOCED((StgClosure*) ptr) || Bdescr((StgPtr) ptr)->gen == oldest_gen)
+
+ switch (info->type) {
+ case MVAR_CLEAN:
+ case MVAR_DIRTY:
+ {
+ StgMVar *mvar = ((StgMVar *)p);
+ if (!CLEAN(mvar->head)) goto dirty_MVAR;
+ if (!CLEAN(mvar->tail)) goto dirty_MVAR;
+ if (!CLEAN(mvar->value)) goto dirty_MVAR;
+ mvar->header.info = &stg_MVAR_CLEAN_info;
+ return true;
+
+dirty_MVAR:
+ mvar->header.info = &stg_MVAR_DIRTY_info;
+ return false;
+ }
+
+ case TVAR:
+ {
+ StgTVar *tvar = ((StgTVar *)p);
+ if (!CLEAN(tvar->current_value)) goto dirty_TVAR;
+ if (!CLEAN(tvar->first_watch_queue_entry)) goto dirty_TVAR;
+ tvar->header.info = &stg_TVAR_CLEAN_info;
+ return true;
+
+dirty_TVAR:
+ tvar->header.info = &stg_TVAR_DIRTY_info;
+ return false;
+ }
+
+ case THUNK:
+ case THUNK_1_0:
+ case THUNK_0_1:
+ case THUNK_1_1:
+ case THUNK_0_2:
+ case THUNK_2_0:
+ {
+ StgPtr end = (StgPtr)((StgThunk *)p)->payload + info->layout.payload.ptrs;
+ for (StgPtr q = (StgPtr)((StgThunk *)p)->payload; q < end; q++) {
+ if (!CLEAN(*q)) return false;
+ }
+ return true;
+ }
+
+ 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 CONSTR:
+ case CONSTR_NOCAF:
+ case CONSTR_1_0:
+ case CONSTR_0_1:
+ case CONSTR_1_1:
+ case CONSTR_0_2:
+ case CONSTR_2_0:
+ case PRIM:
+ {
+ StgPtr end = (StgPtr)((StgClosure *)p)->payload + info->layout.payload.ptrs;
+ for (StgPtr q = (StgPtr)((StgClosure *)p)->payload; q < end; q++) {
+ if (!CLEAN(*q)) return false;
+ }
+ return true;
+ }
+
+ case WEAK:
+ return false; // TODO
+
+ case MUT_VAR_CLEAN:
+ case MUT_VAR_DIRTY:
+ if (!CLEAN(((StgMutVar *)p)->var)) {
+ p->header.info = &stg_MUT_VAR_DIRTY_info;
+ return false;
+ } else {
+ p->header.info = &stg_MUT_VAR_CLEAN_info;
+ return true;
+ }
+
+ case BLOCKING_QUEUE:
+ {
+ StgBlockingQueue *bq = (StgBlockingQueue *)p;
+
+ if (!CLEAN(bq->bh)) goto dirty_BLOCKING_QUEUE;
+ if (!CLEAN(bq->owner)) goto dirty_BLOCKING_QUEUE;
+ if (!CLEAN(bq->queue)) goto dirty_BLOCKING_QUEUE;
+ if (!CLEAN(bq->link)) goto dirty_BLOCKING_QUEUE;
+ bq->header.info = &stg_BLOCKING_QUEUE_CLEAN_info;
+ return true;
+
+dirty_BLOCKING_QUEUE:
+ bq->header.info = &stg_BLOCKING_QUEUE_DIRTY_info;
+ return false;
+ }
+
+ case THUNK_SELECTOR:
+ return CLEAN(((StgSelector *) p)->selectee);
+
+ case ARR_WORDS:
+ return true;
+
+ default:
+ // TODO: the rest
+ return false;
+ }
+#undef CLEAN
+}
+
/* N.B. This happens during the pause so we own all capabilities. */
void nonmovingSweepMutLists()
{
@@ -163,7 +283,7 @@ void nonmovingSweepMutLists()
for (bdescr *bd = old_mut_list; bd; bd = bd->link) {
for (StgPtr p = bd->start; p < bd->free; p++) {
StgClosure **q = (StgClosure**)p;
- if (nonmovingIsAlive(*q)) {
+ if (nonmovingIsAlive(*q) && !is_closure_clean(*q)) {
recordMutableCap(*q, cap, oldest_gen->no);
}
}