Implement ets:all() using scheduler specific data

1 files changed, 475 insertions, 84 deletions

diff --git a/erts/emulator/beam/erl_db.c b/erts/emulator/beam/erl_db.c
index ad11d72d5f..8c4c76e187 100644
--- a/erts/emulator/beam/erl_db.c
+++ b/erts/emulator/beam/erl_db.c
@@ -114,7 +114,12 @@ static struct {
 #define MARK_SLOT_DEAD(i) (meta_main_tab[(i)].u.next_free |= 2)
 #define GET_ANY_SLOT_TAB(i) ((DbTable*)(meta_main_tab[(i)].u.next_free & ~(1|2))) /* dead or alive */
 
+static void
+send_ets_transfer_message(Process *c_p, Process *proc,
+                          ErtsProcLocks *locks,
+                          DbTable *tb, Eterm heir_data);
 static void schedule_free_dbtable(DbTable* tb);
+static void delete_sched_table(Process *c_p, DbTable *tb);
 
 static void table_dec_refc(DbTable *tb, erts_aint_t min_val)
 {
@@ -164,16 +169,32 @@ tid2tab(Eterm tid)
     return tb;
 }
 
+static ERTS_INLINE int
+is_table_alive(DbTable *tb)
+{
+    erts_smp_atomic_t *tbref;
+    DbTable *rtb;
+
+    tbref = erts_smp_binary_to_magic_indirection(tb->common.btid);
+    rtb = (DbTable *) erts_smp_atomic_read_nob(tbref);
+
+    ASSERT(!rtb || rtb == tb);
+
+    return !!rtb;
+}
+
 static ERTS_INLINE void
-tid_clear(DbTable *tb)
+tid_clear(Process *c_p, DbTable *tb)
 {
     DbTable *rtb;
     Binary *btid = tb->common.btid;
     erts_smp_atomic_t *tbref = erts_smp_binary_to_magic_indirection(btid);
     rtb = (DbTable *) erts_smp_atomic_xchg_nob(tbref, (erts_aint_t) NULL);
     ASSERT(!rtb || tb == rtb);
-    if (rtb)
+    if (rtb) {
         table_dec_refc(tb, 1);
+        delete_sched_table(c_p, tb);
+    }
 }
 
 static ERTS_INLINE Eterm
@@ -348,6 +369,99 @@ static void schedule_free_dbtable(DbTable* tb)
 					    sizeof(DbTable));
 }
 
+static ERTS_INLINE void
+save_sched_table(Process *c_p, DbTable *tb)
+{
+    ErtsSchedulerData *esdp = erts_proc_sched_data(c_p);
+    DbTable *first;
+
+    ASSERT(esdp);
+    esdp->ets_tables.count++;
+    erts_smp_refc_inc(&tb->common.refc, 1);
+
+    first = esdp->ets_tables.clist;
+    if (!first) {
+        tb->common.all.next = tb->common.all.prev = tb;
+        esdp->ets_tables.clist = tb;
+    }
+    else {
+        tb->common.all.prev = first->common.all.prev;
+        tb->common.all.next = first;
+        tb->common.all.prev->common.all.next = tb;
+        first->common.all.prev = tb;
+    }
+}
+
+static ERTS_INLINE void
+remove_sched_table(ErtsSchedulerData *esdp, DbTable *tb)
+{
+    ErtsEtsAllYieldData *eaydp;
+    ASSERT(esdp);
+    ASSERT(erts_get_ref_numbers_thr_id(ERTS_MAGIC_BIN_REFN(tb->common.btid))
+           == (Uint32) esdp->no);
+
+    ASSERT(esdp->ets_tables.count > 0);
+    esdp->ets_tables.count--;
+
+    eaydp = ERTS_SCHED_AUX_YIELD_DATA(esdp, ets_all);
+    if (eaydp->ongoing) {
+        /* ets:all() op process list from last to first... */
+        if (eaydp->tab == tb) {
+            if (eaydp->tab == esdp->ets_tables.clist)
+                eaydp->tab = NULL;
+            else
+                eaydp->tab = tb->common.all.prev;
+        }
+    }
+
+    if (tb->common.all.next == tb) {
+        ASSERT(tb->common.all.prev == tb);
+        ASSERT(esdp->ets_tables.clist == tb);
+        esdp->ets_tables.clist = NULL;
+    }
+    else {
+#ifdef DEBUG
+        DbTable *tmp = esdp->ets_tables.clist;
+        do {
+            if (tmp == tb) break;
+            tmp = tmp->common.all.next;
+        } while (tmp != esdp->ets_tables.clist);
+        ASSERT(tmp == tb);
+#endif
+        tb->common.all.prev->common.all.next = tb->common.all.next;
+        tb->common.all.next->common.all.prev = tb->common.all.prev;
+
+        if (esdp->ets_tables.clist == tb)
+            esdp->ets_tables.clist = tb->common.all.next;
+
+    }
+
+    table_dec_refc(tb, 0);
+}
+
+static void
+scheduled_remove_sched_table(void *vtb)
+{
+    remove_sched_table(erts_get_scheduler_data(), (DbTable *) vtb);
+}
+
+static void
+delete_sched_table(Process *c_p, DbTable *tb)
+{
+    ErtsSchedulerData *esdp = erts_proc_sched_data(c_p);
+    Uint32 sid;
+
+    ASSERT(esdp);
+
+    ASSERT(tb->common.btid);
+    sid = erts_get_ref_numbers_thr_id(ERTS_MAGIC_BIN_REFN(tb->common.btid));
+    ASSERT(1 <= sid && sid <= erts_no_schedulers);
+    if (sid == (Uint32) esdp->no)
+        remove_sched_table(esdp, tb);
+    else
+        erts_schedule_misc_aux_work((int) sid, scheduled_remove_sched_table, tb);
+}
+
 static ERTS_INLINE void db_init_lock(DbTable* tb, int use_frequent_read_lock,
 				     char *rwname, char* fixname)
 {
@@ -1322,6 +1436,7 @@ BIF_RETTYPE ets_rename_2(BIF_ALIST_2)
 {
     DbTable* tb;
     Eterm ret;
+    Eterm old_name;
     erts_smp_rwmtx_t *lck1, *lck2;
 
 #ifdef HARDDEBUG
@@ -1338,12 +1453,10 @@ BIF_RETTYPE ets_rename_2(BIF_ALIST_2)
 
     (void) meta_name_tab_bucket(BIF_ARG_2, &lck1);
 
-    if (is_small(BIF_ARG_1)) {
-	Uint slot = unsigned_val(BIF_ARG_1) & meta_main_tab_slot_mask;
-	lck2 = get_meta_main_tab_lock(slot);
-    }
-    else if (is_atom(BIF_ARG_1)) {
-	(void) meta_name_tab_bucket(BIF_ARG_1, &lck2);
+    if (is_atom(BIF_ARG_1)) {
+        old_name = BIF_ARG_1;
+    named_tab:
+	(void) meta_name_tab_bucket(old_name, &lck2);
 	if (lck1 == lck2)
 	    lck2 = NULL;
 	else if (lck1 > lck2) {
@@ -1353,7 +1466,18 @@ BIF_RETTYPE ets_rename_2(BIF_ALIST_2)
 	}
     }
     else {
-	BIF_ERROR(BIF_P, BADARG);
+        Uint slot;
+        tb = tid2tab(BIF_ARG_1);
+        if (!tb)
+            BIF_ERROR(BIF_P, BADARG);
+        else {
+            if (is_atom(tb->common.id)) {
+                old_name = tb->common.id;
+                goto named_tab;
+            }
+            slot = unsigned_val(tb->common.id) & meta_main_tab_slot_mask;
+            lck2 = get_meta_main_tab_lock(slot);
+        }
     }
 
     erts_smp_rwmtx_rwlock(lck1);
@@ -1378,7 +1502,10 @@ BIF_RETTYPE ets_rename_2(BIF_ALIST_2)
     tb->common.id = tb->common.the_name = BIF_ARG_2;
 
  done:
-    ret = tb->common.id;
+    if (is_atom(tb->common.id))
+        ret = tb->common.id;
+    else
+        ret = BIF_ARG_1;
     db_unlock(tb, LCK_WRITE);
     erts_smp_rwmtx_rwunlock(lck1);
     if (lck2)
@@ -1622,6 +1749,8 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
     if (!is_named)
         ret = make_tid(BIF_P, tb);
 
+    save_sched_table(BIF_P, tb);
+
     mmtl = get_meta_main_tab_lock(slot);
     erts_smp_rwmtx_rwlock(mmtl);
     meta_main_tab[slot].u.tb = tb;
@@ -1634,7 +1763,7 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
 	free_slot(slot);
 	erts_smp_rwmtx_rwunlock(mmtl);
 
-        tid_clear(tb);
+        tid_clear(BIF_P, tb);
 
 	db_lock(tb,LCK_WRITE);
 	free_heir_data(tb);
@@ -1825,7 +1954,7 @@ BIF_RETTYPE ets_delete_1(BIF_ALIST_1)
 	UnUseTmpHeap(3,BIF_P);
     }    
 
-    tid_clear(tb);
+    tid_clear(BIF_P, tb);
 
     mmtl = get_meta_main_tab_lock(tb->common.slot);
 #ifdef ERTS_SMP
@@ -1913,12 +2042,8 @@ BIF_RETTYPE ets_give_away_3(BIF_ALIST_3)
     db_meta_unlock(meta_pid_to_tab, LCK_WRITE_REC);
 
     db_unlock(tb,LCK_WRITE);
-    erts_send_message(BIF_P, to_proc, &to_locks,
-		      TUPLE4(buf, am_ETS_TRANSFER,
-			     tb->common.id,
-			     from_pid,
-			     BIF_ARG_3), 
-                      0);
+    send_ets_transfer_message(BIF_P, to_proc, &to_locks,
+                              tb, BIF_ARG_3);
     erts_smp_proc_unlock(to_proc, to_locks);
     UnUseTmpHeap(5,BIF_P);
     BIF_RET(am_true);
@@ -2188,46 +2313,254 @@ BIF_RETTYPE ets_select_delete_2(BIF_ALIST_2)
     return result;
 }
 
-/* 
-** Return a list of tables on this node 
-*/
-BIF_RETTYPE ets_all_0(BIF_ALIST_0)
+/*
+ * ets:all/0
+ *
+ * ets:all() calls ets:internal_request_all/0 which
+ * requests information about all tables from
+ * each scheduler thread. Each scheduler replies
+ * to the calling process with information about
+ * existing tables created on that specific scheduler.
+ */
+
+struct ErtsEtsAllReq_ {
+    erts_smp_atomic32_t refc;
+    Process *proc;
+    ErtsOIRefStorage ref;
+    ErtsEtsAllReqList list[1]; /* one per scheduler */
+};
+
+#define ERTS_ETS_ALL_REQ_SIZE           \
+    (sizeof(ErtsEtsAllReq)              \
+     + (sizeof(ErtsEtsAllReqList)       \
+        * (erts_no_schedulers - 1)))
+
+typedef struct {
+    ErtsEtsAllReq *ongoing;
+    ErlHeapFragment *hfrag;
+    DbTable *tab;
+    ErtsEtsAllReq *queue;
+} ErtsEtsAllData;
+
+/* Tables handled before yielding */
+#define ERTS_ETS_ALL_TB_YCNT 200
+/*
+ * Min yield count required before starting
+ * an operation that will require yield.
+ */
+#define ERTS_ETS_ALL_TB_YCNT_START 10
+
+#ifdef DEBUG
+/* Test yielding... */
+#undef ERTS_ETS_ALL_TB_YCNT
+#undef ERTS_ETS_ALL_TB_YCNT_START
+#define ERTS_ETS_ALL_TB_YCNT 10
+#define ERTS_ETS_ALL_TB_YCNT_START 1
+#endif
+
+static int
+ets_all_reply(ErtsSchedulerData *esdp, ErtsEtsAllReq **reqpp,
+              ErlHeapFragment **hfragpp, DbTable **tablepp,
+              int *yield_count_p)
 {
-    DbTable* tb;
-    Eterm previous;
-    int i;
-    Eterm* hp;
-    Eterm* hendp;
-    int t_tabs_cnt;
-    int t_top;
+    ErtsEtsAllReq *reqp = *reqpp;
+    ErlHeapFragment *hfragp = *hfragpp;
+    int ycount = *yield_count_p;
+    DbTable *tb, *first;
+    Uint sz;
+    Eterm list, msg, ref, *hp;
+    ErlOffHeap *ohp;
+    ErtsMessage *mp;
 
-    erts_smp_spin_lock(&meta_main_tab_main_lock);
-    t_tabs_cnt = meta_main_tab_cnt;
-    t_top = meta_main_tab_top;
-    erts_smp_spin_unlock(&meta_main_tab_main_lock);
+    /*
+     * - save_sched_table() inserts at end of circular list.
+     *
+     * - This function scans from the end so we know that
+     *   the amount of tables to scan wont grow even if we
+     *   yield.
+     *
+     * - remove_sched_table() updates the table we yielded
+     *   on if it removes it.
+     */
+
+    if (hfragp) {
+        /* Restart of a yielded operation... */
+        ASSERT(hfragp->used_size < hfragp->alloc_size);
+        ohp = &hfragp->off_heap;
+        hp = &hfragp->mem[hfragp->used_size];
+        list = *hp;
+        hfragp->used_size = hfragp->alloc_size;
+        first = esdp->ets_tables.clist;
+        tb = *tablepp;
+    }
+    else {
+        /* A new operation... */
+        ASSERT(!*tablepp);
 
-    hp = HAlloc(BIF_P, 2*t_tabs_cnt);
-    hendp = hp + 2*t_tabs_cnt;
+        /* Max heap size needed... */
+        sz = esdp->ets_tables.count;
+        sz *= ERTS_MAGIC_REF_THING_SIZE + 2;
+        sz += 3 + ERTS_REF_THING_SIZE;
+        hfragp = new_message_buffer(sz);
 
-    previous = NIL;
-    for(i = 0; i < t_top; i++) {
-	erts_smp_rwmtx_t *mmtl = get_meta_main_tab_lock(i);
-	erts_smp_rwmtx_rlock(mmtl);
-	if (IS_SLOT_ALIVE(i)) {
-	    if (hp == hendp) {
-		/* Racing table creator, grab some more heap space */
-		t_tabs_cnt = 10;
-		hp = HAlloc(BIF_P, 2*t_tabs_cnt);
-		hendp = hp + 2*t_tabs_cnt;
-	    }
-	    tb = meta_main_tab[i].u.tb;
-	    previous = CONS(hp, tb->common.id, previous);
-	    hp += 2;
-	}
-	erts_smp_rwmtx_runlock(mmtl);
+        hp = &hfragp->mem[0];
+        ohp = &hfragp->off_heap;
+        list = NIL;
+        first = esdp->ets_tables.clist;
+        tb = first ? first->common.all.prev : NULL;
+    }
+
+    if (tb) {
+        while (1) {
+            if (is_table_alive(tb)) {
+                Eterm tid;
+                if (is_atom(tb->common.id))
+                    tid = tb->common.id;
+                else
+                    tid = erts_mk_magic_ref(&hp, ohp, tb->common.btid);
+                list = CONS(hp, tid, list);
+                hp += 2;
+            }
+
+            if (tb == first)
+                break;
+
+            tb = tb->common.all.prev;
+
+            if (--ycount <= 0) {
+                sz = hp - &hfragp->mem[0];
+                ASSERT(hfragp->alloc_size > sz + 1);
+                *hp = list;
+                hfragp->used_size = sz;
+                *hfragpp = hfragp;
+                *reqpp = reqp;
+                *tablepp = tb;
+                *yield_count_p = 0;
+                return 1; /* Yield! */
+            }
+        }
+    }
+
+    ref = erts_oiref_storage_make_ref(&reqp->ref, &hp);
+    msg = TUPLE2(hp, ref, list);
+    hp += 3;
+
+    sz = hp - &hfragp->mem[0];
+    ASSERT(sz <= hfragp->alloc_size);
+
+    hfragp = erts_resize_message_buffer(hfragp, sz, &msg, 1);
+
+    mp = erts_alloc_message(0, NULL);
+    mp->data.heap_frag = hfragp;
+
+    erts_queue_message(reqp->proc, 0, mp, msg, am_system);
+
+    erts_proc_dec_refc(reqp->proc);
+
+    if (erts_smp_atomic32_dec_read_nob(&reqp->refc) == 0)
+        erts_free(ERTS_ALC_T_ETS_ALL_REQ, reqp);
+
+    *reqpp = NULL;
+    *hfragpp = NULL;
+    *tablepp = NULL;
+    *yield_count_p = ycount;
+
+    return 0;
+}
+
+int
+erts_handle_yielded_ets_all_request(ErtsSchedulerData *esdp,
+                                    ErtsEtsAllYieldData *eaydp)
+{
+    int ix = (int) esdp->no - 1;
+    int yc = ERTS_ETS_ALL_TB_YCNT;
+
+    while (1) {
+        if (!eaydp->ongoing) {
+            ErtsEtsAllReq *ongoing;
+
+            if (!eaydp->queue)
+                return 0; /* All work completed! */
+
+            if (yc < ERTS_ETS_ALL_TB_YCNT_START && yc > esdp->ets_tables.count)
+                return 1; /* Yield! */
+
+            eaydp->ongoing = ongoing = eaydp->queue;
+            if (ongoing->list[ix].next == ongoing)
+                eaydp->queue = NULL;
+            else {
+                ongoing->list[ix].next->list[ix].prev = ongoing->list[ix].prev;
+                ongoing->list[ix].prev->list[ix].next = ongoing->list[ix].next;
+                eaydp->queue = ongoing->list[ix].next;
+            }
+            ASSERT(!eaydp->hfrag);
+            ASSERT(!eaydp->tab);
+        }
+
+        if (ets_all_reply(esdp, &eaydp->ongoing, &eaydp->hfrag, &eaydp->tab, &yc))
+            return 1; /* Yield! */
+    }
+}
+
+static void
+handle_ets_all_request(void *vreq)
+{
+    ErtsSchedulerData *esdp = erts_get_scheduler_data();
+    ErtsEtsAllYieldData *eayp = ERTS_SCHED_AUX_YIELD_DATA(esdp, ets_all);
+    ErtsEtsAllReq *req = (ErtsEtsAllReq *) vreq;
+
+    if (!eayp->ongoing && !eayp->queue) {
+        /* No ets:all() operations ongoing... */
+        ErlHeapFragment *hf = NULL;
+        DbTable *tb = NULL;
+        int yc = ERTS_ETS_ALL_TB_YCNT;
+        if (ets_all_reply(esdp, &req, &hf, &tb, &yc)) {
+            /* Yielded... */
+            ASSERT(hf);
+            eayp->ongoing = req;
+            eayp->hfrag = hf;
+            eayp->tab = tb;
+            erts_notify_new_aux_yield_work(esdp);
+        }
+    }
+    else {
+        /* Ongoing ets:all() operations; queue up this request... */
+        int ix = (int) esdp->no - 1;
+        if (!eayp->queue) {
+            req->list[ix].next = req;
+            req->list[ix].prev = req;
+            eayp->queue = req;
+        }
+        else {
+            req->list[ix].next = eayp->queue;
+            req->list[ix].prev = eayp->queue->list[ix].prev;
+            eayp->queue->list[ix].prev = req;
+            req->list[ix].prev->list[ix].next = req;
+        }
     }
-    HRelease(BIF_P, hendp, hp);
-    BIF_RET(previous);
+}
+
+BIF_RETTYPE ets_internal_request_all_0(BIF_ALIST_0)
+{
+    Eterm ref = erts_make_ref(BIF_P);
+    ErtsEtsAllReq *req = erts_alloc(ERTS_ALC_T_ETS_ALL_REQ,
+                                    ERTS_ETS_ALL_REQ_SIZE);
+    erts_smp_atomic32_init_nob(&req->refc,
+			       (erts_aint32_t) erts_no_schedulers);
+    erts_oiref_storage_save(&req->ref, ref);
+    req->proc = BIF_P;
+    erts_proc_add_refc(BIF_P, (Sint) erts_no_schedulers);
+
+#ifdef ERTS_SMP
+    if (erts_no_schedulers > 1)
+	erts_schedule_multi_misc_aux_work(1,
+					  erts_no_schedulers,
+                                          handle_ets_all_request,
+					  (void *) req);
+#endif
+
+    handle_ets_all_request((void *) req);
+    BIF_RET(ref);
 }
 
 
@@ -2788,7 +3121,7 @@ BIF_RETTYPE ets_info_1(BIF_ALIST_1)
     */
 
     if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_INFO, LCK_READ)) == NULL) {
-	if (is_atom(BIF_ARG_1) || is_small(BIF_ARG_1)) {
+	if (is_atom(BIF_ARG_1) || is_ref(BIF_ARG_1)) {
 	    BIF_RET(am_undefined);
 	}
 	BIF_ERROR(BIF_P, BADARG);
@@ -2850,7 +3183,7 @@ BIF_RETTYPE ets_info_2(BIF_ALIST_2)
     Eterm ret = THE_NON_VALUE;
 
     if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_INFO, LCK_READ)) == NULL) {
-	if (is_atom(BIF_ARG_1) || is_small(BIF_ARG_1)) {
+	if (is_atom(BIF_ARG_1) || is_ref(BIF_ARG_1)) {
 	    BIF_RET(am_undefined);
 	}
 	BIF_ERROR(BIF_P, BADARG);
@@ -3140,6 +3473,19 @@ void init_db(ErtsDbSpinCount db_spin_count)
     ms_delete_all = CONS(hp, ms_delete_all,NIL);
 }
 
+void
+erts_ets_sched_spec_data_init(ErtsSchedulerData *esdp)
+{
+    ErtsEtsAllYieldData *eaydp = ERTS_SCHED_AUX_YIELD_DATA(esdp, ets_all);
+    eaydp->ongoing = NULL;
+    eaydp->hfrag = NULL;
+    eaydp->tab = NULL;
+    eaydp->queue = NULL;
+    esdp->ets_tables.clist = NULL;
+    esdp->ets_tables.count = 0;
+}
+
+
 #define ARRAY_CHUNK 100
 
 typedef enum {
@@ -3288,17 +3634,46 @@ retry:
 	ASSERT(arityval(*tpv) == 1);
 	heir_data = tpv[1];
     }
-    erts_send_message(p, to_proc, &to_locks,
-		      TUPLE4(buf,
-			     am_ETS_TRANSFER,
-			     tb->common.id,
-			     p->common.id,
-			     heir_data), 
-                      0);
+    send_ets_transfer_message(p, to_proc, &to_locks, tb, heir_data);
     erts_smp_proc_unlock(to_proc, to_locks);
     return !0;
 }
 
+static void
+send_ets_transfer_message(Process *c_p, Process *proc,
+                          ErtsProcLocks *locks,
+                          DbTable *tb, Eterm heir_data)
+{
+    Uint hsz, hd_sz;
+    ErtsMessage *mp;
+    Eterm *hp;
+    ErlOffHeap *ohp;
+    Eterm tid, hd_copy, msg, sender;
+
+    hsz = 5;
+    if (is_not_atom(tb->common.id))
+        hsz += ERTS_MAGIC_REF_THING_SIZE;
+    if (is_immed(heir_data))
+        hd_sz = 0;
+    else {
+        hd_sz = size_object(heir_data);
+        hsz += hd_sz;
+    }
+
+    mp = erts_alloc_message_heap(proc, locks, hsz, &hp, &ohp);
+    if (is_atom(tb->common.id))
+        tid = tb->common.id;
+    else
+        tid = erts_mk_magic_ref(&hp, ohp, tb->common.btid);
+    if (!hd_sz)
+        hd_copy = heir_data;
+    else
+        hd_copy = copy_struct(heir_data, hd_sz, &hp, ohp);
+    sender = c_p->common.id;
+    msg = TUPLE4(hp, am_ETS_TRANSFER, tid, sender, hd_copy);
+    erts_queue_message(proc, *locks, mp, msg, sender);
+}
+
 /*
  * erts_db_process_exiting() is called when a process terminates.
  * It returns 0 when completely done, and !0 when it wants to
@@ -3384,7 +3759,7 @@ erts_db_process_exiting(Process *c_p, ErtsProcLocks c_p_locks)
 #endif
 			first_call = (tb->common.status & DB_DELETE) == 0;
 			if (first_call) {
-                            tid_clear(tb);
+                            tid_clear(c_p, tb);
 			    /* Clear all access bits. */
 			    tb->common.status &= ~(DB_PROTECTED
 						   | DB_PUBLIC
@@ -3975,21 +4350,30 @@ static void print_table(fmtfn_t to, void *to_arg, int show,  DbTable* tb)
     erts_print(to, to_arg, "Read Concurrency: %T\n", table_info(NULL, tb, am_read_concurrency));
 }
 
+typedef struct {
+    fmtfn_t to;
+    void *to_arg;
+    int show;
+} ErtsPrintDbInfo;
+
+static void
+db_info_print(DbTable *tb, void *vpdbip)
+{
+    ErtsPrintDbInfo *pdbip = (ErtsPrintDbInfo *) vpdbip;
+    erts_print(pdbip->to, pdbip->to_arg, "=ets:%T\n", tb->common.owner);
+    erts_print(pdbip->to, pdbip->to_arg, "Slot: %bpu\n", (Uint) tb);
+    print_table(pdbip->to, pdbip->to_arg, pdbip->show, tb);
+}
+
 void db_info(fmtfn_t to, void *to_arg, int show)    /* Called by break handler */
 {
-    int i;
-    for (i=0; i < db_max_tabs; i++) 
-	if (IS_SLOT_ALIVE(i)) {
-	    erts_print(to, to_arg, "=ets:%T\n", meta_main_tab[i].u.tb->common.owner);
-	    erts_print(to, to_arg, "Slot: %d\n", i);
-	    print_table(to, to_arg, show, meta_main_tab[i].u.tb);
-	}
-#ifdef DEBUG
-    erts_print(to, to_arg, "=internal_ets: Process to table index\n");
-    print_table(to, to_arg, show, meta_pid_to_tab);
-    erts_print(to, to_arg, "=internal_ets: Process to fixation index\n");
-    print_table(to, to_arg, show, meta_pid_to_fixed_tab);
-#endif
+    ErtsPrintDbInfo pdbi;
+
+    pdbi.to = to;
+    pdbi.to_arg = to_arg;
+    pdbi.show = show;
+
+    erts_db_foreach_table(db_info_print, &pdbi);
 }
 
 Uint
@@ -4004,15 +4388,22 @@ erts_get_ets_misc_mem_size(void)
 void
 erts_db_foreach_table(void (*func)(DbTable *, void *), void *arg)
 {
-    int i, j;
-    j = 0;
-    for(i = 0; (i < db_max_tabs && j < meta_main_tab_cnt); i++) {
-	if (IS_SLOT_ALIVE(i)) {
-	    j++;
-	    (*func)(meta_main_tab[i].u.tb, arg);
-	}
+    int ix;
+
+    ASSERT(erts_smp_thr_progress_is_blocking());
+
+    for (ix = 0; ix < erts_no_schedulers; ix++) {
+        ErtsSchedulerData *esdp = ERTS_SCHEDULER_IX(ix);
+        DbTable *first = esdp->ets_tables.clist;
+        if (first) {
+            DbTable *tb = first;
+            do {
+                if (is_table_alive(tb))
+                    (*func)(tb, arg);
+                tb = tb->common.all.next;
+            } while (tb != first);
+        }
     }
-    ASSERT(j == meta_main_tab_cnt);
 }
 
 /* SMP Note: May only be used when system is locked */