Merge branch 'sverker/ets-delete_all_objects-trap/OTP-15078'

* sverker/ets-delete_all_objects-trap/OTP-15078:
  erts: Rename untrapping db_free_*empty*_table
  erts: Make ets:delete_all_objects yield on fixed table
  erts: Optimize ets delete all in fixed table
  erts: Refactor ets select iteration code
  erts: Cleanup ets code
  erts: Optimize ets hash object deallocactions
  erts: Refactor pseudo deleted ets objects
  erts: Make atomic ets:delete_all_objects yield
  erts: Fix reduction bump for ets:delete/1

10 files changed, 919 insertions, 733 deletions

diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab
index 21dda9ff03..7548924178 100644
--- a/erts/emulator/beam/bif.tab
+++ b/erts/emulator/beam/bif.tab
@@ -342,7 +342,6 @@ bif ets:internal_request_all/0
 bif ets:new/2
 bif ets:delete/1
 bif ets:delete/2
-bif ets:delete_all_objects/1
 bif ets:delete_object/2
 bif ets:first/1
 bif ets:is_compiled_ms/1
@@ -373,7 +372,6 @@ bif ets:select_count/2
 bif ets:select_reverse/1
 bif ets:select_reverse/2
 bif ets:select_reverse/3
-bif ets:select_delete/2
 bif ets:select_replace/2
 bif ets:match_spec_compile/1
 bif ets:match_spec_run_r/3
@@ -698,3 +696,5 @@ bif erts_internal:gather_alloc_histograms/1
 bif erts_internal:gather_carrier_info/1
 ubif erlang:map_get/2
 ubif erlang:is_map_key/2
+bif ets:internal_delete_all/2
+bif ets:internal_select_delete/2
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 55450e397f..8b2b1a58c7 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -4682,7 +4682,14 @@ BIF_RETTYPE erts_debug_set_internal_state_2(BIF_ALIST_2)
                                             refbin));
             }
         }
-
+        else if (ERTS_IS_ATOM_STR("ets_force_trap", BIF_ARG_1)) {
+#ifdef ETS_DBG_FORCE_TRAP
+            erts_ets_dbg_force_trap = (BIF_ARG_2 == am_true) ? 1 : 0;
+            BIF_RET(am_ok);
+#else
+            BIF_RET(am_notsup);
+#endif
+        }
     }
 
     BIF_ERROR(BIF_P, BADARG);
diff --git a/erts/emulator/beam/erl_binary.h b/erts/emulator/beam/erl_binary.h
index 46653a8580..7dfd0c273a 100644
--- a/erts/emulator/beam/erl_binary.h
+++ b/erts/emulator/beam/erl_binary.h
@@ -146,9 +146,7 @@ typedef union {
 
 /* A "magic" binary flag */
 #define BIN_FLAG_MAGIC      1
-#define BIN_FLAG_USR1       2 /* Reserved for use by different modules too mark */
-#define BIN_FLAG_USR2       4 /*  certain binaries as special (used by ets) */
-#define BIN_FLAG_DRV        8
+#define BIN_FLAG_DRV        2
 
 #endif /* ERL_BINARY_H__TYPES__ */
 
diff --git a/erts/emulator/beam/erl_db.c b/erts/emulator/beam/erl_db.c
index ca2ebb7c27..3a29f8cf56 100644
--- a/erts/emulator/beam/erl_db.c
+++ b/erts/emulator/beam/erl_db.c
@@ -50,6 +50,34 @@ erts_atomic_t erts_ets_misc_mem_size;
 ** Utility macros
 */
 
+#define DB_BIF_GET_TABLE(TB, WHAT, KIND, BIF_IX) \
+        DB_GET_TABLE(TB, BIF_ARG_1, WHAT, KIND, BIF_IX, NULL, BIF_P)
+
+#define DB_TRAP_GET_TABLE(TB, TID, WHAT, KIND, BIF_EXP) \
+        DB_GET_TABLE(TB, TID, WHAT, KIND, 0, BIF_EXP, BIF_P)
+
+#define DB_GET_TABLE(TB, TID, WHAT, KIND, BIF_IX, BIF_EXP, PROC)         \
+do {                                                                     \
+    Uint freason__;                                                      \
+    if (!(TB = db_get_table(PROC, TID, WHAT, KIND, &freason__))) {       \
+        return db_bif_fail(PROC, freason__, BIF_IX, BIF_EXP);            \
+    }                                                                    \
+}while(0)
+
+static BIF_RETTYPE db_bif_fail(Process* p, Uint freason,
+                               Uint bif_ix, Export* bif_exp)
+{
+    if (freason == TRAP) {
+        if (!bif_exp)
+            bif_exp = bif_export[bif_ix];
+        p->arity = bif_exp->info.mfa.arity;
+        p->i = (BeamInstr*) bif_exp->addressv[erts_active_code_ix()];
+    }
+    p->freason = freason;
+    return THE_NON_VALUE;
+}
+
+
 /* Get a key from any table structure and a tagged object */
 #define TERM_GETKEY(tb, obj) db_getkey((tb)->common.keypos, (obj)) 
 
@@ -326,8 +354,7 @@ struct meta_name_tab_entry* meta_name_tab_bucket(Eterm name,
 typedef enum {
     LCK_READ=1,     /* read only access */
     LCK_WRITE=2,    /* exclusive table write access */
-    LCK_WRITE_REC=3, /* record write access */
-    LCK_NONE=4
+    LCK_WRITE_REC=3 /* record write access */
 } db_lock_kind_t;
 
 extern DbTableMethod db_hash;
@@ -337,9 +364,6 @@ int user_requested_db_max_tabs;
 int erts_ets_realloc_always_moves;
 int erts_ets_always_compress;
 static int db_max_tabs;
-static Eterm ms_delete_all;
-static Eterm ms_delete_all_buff[8]; /* To compare with for deletion 
-				       of all objects */
 
 /* 
 ** Forward decls, static functions 
@@ -351,18 +375,19 @@ static void set_heir(Process* me, DbTable* tb, Eterm heir, UWord heir_data);
 static void free_heir_data(DbTable*);
 static SWord free_fixations_locked(Process* p, DbTable *tb);
 
+static void delete_all_objects_continue(Process* p, DbTable* tb);
 static SWord free_table_continue(Process *p, DbTable *tb, SWord reds);
 static void print_table(fmtfn_t to, void *to_arg, int show,  DbTable* tb);
-static BIF_RETTYPE ets_select_delete_1(BIF_ALIST_1);
+static BIF_RETTYPE ets_select_delete_trap_1(BIF_ALIST_1);
 static BIF_RETTYPE ets_select_count_1(BIF_ALIST_1);
 static BIF_RETTYPE ets_select_replace_1(BIF_ALIST_1);
 static BIF_RETTYPE ets_select_trap_1(BIF_ALIST_1);
 static BIF_RETTYPE ets_delete_trap(BIF_ALIST_1);
 static Eterm table_info(Process* p, DbTable* tb, Eterm What);
 
-static BIF_RETTYPE ets_select1(Process* p, Eterm arg1);
-static BIF_RETTYPE ets_select2(Process* p, Eterm arg1, Eterm arg2);
-static BIF_RETTYPE ets_select3(Process* p, Eterm arg1, Eterm arg2, Eterm arg3);
+static BIF_RETTYPE ets_select1(Process* p, int bif_ix, Eterm arg1);
+static BIF_RETTYPE ets_select2(Process* p, DbTable*, Eterm tid, Eterm ms);
+static BIF_RETTYPE ets_select3(Process* p, DbTable*, Eterm tid, Eterm ms, Sint chunk_size);
 
 
 /* 
@@ -636,15 +661,42 @@ static ERTS_INLINE void db_unlock(DbTable* tb, db_lock_kind_t kind)
     }
 }
 
+static ERTS_INLINE int db_is_exclusive(DbTable* tb, db_lock_kind_t kind)
+{
+    return kind != LCK_READ && tb->common.is_thread_safe;
+}
+
+static DbTable* handle_lacking_permission(Process* p, DbTable* tb,
+                                          db_lock_kind_t kind,
+                                          Uint* freason_p)
+{
+    if (tb->common.status & DB_BUSY) {
+        if (!db_is_exclusive(tb, kind)) {
+            db_unlock(tb, kind);
+            db_lock(tb, LCK_WRITE);
+        }
+        delete_all_objects_continue(p, tb);
+        db_unlock(tb, LCK_WRITE);
+        tb = NULL;
+        *freason_p = TRAP;
+    }
+    else if (p->common.id != tb->common.owner) {
+        db_unlock(tb, kind);
+        tb = NULL;
+        *freason_p = BADARG;
+    }
+    return tb;
+}
+
 static ERTS_INLINE
 DbTable* db_get_table_aux(Process *p,
 			  Eterm id,
 			  int what,
 			  db_lock_kind_t kind,
-			  int meta_already_locked)
+			  int meta_already_locked,
+                          Uint* freason_p)
 {
     DbTable *tb;
-    erts_rwmtx_t *mtl = NULL;
 
     /*
      * IMPORTANT: Only scheduler threads are allowed
@@ -654,13 +706,13 @@ DbTable* db_get_table_aux(Process *p,
     ASSERT(erts_get_scheduler_data());
 
     if (is_atom(id)) {
+        erts_rwmtx_t *mtl;
 	struct meta_name_tab_entry* bucket = meta_name_tab_bucket(id,&mtl);
 	if (!meta_already_locked)
 	    erts_rwmtx_rlock(mtl);
 	else{
 	    ERTS_LC_ASSERT(erts_lc_rwmtx_is_rlocked(mtl)
 			       || erts_lc_rwmtx_is_rwlocked(mtl));
-	    mtl = NULL;
 	}
         tb = NULL;
 	if (bucket->pu.tb != NULL) {
@@ -679,20 +731,29 @@ DbTable* db_get_table_aux(Process *p,
 		}
 	    }
 	}
+        if (!meta_already_locked)
+            erts_rwmtx_runlock(mtl);
     }
     else
         tb = tid2tab(id);
 
     if (tb) {
 	db_lock(tb, kind);
-	if ((tb->common.status & what) == 0
-            && p->common.id != tb->common.owner) {
-	    db_unlock(tb, kind);
-	    tb = NULL;
-	}
+#ifdef ETS_DBG_FORCE_TRAP
+        if (erts_atomic_read_nob(&tb->common.dbg_force_trap) &&
+            erts_atomic_add_read_nob(&tb->common.dbg_force_trap, 2) & 2) {
+            db_unlock(tb, kind);
+            tb = NULL;
+            *freason_p = TRAP;
+        }
+        else
+#endif
+	if (ERTS_UNLIKELY(!(tb->common.status & what)))
+            tb = handle_lacking_permission(p, tb, kind, freason_p);
     }
-    if (mtl)
-	erts_rwmtx_runlock(mtl);
+    else
+        *freason_p = BADARG;
+
     return tb;
 }
 
@@ -700,9 +761,10 @@ static ERTS_INLINE
 DbTable* db_get_table(Process *p,
 		      Eterm id,
 		      int what,
-		      db_lock_kind_t kind)
+		      db_lock_kind_t kind,
+                      Uint* freason_p)
 {
-    return db_get_table_aux(p, id, what, kind, 0);
+    return db_get_table_aux(p, id, what, kind, 0, freason_p);
 }
 
 static int insert_named_tab(Eterm name_atom, DbTable* tb, int have_lock)
@@ -868,9 +930,7 @@ BIF_RETTYPE ets_safe_fixtable_2(BIF_ALIST_2)
 #endif
     kind = (BIF_ARG_2 == am_true) ? LCK_READ : LCK_WRITE_REC; 
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_READ, kind)) == NULL) {
-	    BIF_ERROR(BIF_P, BADARG);
-	}
+    DB_BIF_GET_TABLE(tb, DB_READ, kind, BIF_ets_safe_fixtable_2);
 
     if (BIF_ARG_2 == am_true) {
 	fix_table_locked(BIF_P, tb);
@@ -900,11 +960,7 @@ BIF_RETTYPE ets_first_1(BIF_ALIST_1)
 
     CHECK_TABLES();
 
-    tb = db_get_table(BIF_P, BIF_ARG_1, DB_READ, LCK_READ);
-
-    if (!tb) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_first_1);
 
     cret = tb->common.meth->db_first(BIF_P, tb, &ret);
 
@@ -927,11 +983,7 @@ BIF_RETTYPE ets_next_2(BIF_ALIST_2)
 
     CHECK_TABLES();
 
-    tb = db_get_table(BIF_P, BIF_ARG_1, DB_READ, LCK_READ);
-
-    if (!tb) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_next_2);
 
     cret = tb->common.meth->db_next(BIF_P, tb, BIF_ARG_2, &ret);
 
@@ -954,11 +1006,7 @@ BIF_RETTYPE ets_last_1(BIF_ALIST_1)
 
     CHECK_TABLES();
 
-    tb = db_get_table(BIF_P, BIF_ARG_1, DB_READ, LCK_READ);
-
-    if (!tb) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_last_1);
 
     cret = tb->common.meth->db_last(BIF_P, tb, &ret);
 
@@ -981,11 +1029,7 @@ BIF_RETTYPE ets_prev_2(BIF_ALIST_2)
 
     CHECK_TABLES();
 
-    tb = db_get_table(BIF_P, BIF_ARG_1, DB_READ, LCK_READ);
-
-    if (!tb) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_prev_2);
 
     cret = tb->common.meth->db_prev(BIF_P,tb,BIF_ARG_2,&ret);
 
@@ -1003,21 +1047,15 @@ BIF_RETTYPE ets_prev_2(BIF_ALIST_2)
 BIF_RETTYPE ets_take_2(BIF_ALIST_2)
 {
     DbTable* tb;
-#ifdef DEBUG
     int cret;
-#endif
     Eterm ret;
     CHECK_TABLES();
 
-    tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE_REC);
-    if (!tb) {
-        BIF_ERROR(BIF_P, BADARG);
-    }
-#ifdef DEBUG
-    cret =
-#endif
-        tb->common.meth->db_take(BIF_P, tb, BIF_ARG_2, &ret);
-    ASSERT(cret == DB_ERROR_NONE);
+    DB_BIF_GET_TABLE(tb, DB_WRITE, LCK_WRITE_REC, BIF_ets_take_2);
+
+    cret = tb->common.meth->db_take(BIF_P, tb, BIF_ARG_2, &ret);
+
+    ASSERT(cret == DB_ERROR_NONE); (void)cret;
     db_unlock(tb, LCK_WRITE_REC);
     BIF_RET(ret);
 }
@@ -1035,9 +1073,8 @@ BIF_RETTYPE ets_update_element_3(BIF_ALIST_3)
     DeclareTmpHeap(cell,2,BIF_P);
     DbUpdateHandle handle;
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE_REC)) == NULL) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_WRITE, LCK_WRITE_REC, BIF_ets_update_element_3);
+
     UseTmpHeap(2,BIF_P);
     if (!(tb->common.status & (DB_SET | DB_ORDERED_SET))) {
 	goto bail_out;
@@ -1108,9 +1145,9 @@ bail_out:
 }
 
 static BIF_RETTYPE
-do_update_counter(Process *p, Eterm arg1, Eterm arg2, Eterm arg3, Eterm arg4)
+do_update_counter(Process *p, DbTable* tb,
+                  Eterm arg2, Eterm arg3, Eterm arg4)
 {
-    DbTable* tb;
     int cret = DB_ERROR_BADITEM;
     Eterm upop_list;
     int list_size;
@@ -1126,10 +1163,6 @@ do_update_counter(Process *p, Eterm arg1, Eterm arg2, Eterm arg3, Eterm arg4)
     Eterm* hstart;
     Eterm* hend;
 
-    if ((tb = db_get_table(p, arg1, DB_WRITE, LCK_WRITE_REC)) == NULL) {
-        BIF_ERROR(p, BADARG);
-    }
-
     UseTmpHeap(5, p);
 
     if (!(tb->common.status & (DB_SET | DB_ORDERED_SET))) {
@@ -1303,7 +1336,11 @@ bail_out:
 */
 BIF_RETTYPE ets_update_counter_3(BIF_ALIST_3)
 {
-    return do_update_counter(BIF_P, BIF_ARG_1, BIF_ARG_2, BIF_ARG_3, THE_NON_VALUE);
+    DbTable* tb;
+
+    DB_BIF_GET_TABLE(tb, DB_WRITE, LCK_WRITE_REC, BIF_ets_update_counter_3);
+
+    return do_update_counter(BIF_P, tb, BIF_ARG_2, BIF_ARG_3, THE_NON_VALUE);
 }
 
 /*
@@ -1315,10 +1352,14 @@ BIF_RETTYPE ets_update_counter_3(BIF_ALIST_3)
 */
 BIF_RETTYPE ets_update_counter_4(BIF_ALIST_4)
 {
+    DbTable* tb;
+
     if (is_not_tuple(BIF_ARG_4)) {
         BIF_ERROR(BIF_P, BADARG);
     }
-    return do_update_counter(BIF_P, BIF_ARG_1, BIF_ARG_2, BIF_ARG_3, BIF_ARG_4);
+    DB_BIF_GET_TABLE(tb, DB_WRITE, LCK_WRITE_REC, BIF_ets_update_counter_4);
+
+    return do_update_counter(BIF_P, tb, BIF_ARG_2, BIF_ARG_3, BIF_ARG_4);
 }
 
 
@@ -1339,9 +1380,8 @@ BIF_RETTYPE ets_insert_2(BIF_ALIST_2)
     kind = ((is_list(BIF_ARG_2) && CDR(list_val(BIF_ARG_2)) != NIL)
 	    ? LCK_WRITE : LCK_WRITE_REC);
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, kind)) == NULL) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_WRITE, kind, BIF_ets_insert_2);
+
     if (BIF_ARG_2 == NIL) {
 	db_unlock(tb, kind);
 	BIF_RET(am_true);
@@ -1407,11 +1447,9 @@ BIF_RETTYPE ets_insert_new_2(BIF_ALIST_2)
 
 	    /* More than one object, use LCK_WRITE to keep atomicity */
 	    kind = LCK_WRITE;
-	    tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, kind);
-	    if (tb == NULL) {
-		BIF_ERROR(BIF_P, BADARG);
-	    }
-	    meth = tb->common.meth;
+            DB_BIF_GET_TABLE(tb, DB_WRITE, kind, BIF_ets_insert_new_2);
+
+            meth = tb->common.meth;
 	    for (lst = BIF_ARG_2; is_list(lst); lst = CDR(list_val(lst))) {
 		if (is_not_tuple(CAR(list_val(lst)))
 		    || (arityval(*tuple_val(CAR(list_val(lst))))
@@ -1446,9 +1484,8 @@ BIF_RETTYPE ets_insert_new_2(BIF_ALIST_2)
     /* Only one object (or NIL) 
     */
     kind = LCK_WRITE_REC;
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, kind)) == NULL) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_WRITE, kind, BIF_ets_insert_new_2);
+
     if (BIF_ARG_2 == NIL) {
 	db_unlock(tb, kind);
 	BIF_RET(am_true);
@@ -1487,6 +1524,7 @@ BIF_RETTYPE ets_rename_2(BIF_ALIST_2)
     Eterm ret;
     Eterm old_name;
     erts_rwmtx_t *lck1, *lck2;
+    Uint freason;
 
 #ifdef HARDDEBUG
     erts_fprintf(stderr,
@@ -1531,9 +1569,9 @@ BIF_RETTYPE ets_rename_2(BIF_ALIST_2)
     if (lck2)
 	erts_rwmtx_rwlock(lck2);
 
-    tb = db_get_table_aux(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE, 1);
+    tb = db_get_table_aux(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE, 1, &freason);
     if (!tb)
-	goto badarg;
+	goto fail;
 
     if (is_table_named(tb)) {
         if (!insert_named_tab(BIF_ARG_2, tb, 1))
@@ -1553,13 +1591,18 @@ BIF_RETTYPE ets_rename_2(BIF_ALIST_2)
     if (lck2)
 	erts_rwmtx_rwunlock(lck2);
     BIF_RET(ret);
- badarg:
+
+badarg:
+    freason = BADARG;
+
+fail:
     if (tb)
 	db_unlock(tb, LCK_WRITE);
     erts_rwmtx_rwunlock(lck1);
     if (lck2)
 	erts_rwmtx_rwunlock(lck2);
-    BIF_ERROR(BIF_P, BADARG);    
+
+    return db_bif_fail(BIF_P, freason, BIF_ets_rename_2, NULL);
 }
 
 
@@ -1580,9 +1623,7 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
     Sint keypos;
     int is_named, is_compressed;
     int is_fine_locked, frequent_read;
-#ifdef DEBUG
     int cret;
-#endif
     DbTableMethod* meth;
 
     if (is_not_atom(BIF_ARG_1)) {
@@ -1708,7 +1749,7 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
     tb->common.meth = meth;
     tb->common.the_name = BIF_ARG_1;
     tb->common.status = status;    
-    tb->common.type = status & ERTS_ETS_TABLE_TYPES;
+    tb->common.type = status;
     /* Note, 'type' is *read only* from now on... */
     erts_refc_init(&tb->common.fix_count, 0);
     db_init_lock(tb, status & (DB_FINE_LOCKED|DB_FREQ_READ));
@@ -1720,12 +1761,12 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
 
     tb->common.fixing_procs = NULL;
     tb->common.compress = is_compressed;
-
-#ifdef DEBUG
-    cret = 
+#ifdef ETS_DBG_FORCE_TRAP
+    erts_atomic_init_nob(&tb->common.dbg_force_trap, erts_ets_dbg_force_trap);
 #endif
-	meth->db_create(BIF_P, tb);
-    ASSERT(cret == DB_ERROR_NONE);
+
+    cret = meth->db_create(BIF_P, tb);
+    ASSERT(cret == DB_ERROR_NONE); (void)cret;
 
     make_btid(tb);
 
@@ -1741,7 +1782,7 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
 
 	db_lock(tb,LCK_WRITE);
 	free_heir_data(tb);
-	tb->common.meth->db_free_table(tb);
+	tb->common.meth->db_free_empty_table(tb);
 	db_unlock(tb,LCK_WRITE);
         table_dec_refc(tb, 0);
 	BIF_ERROR(BIF_P, BADARG);
@@ -1767,13 +1808,19 @@ BIF_RETTYPE ets_whereis_1(BIF_ALIST_1)
 {
     DbTable* tb;
     Eterm res;
+    Uint freason;
 
     if (is_not_atom(BIF_ARG_1)) {
         BIF_ERROR(BIF_P, BADARG);
     }
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_INFO, LCK_READ)) == NULL) {
-        BIF_RET(am_undefined);
+    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_INFO, LCK_READ, &freason)) == NULL) {
+        if (freason == BADARG)
+            BIF_RET(am_undefined);
+        else {
+            //ToDo: Could we avoid this
+            return db_bif_fail(BIF_P, freason, BIF_ets_whereis_1, NULL);
+        }
     }
 
     res = make_tid(BIF_P, tb);
@@ -1793,9 +1840,7 @@ BIF_RETTYPE ets_lookup_2(BIF_ALIST_2)
 
     CHECK_TABLES();
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_READ, LCK_READ)) == NULL) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_lookup_2);
 
     cret = tb->common.meth->db_get(BIF_P, tb, BIF_ARG_2, &ret);
 
@@ -1823,9 +1868,7 @@ BIF_RETTYPE ets_member_2(BIF_ALIST_2)
 
     CHECK_TABLES();
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_READ, LCK_READ)) == NULL) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_member_2);
 
     cret = tb->common.meth->db_member(tb, BIF_ARG_2, &ret);
 
@@ -1856,9 +1899,7 @@ BIF_RETTYPE ets_lookup_element_3(BIF_ALIST_3)
 
     CHECK_TABLES();
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_READ, LCK_READ)) == NULL) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_lookup_element_3);
 
     if (is_not_small(BIF_ARG_3) || ((index = signed_val(BIF_ARG_3)) < 1)) {
 	db_unlock(tb, LCK_READ);
@@ -1896,9 +1937,7 @@ BIF_RETTYPE ets_delete_1(BIF_ALIST_1)
 
     CHECK_TABLES();
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE)) == NULL) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_WRITE, LCK_WRITE, BIF_ets_delete_1);
     
     /*
      * Clear all access bits to prevent any ets operation to access the
@@ -1941,7 +1980,8 @@ BIF_RETTYPE ets_delete_1(BIF_ALIST_1)
     reds -= free_fixations_locked(BIF_P, tb);
     db_unlock(tb, LCK_WRITE);
 
-    if (free_table_continue(BIF_P, tb, reds) < 0) {
+    reds = free_table_continue(BIF_P, tb, reds);
+    if (reds < 0) {
 	/*
 	 * Package the DbTable* pointer into a bignum so that it can be safely
 	 * passed through a trap. We used to pass the DbTable* pointer directly
@@ -1970,6 +2010,7 @@ BIF_RETTYPE ets_give_away_3(BIF_ALIST_3)
     Eterm to_pid = BIF_ARG_2;
     Eterm from_pid;
     DbTable* tb = NULL;
+    Uint freason;
 
     if (!is_internal_pid(to_pid)) {
 	goto badarg;
@@ -1979,10 +2020,11 @@ BIF_RETTYPE ets_give_away_3(BIF_ALIST_3)
 	goto badarg;
     }
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE)) == NULL
-	|| tb->common.owner != BIF_P->common.id) {
-	goto badarg;
-    }
+    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE, &freason)) == NULL)
+        goto fail;
+    if (tb->common.owner != BIF_P->common.id)
+        goto badarg;
+
     from_pid = tb->common.owner;
     if (to_pid == from_pid) {
 	goto badarg;  /* or should we be idempotent? return false maybe */
@@ -2001,9 +2043,12 @@ BIF_RETTYPE ets_give_away_3(BIF_ALIST_3)
     BIF_RET(am_true);
 
 badarg:
+    freason = BADARG;
+fail:
     if (to_proc != NULL && to_proc != BIF_P) erts_proc_unlock(to_proc, to_locks);
     if (tb != NULL) db_unlock(tb, LCK_WRITE);
-    BIF_ERROR(BIF_P, BADARG);
+
+    return db_bif_fail(BIF_P, freason, BIF_ets_give_away_3, NULL);
 }
 
 BIF_RETTYPE ets_setopts_2(BIF_ALIST_2)
@@ -2054,11 +2099,13 @@ BIF_RETTYPE ets_setopts_2(BIF_ALIST_2)
 	}
     }
 
-    if (tail != NIL
-	|| (tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE)) == NULL
-	|| tb->common.owner != BIF_P->common.id) {
+    if (tail != NIL)
+        goto badarg;
+
+    DB_BIF_GET_TABLE(tb, DB_WRITE, LCK_WRITE, BIF_ets_setopts_2);
+
+    if (tb->common.owner != BIF_P->common.id)
 	goto badarg;
-    }
 
     if (heir_data != THE_NON_VALUE) {
 	free_heir_data(tb);
@@ -2082,23 +2129,84 @@ badarg:
 }
 
 /* 
-** BIF to erase a whole table and release all memory it holds 
-*/
-BIF_RETTYPE ets_delete_all_objects_1(BIF_ALIST_1)
+ * Common for delete_all_objects and select_delete(DeleteAll).
+ */
+BIF_RETTYPE ets_internal_delete_all_2(BIF_ALIST_2)
 {
+    SWord initial_reds = ERTS_BIF_REDS_LEFT(BIF_P);
+    SWord reds = initial_reds;
+    Eterm nitems;
     DbTable* tb;
 
     CHECK_TABLES();
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE)) == NULL) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_WRITE, LCK_WRITE, BIF_ets_internal_delete_all_2);
 
-    tb->common.meth->db_delete_all_objects(BIF_P, tb);
+    if (BIF_ARG_2 == am_undefined) {
+        nitems = erts_make_integer(erts_atomic_read_nob(&tb->common.nitems),
+                                   BIF_P);
+
+        reds = tb->common.meth->db_delete_all_objects(BIF_P, tb, reds);
+
+        ASSERT(!(tb->common.status & DB_BUSY));
+
+        if (reds < 0) {
+            /*
+             * Oboy, need to trap AND need to be atomic.
+             * Solved by cooperative trapping where every process trying to
+             * access this table (including this process) will "fail" to lookup
+             * the table and instead pitch in deleting objects
+             * (in delete_all_objects_continue) and then trap to self.
+             */
+            ASSERT((tb->common.status & (DB_PRIVATE|DB_PROTECTED|DB_PUBLIC))
+                   ==
+                   (tb->common.type & (DB_PRIVATE|DB_PROTECTED|DB_PUBLIC)));
+            tb->common.status &= ~(DB_PRIVATE|DB_PROTECTED|DB_PUBLIC);
+            tb->common.status |= DB_BUSY;
+            db_unlock(tb, LCK_WRITE);
+            BUMP_ALL_REDS(BIF_P);
+            BIF_TRAP2(bif_export[BIF_ets_internal_delete_all_2], BIF_P,
+                      BIF_ARG_1, nitems);
+        }
+        else {
+            /* Done, no trapping needed */
+            BUMP_REDS(BIF_P, (initial_reds - reds));
+        }
+
+    }
+    else {
+        /*
+         * The table lookup succeeded and second argument is nitems
+         * and not 'undefined', which means we have trapped at least once
+         * and are now done.
+         */
+        nitems = BIF_ARG_2;
+    }
 
     db_unlock(tb, LCK_WRITE);
+    BIF_RET(nitems);
+}
 
-    BIF_RET(am_true);
+static void delete_all_objects_continue(Process* p, DbTable* tb)
+{
+    SWord initial_reds = ERTS_BIF_REDS_LEFT(p);
+    SWord reds = initial_reds;
+
+    ERTS_LC_ASSERT(erts_lc_rwmtx_is_rwlocked(&tb->common.rwlock));
+
+    if ((tb->common.status & (DB_DELETE|DB_BUSY)) != DB_BUSY)
+        return;
+
+    reds = tb->common.meth->db_delete_all_objects(p, tb, reds);
+    
+    if (reds < 0) {
+        BUMP_ALL_REDS(p);
+    }
+    else {
+        tb->common.status |= tb->common.type & (DB_PRIVATE|DB_PROTECTED|DB_PUBLIC);
+        tb->common.status &= ~DB_BUSY;
+        BUMP_REDS(p, (initial_reds - reds));
+    }
 }
 
 /* 
@@ -2114,9 +2222,7 @@ BIF_RETTYPE ets_delete_2(BIF_ALIST_2)
 
     CHECK_TABLES();
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE_REC)) == NULL) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_WRITE, LCK_WRITE_REC, BIF_ets_delete_2);
 
     cret = tb->common.meth->db_erase(tb,BIF_ARG_2,&ret);
 
@@ -2143,9 +2249,8 @@ BIF_RETTYPE ets_delete_object_2(BIF_ALIST_2)
 
     CHECK_TABLES();
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE_REC)) == NULL) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_WRITE, LCK_WRITE_REC, BIF_ets_delete_object_2);
+
     if (is_not_tuple(BIF_ARG_2) || 
 	(arityval(*tuple_val(BIF_ARG_2)) < tb->common.keypos)) {
 	db_unlock(tb, LCK_WRITE_REC);
@@ -2168,7 +2273,7 @@ BIF_RETTYPE ets_delete_object_2(BIF_ALIST_2)
 /*
 ** This is for trapping, cannot be called directly.
 */
-static BIF_RETTYPE ets_select_delete_1(BIF_ALIST_1)
+static BIF_RETTYPE ets_select_delete_trap_1(BIF_ALIST_1)
 {
     Process *p = BIF_P;
     Eterm a1 = BIF_ARG_1;
@@ -2178,15 +2283,14 @@ static BIF_RETTYPE ets_select_delete_1(BIF_ALIST_1)
     Eterm ret;
     Eterm *tptr;
     db_lock_kind_t kind = LCK_WRITE_REC;
-    
+
     CHECK_TABLES();
     ASSERT(is_tuple(a1));
     tptr = tuple_val(a1);
     ASSERT(arityval(*tptr) >= 1);
     
-    if ((tb = db_get_table(p, tptr[1], DB_WRITE, kind)) == NULL) {
-	BIF_ERROR(p,BADARG);
-    }
+    DB_TRAP_GET_TABLE(tb, tptr[1], DB_WRITE, kind,
+                      &ets_select_delete_continue_exp);
 
     cret = tb->common.meth->db_select_delete_continue(p,tb,a1,&ret);
 
@@ -2210,7 +2314,10 @@ static BIF_RETTYPE ets_select_delete_1(BIF_ALIST_1)
 }
     
 
-BIF_RETTYPE ets_select_delete_2(BIF_ALIST_2)
+/*
+ * ets:select_delete/2 without special case for "delete-all".
+ */
+BIF_RETTYPE ets_internal_select_delete_2(BIF_ALIST_2)
 {
     BIF_RETTYPE result;
     DbTable* tb;
@@ -2220,20 +2327,8 @@ BIF_RETTYPE ets_select_delete_2(BIF_ALIST_2)
 
     CHECK_TABLES();
 
-    if(eq(BIF_ARG_2, ms_delete_all)) {
-	int nitems;
-	if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE)) == NULL) {
-	    BIF_ERROR(BIF_P, BADARG);
-	}
-	nitems = erts_atomic_read_nob(&tb->common.nitems);
-	tb->common.meth->db_delete_all_objects(BIF_P, tb);
-	db_unlock(tb, LCK_WRITE);
-	BIF_RET(erts_make_integer(nitems,BIF_P));
-    }
+    DB_BIF_GET_TABLE(tb, DB_WRITE, LCK_WRITE_REC, BIF_ets_internal_select_delete_2);
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE_REC)) == NULL) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
     safety = ITERATION_SAFETY(BIF_P,tb);
     if (safety == ITER_UNSAFE) {
 	local_fix_table(tb);
@@ -2525,9 +2620,8 @@ BIF_RETTYPE ets_slot_2(BIF_ALIST_2)
 
     CHECK_TABLES();
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_READ, LCK_READ)) == NULL) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_slot_2);
+
     /* The slot number is checked in table specific code. */
     cret = tb->common.meth->db_slot(BIF_P, tb, BIF_ARG_2, &ret);
     db_unlock(tb, LCK_READ);
@@ -2547,41 +2641,53 @@ BIF_RETTYPE ets_slot_2(BIF_ALIST_2)
 
 BIF_RETTYPE ets_match_1(BIF_ALIST_1)
 {
-    return ets_select1(BIF_P, BIF_ARG_1);
+    return ets_select1(BIF_P, BIF_ets_match_1, BIF_ARG_1);
 }
 
 BIF_RETTYPE ets_match_2(BIF_ALIST_2)
 {
+    DbTable* tb;
     Eterm ms;
     DeclareTmpHeap(buff,8,BIF_P);
     Eterm *hp = buff;
     Eterm res;
 
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_match_2);
+
     UseTmpHeap(8,BIF_P);
     ms = CONS(hp, am_DollarDollar, NIL);
     hp += 2;
     ms = TUPLE3(hp, BIF_ARG_2, NIL, ms); 
     hp += 4;
     ms = CONS(hp, ms, NIL);
-    res = ets_select2(BIF_P, BIF_ARG_1, ms);
+    res = ets_select2(BIF_P, tb, BIF_ARG_1, ms);
     UnUseTmpHeap(8,BIF_P);
     return res;
 }
 
 BIF_RETTYPE ets_match_3(BIF_ALIST_3)
 {
+    DbTable* tb;
     Eterm ms;
+    Sint chunk_size;
     DeclareTmpHeap(buff,8,BIF_P);
     Eterm *hp = buff;
     Eterm res;
 
+    /* Chunk size strictly greater than 0 */
+    if (is_not_small(BIF_ARG_3) || (chunk_size = signed_val(BIF_ARG_3)) <= 0) {
+        BIF_ERROR(BIF_P, BADARG);
+    }
+
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_match_3);
+
     UseTmpHeap(8,BIF_P);
     ms = CONS(hp, am_DollarDollar, NIL);
     hp += 2;
     ms = TUPLE3(hp, BIF_ARG_2, NIL, ms); 
     hp += 4;
     ms = CONS(hp, ms, NIL);
-    res = ets_select3(BIF_P, BIF_ARG_1, ms, BIF_ARG_3);
+    res = ets_select3(BIF_P, tb, BIF_ARG_1, ms, chunk_size);
     UnUseTmpHeap(8,BIF_P);
     return res;
 }
@@ -2589,34 +2695,35 @@ BIF_RETTYPE ets_match_3(BIF_ALIST_3)
 
 BIF_RETTYPE ets_select_3(BIF_ALIST_3)
 {
-    return ets_select3(BIF_P, BIF_ARG_1, BIF_ARG_2, BIF_ARG_3);
+    DbTable* tb;
+    Sint chunk_size;
+
+    /* Chunk size strictly greater than 0 */
+    if (is_not_small(BIF_ARG_3) || (chunk_size = signed_val(BIF_ARG_3)) <= 0) {
+        BIF_ERROR(BIF_P, BADARG);
+    }
+
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_select_3);
+
+    return ets_select3(BIF_P, tb, BIF_ARG_1, BIF_ARG_2, chunk_size);
 }
 
 static BIF_RETTYPE
-ets_select3(Process* p, Eterm arg1, Eterm arg2, Eterm arg3)
+ets_select3(Process* p, DbTable* tb, Eterm tid, Eterm ms, Sint chunk_size)
 {
     BIF_RETTYPE result;
-    DbTable* tb;
     int cret;
     Eterm ret;
-    Sint chunk_size;
     enum DbIterSafety safety;
 
     CHECK_TABLES();
 
-    /* Chunk size strictly greater than 0 */
-    if (is_not_small(arg3) || (chunk_size = signed_val(arg3)) <= 0) {
-	BIF_ERROR(p, BADARG);
-    }
-    if ((tb = db_get_table(p, arg1, DB_READ, LCK_READ)) == NULL) {
-	BIF_ERROR(p, BADARG);
-    }
     safety = ITERATION_SAFETY(p,tb);
     if (safety == ITER_UNSAFE) {
 	local_fix_table(tb);
     }
-    cret = tb->common.meth->db_select_chunk(p, tb, arg1,
-					    arg2, chunk_size,
+    cret = tb->common.meth->db_select_chunk(p, tb, tid,
+					    ms, chunk_size,
 					    0 /* not reversed */,
 					    &ret);
     if (DID_TRAP(p,ret) && safety != ITER_SAFE) {
@@ -2662,9 +2769,8 @@ static BIF_RETTYPE ets_select_trap_1(BIF_ALIST_1)
     tptr = tuple_val(a1);
     ASSERT(arityval(*tptr) >= 1);
 
-    if ((tb = db_get_table(p, tptr[1], DB_READ, kind)) == NULL) {
-	BIF_ERROR(p, BADARG);
-    }
+    DB_TRAP_GET_TABLE(tb, tptr[1], DB_READ, kind,
+                      &ets_select_continue_exp);
 
     cret = tb->common.meth->db_select_continue(p, tb, a1,
 					       &ret);
@@ -2694,10 +2800,10 @@ static BIF_RETTYPE ets_select_trap_1(BIF_ALIST_1)
 
 BIF_RETTYPE ets_select_1(BIF_ALIST_1)
 {
-    return ets_select1(BIF_P, BIF_ARG_1);
+    return ets_select1(BIF_P, BIF_ets_select_1, BIF_ARG_1);
 }
 
-static BIF_RETTYPE ets_select1(Process *p, Eterm arg1)
+static BIF_RETTYPE ets_select1(Process *p, int bif_ix, Eterm arg1)
 {
     BIF_RETTYPE result;
     DbTable* tb;
@@ -2719,10 +2825,10 @@ static BIF_RETTYPE ets_select1(Process *p, Eterm arg1)
 	BIF_ERROR(p, BADARG);
     }
     tptr = tuple_val(arg1);
-    if (arityval(*tptr) < 1 ||
-	(tb = db_get_table(p, tptr[1], DB_READ, LCK_READ)) == NULL) {
-	BIF_ERROR(p, BADARG);
-    }
+    if (arityval(*tptr) < 1)
+        BIF_ERROR(p, BADARG);
+
+    DB_GET_TABLE(tb, tptr[1], DB_READ, LCK_READ, bif_ix, NULL, p);
 
     safety = ITERATION_SAFETY(p,tb);
     if (safety == ITER_UNSAFE) {
@@ -2758,33 +2864,27 @@ static BIF_RETTYPE ets_select1(Process *p, Eterm arg1)
 
 BIF_RETTYPE ets_select_2(BIF_ALIST_2)
 {
-    return ets_select2(BIF_P, BIF_ARG_1, BIF_ARG_2);
+    DbTable* tb;
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_select_2);
+    return ets_select2(BIF_P, tb, BIF_ARG_1, BIF_ARG_2);
 }
 
 static BIF_RETTYPE
-ets_select2(Process* p, Eterm arg1, Eterm arg2)
+ets_select2(Process* p, DbTable* tb, Eterm tid, Eterm ms)
 {
     BIF_RETTYPE result;
-    DbTable* tb;
     int cret;
     enum DbIterSafety safety;
     Eterm ret;
 
     CHECK_TABLES();
 
-    /*
-     * Make sure that the table exists.
-     */
-
-    if ((tb = db_get_table(p, arg1, DB_READ, LCK_READ)) == NULL) {
-	BIF_ERROR(p, BADARG);
-    }
     safety = ITERATION_SAFETY(p,tb);
     if (safety == ITER_UNSAFE) {
 	local_fix_table(tb);
     }
 
-    cret = tb->common.meth->db_select(p, tb, arg1, arg2, 0, &ret);
+    cret = tb->common.meth->db_select(p, tb, tid, ms, 0, &ret);
 
     if (DID_TRAP(p,ret) && safety != ITER_SAFE) {
 	fix_table_locked(p, tb);
@@ -2827,9 +2927,9 @@ static BIF_RETTYPE ets_select_count_1(BIF_ALIST_1)
 
     tptr = tuple_val(a1);
     ASSERT(arityval(*tptr) >= 1);
-    if ((tb = db_get_table(p, tptr[1], DB_READ, kind)) == NULL) {
-	BIF_ERROR(p, BADARG);
-    }
+
+    DB_TRAP_GET_TABLE(tb, tptr[1], DB_READ, kind,
+                      &ets_select_count_continue_exp);
 
     cret = tb->common.meth->db_select_count_continue(p, tb, a1, &ret);
 
@@ -2864,13 +2964,9 @@ BIF_RETTYPE ets_select_count_2(BIF_ALIST_2)
     Eterm ret;
 
     CHECK_TABLES();
-    /*
-     * Make sure that the table exists.
-     */
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_READ, LCK_READ)) == NULL) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_select_count_2);
+
     safety = ITERATION_SAFETY(BIF_P,tb);
     if (safety == ITER_UNSAFE) {
 	local_fix_table(tb);
@@ -2920,9 +3016,8 @@ static BIF_RETTYPE ets_select_replace_1(BIF_ALIST_1)
     tptr = tuple_val(a1);
     ASSERT(arityval(*tptr) >= 1);
 
-    if ((tb = db_get_table(p, tptr[1], DB_WRITE, kind)) == NULL) {
-        BIF_ERROR(p,BADARG);
-    }
+    DB_TRAP_GET_TABLE(tb, tptr[1], DB_WRITE, kind,
+                      &ets_select_replace_continue_exp);
 
     cret = tb->common.meth->db_select_replace_continue(p,tb,a1,&ret);
 
@@ -2956,9 +3051,7 @@ BIF_RETTYPE ets_select_replace_2(BIF_ALIST_2)
 
     CHECK_TABLES();
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE_REC)) == NULL) {
-        BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_WRITE, LCK_WRITE_REC, BIF_ets_select_replace_2);
 
     if (tb->common.status & DB_BAG) {
         /* Bag implementation presented both semantic consistency
@@ -3009,13 +3102,8 @@ BIF_RETTYPE ets_select_reverse_3(BIF_ALIST_3)
     Sint chunk_size;
 
     CHECK_TABLES();
-    /*
-     * Make sure that the table exists.
-     */
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_READ, LCK_READ)) == NULL) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_select_reverse_3);
     
     /* Chunk size strictly greater than 0 */
     if (is_not_small(BIF_ARG_3) || (chunk_size = signed_val(BIF_ARG_3)) <= 0) {
@@ -3053,7 +3141,7 @@ BIF_RETTYPE ets_select_reverse_3(BIF_ALIST_3)
 
 BIF_RETTYPE ets_select_reverse_1(BIF_ALIST_1)
 {
-    return ets_select1(BIF_P, BIF_ARG_1);
+    return ets_select1(BIF_P, BIF_ets_select_reverse_1, BIF_ARG_1);
 }
 
 BIF_RETTYPE ets_select_reverse_2(BIF_ALIST_2)
@@ -3065,13 +3153,9 @@ BIF_RETTYPE ets_select_reverse_2(BIF_ALIST_2)
     Eterm ret;
 
     CHECK_TABLES();
-    /*
-     * Make sure that the table exists.
-     */
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_READ, LCK_READ)) == NULL) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_select_reverse_2);
+
     safety = ITERATION_SAFETY(BIF_P,tb);
     if (safety == ITER_UNSAFE) {
 	local_fix_table(tb);
@@ -3103,45 +3187,63 @@ BIF_RETTYPE ets_select_reverse_2(BIF_ALIST_2)
 
 
 /* 
-** ets:match_object(Continuation), ets:match_object(Table, Pattern), ets:match_object(Table,Pattern,ChunkSize) 
+** ets:match_object(Continuation)
 */
 BIF_RETTYPE ets_match_object_1(BIF_ALIST_1)
 {
-    return ets_select1(BIF_P, BIF_ARG_1);
+    return ets_select1(BIF_P, BIF_ets_match_object_1, BIF_ARG_1);
 }
 
+/*
+** ets:match_object(Table, Pattern)
+*/
 BIF_RETTYPE ets_match_object_2(BIF_ALIST_2)
 {
+    DbTable* tb;
     Eterm ms;
     DeclareTmpHeap(buff,8,BIF_P);
     Eterm *hp = buff;
     Eterm res;
 
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_match_object_2);
+
     UseTmpHeap(8,BIF_P);
     ms = CONS(hp, am_DollarUnderscore, NIL);
     hp += 2;
     ms = TUPLE3(hp, BIF_ARG_2, NIL, ms); 
     hp += 4;
     ms = CONS(hp, ms, NIL);
-    res = ets_select2(BIF_P, BIF_ARG_1, ms);
+    res = ets_select2(BIF_P, tb, BIF_ARG_1, ms);
     UnUseTmpHeap(8,BIF_P);
     return res;
 }
 
+/*
+** ets:match_object(Table,Pattern,ChunkSize)
+*/
 BIF_RETTYPE ets_match_object_3(BIF_ALIST_3)
 {
+    DbTable* tb;
+    Sint chunk_size;
     Eterm ms;
     DeclareTmpHeap(buff,8,BIF_P);
     Eterm *hp = buff;
     Eterm res;
 
+    /* Chunk size strictly greater than 0 */
+    if (is_not_small(BIF_ARG_3) || (chunk_size = signed_val(BIF_ARG_3)) <= 0) {
+        BIF_ERROR(BIF_P, BADARG);
+    }
+
+    DB_BIF_GET_TABLE(tb, DB_READ, LCK_READ, BIF_ets_match_object_3);
+
     UseTmpHeap(8,BIF_P);
     ms = CONS(hp, am_DollarUnderscore, NIL);
     hp += 2;
     ms = TUPLE3(hp, BIF_ARG_2, NIL, ms); 
     hp += 4;
     ms = CONS(hp, ms, NIL);
-    res = ets_select3(BIF_P, BIF_ARG_1, ms, BIF_ARG_3);
+    res = ets_select3(BIF_P, tb, BIF_ARG_1, ms, chunk_size);
     UnUseTmpHeap(8,BIF_P);
     return res;
 }
@@ -3162,16 +3264,17 @@ BIF_RETTYPE ets_info_1(BIF_ALIST_1)
     Eterm res;
     int i;
     Eterm* hp;
+    Uint freason;
     /*Process* rp = NULL;*/
     /* If/when we implement lockless private tables:
     Eterm owner;
     */
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_INFO, LCK_READ)) == NULL) {
-	if (is_atom(BIF_ARG_1) || is_ref(BIF_ARG_1)) {
+    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_INFO, LCK_READ, &freason)) == NULL) {
+	if (freason == BADARG && (is_atom(BIF_ARG_1) || is_ref(BIF_ARG_1)))
 	    BIF_RET(am_undefined);
-	}
-	BIF_ERROR(BIF_P, BADARG);
+	else
+            return db_bif_fail(BIF_P, freason, BIF_ets_info_1, NULL);
     }
 
     /* If/when we implement lockless private tables:
@@ -3228,12 +3331,13 @@ BIF_RETTYPE ets_info_2(BIF_ALIST_2)
 {
     DbTable* tb;
     Eterm ret = THE_NON_VALUE;
+    Uint freason;
 
-    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_INFO, LCK_READ)) == NULL) {
-	if (is_atom(BIF_ARG_1) || is_ref(BIF_ARG_1)) {
+    if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_INFO, LCK_READ, &freason)) == NULL) {
+	if (freason == BADARG && (is_atom(BIF_ARG_1) || is_ref(BIF_ARG_1)))
 	    BIF_RET(am_undefined);
-	}
-	BIF_ERROR(BIF_P, BADARG);
+        else
+            return db_bif_fail(BIF_P, freason, BIF_ets_info_2, NULL);
     }
     ret = table_info(BIF_P, tb, BIF_ARG_2);
     db_unlock(tb, LCK_READ);
@@ -3321,7 +3425,6 @@ int erts_ets_rwmtx_spin_count = -1;
 void init_db(ErtsDbSpinCount db_spin_count)
 {
     int i;
-    Eterm *hp;
     unsigned bits;
     size_t size;
 
@@ -3403,7 +3506,7 @@ void init_db(ErtsDbSpinCount db_spin_count)
     /* Non visual BIF to trap to. */
     erts_init_trap_export(&ets_select_delete_continue_exp,
 			  am_ets, am_atom_put("delete_trap",11), 1,
-			  &ets_select_delete_1);
+			  &ets_select_delete_trap_1);
 
     /* Non visual BIF to trap to. */
     erts_init_trap_export(&ets_select_count_continue_exp,
@@ -3424,13 +3527,6 @@ void init_db(ErtsDbSpinCount db_spin_count)
     erts_init_trap_export(&ets_delete_continue_exp,
 			  am_ets, am_atom_put("delete_trap",11), 1,
 			  &ets_delete_trap);
-
-    hp = ms_delete_all_buff;
-    ms_delete_all = CONS(hp, am_true, NIL);
-    hp += 2;
-    ms_delete_all = TUPLE3(hp,am_Underscore,NIL,ms_delete_all);
-    hp +=4;
-    ms_delete_all = CONS(hp, ms_delete_all,NIL);
 }
 
 void
@@ -3792,7 +3888,8 @@ unlocked:
 	    erts_rwmtx_runlock(&tb->common.rwlock);
 	    erts_rwmtx_rwlock(&tb->common.rwlock);
 	    *kind_p = LCK_WRITE;
-	    if (tb->common.status & DB_DELETE) return;
+	    if (tb->common.status & (DB_DELETE|DB_BUSY))
+                return;
 	}
 	db_unfix_table_hash(&(tb->hash));
     }
@@ -3940,7 +4037,8 @@ static BIF_RETTYPE ets_delete_trap(BIF_ALIST_1)
 
     ASSERT(*ptr == make_pos_bignum_header(1));
 
-    if (free_table_continue(BIF_P, tb, reds) < 0) {
+    reds = free_table_continue(BIF_P, tb, reds);
+    if (reds < 0) {
         BUMP_ALL_REDS(BIF_P);
         BIF_TRAP1(&ets_delete_continue_exp, BIF_P, cont);
     }
@@ -4321,5 +4419,8 @@ void erts_lcnt_update_db_locks(int enable) {
     erts_schedule_multi_misc_aux_work(0, erts_no_schedulers,
         &lcnt_update_db_locks_per_sched, (void*)(UWord)enable);
 }
-
 #endif /* ERTS_ENABLE_LOCK_COUNT */
+
+#ifdef ETS_DBG_FORCE_TRAP
+erts_aint_t erts_ets_dbg_force_trap = 0;
+#endif
diff --git a/erts/emulator/beam/erl_db.h b/erts/emulator/beam/erl_db.h
index eb6da2c9fb..db86c81914 100644
--- a/erts/emulator/beam/erl_db.h
+++ b/erts/emulator/beam/erl_db.h
@@ -135,6 +135,10 @@ void erts_lcnt_enable_db_lock_count(DbTable *tb, int enable);
 void erts_lcnt_update_db_locks(int enable);
 #endif
 
+#ifdef ETS_DBG_FORCE_TRAP
+extern erts_aint_t erts_ets_dbg_force_trap;
+#endif
+
 #endif /* ERL_DB_H__ */
 
 #if defined(ERTS_WANT_DB_INTERNAL__) && !defined(ERTS_HAVE_DB_INTERNAL__)
diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c
index cb5c496e90..74d63325e6 100644
--- a/erts/emulator/beam/erl_db_hash.c
+++ b/erts/emulator/beam/erl_db_hash.c
@@ -21,6 +21,7 @@
 /*
 ** Implementation of unordered ETS tables.
 ** The tables are implemented as linear dynamic hash tables.
+** https://en.wikipedia.org/wiki/Linear_hashing
 */
 
 /* SMP:
@@ -148,20 +149,14 @@ static ERTS_INLINE Uint hash_to_ix(DbTableHash* tb, HashValue hval)
     return ix;
 }
 
-/* Remember a slot containing a pseudo-deleted item (INVALID_HASH)
- * Return false if we got raced by unfixing thread
- * and the object should be deleted for real.
- */
-static ERTS_INLINE int add_fixed_deletion(DbTableHash* tb, int ix,
-                                          erts_aint_t fixated_by_me)
+
+static ERTS_INLINE int link_fixdel(DbTableHash* tb,
+                                   FixedDeletion* fixd,
+                                   erts_aint_t fixated_by_me)
 {
     erts_aint_t was_next;
     erts_aint_t exp_next;
-    FixedDeletion* fixd = (FixedDeletion*) erts_db_alloc(ERTS_ALC_T_DB_FIX_DEL,
-							 (DbTable *) tb,
-							 sizeof(FixedDeletion));
-    ERTS_ETS_MISC_MEM_ADD(sizeof(FixedDeletion));
-    fixd->slot = ix;
+
     was_next = erts_atomic_read_acqb(&tb->fixdel);
     do { /* Lockless atomic insertion in linked list: */
         if (NFIXED(tb) <= fixated_by_me) {
@@ -178,14 +173,33 @@ static ERTS_INLINE int add_fixed_deletion(DbTableHash* tb, int ix,
     return 1;
 }
 
+/* Remember a slot containing a pseudo-deleted item
+ * Return false if we got raced by unfixing thread
+ * and the object should be deleted for real.
+ */
+static int add_fixed_deletion(DbTableHash* tb, int ix,
+                              erts_aint_t fixated_by_me)
+{
+    FixedDeletion* fixd = (FixedDeletion*) erts_db_alloc(ERTS_ALC_T_DB_FIX_DEL,
+							 (DbTable *) tb,
+							 sizeof(FixedDeletion));
+    ERTS_ETS_MISC_MEM_ADD(sizeof(FixedDeletion));
+    fixd->slot = ix;
+    fixd->all = 0;
+    return link_fixdel(tb, fixd, fixated_by_me);
+}
+
+
+static ERTS_INLINE int is_pseudo_deleted(HashDbTerm* p)
+{
+    return p->pseudo_deleted;
+}
 
-#define MAX_HASH 0xEFFFFFFFUL
-#define INVALID_HASH 0xFFFFFFFFUL
 
 /* optimised version of make_hash (normal case? atomic key) */
 #define MAKE_HASH(term) \
     ((is_atom(term) ? (atom_tab(atom_val(term))->slot.bucket.hvalue) : \
-      make_internal_hash(term, 0)) % MAX_HASH)
+      make_internal_hash(term, 0)) & MAX_HASH_MASK)
 
 #  define DB_HASH_LOCK_MASK (DB_HASH_LOCK_CNT-1)
 #  define GET_LOCK(tb,hval) (&(tb)->locks->lck_vec[(hval) & DB_HASH_LOCK_MASK].lck)
@@ -270,17 +284,22 @@ static ERTS_INLINE Sint next_slot_w(DbTableHash* tb, Uint ix,
 }
 
 
-/*
- * Some special binary flags
- */
-#define BIN_FLAG_ALL_OBJECTS         BIN_FLAG_USR1
-
 
 static ERTS_INLINE void free_term(DbTableHash *tb, HashDbTerm* p)
 {
     db_free_term((DbTable*)tb, p, offsetof(HashDbTerm, dbterm));
 }
 
+static ERTS_INLINE void free_term_list(DbTableHash *tb, HashDbTerm* p)
+{
+    while (p) {
+        HashDbTerm* next = p->next;
+        free_term(tb, p);
+        p = next;
+    }
+}
+
+
 /*
  * Local types 
  */
@@ -290,9 +309,6 @@ struct mp_prefound {
 };
 
 struct mp_info {
-    int all_objects;		/* True if complete objects are always
-				 * returned from the match_spec (can use 
-				 * copy_shallow on the return value) */
     int something_can_match;	/* The match_spec is not "impossible" */
     int key_given;
     struct mp_prefound dlists[10];  /* Default list of "pre-found" buckets */
@@ -402,7 +418,7 @@ static void db_print_hash(fmtfn_t to,
 			  void *to_arg,
 			  int show,
 			  DbTable *tbl);
-static int db_free_table_hash(DbTable *tbl);
+static int db_free_empty_table_hash(DbTable *tbl);
 
 static SWord db_free_table_continue_hash(DbTable *tbl, SWord reds);
 
@@ -411,7 +427,7 @@ static void db_foreach_offheap_hash(DbTable *,
 				    void (*)(ErlOffHeap *, void *),
 				    void *);
 
-static int db_delete_all_objects_hash(Process* p, DbTable* tbl);
+static SWord db_delete_all_objects_hash(Process* p, DbTable* tbl, SWord reds);
 #ifdef HARDDEBUG
 static void db_check_table_hash(DbTableHash *tb);
 #endif
@@ -436,7 +452,8 @@ static ERTS_INLINE void try_shrink(DbTableHash* tb)
 static ERTS_INLINE int has_live_key(DbTableHash* tb, HashDbTerm* b,
 				    Eterm key, HashValue hval)
 {
-    if (b->hvalue != hval) return 0;
+    if (b->hvalue != hval || is_pseudo_deleted(b))
+        return 0;
     else {
 	Eterm itemKey = GETKEY(tb, b->dbterm.tpl);
 	ASSERT(!is_header(itemKey));
@@ -449,7 +466,8 @@ static ERTS_INLINE int has_live_key(DbTableHash* tb, HashDbTerm* b,
 static ERTS_INLINE int has_key(DbTableHash* tb, HashDbTerm* b,
 			       Eterm key, HashValue hval)
 {
-    if (b->hvalue != hval && b->hvalue != INVALID_HASH) return 0;
+    if (b->hvalue != hval)
+        return 0;
     else {
 	Eterm itemKey = GETKEY(tb, b->dbterm.tpl);
 	ASSERT(!is_header(itemKey));
@@ -513,7 +531,7 @@ DbTableMethod db_hash =
     db_select_replace_continue_hash,
     db_take_hash,
     db_delete_all_objects_hash,
-    db_free_table_hash,
+    db_free_empty_table_hash,
     db_free_table_continue_hash,
     db_print_hash,
     db_foreach_offheap_hash,
@@ -570,51 +588,61 @@ SWord db_unfix_table_hash(DbTableHash *tb)
     SWord work = 0;
 
     ERTS_LC_ASSERT(erts_lc_rwmtx_is_rwlocked(&tb->common.rwlock)
-		       || (erts_lc_rwmtx_is_rlocked(&tb->common.rwlock)
-			   && !tb->common.is_thread_safe));
+                   || (erts_lc_rwmtx_is_rlocked(&tb->common.rwlock)
+                       && !tb->common.is_thread_safe));
 restart:
     fixdel = (FixedDeletion*) erts_atomic_xchg_mb(&tb->fixdel,
-                                                      (erts_aint_t) NULL);
-    while (fixdel != NULL) {
-	FixedDeletion *fx = fixdel;
-	int ix = fx->slot;
-	HashDbTerm **bp;
-	HashDbTerm *b;
-	erts_rwmtx_t* lck = WLOCK_HASH(tb,ix);
-
-	if (IS_FIXED(tb)) { /* interrupted by fixer */
-	    WUNLOCK_HASH(lck);
-	    restore_fixdel(tb,fixdel);
-	    if (!IS_FIXED(tb)) {
-		goto restart; /* unfixed again! */
-	    }
-	    return work;
-	}
-	if (ix < NACTIVE(tb)) {
-	    bp = &BUCKET(tb, ix);
-	    b = *bp;
-	    
-	    while (b != NULL) {
-		if (b->hvalue == INVALID_HASH) {
-		    *bp = b->next;
-		    free_term(tb, b);
-		    work++;
-		    b = *bp;
-		} else {
-		    bp = &b->next;
-		    b = b->next;
-		}
-	    }
-	}
-	/* else slot has been joined and purged by shrink() */
-	WUNLOCK_HASH(lck);
-	fixdel = fx->next;
-	erts_db_free(ERTS_ALC_T_DB_FIX_DEL,
-		     (DbTable *) tb,
-		     (void *) fx,
-		     sizeof(FixedDeletion));
-	ERTS_ETS_MISC_MEM_ADD(-sizeof(FixedDeletion));
-	work++;
+                                                  (erts_aint_t) NULL);
+    while (fixdel) {
+        FixedDeletion *free_me;
+
+        do {
+            HashDbTerm **bp;
+            HashDbTerm *b;
+            HashDbTerm *free_us = NULL;
+            erts_rwmtx_t* lck;
+
+            lck = WLOCK_HASH(tb, fixdel->slot);
+
+            if (IS_FIXED(tb)) { /* interrupted by fixer */
+                WUNLOCK_HASH(lck);
+                restore_fixdel(tb,fixdel);
+                if (!IS_FIXED(tb)) {
+                    goto restart; /* unfixed again! */
+                }
+                return work;
+            }
+            if (fixdel->slot < NACTIVE(tb)) {
+                bp = &BUCKET(tb, fixdel->slot);
+                b = *bp;
+
+                while (b != NULL) {
+                    if (is_pseudo_deleted(b)) {
+                        HashDbTerm* nxt = b->next;
+                        b->next = free_us;
+                        free_us = b;
+                        work++;
+                        b = *bp = nxt;
+                    } else {
+                        bp = &b->next;
+                        b = b->next;
+                    }
+                }
+            }
+            /* else slot has been joined and purged by shrink() */
+            WUNLOCK_HASH(lck);
+            free_term_list(tb, free_us);
+
+        }while (fixdel->all && fixdel->slot-- > 0);
+
+        free_me = fixdel;
+        fixdel = fixdel->next;
+        erts_db_free(ERTS_ALC_T_DB_FIX_DEL,
+                     (DbTable *) tb,
+                     (void *) free_me,
+                     sizeof(FixedDeletion));
+        ERTS_ETS_MISC_MEM_ADD(-sizeof(FixedDeletion));
+        work++;
     }
 
     /* ToDo: Maybe try grow/shrink the table as well */
@@ -764,8 +792,9 @@ int db_put_hash(DbTable *tbl, Eterm obj, int key_clash_fail)
     */
     if (tb->common.status & DB_SET) {
 	HashDbTerm* bnext = b->next;
-	if (b->hvalue == INVALID_HASH) {
+	if (is_pseudo_deleted(b)) {
 	    erts_atomic_inc_nob(&tb->common.nitems);
+            b->pseudo_deleted = 0;
 	}
 	else if (key_clash_fail) {
 	    ret = DB_ERROR_BADKEY;
@@ -773,14 +802,14 @@ int db_put_hash(DbTable *tbl, Eterm obj, int key_clash_fail)
 	}
 	q = replace_dbterm(tb, b, obj);
 	q->next = bnext;
-	q->hvalue = hval; /* In case of INVALID_HASH */
+	ASSERT(q->hvalue == hval);
 	*bp = q;
 	goto Ldone;
     }
     else if (key_clash_fail) { /* && (DB_BAG || DB_DUPLICATE_BAG) */
 	q = b;
 	do {
-	    if (q->hvalue != INVALID_HASH) {
+	    if (!is_pseudo_deleted(q)) {
 		ret = DB_ERROR_BADKEY;
 		goto Ldone;
 	    }
@@ -792,9 +821,10 @@ int db_put_hash(DbTable *tbl, Eterm obj, int key_clash_fail)
 	q = b;
 	do {
 	    if (db_eq(&tb->common,obj,&q->dbterm)) {
-		if (q->hvalue == INVALID_HASH) {
+		if (is_pseudo_deleted(q)) {
 		    erts_atomic_inc_nob(&tb->common.nitems);
-		    q->hvalue = hval;
+                    q->pseudo_deleted = 0;
+		    ASSERT(q->hvalue == hval);
 		    if (q != b) { /* must move to preserve key insertion order */
 			*qp = q->next;
 			q->next = b;
@@ -812,6 +842,7 @@ int db_put_hash(DbTable *tbl, Eterm obj, int key_clash_fail)
 Lnew:
     q = new_dbterm(tb, obj);
     q->hvalue = hval;
+    q->pseudo_deleted = 0;
     q->next = b;
     *bp = q;
     nitems = erts_atomic_inc_read_nob(&tb->common.nitems);
@@ -839,7 +870,7 @@ get_term_list(Process *p, DbTableHash *tb, Eterm key, HashValue hval,
 
     if (tb->common.status & (DB_BAG | DB_DUPLICATE_BAG)) {
         while (b2 && has_key(tb, b2, key, hval)) {
-	    if (b2->hvalue != INVALID_HASH)
+	    if (!is_pseudo_deleted(b2))
 		sz += b2->dbterm.size + 2;
 
             b2 = b2->next;
@@ -935,7 +966,7 @@ static int db_get_element_hash(Process *p, DbTable *tbl,
 
 		while(b2 != NULL && has_key(tb,b2,key,hval)) {
 		    if (ndex > arityval(b2->dbterm.tpl[0])
-			&& b2->hvalue != INVALID_HASH) {
+			&& !is_pseudo_deleted(b2)) {
 			retval = DB_ERROR_BADITEM;
 			goto done;
 		    }
@@ -943,7 +974,7 @@ static int db_get_element_hash(Process *p, DbTable *tbl,
 		}
 		b = b1;
 		while(b != b2) {
-		    if (b->hvalue != INVALID_HASH) {
+		    if (!is_pseudo_deleted(b)) {
 			Eterm *hp;
 			Eterm copy = db_copy_element_from_ets(&tb->common, p,
 							      &b->dbterm, ndex, &hp, 2);
@@ -978,6 +1009,7 @@ int db_erase_hash(DbTable *tbl, Eterm key, Eterm *ret)
     int ix;
     HashDbTerm** bp;
     HashDbTerm* b;
+    HashDbTerm* free_us = NULL;
     erts_rwmtx_t* lck;
     int nitems_diff = 0;
 
@@ -993,16 +1025,17 @@ int db_erase_hash(DbTable *tbl, Eterm key, Eterm *ret)
 	    if (nitems_diff == -1 && IS_FIXED(tb)
                 && add_fixed_deletion(tb, ix, 0)) {
 		/* Pseudo remove (no need to keep several of same key) */
-		b->hvalue = INVALID_HASH;
+		b->pseudo_deleted = 1;
 	    } else {
-		*bp = b->next;
-		free_term(tb, b);
-		b = *bp;
+		HashDbTerm* next = b->next;
+                b->next = free_us;
+		free_us = b;
+		b = *bp = next;
 		continue;
 	    }
 	}
 	else {
-	    if (nitems_diff && b->hvalue != INVALID_HASH)
+	    if (nitems_diff && !is_pseudo_deleted(b))
 		break;
 	}
 	bp = &b->next;
@@ -1013,6 +1046,7 @@ int db_erase_hash(DbTable *tbl, Eterm key, Eterm *ret)
 	erts_atomic_add_nob(&tb->common.nitems, nitems_diff);
 	try_shrink(tb);
     }
+    free_term_list(tb, free_us);
     *ret = am_true;
     return DB_ERROR_NONE;
 }    
@@ -1027,6 +1061,7 @@ static int db_erase_object_hash(DbTable *tbl, Eterm object, Eterm *ret)
     int ix;
     HashDbTerm** bp;
     HashDbTerm* b;
+    HashDbTerm* free_us = NULL;
     erts_rwmtx_t* lck;
     int nitems_diff = 0;
     int nkeys = 0;
@@ -1045,13 +1080,14 @@ static int db_erase_object_hash(DbTable *tbl, Eterm object, Eterm *ret)
 	    if (db_eq(&tb->common,object, &b->dbterm)) {
 		--nitems_diff;
 		if (nkeys==1 && IS_FIXED(tb) && add_fixed_deletion(tb,ix,0)) {
-		    b->hvalue = INVALID_HASH;        /* Pseudo remove */
+		    b->pseudo_deleted = 1;
 		    bp = &b->next;
 		    b = b->next;
 		} else {
-		    *bp = b->next;
-		    free_term(tb, b);
-		    b = *bp;
+                    HashDbTerm* next = b->next;
+		    b->next = free_us;
+                    free_us = b;
+		    b = *bp = next;
 		}
 		if (tb->common.status & (DB_DUPLICATE_BAG)) {
 		    continue;
@@ -1060,7 +1096,7 @@ static int db_erase_object_hash(DbTable *tbl, Eterm object, Eterm *ret)
 		}
 	    }
 	}
-	else if (nitems_diff && b->hvalue != INVALID_HASH) {
+	else if (nitems_diff && !is_pseudo_deleted(b)) {
 	    break;
 	}
 	bp = &b->next;
@@ -1071,6 +1107,7 @@ static int db_erase_object_hash(DbTable *tbl, Eterm object, Eterm *ret)
 	erts_atomic_add_nob(&tb->common.nitems, nitems_diff);
 	try_shrink(tb);
     }
+    free_term_list(tb, free_us);
     *ret = am_true;
     return DB_ERROR_NONE;
 }    
@@ -1106,28 +1143,19 @@ static int db_slot_hash(Process *p, DbTable *tbl, Eterm slot_term, Eterm *ret)
 
 
 /*
- * This is just here so I can take care of the return value 
- * that is to be sent during a trap (the BIF_TRAP macros explicitly returns)
- */
-static BIF_RETTYPE bif_trap1(Export *bif,
-			      Process *p, 
-			      Eterm p1) 
-{
-    BIF_TRAP1(bif, p, p1);
-}
-
-
-/*
  * Match traversal callbacks
  */
 
+typedef struct match_callbacks_t_ match_callbacks_t;
+struct match_callbacks_t_
+{
 /* Called when no match is possible.
  *      context_ptr: Pointer to context
  *      ret: Pointer to traversal function term return.
  *
  * Both the direct return value and 'ret' are used as the traversal function return values.
  */
-typedef int (*mtraversal_on_nothing_can_match_t)(void* context_ptr, Eterm* ret);
+    int (*on_nothing_can_match)(match_callbacks_t* ctx, Eterm* ret);
 
 /* Called for each match result.
  *      context_ptr: Pointer to context
@@ -1138,8 +1166,8 @@ typedef int (*mtraversal_on_nothing_can_match_t)(void* context_ptr, Eterm* ret);
  *
  * Should return 1 for successful match, 0 otherwise.
  */
-typedef int (*mtraversal_on_match_res_t)(void* context_ptr, Sint slot_ix, HashDbTerm*** current_ptr_ptr,
-                                         Eterm match_res);
+    int (*on_match_res)(match_callbacks_t* ctx, Sint slot_ix,
+                        HashDbTerm*** current_ptr_ptr, Eterm match_res);
 
 /* Called when either we've matched enough elements in this cycle or EOT was reached.
  *      context_ptr: Pointer to context
@@ -1152,8 +1180,8 @@ typedef int (*mtraversal_on_match_res_t)(void* context_ptr, Sint slot_ix, HashDb
  * Both the direct return value and 'ret' are used as the traversal function return values.
  * If *mpp is set to NULL, it won't be deallocated (useful for trapping.)
  */
-typedef int (*mtraversal_on_loop_ended_t)(void* context_ptr, Sint slot_ix, Sint got,
-                                          Sint iterations_left, Binary** mpp, Eterm* ret);
+    int (*on_loop_ended)(match_callbacks_t* ctx, Sint slot_ix, Sint got,
+                         Sint iterations_left, Binary** mpp, Eterm* ret);
 
 /* Called when it's time to trap
  *      context_ptr: Pointer to context
@@ -1165,7 +1193,11 @@ typedef int (*mtraversal_on_loop_ended_t)(void* context_ptr, Sint slot_ix, Sint
  * Both the direct return value and 'ret' are used as the traversal function return values.
  * If *mpp is set to NULL, it won't be deallocated (useful for trapping.)
  */
-typedef int (*mtraversal_on_trap_t)(void* context_ptr, Sint slot_ix, Sint got, Binary** mpp, Eterm* ret);
+    int (*on_trap)(match_callbacks_t* ctx, Sint slot_ix, Sint got, Binary** mpp,
+                   Eterm* ret);
+
+};
+
 
 /*
  * Begin hash table match traversal
@@ -1178,11 +1210,7 @@ static int match_traverse(Process* p, DbTableHash* tb,
                           Eterm** hpp,          /* Heap */
                           int lock_for_write,   /* Set to 1 if we're going to delete or
                                                    modify existing terms */
-                          mtraversal_on_nothing_can_match_t on_nothing_can_match,
-                          mtraversal_on_match_res_t on_match_res,
-                          mtraversal_on_loop_ended_t on_loop_ended,
-                          mtraversal_on_trap_t on_trap,
-                          void* context_ptr, /* State for callbacks above */
+                          match_callbacks_t* ctx,
                           Eterm* ret)
 {
     Sint slot_ix;                  /* Slot index */
@@ -1212,14 +1240,10 @@ static int match_traverse(Process* p, DbTableHash* tb,
 
     if (!mpi.something_can_match) {
         /* Can't possibly match anything */
-        ret_value = on_nothing_can_match(context_ptr, ret);
+        ret_value = ctx->on_nothing_can_match(ctx, ret);
         goto done;
     }
 
-    if (mpi.all_objects) {
-        mpi.mp->intern.flags |= BIN_FLAG_ALL_OBJECTS;
-    }
-
     /*
      * Look for initial slot / bucket
      */
@@ -1235,7 +1259,8 @@ static int match_traverse(Process* p, DbTableHash* tb,
             }
             slot_ix = next_slot_function(tb,slot_ix,&lck);
             if (slot_ix == 0) {
-                ret_value = on_loop_ended(context_ptr, slot_ix, got, iterations_left, &mpi.mp, ret);
+                ret_value = ctx->on_loop_ended(ctx, slot_ix, got, iterations_left,
+                                               &mpi.mp, ret);
                 goto done;
             }
         }
@@ -1253,11 +1278,11 @@ static int match_traverse(Process* p, DbTableHash* tb,
      */
     for(;;) {
         if (*current_ptr != NULL) {
-            if ((*current_ptr)->hvalue != INVALID_HASH) {
-                match_res = db_match_dbterm(&tb->common, p, mpi.mp, 0,
+            if (!is_pseudo_deleted(*current_ptr)) {
+                match_res = db_match_dbterm(&tb->common, p, mpi.mp,
                                             &(*current_ptr)->dbterm, hpp, 2);
                 saved_current = *current_ptr;
-                if (on_match_res(context_ptr, slot_ix, &current_ptr, match_res)) {
+                if (ctx->on_match_res(ctx, slot_ix, &current_ptr, match_res)) {
                     ++got;
                 }
                 --iterations_left;
@@ -1271,7 +1296,7 @@ static int match_traverse(Process* p, DbTableHash* tb,
         else if (mpi.key_given) {  /* Key is bound */
             unlock_hash_function(lck);
             if (current_list_pos == mpi.num_lists) {
-                ret_value = on_loop_ended(context_ptr, -1, got, iterations_left, &mpi.mp, ret);
+                ret_value = ctx->on_loop_ended(ctx, -1, got, iterations_left, &mpi.mp, ret);
                 goto done;
             } else {
                 slot_ix = mpi.lists[current_list_pos].ix;
@@ -1296,18 +1321,18 @@ static int match_traverse(Process* p, DbTableHash* tb,
                  * Since many heap fragments will make the GC slower, trap and GC now.
                  */
                 unlock_hash_function(lck);
-                ret_value = on_trap(context_ptr, slot_ix, got, &mpi.mp, ret);
+                ret_value = ctx->on_trap(ctx, slot_ix, got, &mpi.mp, ret);
                 goto done;
             }
             current_ptr = &BUCKET(tb,slot_ix);
         }
     }
 
-    ret_value = on_loop_ended(context_ptr, slot_ix, got, iterations_left, &mpi.mp, ret);
+    ret_value = ctx->on_loop_ended(ctx, slot_ix, got, iterations_left, &mpi.mp, ret);
 
 done:
     /* We should only jump directly to this label if
-     * we've already called on_nothing_can_match / on_loop_ended / on_trap
+     * we've already called ctx->nothing_can_match / loop_ended / trap
      */
     if (mpi.mp != NULL) {
         erts_bin_free(mpi.mp);
@@ -1332,13 +1357,9 @@ static int match_traverse_continue(Process* p, DbTableHash* tb,
                                    Binary** mpp,         /* Existing match program */
                                    int lock_for_write,   /* Set to 1 if we're going to delete or
                                                             modify existing terms */
-                                   mtraversal_on_match_res_t on_match_res,
-                                   mtraversal_on_loop_ended_t on_loop_ended,
-                                   mtraversal_on_trap_t on_trap,
-                                   void* context_ptr, /* For callbacks */
+                                   match_callbacks_t* ctx,
                                    Eterm* ret)
 {
-    int all_objects = (*mpp)->intern.flags & BIN_FLAG_ALL_OBJECTS;
     HashDbTerm** current_ptr;  /* Refers to either the bucket pointer or
                                        * the 'next' pointer in the previous term
                                        */
@@ -1362,7 +1383,7 @@ static int match_traverse_continue(Process* p, DbTableHash* tb,
        || (chunk_size && got >= chunk_size))
     {
         /* Already got all or enough in the match_list */
-        ret_value = on_loop_ended(context_ptr, slot_ix, got, iterations_left, mpp, ret);
+        ret_value = ctx->on_loop_ended(ctx, slot_ix, got, iterations_left, mpp, ret);
         goto done;
     }
 
@@ -1380,11 +1401,11 @@ static int match_traverse_continue(Process* p, DbTableHash* tb,
     current_ptr = &BUCKET(tb,slot_ix);
     for(;;) {
         if (*current_ptr != NULL) {
-            if ((*current_ptr)->hvalue != INVALID_HASH) {
-                match_res = db_match_dbterm(&tb->common, p, *mpp, all_objects,
+            if (!is_pseudo_deleted(*current_ptr)) {
+                match_res = db_match_dbterm(&tb->common, p, *mpp,
                                             &(*current_ptr)->dbterm, hpp, 2);
                 saved_current = *current_ptr;
-                if (on_match_res(context_ptr, slot_ix, &current_ptr, match_res)) {
+                if (ctx->on_match_res(ctx, slot_ix, &current_ptr, match_res)) {
                     ++got;
                 }
                 --iterations_left;
@@ -1410,14 +1431,14 @@ static int match_traverse_continue(Process* p, DbTableHash* tb,
                  * Since many heap fragments will make the GC slower, trap and GC now.
                  */
                 unlock_hash_function(lck);
-                ret_value = on_trap(context_ptr, slot_ix, got, mpp, ret);
+                ret_value = ctx->on_trap(ctx, slot_ix, got, mpp, ret);
                 goto done;
             }
             current_ptr = &BUCKET(tb,slot_ix);
         }
     }
 
-    ret_value = on_loop_ended(context_ptr, slot_ix, got, iterations_left, mpp, ret);
+    ret_value = ctx->on_loop_ended(ctx, slot_ix, got, iterations_left, mpp, ret);
 
 done:
     /* We should only jump directly to this label if
@@ -1434,7 +1455,7 @@ done:
  * as well as their continuation-handling counterparts.
  */
 
-static ERTS_INLINE int on_mtraversal_simple_trap(Export* trap_function,
+static ERTS_INLINE int on_simple_trap(Export* trap_function,
                                                  Process* p,
                                                  DbTableHash* tb,
                                                  Eterm tid,
@@ -1480,16 +1501,16 @@ static ERTS_INLINE int on_mtraversal_simple_trap(Export* trap_function,
             make_small(slot_ix),
             mpb,
             egot);
-    *ret = bif_trap1(trap_function, p, continuation);
+    ERTS_BIF_PREP_TRAP1(*ret, trap_function, p, continuation);
     return DB_ERROR_NONE;
 }
 
-static ERTS_INLINE int unpack_simple_mtraversal_continuation(Eterm continuation,
-                                                             Eterm** tptr_ptr,
-                                                             Eterm* tid_ptr,
-                                                             Sint* slot_ix_p,
-                                                             Binary** mpp,
-                                                             Sint* got_p)
+static ERTS_INLINE int unpack_simple_continuation(Eterm continuation,
+                                                  Eterm** tptr_ptr,
+                                                  Eterm* tid_ptr,
+                                                  Sint* slot_ix_p,
+                                                  Binary** mpp,
+                                                  Sint* got_p)
 {
     Eterm* tptr;
     ASSERT(is_tuple(continuation));
@@ -1524,6 +1545,7 @@ static ERTS_INLINE int unpack_simple_mtraversal_continuation(Eterm continuation,
 #define MAX_SELECT_CHUNK_ITERATIONS 1000
 
 typedef struct {
+    match_callbacks_t base;
     Process* p;
     DbTableHash* tb;
     Eterm tid;
@@ -1531,83 +1553,86 @@ typedef struct {
     Sint chunk_size;
     Eterm match_list;
     Eterm* prev_continuation_tptr;
-} mtraversal_select_chunk_context_t;
+} select_chunk_context_t;
 
-static int mtraversal_select_chunk_on_nothing_can_match(void* context_ptr, Eterm* ret) {
-    mtraversal_select_chunk_context_t* sc_context_ptr = (mtraversal_select_chunk_context_t*) context_ptr;
-    *ret = (sc_context_ptr->chunk_size > 0 ? am_EOT : NIL);
+static int select_chunk_on_nothing_can_match(match_callbacks_t* ctx_base, Eterm* ret)
+{
+    select_chunk_context_t* ctx = (select_chunk_context_t*) ctx_base;
+    *ret = (ctx->chunk_size > 0 ? am_EOT : NIL);
     return DB_ERROR_NONE;
 }
 
-static int mtraversal_select_chunk_on_match_res(void* context_ptr, Sint slot_ix,
-                                                HashDbTerm*** current_ptr_ptr,
-                                                Eterm match_res)
+static int select_chunk_on_match_res(match_callbacks_t* ctx_base, Sint slot_ix,
+                                     HashDbTerm*** current_ptr_ptr,
+                                     Eterm match_res)
 {
-    mtraversal_select_chunk_context_t* sc_context_ptr = (mtraversal_select_chunk_context_t*) context_ptr;
+    select_chunk_context_t* ctx = (select_chunk_context_t*) ctx_base;
     if (is_value(match_res)) {
-        sc_context_ptr->match_list = CONS(sc_context_ptr->hp, match_res, sc_context_ptr->match_list);
+        ctx->match_list = CONS(ctx->hp, match_res, ctx->match_list);
         return 1;
     }
     return 0;
 }
 
-static int mtraversal_select_chunk_on_loop_ended(void* context_ptr, Sint slot_ix, Sint got,
-                                                 Sint iterations_left, Binary** mpp, Eterm* ret)
+static int select_chunk_on_loop_ended(match_callbacks_t* ctx_base,
+                                      Sint slot_ix, Sint got,
+                                      Sint iterations_left, Binary** mpp,
+                                      Eterm* ret)
 {
-    mtraversal_select_chunk_context_t* sc_context_ptr = (mtraversal_select_chunk_context_t*) context_ptr;
+    select_chunk_context_t* ctx = (select_chunk_context_t*) ctx_base;
     Eterm mpb;
 
     if (iterations_left == MAX_SELECT_CHUNK_ITERATIONS) {
         /* We didn't get to iterate a single time, which means EOT */
-        ASSERT(sc_context_ptr->match_list == NIL);
-        *ret = (sc_context_ptr->chunk_size > 0 ? am_EOT : NIL);
+        ASSERT(ctx->match_list == NIL);
+        *ret = (ctx->chunk_size > 0 ? am_EOT : NIL);
         return DB_ERROR_NONE;
     }
     else {
         ASSERT(iterations_left < MAX_SELECT_CHUNK_ITERATIONS);
-        BUMP_REDS(sc_context_ptr->p, MAX_SELECT_CHUNK_ITERATIONS - iterations_left);
-        if (sc_context_ptr->chunk_size) {
+        BUMP_REDS(ctx->p, MAX_SELECT_CHUNK_ITERATIONS - iterations_left);
+        if (ctx->chunk_size) {
             Eterm continuation;
             Eterm rest = NIL;
             Sint rest_size = 0;
 
-            if (got > sc_context_ptr->chunk_size) { /* Split list in return value and 'rest' */
-                Eterm tmp = sc_context_ptr->match_list;
-                rest = sc_context_ptr->match_list;
-                while (got-- > sc_context_ptr->chunk_size + 1) {
+            if (got > ctx->chunk_size) { /* Split list in return value and 'rest' */
+                Eterm tmp = ctx->match_list;
+                rest = ctx->match_list;
+                while (got-- > ctx->chunk_size + 1) {
                     tmp = CDR(list_val(tmp));
                     ++rest_size;
                 }
                 ++rest_size;
-                sc_context_ptr->match_list = CDR(list_val(tmp));
+                ctx->match_list = CDR(list_val(tmp));
                 CDR(list_val(tmp)) = NIL; /* Destructive, the list has never
                                              been in 'user space' */
             }
             if (rest != NIL || slot_ix >= 0) { /* Need more calls */
-                Eterm tid = sc_context_ptr->tid;
-                sc_context_ptr->hp = HAllocX(sc_context_ptr->p,
-                                             3 + 7 + ERTS_MAGIC_REF_THING_SIZE,
-                                             ERTS_MAGIC_REF_THING_SIZE);
-                mpb = erts_db_make_match_prog_ref(sc_context_ptr->p, *mpp, &sc_context_ptr->hp);
+                Eterm tid = ctx->tid;
+                ctx->hp = HAllocX(ctx->p,
+                                  3 + 7 + ERTS_MAGIC_REF_THING_SIZE,
+                                  ERTS_MAGIC_REF_THING_SIZE);
+                mpb = erts_db_make_match_prog_ref(ctx->p, *mpp, &ctx->hp);
                 if (is_atom(tid))
-                    tid = erts_db_make_tid(sc_context_ptr->p,
-                                           &sc_context_ptr->tb->common);
+                    tid = erts_db_make_tid(ctx->p,
+                                           &ctx->tb->common);
                 continuation = TUPLE6(
-                        sc_context_ptr->hp,
+                        ctx->hp,
                         tid,
                         make_small(slot_ix),
-                        make_small(sc_context_ptr->chunk_size),
+                        make_small(ctx->chunk_size),
                         mpb, rest,
                         make_small(rest_size));
                 *mpp = NULL; /* Otherwise the caller will destroy it */
-                sc_context_ptr->hp += 7;
-                *ret = TUPLE2(sc_context_ptr->hp, sc_context_ptr->match_list, continuation);
+                ctx->hp += 7;
+                *ret = TUPLE2(ctx->hp, ctx->match_list, continuation);
                 return DB_ERROR_NONE;
             } else { /* All data is exhausted */
-                if (sc_context_ptr->match_list != NIL) { /* No more data to search but still a
+                if (ctx->match_list != NIL) { /* No more data to search but still a
                                                             result to return to the caller */
-                    sc_context_ptr->hp = HAlloc(sc_context_ptr->p, 3);
-                    *ret = TUPLE2(sc_context_ptr->hp, sc_context_ptr->match_list, am_EOT);
+                    ctx->hp = HAlloc(ctx->p, 3);
+                    *ret = TUPLE2(ctx->hp, ctx->match_list, am_EOT);
                     return DB_ERROR_NONE;
                 } else { /* Reached the end of the ttable with no data to return */
                     *ret = am_EOT;
@@ -1615,82 +1640,88 @@ static int mtraversal_select_chunk_on_loop_ended(void* context_ptr, Sint slot_ix
                 }
             }
         }
-        *ret = sc_context_ptr->match_list;
+        *ret = ctx->match_list;
         return DB_ERROR_NONE;
     }
 }
 
-static int mtraversal_select_chunk_on_trap(void* context_ptr, Sint slot_ix, Sint got,
-                                           Binary** mpp, Eterm* ret)
+static int select_chunk_on_trap(match_callbacks_t* ctx_base,
+                                Sint slot_ix, Sint got,
+                                Binary** mpp, Eterm* ret)
 {
-    mtraversal_select_chunk_context_t* sc_context_ptr = (mtraversal_select_chunk_context_t*) context_ptr;
+    select_chunk_context_t* ctx = (select_chunk_context_t*) ctx_base;
     Eterm mpb;
     Eterm continuation;
     Eterm* hp;
 
-    BUMP_ALL_REDS(sc_context_ptr->p);
+    BUMP_ALL_REDS(ctx->p);
 
-    if (sc_context_ptr->prev_continuation_tptr == NULL) {
-        Eterm tid = sc_context_ptr->tid;
+    if (ctx->prev_continuation_tptr == NULL) {
+        Eterm tid = ctx->tid;
         /* First time we're trapping */
-        hp = HAllocX(sc_context_ptr->p, 7 + ERTS_MAGIC_REF_THING_SIZE,
+        hp = HAllocX(ctx->p, 7 + ERTS_MAGIC_REF_THING_SIZE,
                      ERTS_MAGIC_REF_THING_SIZE);
         if (is_atom(tid))
-            tid = erts_db_make_tid(sc_context_ptr->p, &sc_context_ptr->tb->common);
-        mpb = erts_db_make_match_prog_ref(sc_context_ptr->p, *mpp, &hp);
+            tid = erts_db_make_tid(ctx->p, &ctx->tb->common);
+        mpb = erts_db_make_match_prog_ref(ctx->p, *mpp, &hp);
         continuation = TUPLE6(
                 hp,
                 tid,
                 make_small(slot_ix),
-                make_small(sc_context_ptr->chunk_size),
+                make_small(ctx->chunk_size),
                 mpb,
-                sc_context_ptr->match_list,
+                ctx->match_list,
                 make_small(got));
         *mpp = NULL; /* otherwise the caller will destroy it */
     }
     else {
         /* Not the first time we're trapping; reuse continuation terms */
-        hp = HAlloc(sc_context_ptr->p, 7);
+        hp = HAlloc(ctx->p, 7);
         continuation = TUPLE6(
                 hp,
-                sc_context_ptr->prev_continuation_tptr[1],
+                ctx->prev_continuation_tptr[1],
                 make_small(slot_ix),
-                sc_context_ptr->prev_continuation_tptr[3],
-                sc_context_ptr->prev_continuation_tptr[4],
-                sc_context_ptr->match_list,
+                ctx->prev_continuation_tptr[3],
+                ctx->prev_continuation_tptr[4],
+                ctx->match_list,
                 make_small(got));
     }
-    *ret = bif_trap1(&ets_select_continue_exp, sc_context_ptr->p, continuation);
+    ERTS_BIF_PREP_TRAP1(*ret, &ets_select_continue_exp, ctx->p,
+                        continuation);
     return DB_ERROR_NONE;
 }
 
-static int db_select_hash(Process *p, DbTable *tbl, Eterm tid, Eterm pattern, int reverse, Eterm *ret) {
+static int db_select_hash(Process *p, DbTable *tbl, Eterm tid, Eterm pattern,
+                          int reverse, Eterm *ret)
+{
     return db_select_chunk_hash(p, tbl, tid, pattern, 0, reverse, ret);
 }
 
-static int db_select_chunk_hash(Process *p, DbTable *tbl, Eterm tid, Eterm pattern, Sint chunk_size,
+static int db_select_chunk_hash(Process *p, DbTable *tbl, Eterm tid,
+                                Eterm pattern, Sint chunk_size,
                                 int reverse, Eterm *ret)
 {
-    mtraversal_select_chunk_context_t sc_context;
-    sc_context.p = p;
-    sc_context.tb = &tbl->hash;
-    sc_context.tid = tid;
-    sc_context.hp = NULL;
-    sc_context.chunk_size = chunk_size;
-    sc_context.match_list = NIL;
-    sc_context.prev_continuation_tptr = NULL;
+    select_chunk_context_t ctx;
+
+    ctx.base.on_nothing_can_match = select_chunk_on_nothing_can_match;
+    ctx.base.on_match_res         = select_chunk_on_match_res;
+    ctx.base.on_loop_ended        = select_chunk_on_loop_ended;
+    ctx.base.on_trap              = select_chunk_on_trap,
+    ctx.p = p;
+    ctx.tb = &tbl->hash;
+    ctx.tid = tid;
+    ctx.hp = NULL;
+    ctx.chunk_size = chunk_size;
+    ctx.match_list = NIL;
+    ctx.prev_continuation_tptr = NULL;
 
     return match_traverse(
-            sc_context.p, sc_context.tb,
+            ctx.p, ctx.tb,
             pattern, NULL,
-            sc_context.chunk_size,
+            ctx.chunk_size,
             MAX_SELECT_CHUNK_ITERATIONS,
-            &sc_context.hp, 0,
-            mtraversal_select_chunk_on_nothing_can_match,
-            mtraversal_select_chunk_on_match_res,
-            mtraversal_select_chunk_on_loop_ended,
-            mtraversal_select_chunk_on_trap,
-            &sc_context, ret);
+            &ctx.hp, 0,
+            &ctx.base, ret);
 }
 
 /*
@@ -1699,47 +1730,50 @@ static int db_select_chunk_hash(Process *p, DbTable *tbl, Eterm tid, Eterm patte
  *
  */
 
-static int mtraversal_select_chunk_continue_on_loop_ended(void* context_ptr, Sint slot_ix, Sint got,
-                                                          Sint iterations_left, Binary** mpp, Eterm* ret)
+static
+int select_chunk_continue_on_loop_ended(match_callbacks_t* ctx_base,
+                                        Sint slot_ix, Sint got,
+                                        Sint iterations_left, Binary** mpp,
+                                        Eterm* ret)
 {
-    mtraversal_select_chunk_context_t* sc_context_ptr = (mtraversal_select_chunk_context_t*) context_ptr;
+    select_chunk_context_t* ctx = (select_chunk_context_t*) ctx_base;
     Eterm continuation;
     Eterm rest = NIL;
     Eterm* hp;
 
     ASSERT(iterations_left <= MAX_SELECT_CHUNK_ITERATIONS);
-    BUMP_REDS(sc_context_ptr->p, MAX_SELECT_CHUNK_ITERATIONS - iterations_left);
-    if (sc_context_ptr->chunk_size) {
+    BUMP_REDS(ctx->p, MAX_SELECT_CHUNK_ITERATIONS - iterations_left);
+    if (ctx->chunk_size) {
         Sint rest_size = 0;
-        if (got > sc_context_ptr->chunk_size) {
+        if (got > ctx->chunk_size) {
             /* Cannot write destructively here,
                the list may have
                been in user space */
-            hp = HAlloc(sc_context_ptr->p, (got - sc_context_ptr->chunk_size) * 2);
-            while (got-- > sc_context_ptr->chunk_size) {
-                rest = CONS(hp, CAR(list_val(sc_context_ptr->match_list)), rest);
+            hp = HAlloc(ctx->p, (got - ctx->chunk_size) * 2);
+            while (got-- > ctx->chunk_size) {
+                rest = CONS(hp, CAR(list_val(ctx->match_list)), rest);
                 hp += 2;
-                sc_context_ptr->match_list = CDR(list_val(sc_context_ptr->match_list));
+                ctx->match_list = CDR(list_val(ctx->match_list));
                 ++rest_size;
             }
         }
         if (rest != NIL || slot_ix >= 0) {
-            hp = HAlloc(sc_context_ptr->p, 3 + 7);
+            hp = HAlloc(ctx->p, 3 + 7);
             continuation = TUPLE6(
                     hp,
-                    sc_context_ptr->prev_continuation_tptr[1],
+                    ctx->prev_continuation_tptr[1],
                     make_small(slot_ix),
-                    sc_context_ptr->prev_continuation_tptr[3],
-                    sc_context_ptr->prev_continuation_tptr[4],
+                    ctx->prev_continuation_tptr[3],
+                    ctx->prev_continuation_tptr[4],
                     rest,
                     make_small(rest_size));
             hp += 7;
-            *ret = TUPLE2(hp, sc_context_ptr->match_list, continuation);
+            *ret = TUPLE2(hp, ctx->match_list, continuation);
             return DB_ERROR_NONE;
         } else {
-            if (sc_context_ptr->match_list != NIL) {
-                hp = HAlloc(sc_context_ptr->p, 3);
-                *ret = TUPLE2(hp, sc_context_ptr->match_list, am_EOT);
+            if (ctx->match_list != NIL) {
+                hp = HAlloc(ctx->p, 3);
+                *ret = TUPLE2(hp, ctx->match_list, am_EOT);
                 return DB_ERROR_NONE;
             } else {
                 *ret = am_EOT;
@@ -1747,15 +1781,17 @@ static int mtraversal_select_chunk_continue_on_loop_ended(void* context_ptr, Sin
             }
         }
     }
-    *ret = sc_context_ptr->match_list;
+    *ret = ctx->match_list;
     return DB_ERROR_NONE;
 }
 
 /*
  * This is called when select traps
  */
-static int db_select_continue_hash(Process* p, DbTable* tbl, Eterm continuation, Eterm* ret) {
-    mtraversal_select_chunk_context_t sc_context = {0};
+static int db_select_continue_hash(Process* p, DbTable* tbl, Eterm continuation,
+                                   Eterm* ret)
+{
+    select_chunk_context_t ctx;
     Eterm* tptr;
     Eterm tid;
     Binary* mp;
@@ -1790,21 +1826,21 @@ static int db_select_continue_hash(Process* p, DbTable* tbl, Eterm continuation,
     match_list = tptr[5];
 
     /* Proceed */
-    sc_context.p = p;
-    sc_context.tb = &tbl->hash;
-    sc_context.tid = tid;
-    sc_context.hp = NULL;
-    sc_context.chunk_size = chunk_size;
-    sc_context.match_list = match_list;
-    sc_context.prev_continuation_tptr = tptr;
+    ctx.base.on_match_res  = select_chunk_on_match_res;
+    ctx.base.on_loop_ended = select_chunk_continue_on_loop_ended;
+    ctx.base.on_trap       = select_chunk_on_trap;
+    ctx.p = p;
+    ctx.tb = &tbl->hash;
+    ctx.tid = tid;
+    ctx.hp = NULL;
+    ctx.chunk_size = chunk_size;
+    ctx.match_list = match_list;
+    ctx.prev_continuation_tptr = tptr;
 
     return match_traverse_continue(
-            sc_context.p, sc_context.tb, sc_context.chunk_size,
-            iterations_left, &sc_context.hp, slot_ix, got, &mp, 0,
-            mtraversal_select_chunk_on_match_res, /* Reuse callback */
-            mtraversal_select_chunk_continue_on_loop_ended,
-            mtraversal_select_chunk_on_trap,      /* Reuse callback */
-            &sc_context, ret);
+            ctx.p, ctx.tb, ctx.chunk_size,
+            iterations_left, &ctx.hp, slot_ix, got, &mp, 0,
+            &ctx.base, ret);
 
 badparam:
     *ret = NIL;
@@ -1823,75 +1859,83 @@ badparam:
 #define MAX_SELECT_COUNT_ITERATIONS 1000
 
 typedef struct {
+    match_callbacks_t base;
     Process* p;
     DbTableHash* tb;
     Eterm tid;
-    Eterm* hp;
     Eterm* prev_continuation_tptr;
-} mtraversal_select_count_context_t;
+} select_count_context_t;
 
-static int mtraversal_select_count_on_nothing_can_match(void* context_ptr, Eterm* ret) {
+static int select_count_on_nothing_can_match(match_callbacks_t* ctx_base,
+                                             Eterm* ret)
+{
     *ret = make_small(0);
     return DB_ERROR_NONE;
 }
 
-static int mtraversal_select_count_on_match_res(void* context_ptr, Sint slot_ix,
-                                                HashDbTerm*** current_ptr_ptr,
-                                                Eterm match_res)
+static int select_count_on_match_res(match_callbacks_t* ctx_base, Sint slot_ix,
+                                     HashDbTerm*** current_ptr_ptr,
+                                     Eterm match_res)
 {
     return (match_res == am_true);
 }
 
-static int mtraversal_select_count_on_loop_ended(void* context_ptr, Sint slot_ix, Sint got,
-                                                 Sint iterations_left, Binary** mpp, Eterm* ret)
+static int select_count_on_loop_ended(match_callbacks_t* ctx_base,
+                                      Sint slot_ix, Sint got,
+                                      Sint iterations_left, Binary** mpp,
+                                      Eterm* ret)
 {
-    mtraversal_select_count_context_t* scnt_context_ptr = (mtraversal_select_count_context_t*) context_ptr;
+    select_count_context_t* ctx = (select_count_context_t*) ctx_base;
     ASSERT(iterations_left <= MAX_SELECT_COUNT_ITERATIONS);
-    BUMP_REDS(scnt_context_ptr->p, MAX_SELECT_COUNT_ITERATIONS - iterations_left);
-    *ret = erts_make_integer(got, scnt_context_ptr->p);
+    BUMP_REDS(ctx->p, MAX_SELECT_COUNT_ITERATIONS - iterations_left);
+    *ret = erts_make_integer(got, ctx->p);
     return DB_ERROR_NONE;
 }
 
-static int mtraversal_select_count_on_trap(void* context_ptr, Sint slot_ix, Sint got,
-                                           Binary** mpp, Eterm* ret)
+static int select_count_on_trap(match_callbacks_t* ctx_base,
+                                Sint slot_ix, Sint got,
+                                Binary** mpp, Eterm* ret)
 {
-    mtraversal_select_count_context_t* scnt_context_ptr = (mtraversal_select_count_context_t*) context_ptr;
-    return on_mtraversal_simple_trap(
+    select_count_context_t* ctx = (select_count_context_t*) ctx_base;
+    return on_simple_trap(
             &ets_select_count_continue_exp,
-            scnt_context_ptr->p,
-            scnt_context_ptr->tb,
-            scnt_context_ptr->tid,
-            scnt_context_ptr->prev_continuation_tptr,
+            ctx->p,
+            ctx->tb,
+            ctx->tid,
+            ctx->prev_continuation_tptr,
             slot_ix, got, mpp, ret);
 }
 
-static int db_select_count_hash(Process *p, DbTable *tbl, Eterm tid, Eterm pattern, Eterm *ret) {
-    mtraversal_select_count_context_t scnt_context = {0};
+static int db_select_count_hash(Process *p, DbTable *tbl, Eterm tid,
+                                Eterm pattern, Eterm *ret)
+{
+    select_count_context_t ctx;
     Sint iterations_left = MAX_SELECT_COUNT_ITERATIONS;
     Sint chunk_size = 0;
 
-    scnt_context.p = p;
-    scnt_context.tb = &tbl->hash;
-    scnt_context.tid = tid;
-    scnt_context.hp = NULL;
-    scnt_context.prev_continuation_tptr = NULL;
+    ctx.base.on_nothing_can_match = select_count_on_nothing_can_match;
+    ctx.base.on_match_res         = select_count_on_match_res;
+    ctx.base.on_loop_ended        = select_count_on_loop_ended;
+    ctx.base.on_trap              = select_count_on_trap;
+    ctx.p = p;
+    ctx.tb = &tbl->hash;
+    ctx.tid = tid;
+    ctx.prev_continuation_tptr = NULL;
 
     return match_traverse(
-            scnt_context.p, scnt_context.tb,
+            ctx.p, ctx.tb,
             pattern, NULL,
             chunk_size, iterations_left, NULL, 0,
-            mtraversal_select_count_on_nothing_can_match,
-            mtraversal_select_count_on_match_res,
-            mtraversal_select_count_on_loop_ended,
-            mtraversal_select_count_on_trap,
-            &scnt_context, ret);
+            &ctx.base, ret);
 }
 
 /*
  * This is called when select_count traps
  */
-static int db_select_count_continue_hash(Process* p, DbTable* tbl, Eterm continuation, Eterm* ret) {
-    mtraversal_select_count_context_t scnt_context = {0};
+static int db_select_count_continue_hash(Process* p, DbTable* tbl,
+                                         Eterm continuation, Eterm* ret)
+{
+    select_count_context_t ctx;
     Eterm* tptr;
     Eterm tid;
     Binary* mp;
@@ -1900,25 +1944,24 @@ static int db_select_count_continue_hash(Process* p, DbTable* tbl, Eterm continu
     Sint chunk_size = 0;
     *ret = NIL;
 
-    if (unpack_simple_mtraversal_continuation(continuation, &tptr, &tid, &slot_ix, &mp, &got)) {
+    if (unpack_simple_continuation(continuation, &tptr, &tid, &slot_ix, &mp, &got)) {
         *ret = NIL;
         return DB_ERROR_BADPARAM;
     }
 
-    scnt_context.p = p;
-    scnt_context.tb = &tbl->hash;
-    scnt_context.tid = tid;
-    scnt_context.hp = NULL;
-    scnt_context.prev_continuation_tptr = tptr;
+    ctx.base.on_match_res  = select_count_on_match_res;
+    ctx.base.on_loop_ended = select_count_on_loop_ended;
+    ctx.base.on_trap       = select_count_on_trap;
+    ctx.p = p;
+    ctx.tb = &tbl->hash;
+    ctx.tid = tid;
+    ctx.prev_continuation_tptr = tptr;
 
     return match_traverse_continue(
-            scnt_context.p, scnt_context.tb, chunk_size,
+            ctx.p, ctx.tb, chunk_size,
             MAX_SELECT_COUNT_ITERATIONS,
             NULL, slot_ix, got, &mp, 0,
-            mtraversal_select_count_on_match_res,  /* Reuse callback */
-            mtraversal_select_count_on_loop_ended, /* Reuse callback */
-            mtraversal_select_count_on_trap,       /* Reuse callback */
-            &scnt_context, ret);
+            &ctx.base, ret);
 }
 
 #undef MAX_SELECT_COUNT_ITERATIONS
@@ -1933,104 +1976,119 @@ static int db_select_count_continue_hash(Process* p, DbTable* tbl, Eterm continu
 #define MAX_SELECT_DELETE_ITERATIONS 1000
 
 typedef struct {
+    match_callbacks_t base;
     Process* p;
     DbTableHash* tb;
     Eterm tid;
-    Eterm* hp;
     Eterm* prev_continuation_tptr;
     erts_aint_t fixated_by_me;
     Uint last_pseudo_delete;
-} mtraversal_select_delete_context_t;
+    HashDbTerm* free_us;
+} select_delete_context_t;
 
-static int mtraversal_select_delete_on_nothing_can_match(void* context_ptr, Eterm* ret) {
+static int select_delete_on_nothing_can_match(match_callbacks_t* ctx_base,
+                                              Eterm* ret)
+{
     *ret = make_small(0);
     return DB_ERROR_NONE;
 }
 
-static int mtraversal_select_delete_on_match_res(void* context_ptr, Sint slot_ix,
-                                                 HashDbTerm*** current_ptr_ptr,
-                                                 Eterm match_res)
+static int select_delete_on_match_res(match_callbacks_t* ctx_base, Sint slot_ix,
+                                      HashDbTerm*** current_ptr_ptr,
+                                      Eterm match_res)
 {
     HashDbTerm** current_ptr = *current_ptr_ptr;
-    mtraversal_select_delete_context_t* sd_context_ptr = (mtraversal_select_delete_context_t*) context_ptr;
+    select_delete_context_t* ctx = (select_delete_context_t*) ctx_base;
     HashDbTerm* del;
     if (match_res != am_true)
         return 0;
 
-    if (NFIXED(sd_context_ptr->tb) > sd_context_ptr->fixated_by_me) { /* fixated by others? */
-        if (slot_ix != sd_context_ptr->last_pseudo_delete) {
-            if (!add_fixed_deletion(sd_context_ptr->tb, slot_ix, sd_context_ptr->fixated_by_me))
+    if (NFIXED(ctx->tb) > ctx->fixated_by_me) { /* fixated by others? */
+        if (slot_ix != ctx->last_pseudo_delete) {
+            if (!add_fixed_deletion(ctx->tb, slot_ix, ctx->fixated_by_me))
                 goto do_erase;
-            sd_context_ptr->last_pseudo_delete = slot_ix;
+            ctx->last_pseudo_delete = slot_ix;
         }
-        (*current_ptr)->hvalue = INVALID_HASH;
+        (*current_ptr)->pseudo_deleted = 1;
     }
     else {
     do_erase:
         del = *current_ptr;
         *current_ptr = (*current_ptr)->next; // replace pointer to term using next
-        free_term(sd_context_ptr->tb, del);
+        del->next = ctx->free_us;
+        ctx->free_us = del;
     }
-    erts_atomic_dec_nob(&sd_context_ptr->tb->common.nitems);
+    erts_atomic_dec_nob(&ctx->tb->common.nitems);
 
     return 1;
 }
 
-static int mtraversal_select_delete_on_loop_ended(void* context_ptr, Sint slot_ix, Sint got,
-                                                  Sint iterations_left, Binary** mpp, Eterm* ret)
+static int select_delete_on_loop_ended(match_callbacks_t* ctx_base,
+                                       Sint slot_ix, Sint got,
+                                       Sint iterations_left, Binary** mpp,
+                                       Eterm* ret)
 {
-    mtraversal_select_delete_context_t* sd_context_ptr = (mtraversal_select_delete_context_t*) context_ptr;
+    select_delete_context_t* ctx = (select_delete_context_t*) ctx_base;
+    free_term_list(ctx->tb, ctx->free_us);
+    ctx->free_us = NULL;
     ASSERT(iterations_left <= MAX_SELECT_DELETE_ITERATIONS);
-    BUMP_REDS(sd_context_ptr->p, MAX_SELECT_DELETE_ITERATIONS - iterations_left);
+    BUMP_REDS(ctx->p, MAX_SELECT_DELETE_ITERATIONS - iterations_left);
     if (got) {
-	try_shrink(sd_context_ptr->tb);
+	try_shrink(ctx->tb);
     }
-    *ret = erts_make_integer(got, sd_context_ptr->p);
+    *ret = erts_make_integer(got, ctx->p);
     return DB_ERROR_NONE;
 }
 
-static int mtraversal_select_delete_on_trap(void* context_ptr, Sint slot_ix, Sint got,
-                                            Binary** mpp, Eterm* ret)
+static int select_delete_on_trap(match_callbacks_t* ctx_base,
+                                 Sint slot_ix, Sint got,
+                                 Binary** mpp, Eterm* ret)
 {
-    mtraversal_select_delete_context_t* sd_context_ptr = (mtraversal_select_delete_context_t*) context_ptr;
-    return on_mtraversal_simple_trap(
+    select_delete_context_t* ctx = (select_delete_context_t*) ctx_base;
+    free_term_list(ctx->tb, ctx->free_us);
+    ctx->free_us = NULL;
+    return on_simple_trap(
             &ets_select_delete_continue_exp,
-            sd_context_ptr->p,
-            sd_context_ptr->tb,
-            sd_context_ptr->tid,
-            sd_context_ptr->prev_continuation_tptr,
+            ctx->p,
+            ctx->tb,
+            ctx->tid,
+            ctx->prev_continuation_tptr,
             slot_ix, got, mpp, ret);
 }
 
-static int db_select_delete_hash(Process *p, DbTable *tbl, Eterm tid, Eterm pattern, Eterm *ret) {
-    mtraversal_select_delete_context_t sd_context = {0};
+static int db_select_delete_hash(Process *p, DbTable *tbl, Eterm tid,
+                                 Eterm pattern, Eterm *ret)
+{
+    select_delete_context_t ctx;
     Sint chunk_size = 0;
 
-    sd_context.p = p;
-    sd_context.tb = &tbl->hash;
-    sd_context.tid = tid;
-    sd_context.hp = NULL;
-    sd_context.prev_continuation_tptr = NULL;
-    sd_context.fixated_by_me = sd_context.tb->common.is_thread_safe ? 0 : 1; /* TODO: something nicer */
-    sd_context.last_pseudo_delete = (Uint) -1;
+    ctx.base.on_nothing_can_match = select_delete_on_nothing_can_match;
+    ctx.base.on_match_res         = select_delete_on_match_res;
+    ctx.base.on_loop_ended        = select_delete_on_loop_ended;
+    ctx.base.on_trap              = select_delete_on_trap;
+    ctx.p = p;
+    ctx.tb = &tbl->hash;
+    ctx.tid = tid;
+    ctx.prev_continuation_tptr = NULL;
+    ctx.fixated_by_me = ctx.tb->common.is_thread_safe ? 0 : 1; /* TODO: something nicer */
+    ctx.last_pseudo_delete = (Uint) -1;
+    ctx.free_us = NULL;
 
     return match_traverse(
-            sd_context.p, sd_context.tb,
+            ctx.p, ctx.tb,
             pattern, NULL,
             chunk_size,
             MAX_SELECT_DELETE_ITERATIONS, NULL, 1,
-            mtraversal_select_delete_on_nothing_can_match,
-            mtraversal_select_delete_on_match_res,
-            mtraversal_select_delete_on_loop_ended,
-            mtraversal_select_delete_on_trap,
-            &sd_context, ret);
+            &ctx.base, ret);
 }
 
 /*
  * This is called when select_delete traps
  */
-static int db_select_delete_continue_hash(Process* p, DbTable* tbl, Eterm continuation, Eterm* ret) {
-    mtraversal_select_delete_context_t sd_context = {0};
+static int db_select_delete_continue_hash(Process* p, DbTable* tbl,
+                                          Eterm continuation, Eterm* ret)
+{
+    select_delete_context_t ctx;
     Eterm* tptr;
     Eterm tid;
     Binary* mp;
@@ -2038,27 +2096,27 @@ static int db_select_delete_continue_hash(Process* p, DbTable* tbl, Eterm contin
     Sint slot_ix;
     Sint chunk_size = 0;
 
-    if (unpack_simple_mtraversal_continuation(continuation, &tptr, &tid, &slot_ix, &mp, &got)) {
+    if (unpack_simple_continuation(continuation, &tptr, &tid, &slot_ix, &mp, &got)) {
         *ret = NIL;
         return DB_ERROR_BADPARAM;
     }
 
-    sd_context.p = p;
-    sd_context.tb = &tbl->hash;
-    sd_context.tid = tid;
-    sd_context.hp = NULL;
-    sd_context.prev_continuation_tptr = tptr;
-    sd_context.fixated_by_me = ONLY_WRITER(p, sd_context.tb) ? 0 : 1; /* TODO: something nicer */
-    sd_context.last_pseudo_delete = (Uint) -1;
+    ctx.base.on_match_res  = select_delete_on_match_res;
+    ctx.base.on_loop_ended = select_delete_on_loop_ended;
+    ctx.base.on_trap       = select_delete_on_trap;
+    ctx.p = p;
+    ctx.tb = &tbl->hash;
+    ctx.tid = tid;
+    ctx.prev_continuation_tptr = tptr;
+    ctx.fixated_by_me = ONLY_WRITER(p, ctx.tb) ? 0 : 1; /* TODO: something nicer */
+    ctx.last_pseudo_delete = (Uint) -1;
+    ctx.free_us = NULL;
 
     return match_traverse_continue(
-            sd_context.p, sd_context.tb, chunk_size,
+            ctx.p, ctx.tb, chunk_size,
             MAX_SELECT_DELETE_ITERATIONS,
             NULL, slot_ix, got, &mp, 1,
-            mtraversal_select_delete_on_match_res,  /* Reuse callback */
-            mtraversal_select_delete_on_loop_ended, /* Reuse callback */
-            mtraversal_select_delete_on_trap,       /* Reuse callback */
-            &sd_context, ret);
+            &ctx.base, ret);
 }
 
 #undef MAX_SELECT_DELETE_ITERATIONS
@@ -2073,24 +2131,26 @@ static int db_select_delete_continue_hash(Process* p, DbTable* tbl, Eterm contin
 #define MAX_SELECT_REPLACE_ITERATIONS 1000
 
 typedef struct {
+    match_callbacks_t base;
     Process* p;
     DbTableHash* tb;
     Eterm tid;
-    Eterm* hp;
     Eterm* prev_continuation_tptr;
-} mtraversal_select_replace_context_t;
+} select_replace_context_t;
 
-static int mtraversal_select_replace_on_nothing_can_match(void* context_ptr, Eterm* ret) {
+static int select_replace_on_nothing_can_match(match_callbacks_t* ctx_base,
+                                               Eterm* ret)
+{
     *ret = make_small(0);
     return DB_ERROR_NONE;
 }
 
-static int mtraversal_select_replace_on_match_res(void* context_ptr, Sint slot_ix,
-                                                  HashDbTerm*** current_ptr_ptr,
-                                                  Eterm match_res)
+static int select_replace_on_match_res(match_callbacks_t* ctx_base, Sint slot_ix,
+                                       HashDbTerm*** current_ptr_ptr,
+                                       Eterm match_res)
 {
-    mtraversal_select_replace_context_t* sr_context_ptr = (mtraversal_select_replace_context_t*) context_ptr;
-    DbTableHash* tb = sr_context_ptr->tb;
+    select_replace_context_t* ctx = (select_replace_context_t*) ctx_base;
+    DbTableHash* tb = ctx->tb;
     HashDbTerm* new;
     HashDbTerm* next;
     HashValue hval;
@@ -2106,6 +2166,7 @@ static int mtraversal_select_replace_on_match_res(void* context_ptr, Sint slot_i
         new = new_dbterm(tb, match_res);
         new->next = next;
         new->hvalue = hval;
+        new->pseudo_deleted = 0;
         free_term(tb, **current_ptr_ptr);
         **current_ptr_ptr = new; /* replace 'next' pointer in previous object */
         *current_ptr_ptr = &((**current_ptr_ptr)->next); /* advance to next object */
@@ -2114,35 +2175,37 @@ static int mtraversal_select_replace_on_match_res(void* context_ptr, Sint slot_i
     return 0;
 }
 
-static int mtraversal_select_replace_on_loop_ended(void* context_ptr, Sint slot_ix, Sint got,
-                                                   Sint iterations_left, Binary** mpp, Eterm* ret)
+static int select_replace_on_loop_ended(match_callbacks_t* ctx_base, Sint slot_ix,
+                                        Sint got, Sint iterations_left,
+                                        Binary** mpp, Eterm* ret)
 {
-    mtraversal_select_replace_context_t* sr_context_ptr = (mtraversal_select_replace_context_t*) context_ptr;
+    select_replace_context_t* ctx = (select_replace_context_t*) ctx_base;
     ASSERT(iterations_left <= MAX_SELECT_REPLACE_ITERATIONS);
     /* the more objects we've replaced, the more reductions we've consumed */
-    BUMP_REDS(sr_context_ptr->p,
+    BUMP_REDS(ctx->p,
               MIN(MAX_SELECT_REPLACE_ITERATIONS * 2,
                   (MAX_SELECT_REPLACE_ITERATIONS - iterations_left) + (int)got));
-    *ret = erts_make_integer(got, sr_context_ptr->p);
+    *ret = erts_make_integer(got, ctx->p);
     return DB_ERROR_NONE;
 }
 
-static int mtraversal_select_replace_on_trap(void* context_ptr, Sint slot_ix, Sint got,
-                                             Binary** mpp, Eterm* ret)
+static int select_replace_on_trap(match_callbacks_t* ctx_base,
+                                  Sint slot_ix, Sint got,
+                                  Binary** mpp, Eterm* ret)
 {
-    mtraversal_select_replace_context_t* sr_context_ptr = (mtraversal_select_replace_context_t*) context_ptr;
-    return on_mtraversal_simple_trap(
+    select_replace_context_t* ctx = (select_replace_context_t*) ctx_base;
+    return on_simple_trap(
             &ets_select_replace_continue_exp,
-            sr_context_ptr->p,
-            sr_context_ptr->tb,
-            sr_context_ptr->tid,
-            sr_context_ptr->prev_continuation_tptr,
+            ctx->p,
+            ctx->tb,
+            ctx->tid,
+            ctx->prev_continuation_tptr,
             slot_ix, got, mpp, ret);
 }
 
 static int db_select_replace_hash(Process *p, DbTable *tbl, Eterm tid, Eterm pattern, Eterm *ret)
 {
-    mtraversal_select_replace_context_t sr_context = {0};
+    select_replace_context_t ctx;
     Sint chunk_size = 0;
 
     /* Bag implementation presented both semantic consistency and performance issues,
@@ -2150,22 +2213,21 @@ static int db_select_replace_hash(Process *p, DbTable *tbl, Eterm tid, Eterm pat
      */
     ASSERT(!(tbl->hash.common.status & DB_BAG));
 
-    sr_context.p = p;
-    sr_context.tb = &tbl->hash;
-    sr_context.tid = tid;
-    sr_context.hp = NULL;
-    sr_context.prev_continuation_tptr = NULL;
+    ctx.base.on_nothing_can_match = select_replace_on_nothing_can_match;
+    ctx.base.on_match_res         = select_replace_on_match_res;
+    ctx.base.on_loop_ended        = select_replace_on_loop_ended;
+    ctx.base.on_trap              = select_replace_on_trap;
+    ctx.p = p;
+    ctx.tb = &tbl->hash;
+    ctx.tid = tid;
+    ctx.prev_continuation_tptr = NULL;
 
     return match_traverse(
-            sr_context.p, sr_context.tb,
+            ctx.p, ctx.tb,
             pattern, db_match_keeps_key,
             chunk_size,
             MAX_SELECT_REPLACE_ITERATIONS, NULL, 1,
-            mtraversal_select_replace_on_nothing_can_match,
-            mtraversal_select_replace_on_match_res,
-            mtraversal_select_replace_on_loop_ended,
-            mtraversal_select_replace_on_trap,
-            &sr_context, ret);
+            &ctx.base, ret);
 }
 
 /*
@@ -2173,7 +2235,7 @@ static int db_select_replace_hash(Process *p, DbTable *tbl, Eterm tid, Eterm pat
  */
 static int db_select_replace_continue_hash(Process* p, DbTable* tbl, Eterm continuation, Eterm* ret)
 {
-    mtraversal_select_replace_context_t sr_context = {0};
+    select_replace_context_t ctx;
     Eterm* tptr;
     Eterm tid ;
     Binary* mp;
@@ -2182,26 +2244,25 @@ static int db_select_replace_continue_hash(Process* p, DbTable* tbl, Eterm conti
     Sint chunk_size = 0;
     *ret = NIL;
 
-    if (unpack_simple_mtraversal_continuation(continuation, &tptr, &tid, &slot_ix, &mp, &got)) {
+    if (unpack_simple_continuation(continuation, &tptr, &tid, &slot_ix, &mp, &got)) {
         *ret = NIL;
         return DB_ERROR_BADPARAM;
     }
 
     /* Proceed */
-    sr_context.p = p;
-    sr_context.tb = &tbl->hash;
-    sr_context.tid = tid;
-    sr_context.hp = NULL;
-    sr_context.prev_continuation_tptr = tptr;
+    ctx.base.on_match_res  = select_replace_on_match_res;
+    ctx.base.on_loop_ended = select_replace_on_loop_ended;
+    ctx.base.on_trap       = select_replace_on_trap;
+    ctx.p = p;
+    ctx.tb = &tbl->hash;
+    ctx.tid = tid;
+    ctx.prev_continuation_tptr = tptr;
 
     return match_traverse_continue(
-            sr_context.p, sr_context.tb, chunk_size,
+            ctx.p, ctx.tb, chunk_size,
             MAX_SELECT_REPLACE_ITERATIONS,
             NULL, slot_ix, got, &mp, 1,
-            mtraversal_select_replace_on_match_res,  /* Reuse callback */
-            mtraversal_select_replace_on_loop_ended, /* Reuse callback */
-            mtraversal_select_replace_on_trap,       /* Reuse callback */
-            &sr_context, ret);
+            &ctx.base, ret);
 }
 
 
@@ -2209,6 +2270,7 @@ static int db_take_hash(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
 {
     DbTableHash *tb = &tbl->hash;
     HashDbTerm **bp, *b;
+    HashDbTerm *free_us = NULL;
     HashValue hval = MAKE_HASH(key);
     erts_rwmtx_t *lck = WLOCK_HASH(tb, hval);
     int ix = hash_to_ix(tb, hval);
@@ -2226,12 +2288,13 @@ static int db_take_hash(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
                     && add_fixed_deletion(tb, ix, 0)) {
                     /* Pseudo remove (no need to keep several of same key) */
                     bp = &b->next;
-                    b->hvalue = INVALID_HASH;
+                    b->pseudo_deleted = 1;
                     b = b->next;
                 } else {
-                    *bp = b->next;
-                    free_term(tb, b);
-                    b = *bp;
+                    HashDbTerm* next = b->next;
+                    b->next = free_us;
+                    free_us = b;
+                    b = *bp = next;
                 }
             }
             break;
@@ -2242,6 +2305,7 @@ static int db_take_hash(Process *p, DbTable *tbl, Eterm key, Eterm *ret)
         erts_atomic_add_nob(&tb->common.nitems, nitems_diff);
         try_shrink(tb);
     }
+    free_term_list(tb, free_us);
     return DB_ERROR_NONE;
 }
 
@@ -2255,25 +2319,52 @@ void db_initialize_hash(void)
 }
 
 
-int db_mark_all_deleted_hash(DbTable *tbl)
+static SWord db_mark_all_deleted_hash(DbTable *tbl, SWord reds)
 {
+    const int LOOPS_PER_REDUCTION  = 8;
     DbTableHash *tb = &tbl->hash;
-    HashDbTerm* list;
+    FixedDeletion* fixdel;
+    SWord loops = reds * LOOPS_PER_REDUCTION;
     int i;
 
     ERTS_LC_ASSERT(IS_TAB_WLOCKED(tb));
 
-    for (i = 0; i < NACTIVE(tb); i++) {
-	if ((list = BUCKET(tb,i)) != NULL) {
-	    add_fixed_deletion(tb, i, 0);
-	    do {
-		list->hvalue = INVALID_HASH;
-		list = list->next;
-	    }while(list != NULL);
-	}
+    fixdel = (FixedDeletion*) erts_atomic_read_nob(&tb->fixdel);
+    if (fixdel && fixdel->trap) {
+        /* Continue after trap */
+        ASSERT(fixdel->all);
+        ASSERT(fixdel->slot < NACTIVE(tb));
+        i = fixdel->slot;
+    }
+    else {
+        /* First call */
+        fixdel = erts_db_alloc(ERTS_ALC_T_DB_FIX_DEL,
+                               (DbTable *) tb,
+                               sizeof(FixedDeletion));
+        ERTS_ETS_MISC_MEM_ADD(sizeof(FixedDeletion));
+        link_fixdel(tb, fixdel, 0);
+        i = 0;
     }
+
+    do {
+        HashDbTerm* b;
+	for (b = BUCKET(tb,i); b; b = b->next)
+            b->pseudo_deleted = 1;
+    } while (++i < NACTIVE(tb) && --loops > 0);
+
+    if (i < NACTIVE(tb)) {
+         /* Yield */
+        fixdel->slot = i;
+        fixdel->all = 0;
+        fixdel->trap = 1;
+        return -1;
+    }
+
+    fixdel->slot = NACTIVE(tb) - 1;
+    fixdel->all = 1;
+    fixdel->trap = 0;
     erts_atomic_set_nob(&tb->common.nitems, 0);
-    return DB_ERROR_NONE;
+    return loops < 0 ? 0 : loops / LOOPS_PER_REDUCTION;
 }
 
 
@@ -2316,7 +2407,7 @@ static void db_print_hash(fmtfn_t to, void *to_arg, int show, DbTable *tbl)
 		continue;
 	    erts_print(to, to_arg, "%d: [", i);
 	    while(list != 0) {
-		if (list->hvalue == INVALID_HASH)
+		if (is_pseudo_deleted(list))
 		    erts_print(to, to_arg, "*");
 		if (tb->common.compress) {
 		    Eterm key = GETKEY(tb, list->dbterm.tpl);
@@ -2335,9 +2426,9 @@ static void db_print_hash(fmtfn_t to, void *to_arg, int show, DbTable *tbl)
     }
 }
 
-/* release all memory occupied by a single table */
-static int db_free_table_hash(DbTable *tbl)
+static int db_free_empty_table_hash(DbTable *tbl)
 {
+    ASSERT(NITEMS(tbl) == 0);
     while (db_free_table_continue_hash(tbl, ERTS_SWORD_MAX) < 0)
 	;
     return 0;
@@ -2415,7 +2506,6 @@ static int analyze_pattern(DbTableHash *tb, Eterm pattern,
     mpi->num_lists = 0;
     mpi->key_given = 1;
     mpi->something_can_match = 0;
-    mpi->all_objects = 1;
     mpi->mp = NULL;
 
     for (lst = pattern; is_list(lst); lst = CDR(list_val(lst)))
@@ -2468,7 +2558,6 @@ static int analyze_pattern(DbTableHash *tb, Eterm pattern,
 
 	if (!is_list(body) || CDR(list_val(body)) != NIL ||
 	    CAR(list_val(body)) != am_DollarUnderscore) {
-	    mpi->all_objects = 0;
 	}
 	++i;
 	if (!(mpi->key_given)) {
@@ -2682,7 +2771,7 @@ static Eterm build_term_list(Process* p, HashDbTerm* ptr1, HashDbTerm* ptr2,
     if (!sz) {
 	ptr = ptr1;
 	while(ptr != ptr2) {
-	    if (ptr->hvalue != INVALID_HASH)
+	    if (!is_pseudo_deleted(ptr))
 		sz += ptr->dbterm.size + 2;
 	    ptr = ptr->next;
 	}
@@ -2693,7 +2782,7 @@ static Eterm build_term_list(Process* p, HashDbTerm* ptr1, HashDbTerm* ptr2,
 
     ptr = ptr1;
     while(ptr != ptr2) {
-	if (ptr->hvalue != INVALID_HASH) {
+	if (!is_pseudo_deleted(ptr)) {
 	    copy = db_copy_object_from_ets(&tb->common, &ptr->dbterm, &hp, &MSO(p));
 	    list = CONS(hp, copy, list);
 	    hp  += 2;
@@ -2786,7 +2875,7 @@ static void grow(DbTableHash* tb, int nitems)
         p = *pnext;
         to_pnext = &BUCKET(tb, to_ix);
         while (p != NULL) {
-            if (p->hvalue == INVALID_HASH) { /* rare but possible with fine locking */
+            if (is_pseudo_deleted(p)) { /* rare but possible with fine locking */
                 *pnext = p->next;
                 free_term(tb, p);
                 p = *pnext;
@@ -2859,7 +2948,7 @@ static void shrink(DbTableHash* tb, int nitems)
          * as we must step through "src" anyway to purge pseudo deleted.
          */
         while(*bp != NULL) {
-            if ((*bp)->hvalue == INVALID_HASH) {
+            if (is_pseudo_deleted(*bp)) {
                 HashDbTerm* deleted = *bp;
                 *bp = deleted->next;
                 free_term(tb, deleted);
@@ -2917,7 +3006,7 @@ static HashDbTerm* next_live(DbTableHash *tb, Uint *iptr, erts_rwmtx_t** lck_ptr
     ERTS_LC_ASSERT(IS_HASH_RLOCKED(tb,*iptr));
 
     for ( ; list != NULL; list = list->next) {
-	if (list->hvalue != INVALID_HASH)
+	if (!is_pseudo_deleted(list))
 	    return list;        
     }
 
@@ -2926,7 +3015,7 @@ static HashDbTerm* next_live(DbTableHash *tb, Uint *iptr, erts_rwmtx_t** lck_ptr
 
 	list = BUCKET(tb,i);
 	while (list != NULL) {
-	    if (list->hvalue != INVALID_HASH) {
+	    if (!is_pseudo_deleted(list)) {
 		*iptr = i;
 		return list;        
 	    }
@@ -2959,7 +3048,7 @@ db_lookup_dbterm_hash(Process *p, DbTable *tbl, Eterm key, Eterm obj,
             break;
         }
         if (has_key(tb, b, key, hval)) {
-            if (b->hvalue != INVALID_HASH) {
+            if (!is_pseudo_deleted(b)) {
                 goto Ldone;
             }
             break;
@@ -2989,16 +3078,18 @@ db_lookup_dbterm_hash(Process *p, DbTable *tbl, Eterm key, Eterm obj,
             HashDbTerm *q = new_dbterm(tb, obj);
 
             q->hvalue = hval;
+            q->pseudo_deleted = 0;
             q->next = NULL;
             *bp = b = q;
             flags |= DB_INC_TRY_GROW;
         } else {
             HashDbTerm *q, *next = b->next;
 
-            ASSERT(b->hvalue == INVALID_HASH);
+            ASSERT(is_pseudo_deleted(b));
             q = replace_dbterm(tb, b, obj);
             q->next = next;
-            q->hvalue = hval;
+            ASSERT(q->hvalue == hval);
+            q->pseudo_deleted = 0;
             *bp = b = q;
             erts_atomic_inc_nob(&tb->common.nitems);
         }
@@ -3036,7 +3127,7 @@ db_finalize_dbterm_hash(int cret, DbUpdateHandle* handle)
     if (handle->flags & DB_NEW_OBJECT && cret != DB_ERROR_NONE) {
         if (IS_FIXED(tb) && add_fixed_deletion(tb, hash_to_ix(tb, b->hvalue),
                                                0)) {
-            b->hvalue = INVALID_HASH;
+            b->pseudo_deleted = 1;
         } else {
             *bp = b->next;
             free_me = b;
@@ -3073,16 +3164,19 @@ db_finalize_dbterm_hash(int cret, DbUpdateHandle* handle)
     return;
 }
 
-static int db_delete_all_objects_hash(Process* p, DbTable* tbl)
+static SWord db_delete_all_objects_hash(Process* p, DbTable* tbl, SWord reds)
 {
     if (IS_FIXED(tbl)) {
-	db_mark_all_deleted_hash(tbl);
+	reds = db_mark_all_deleted_hash(tbl, reds);
     } else {
-	db_free_table_hash(tbl);
+        reds = db_free_table_continue_hash(tbl, reds);
+        if (reds < 0)
+            return reds;
+
 	db_create_hash(p, tbl);
 	erts_atomic_set_nob(&tbl->hash.common.nitems, 0);
     }
-    return 0;
+    return reds;
 }
 
 void db_foreach_offheap_hash(DbTable *tbl,
@@ -3125,7 +3219,7 @@ void db_calc_stats_hash(DbTableHash* tb, DbHashStats* stats)
 	len = 0;
 	for (b = BUCKET(tb,ix); b!=NULL; b=b->next) {
 	    len++;
-            if (b->hvalue == INVALID_HASH)
+            if (is_pseudo_deleted(b))
                 ++kept_items;
 	}
 	sum += len;
diff --git a/erts/emulator/beam/erl_db_hash.h b/erts/emulator/beam/erl_db_hash.h
index 7d27609825..08e5b13db1 100644
--- a/erts/emulator/beam/erl_db_hash.h
+++ b/erts/emulator/beam/erl_db_hash.h
@@ -24,13 +24,26 @@
 #include "erl_db_util.h" /* DbTerm & DbTableCommon */
 
 typedef struct fixed_deletion {
-    int slot;
+    UWord slot : sizeof(UWord)*8 - 2;
+    UWord all : 1;
+    UWord trap : 1;
     struct fixed_deletion *next;
 } FixedDeletion;
 
+
+typedef Uint32 HashVal;
+
 typedef struct hash_db_term {
     struct  hash_db_term* next;  /* next bucket */
-    HashValue  hvalue;        /* stored hash value */
+#if SIZEOF_VOID_P == 4
+    Uint32 hvalue : 31;     /* stored hash value */
+    Uint32 pseudo_deleted : 1;
+# define MAX_HASH_MASK (((Uint32)1 << 31)-1)
+#elif SIZEOF_VOID_P == 8
+    Uint32 hvalue;
+    Uint32 pseudo_deleted;
+# define MAX_HASH_MASK ((Uint32)(Sint32)-1)
+#endif
     DbTerm dbterm;         /* The actual term */
 } HashDbTerm;
 
@@ -86,9 +99,6 @@ int db_get_hash(Process *p, DbTable *tbl, Eterm key, Eterm *ret);
 
 int db_erase_hash(DbTable *tbl, Eterm key, Eterm *ret);
 
-/* not yet in method table */
-int db_mark_all_deleted_hash(DbTable *tbl);
-
 typedef struct {
     float avg_chain_len;
     float std_dev_chain_len;
diff --git a/erts/emulator/beam/erl_db_tree.c b/erts/emulator/beam/erl_db_tree.c
index 5a276b9d88..0692583dd4 100644
--- a/erts/emulator/beam/erl_db_tree.c
+++ b/erts/emulator/beam/erl_db_tree.c
@@ -170,11 +170,6 @@ static ERTS_INLINE TreeDbTerm* replace_dbterm(DbTableTree *tb, TreeDbTerm* old,
 #define DIR_END 2 
 
 /*
- * Special binary flag
- */
-#define BIN_FLAG_ALL_OBJECTS         BIN_FLAG_USR1
-
-/*
  * Number of records to delete before trapping.
  */
 #define DELETE_RECORD_LIMIT 12000
@@ -218,9 +213,6 @@ static void do_dump_tree2(DbTableTree*, int to, void *to_arg, int show,
  * functions.
  */
 struct mp_info {
-    int all_objects;		/* True if complete objects are always
-				 * returned from the match_spec (can use 
-				 * copy_shallow on the return value) */
     int something_can_match;	/* The match_spec is not "impossible" */
     int some_limitation;	/* There is some limitation on the search
 				 * area, i. e. least and/or most is set.*/
@@ -248,7 +240,6 @@ struct select_context {
     Eterm *lastobj;
     Sint32 max;
     int keypos;
-    int all_objects;
     Sint got;
     Sint chunk_size;
 };
@@ -263,7 +254,6 @@ struct select_count_context {
     Eterm *lastobj;
     Sint32 max;
     int keypos;
-    int all_objects;
     Sint got;
 };
 
@@ -293,7 +283,6 @@ struct select_replace_context {
     Eterm *lastobj;
     Sint32 max;
     int keypos;
-    int all_objects;
     Sint replaced;
 };
 
@@ -428,7 +417,7 @@ static int db_select_replace_continue_tree(Process *p, DbTable *tbl,
 static int db_take_tree(Process *, DbTable *, Eterm, Eterm *);
 static void db_print_tree(fmtfn_t to, void *to_arg,
 			  int show, DbTable *tbl);
-static int db_free_table_tree(DbTable *tbl);
+static int db_free_empty_table_tree(DbTable *tbl);
 
 static SWord db_free_table_continue_tree(DbTable *tbl, SWord);
 
@@ -436,7 +425,7 @@ static void db_foreach_offheap_tree(DbTable *,
 				    void (*)(ErlOffHeap *, void *),
 				    void *);
 
-static int db_delete_all_objects_tree(Process* p, DbTable* tbl);
+static SWord db_delete_all_objects_tree(Process* p, DbTable* tbl, SWord reds);
 
 #ifdef HARDDEBUG
 static void db_check_table_tree(DbTable *tbl);
@@ -481,7 +470,7 @@ DbTableMethod db_tree =
     db_select_replace_continue_tree,
     db_take_tree,
     db_delete_all_objects_tree,
-    db_free_table_tree,
+    db_free_empty_table_tree,
     db_free_table_continue_tree,
     db_print_tree,
     db_foreach_offheap_tree,
@@ -992,7 +981,6 @@ static int db_select_continue_tree(Process *p,
     sc.lastobj = NULL;
     sc.max = 1000;
     sc.keypos = tb->common.keypos;
-    sc.all_objects = mp->intern.flags & BIN_FLAG_ALL_OBJECTS;
     sc.chunk_size = chunk_size;
     reverse = unsigned_val(tptr[7]);
     sc.got = signed_val(tptr[8]);
@@ -1143,7 +1131,6 @@ static int db_select_tree(Process *p, DbTable *tbl, Eterm tid,
     }
 
     sc.mp = mpi.mp;
-    sc.all_objects = mpi.all_objects;
 
     if (!mpi.got_partial && mpi.some_limitation && 
 	CMP_EQ(mpi.least,mpi.most)) {
@@ -1183,8 +1170,6 @@ static int db_select_tree(Process *p, DbTable *tbl, Eterm tid,
     sz = size_object(key);
     hp = HAlloc(p, 9 + sz + ERTS_MAGIC_REF_THING_SIZE);
     key = copy_struct(key, sz, &hp, &MSO(p));
-    if (mpi.all_objects)
-	(mpi.mp)->intern.flags |= BIN_FLAG_ALL_OBJECTS;
     mpb= erts_db_make_match_prog_ref(p,mpi.mp,&hp);
 	    
     continuation = TUPLE8
@@ -1346,7 +1331,6 @@ static int db_select_count_tree(Process *p, DbTable *tbl, Eterm tid,
     }
 
     sc.mp = mpi.mp;
-    sc.all_objects = mpi.all_objects;
 
     if (!mpi.got_partial && mpi.some_limitation && 
 	CMP_EQ(mpi.least,mpi.most)) {
@@ -1381,8 +1365,6 @@ static int db_select_count_tree(Process *p, DbTable *tbl, Eterm tid,
 	hp += BIG_UINT_HEAP_SIZE;
     }
     key = copy_struct(key, sz, &hp, &MSO(p));
-    if (mpi.all_objects)
-	(mpi.mp)->intern.flags |= BIN_FLAG_ALL_OBJECTS;
     mpb = erts_db_make_match_prog_ref(p,mpi.mp,&hp);
 	    
     continuation = TUPLE5
@@ -1449,7 +1431,6 @@ static int db_select_chunk_tree(Process *p, DbTable *tbl, Eterm tid,
     }
 
     sc.mp = mpi.mp;
-    sc.all_objects = mpi.all_objects;
 
     if (!mpi.got_partial && mpi.some_limitation && 
 	CMP_EQ(mpi.least,mpi.most)) {
@@ -1506,8 +1487,6 @@ static int db_select_chunk_tree(Process *p, DbTable *tbl, Eterm tid,
 	sz = size_object(key);
 	hp = HAlloc(p, 9 + sz + ERTS_MAGIC_REF_THING_SIZE);
 	key = copy_struct(key, sz, &hp, &MSO(p));
-	if (mpi.all_objects)
-	    (mpi.mp)->intern.flags |= BIN_FLAG_ALL_OBJECTS;
 	mpb = erts_db_make_match_prog_ref(p,mpi.mp,&hp);
 	
 	continuation = TUPLE8
@@ -1532,8 +1511,6 @@ static int db_select_chunk_tree(Process *p, DbTable *tbl, Eterm tid,
     hp = HAlloc(p, 9 + sz + ERTS_MAGIC_REF_THING_SIZE);
     key = copy_struct(key, sz, &hp, &MSO(p));
 
-    if (mpi.all_objects)
-	(mpi.mp)->intern.flags |= BIN_FLAG_ALL_OBJECTS;
     mpb = erts_db_make_match_prog_ref(p,mpi.mp,&hp);
     continuation = TUPLE8
 	(hp,
@@ -1882,7 +1859,6 @@ static int db_select_replace_tree(Process *p, DbTable *tbl, Eterm tid,
     }
 
     sc.mp = mpi.mp;
-    sc.all_objects = mpi.all_objects;
 
     stack = get_static_stack(tb);
     if (!mpi.got_partial && mpi.some_limitation &&
@@ -1928,8 +1904,6 @@ static int db_select_replace_tree(Process *p, DbTable *tbl, Eterm tid,
         hp += BIG_UINT_HEAP_SIZE;
     }
     key = copy_struct(key, sz, &hp, &MSO(p));
-    if (mpi.all_objects)
-        (mpi.mp)->intern.flags |= BIN_FLAG_ALL_OBJECTS;
     mpb = erts_db_make_match_prog_ref(p,mpi.mp,&hp);
 
     continuation = TUPLE5
@@ -1995,8 +1969,9 @@ static void db_print_tree(fmtfn_t to, void *to_arg,
 }
 
 /* release all memory occupied by a single table */
-static int db_free_table_tree(DbTable *tbl)
+static int db_free_empty_table_tree(DbTable *tbl)
 {
+    ASSERT(tbl->tree.root == NULL);
     while (db_free_table_continue_tree(tbl, ERTS_SWORD_MAX) < 0)
 	;
     return 1;
@@ -2023,12 +1998,14 @@ static SWord db_free_table_continue_tree(DbTable *tbl, SWord reds)
     return reds;
 }
 
-static int db_delete_all_objects_tree(Process* p, DbTable* tbl)
+static SWord db_delete_all_objects_tree(Process* p, DbTable* tbl, SWord reds)
 {
-    db_free_table_tree(tbl);
+    reds = db_free_table_continue_tree(tbl, reds);
+    if (reds < 0)
+        return reds;
     db_create_tree(p, tbl);
     erts_atomic_set_nob(&tbl->tree.common.nitems, 0);
-    return 0;
+    return reds;
 }
 
 static void do_db_tree_foreach_offheap(TreeDbTerm *,
@@ -2214,7 +2191,6 @@ static int analyze_pattern(DbTableTree *tb, Eterm pattern,
     mpi->got_partial = 0;
     mpi->something_can_match = 0;
     mpi->mp = NULL;
-    mpi->all_objects = 1;
     mpi->save_term = NULL;
 
     for (lst = pattern; is_list(lst); lst = CDR(list_val(lst)))
@@ -2264,7 +2240,6 @@ static int analyze_pattern(DbTableTree *tb, Eterm pattern,
 
 	if (!is_list(body) || CDR(list_val(body)) != NIL ||
 	    CAR(list_val(body)) != am_DollarUnderscore) {
-	    mpi->all_objects = 0;
 	}
 	++i;
 
@@ -3339,8 +3314,7 @@ static int doit_select(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 			   GETKEY_WITH_POS(sc->keypos, this->dbterm.tpl)) > 0))) {
 	return 0;
     }
-    ret = db_match_dbterm(&tb->common,sc->p,sc->mp,sc->all_objects,
-			  &this->dbterm, &hp, 2);
+    ret = db_match_dbterm(&tb->common, sc->p, sc->mp, &this->dbterm, &hp, 2);
     if (is_value(ret)) {
 	sc->accum = CONS(hp, ret, sc->accum);
     }
@@ -3371,8 +3345,7 @@ static int doit_select_count(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 			  GETKEY_WITH_POS(sc->keypos, this->dbterm.tpl)) > 0)) {
 	return 0;
     }
-    ret = db_match_dbterm(&tb->common, sc->p, sc->mp, 0,
-			  &this->dbterm, NULL, 0);
+    ret = db_match_dbterm(&tb->common, sc->p, sc->mp, &this->dbterm, NULL, 0);
     if (ret == am_true) {
 	++(sc->got);
     }
@@ -3401,8 +3374,7 @@ static int doit_select_chunk(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 	return 0;
     }
 
-    ret = db_match_dbterm(&tb->common, sc->p, sc->mp, sc->all_objects,
-			  &this->dbterm, &hp, 2);
+    ret = db_match_dbterm(&tb->common, sc->p, sc->mp, &this->dbterm, &hp, 2);
     if (is_value(ret)) {
 	++(sc->got);
 	sc->accum = CONS(hp, ret, sc->accum);
@@ -3437,8 +3409,7 @@ static int doit_select_delete(DbTableTree *tb, TreeDbTerm *this, void *ptr,
 	cmp_partly_bound(sc->end_condition, 
 			 GETKEY_WITH_POS(sc->keypos, this->dbterm.tpl)) > 0)
 	return 0;
-    ret = db_match_dbterm(&tb->common, sc->p, sc->mp, 0,
-			  &this->dbterm, NULL, 0);
+    ret = db_match_dbterm(&tb->common, sc->p, sc->mp, &this->dbterm, NULL, 0);
     if (ret == am_true) {
 	key = GETKEY(sc->tb, this->dbterm.tpl);
 	linkout_tree(sc->tb, key);
@@ -3465,8 +3436,7 @@ static int doit_select_replace(DbTableTree *tb, TreeDbTerm **this, void *ptr,
 			  GETKEY_WITH_POS(sc->keypos, (*this)->dbterm.tpl)) > 0)) {
 	return 0;
     }
-    ret = db_match_dbterm(&tb->common, sc->p, sc->mp, 0,
-			  &(*this)->dbterm, NULL, 0);
+    ret = db_match_dbterm(&tb->common, sc->p, sc->mp, &(*this)->dbterm, NULL, 0);
 
     if (is_value(ret)) {
         TreeDbTerm* new;
diff --git a/erts/emulator/beam/erl_db_util.c b/erts/emulator/beam/erl_db_util.c
index ef22cda1f0..37d261d0df 100644
--- a/erts/emulator/beam/erl_db_util.c
+++ b/erts/emulator/beam/erl_db_util.c
@@ -5333,7 +5333,7 @@ void db_free_tmp_uncompressed(DbTerm* obj)
 }
 
 Eterm db_match_dbterm(DbTableCommon* tb, Process* c_p, Binary* bprog,
-			     int all, DbTerm* obj, Eterm** hpp, Uint extra)
+                      DbTerm* obj, Eterm** hpp, Uint extra)
 {
     enum erts_pam_run_flags flags;
     Uint32 dummy;
diff --git a/erts/emulator/beam/erl_db_util.h b/erts/emulator/beam/erl_db_util.h
index 6b126f35d6..73d242449e 100644
--- a/erts/emulator/beam/erl_db_util.h
+++ b/erts/emulator/beam/erl_db_util.h
@@ -32,6 +32,7 @@
 ** DMC_DEBUG does NOT need DEBUG, but DEBUG needs DMC_DEBUG
 */
 #define DMC_DEBUG 1
+#define ETS_DBG_FORCE_TRAP 1
 #endif
 
 /*
@@ -180,10 +181,9 @@ typedef struct db_table_method
             Eterm* ret);
     int (*db_take)(Process *, DbTable *, Eterm, Eterm *);
 
-    int (*db_delete_all_objects)(Process* p,
-				 DbTable* db /* [in out] */ );
+    SWord (*db_delete_all_objects)(Process* p, DbTable* db, SWord reds);
 
-    int (*db_free_table)(DbTable* db /* [in out] */ );
+    int (*db_free_empty_table)(DbTable* db);
     SWord (*db_free_table_continue)(DbTable* db, SWord reds);
     
     void (*db_print)(fmtfn_t to,
@@ -267,6 +267,10 @@ typedef struct db_table_common {
     Uint32 status;            /* bit masks defined  below */
     int keypos;               /* defaults to 1 */
     int compress;
+
+#ifdef ETS_DBG_FORCE_TRAP
+    erts_atomic_t dbg_force_trap;  /* &1 force enabled, &2 trap this call */
+#endif
 } DbTableCommon;
 
 /* These are status bit patterns */
@@ -281,9 +285,7 @@ typedef struct db_table_common {
 #define DB_FINE_LOCKED   (1 << 8) /* write_concurrency */
 #define DB_FREQ_READ     (1 << 9) /* read_concurrency */
 #define DB_NAMED_TABLE   (1 << 10)
-
-#define ERTS_ETS_TABLE_TYPES (DB_BAG|DB_SET|DB_DUPLICATE_BAG|DB_ORDERED_SET\
-                              |DB_FINE_LOCKED|DB_FREQ_READ|DB_NAMED_TABLE)
+#define DB_BUSY          (1 << 11)
 
 #define IS_HASH_TABLE(Status) (!!((Status) & \
 				  (DB_BAG | DB_SET | DB_DUPLICATE_BAG)))
@@ -469,7 +471,7 @@ Binary *db_match_compile(Eterm *matchexpr, Eterm *guards,
 /* Returns newly allocated MatchProg binary with refc == 0*/
 
 Eterm db_match_dbterm(DbTableCommon* tb, Process* c_p, Binary* bprog,
-		      int all, DbTerm* obj, Eterm** hpp, Uint extra);
+		      DbTerm* obj, Eterm** hpp, Uint extra);
 
 Eterm db_prog_match(Process *p, Process *self,
                     Binary *prog, Eterm term,