Merge branch 'sverker/update_counter-deadlock/ERL-188/OTP-13731' into maint-19

* sverker/update_counter-deadlock/ERL-188/OTP-13731:
  erts: Add test ets_SUITE:update_counter_table_growth
  erts: Fix deadlock in ets:update_counter/4
  erts: Optimize db_finalize_dbterm_hash

3 files changed, 38 insertions, 18 deletions

diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c
index 74979f984a..12ae086b31 100644
--- a/erts/emulator/beam/erl_db_hash.c
+++ b/erts/emulator/beam/erl_db_hash.c
@@ -2866,15 +2866,7 @@ db_lookup_dbterm_hash(Process *p, DbTable *tbl, Eterm key, Eterm obj,
             q->hvalue = hval;
             q->next = NULL;
             *bp = b = q;
-
-            {
-                int nitems = erts_smp_atomic_inc_read_nob(&tb->common.nitems);
-                int nactive = NACTIVE(tb);
-
-                if (nitems > nactive * (CHAIN_LEN + 1) && !IS_FIXED(tb)) {
-                    grow(tb, nactive);
-                }
-            }
+            flags |= DB_INC_TRY_GROW;
         } else {
             HashDbTerm *q, *next = b->next;
 
@@ -2910,6 +2902,7 @@ db_finalize_dbterm_hash(int cret, DbUpdateHandle* handle)
     HashDbTerm **bp = (HashDbTerm **) handle->bp;
     HashDbTerm *b = *bp;
     erts_smp_rwmtx_t* lck = (erts_smp_rwmtx_t*) handle->lck;
+    HashDbTerm* free_me = NULL;
 
     ERTS_SMP_LC_ASSERT(IS_HASH_WLOCKED(tb, lck));  /* locked by db_lookup_dbterm_hash */
 
@@ -2921,21 +2914,34 @@ db_finalize_dbterm_hash(int cret, DbUpdateHandle* handle)
             b->hvalue = INVALID_HASH;
         } else {
             *bp = b->next;
-            free_term(tb, b);
+            free_me = b;
         }
 
         WUNLOCK_HASH(lck);
         erts_smp_atomic_dec_nob(&tb->common.nitems);
         try_shrink(tb);
-    } else if (handle->flags & DB_MUST_RESIZE) {
-	db_finalize_resize(handle, offsetof(HashDbTerm,dbterm));
-	WUNLOCK_HASH(lck);
-
-	free_term(tb, b);
-    }
-    else {
-	WUNLOCK_HASH(lck);
+    } else {
+        if (handle->flags & DB_MUST_RESIZE) {
+            db_finalize_resize(handle, offsetof(HashDbTerm,dbterm));
+            free_me = b;
+        }
+        if (handle->flags & DB_INC_TRY_GROW) {
+            int nactive;
+            int nitems = erts_smp_atomic_inc_read_nob(&tb->common.nitems);
+            WUNLOCK_HASH(lck);
+            nactive = NACTIVE(tb);
+
+            if (nitems > nactive * (CHAIN_LEN + 1) && !IS_FIXED(tb)) {
+                grow(tb, nactive);
+            }
+        } else {
+            WUNLOCK_HASH(lck);
+        }
     }
+
+    if (free_me)
+        free_term(tb, free_me);
+
 #ifdef DEBUG
     handle->dbterm = 0;
 #endif
diff --git a/erts/emulator/beam/erl_db_util.h b/erts/emulator/beam/erl_db_util.h
index 60f7067d70..4acedbfed0 100644
--- a/erts/emulator/beam/erl_db_util.h
+++ b/erts/emulator/beam/erl_db_util.h
@@ -79,6 +79,7 @@ typedef union db_table DbTable;
 
 #define DB_MUST_RESIZE 1
 #define DB_NEW_OBJECT 2
+#define DB_INC_TRY_GROW 4
 
 /* Info about a database entry while it's being updated
  * (by update_counter or update_element)
diff --git a/lib/stdlib/test/ets_SUITE.erl b/lib/stdlib/test/ets_SUITE.erl
index 8c1c625676..b02d17bdb6 100644
--- a/lib/stdlib/test/ets_SUITE.erl
+++ b/lib/stdlib/test/ets_SUITE.erl
@@ -47,6 +47,7 @@
 	 fixtable_next/1, fixtable_insert/1, rename/1, rename_unnamed/1, evil_rename/1,
 	 update_element/1, update_counter/1, evil_update_counter/1, partly_bound/1, match_heavy/1]).
 -export([update_counter_with_default/1]).
+-export([update_counter_table_growth/1]).
 -export([member/1]).
 -export([memory/1]).
 -export([select_fail/1]).
@@ -100,6 +101,7 @@
 	 heavy_lookup_element_do/1, member_do/1, otp_5340_do/1, otp_7665_do/1, meta_wb_do/1,
 	 do_heavy_concurrent/1, tab2file2_do/2, exit_large_table_owner_do/2,
          types_do/1, sleeper/0, memory_do/1, update_counter_with_default_do/1,
+	 update_counter_table_growth_do/1,
 	 ms_tracee_dummy/1, ms_tracee_dummy/2, ms_tracee_dummy/3, ms_tracee_dummy/4
 	]).
 
@@ -137,6 +139,7 @@ all() ->
      rename, rename_unnamed, evil_rename, update_element,
      update_counter, evil_update_counter,
      update_counter_with_default, partly_bound,
+     update_counter_table_growth,
      match_heavy, {group, fold}, member, t_delete_object,
      t_init_table, t_whitebox, t_delete_all_objects,
      t_insert_list, t_test_ms, t_select_delete, t_ets_dets,
@@ -1955,6 +1958,16 @@ update_counter_with_default_do(Opts) ->
 
     ok.
 
+update_counter_table_growth(_Config) ->
+    repeat_for_opts(update_counter_table_growth_do).
+
+update_counter_table_growth_do(Opts) ->
+    Set = ets_new(b, [set | Opts]),
+    [ets:update_counter(Set, N, {2, 1}, {N, 1}) || N <- lists:seq(1,10000)],
+    OrderedSet = ets_new(b, [ordered_set | Opts]),
+    [ets:update_counter(OrderedSet, N, {2, 1}, {N, 1}) || N <- lists:seq(1,10000)],
+    ok.
+
 %% Check that a first-next sequence always works on a fixed table.
 fixtable_next(Config) when is_list(Config) ->
     repeat_for_opts(fixtable_next_do, [write_concurrency,all_types]).