erts: Fix faulty ASSERT of table fixation counter

Cannot read fix->counter safely without table lock.

2 files changed, 4 insertions, 10 deletions

diff --git a/erts/emulator/beam/erl_db.c b/erts/emulator/beam/erl_db.c
index 17e0f2aeec..e84171649c 100644
--- a/erts/emulator/beam/erl_db.c
+++ b/erts/emulator/beam/erl_db.c
@@ -3607,14 +3607,8 @@ static SWord proc_cleanup_fixed_table(Process* p, DbFixation* fix)
 	    ASSERT(sizeof(DbFixation) == ERTS_ALC_DBG_BLK_SZ(fix));
 	    ERTS_DB_ALC_MEM_UPDATE_(tb, sizeof(DbFixation), 0);
 	}
-	else {
-	    ASSERT(fix->counter == 0);
-	}
 	db_unlock(tb, LCK_WRITE_REC);
     }
-    else {
-	ASSERT(fix->counter == 0);
-    }
 
     erts_bin_release(fix->tabs.btid);
     erts_free(ERTS_ALC_T_DB_FIXATION, fix);
@@ -3856,11 +3850,8 @@ static void free_fixations_op(DbFixation* fix, void* vctx)
 {
     struct free_fixations_ctx* ctx = (struct free_fixations_ctx*) vctx;
     erts_aint_t diff;
-#ifdef DEBUG
-    DbTable* dbg_tb = btid2tab(fix->tabs.btid);
-#endif
 
-    ASSERT(!dbg_tb || dbg_tb == ctx->tb);
+    ASSERT(!btid2tab(fix->tabs.btid));
     ASSERT(fix->counter > 0);
     ASSERT(ctx->tb->common.status & DB_DELETE);
 
diff --git a/erts/emulator/beam/erl_db_util.h b/erts/emulator/beam/erl_db_util.h
index 19055c6110..7ce104a84c 100644
--- a/erts/emulator/beam/erl_db_util.h
+++ b/erts/emulator/beam/erl_db_util.h
@@ -220,6 +220,9 @@ typedef struct db_fixation {
         Process* p;
     } procs;
 
+    /* Number of fixations on table from procs.p
+     * Protected by table write lock or read lock + fixlock
+     */
     Uint counter;
 } DbFixation;