erts: Remove hashmap probabilistic heap overestimation

by adding a dynamic heap factory.

"binary_to_term" is now a hybrid solution with both
a call to decoded_size() to calculate needed heap space
AND possible dynamic allocation of more heap space
if needed for big maps.

The heap size returned from decoded_size() is guaranteed
to be sufficient for all term heap data except for hashmap
nodes. All hashmap nodes are created at the end of dec_term()
by invoking the heap factory interface that may allocate more
heap space on process heap or in fragments.

With this commit it is no longer guaranteed that a message
is confined to only one heap fragment.

1 files changed, 0 insertions, 1 deletions

diff --git a/erts/emulator/beam/erl_db_hash.c b/erts/emulator/beam/erl_db_hash.c
index 383ee7c430..6e50e9c5b4 100644
--- a/erts/emulator/beam/erl_db_hash.c
+++ b/erts/emulator/beam/erl_db_hash.c
@@ -1049,7 +1049,6 @@ static int db_get_element_hash(Process *p, DbTable *tbl,
 			Eterm copy = db_copy_element_from_ets(&tb->common, p,
 							      &b->dbterm, ndex, &hp, 2);
 			elem_list = CONS(hp, copy, elem_list);
-			hp += 2;
 		    }
 		    b = b->next;
 		}