[PATCH 05/12] alter: allocate triggers before the point of no return
Vladimir Davydov
vdavydov.dev at gmail.com
Sat Apr 7 16:38:02 MSK 2018
Trigger allocation, as any other memory allocation, is allowed to fail.
If this happens in alter_space_do, the space will be left in an
inconsistent state. Let's move trigger allocation to the beginning of
alter_space_do and add a comment denoting the point of no return.
---
src/box/alter.cc | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/src/box/alter.cc b/src/box/alter.cc
index 36310f1c..9d0c4c23 100644
--- a/src/box/alter.cc
+++ b/src/box/alter.cc
@@ -803,6 +803,11 @@ alter_space_rollback(struct trigger *trigger, void * /* event */)
static void
alter_space_do(struct txn *txn, struct alter_space *alter)
{
+ /* Prepare triggers while we may fail. */
+ struct trigger *on_commit, *on_rollback;
+ on_commit = txn_alter_trigger_new(alter_space_commit, alter);
+ on_rollback = txn_alter_trigger_new(alter_space_rollback, alter);
+
/* Create a definition of the new space. */
space_dump_def(alter->old_space, &alter->key_list);
class AlterSpaceOp *op;
@@ -853,6 +858,11 @@ alter_space_do(struct txn *txn, struct alter_space *alter)
throw;
}
+ /*
+ * This function must not throw exceptions or yield after
+ * this point.
+ */
+
/* Rebuild index maps once for all indexes. */
space_fill_index_map(alter->old_space);
space_fill_index_map(alter->new_space);
@@ -873,11 +883,7 @@ alter_space_do(struct txn *txn, struct alter_space *alter)
* finish or rollback the DDL depending on the results of
* writing to WAL.
*/
- struct trigger *on_commit =
- txn_alter_trigger_new(alter_space_commit, alter);
txn_on_commit(txn, on_commit);
- struct trigger *on_rollback =
- txn_alter_trigger_new(alter_space_rollback, alter);
txn_on_rollback(txn, on_rollback);
}
--
2.11.0
More information about the Tarantool-patches
mailing list