Merge "reinvent xdist hooks in terms of pytest fixtures"

1 files changed, 21 insertions, 0 deletions

diff --git a/lib/sqlalchemy/dialects/postgresql/provision.py b/lib/sqlalchemy/dialects/postgresql/provision.py
index d345cdfdf..70c390800 100644
--- a/lib/sqlalchemy/dialects/postgresql/provision.py
+++ b/lib/sqlalchemy/dialects/postgresql/provision.py
@@ -8,6 +8,7 @@ from ...testing.provision import drop_all_schema_objects_post_tables
 from ...testing.provision import drop_all_schema_objects_pre_tables
 from ...testing.provision import drop_db
 from ...testing.provision import log
+from ...testing.provision import prepare_for_drop_tables
 from ...testing.provision import set_default_schema_on_connection
 from ...testing.provision import temp_table_keyword_args
 
@@ -102,3 +103,23 @@ def drop_all_schema_objects_post_tables(cfg, eng):
                     postgresql.ENUM(name=enum["name"], schema=enum["schema"])
                 )
             )
+
+
+@prepare_for_drop_tables.for_db("postgresql")
+def prepare_for_drop_tables(config, connection):
+    """Ensure there are no locks on the current username/database."""
+
+    result = connection.exec_driver_sql(
+        "select pid, state, wait_event_type, query "
+        # "select pg_terminate_backend(pid), state, wait_event_type "
+        "from pg_stat_activity where "
+        "usename=current_user "
+        "and datname=current_database() and state='idle in transaction' "
+        "and pid != pg_backend_pid()"
+    )
+    rows = result.all()  # noqa
+    assert not rows, (
+        "PostgreSQL may not be able to DROP tables due to "
+        "idle in transaction: %s"
+        % ("; ".join(row._mapping["query"] for row in rows))
+    )