* general; updates and deletes have additional problems especially around
* combo CIDs.)
*
+ * We don't try to use parallel mode unless interruptible. The leader
+ * expects ProcessInterrupts() calls to reach HandleParallelMessages().
+ * Even if we called HandleParallelMessages() another way, starting a
+ * parallel worker is too delay-prone to be prudent when uncancellable.
+ *
* For now, we don't try to use parallel mode if we're running inside a
* parallel worker. We might eventually be able to relax this
* restriction, but for now it seems best not to have parallel workers
parse->commandType == CMD_SELECT &&
!parse->hasModifyingCTE &&
max_parallel_workers_per_gather > 0 &&
+ INTERRUPTS_CAN_BE_PROCESSED() &&
!IsParallelWorker())
{
/* all the cheap tests pass, so scan the query tree */
drop function set_and_report_role();
drop function set_role_and_error(int);
drop role regress_parallel_worker;
+-- don't freeze in ParallelFinish while holding an LWLock
+BEGIN;
+CREATE FUNCTION my_cmp (int4, int4)
+RETURNS int LANGUAGE sql AS
+$$
+ SELECT
+ CASE WHEN $1 < $2 THEN -1
+ WHEN $1 > $2 THEN 1
+ ELSE 0
+ END;
+$$;
+CREATE TABLE parallel_hang (i int4);
+INSERT INTO parallel_hang
+ (SELECT * FROM generate_series(1, 400) gs);
+CREATE OPERATOR CLASS int4_custom_ops FOR TYPE int4 USING btree AS
+ OPERATOR 1 < (int4, int4), OPERATOR 2 <= (int4, int4),
+ OPERATOR 3 = (int4, int4), OPERATOR 4 >= (int4, int4),
+ OPERATOR 5 > (int4, int4), FUNCTION 1 my_cmp(int4, int4);
+CREATE UNIQUE INDEX parallel_hang_idx
+ ON parallel_hang
+ USING btree (i int4_custom_ops);
+SET force_parallel_mode = on;
+DELETE FROM parallel_hang WHERE 380 <= i AND i <= 420;
+ROLLBACK;
drop function set_and_report_role();
drop function set_role_and_error(int);
drop role regress_parallel_worker;
+
+-- don't freeze in ParallelFinish while holding an LWLock
+BEGIN;
+
+CREATE FUNCTION my_cmp (int4, int4)
+RETURNS int LANGUAGE sql AS
+$$
+ SELECT
+ CASE WHEN $1 < $2 THEN -1
+ WHEN $1 > $2 THEN 1
+ ELSE 0
+ END;
+$$;
+
+CREATE TABLE parallel_hang (i int4);
+INSERT INTO parallel_hang
+ (SELECT * FROM generate_series(1, 400) gs);
+
+CREATE OPERATOR CLASS int4_custom_ops FOR TYPE int4 USING btree AS
+ OPERATOR 1 < (int4, int4), OPERATOR 2 <= (int4, int4),
+ OPERATOR 3 = (int4, int4), OPERATOR 4 >= (int4, int4),
+ OPERATOR 5 > (int4, int4), FUNCTION 1 my_cmp(int4, int4);
+
+CREATE UNIQUE INDEX parallel_hang_idx
+ ON parallel_hang
+ USING btree (i int4_custom_ops);
+
+SET force_parallel_mode = on;
+DELETE FROM parallel_hang WHERE 380 <= i AND i <= 420;
+
+ROLLBACK;