Re: releasing ParallelApplyTxnHash when pa_launch_parallel_worker returns NULL

On Tue, Jan 10, 2023 at 9:26 AM Ted Yu <yuzhihong(at)gmail(dot)com> wrote:

>
>
> On Tue, Jan 10, 2023 at 9:25 AM Ted Yu <yuzhihong(at)gmail(dot)com> wrote:
>
>> Hi,
>> I was reading src/backend/replication/logical/applyparallelworker.c .
>> In `pa_allocate_worker`, when pa_launch_parallel_worker returns NULL, I
>> think the `ParallelApplyTxnHash` should be released.
>>
>> Please see the patch.
>>
>> Thanks
>>
> Here is the patch :-)
>

In `pa_process_spooled_messages_if_required`, the `pa_unlock_stream` call
immediately follows `pa_lock_stream`.
I assume the following is the intended sequence of calls. If this is the
case, I can add it to the patch.

Cheers

diff --git a/src/backend/replication/logical/applyparallelworker.c
b/src/backend/replication/logical/applyparallelworker.c
index 2e5914d5d9..9879b3fff2 100644
--- a/src/backend/replication/logical/applyparallelworker.c
+++ b/src/backend/replication/logical/applyparallelworker.c
@@ -684,9 +684,9 @@ pa_process_spooled_messages_if_required(void)
if (fileset_state == FS_SERIALIZE_IN_PROGRESS)
{
pa_lock_stream(MyParallelShared->xid, AccessShareLock);
- pa_unlock_stream(MyParallelShared->xid, AccessShareLock);

fileset_state = pa_get_fileset_state();
+ pa_unlock_stream(MyParallelShared->xid, AccessShareLock);
}

/*