Re: A method to asynchronously LISTEN ?

The question being asked is whether executeUpdate method performs
synchronous execution of the listener function queue during its execution.

This after sending the command to the server and the server completing
execution of the NOTIFY. This assumes that the server places the
notification on the channel for pick-up immediately (which will not be the
case within a transaction).

While the client is, IIRC, synchronous, thus the local order of operations
can be controlled, the server is asynchronous and thus this test is exposed
to timing issues. Maybe we need something like conn.listenSync() that
blocks until a notification payload is received on the connection...?

David J.

On Mon, Feb 25, 2019 at 8:14 AM Dave Cramer <pg(at)fastcrypt(dot)com> wrote:

> Philippe
>
>
>
>
> On Mon, 25 Feb 2019 at 04:15, Philippe Ebersohl <
> philippe(dot)ebersohl(at)dalim(dot)com> wrote:
>
>> Hello Dave,
>>
>> This is, sir, what we would like !
>>
>> However looking at line 47-50 of
>> pgjdbc/src/test/java/org/postgresql/test/jdbc2/NotifyTest.java
>> <https://github.com/pgjdbc/pgjdbc/pull/579/commits/229d10adf6686805004491a0d94de076d8e1a3ea#diff-d8d2d4b4d2f26fb01b761a7a12be0741>
>>
>> How do we guaranty that the listener is called before the assertTrue() is
>> fired ?
>>
>> stmt.executeUpdate("NOTIFY mynotification");
>>
>>
>>
>> assertTrue(flag.get());
>>
>
> I'm not sure exactly what you mean
>
> Dave Cramer
>
> davec(at)postgresintl(dot)com
> www.postgresintl.com
>
>
> *From: *"Dave Cramer" <pg(at)fastcrypt(dot)com>
>> *To: *"Philippe Ebersohl" <philippe(dot)ebersohl(at)dalim(dot)com>
>> *Cc: *"List" <pgsql-jdbc(at)postgresql(dot)org>
>> *Sent: *Friday, 22 February, 2019 20:03:46
>> *Subject: *Re: A method to asynchronously LISTEN ?
>>
>> Hi Philippe,
>> So this is old, but I didn't get much response
>> https://github.com/pgjdbc/pgjdbc/pull/579
>>
>> have a look and see if it works for you. If so we can look at putting it
>> in.
>>
>> Dave Cramer
>>
>> davec(at)postgresintl(dot)com
>> www.postgresintl.com
>>
>>
>> On Sat, 16 Feb 2019 at 03:36, Philippe Ebersohl <
>> philippe(dot)ebersohl(at)dalim(dot)com> wrote:
>>
>>> Hello,
>>> I checked the documentation and FAQ at jdbc.postgresql.org
>>> Is there a roadmap of feature implementation for the jdbc driver ?
>>>
>>> Are there plans to include something similar to
>>> the PGNotificationListener found in pgjdbc-ng?
>>> Which does not require to send SELECT to the postgres.
>>>
>>> We would if possible only use one postgresql jdbc driver.
>>>
>>> I hope I hit the right list for my questions.
>>> Thank you.
>>>
>>> Best regards,
>>> Philippe Ebersohl
>>>
>>>
>>>
>>> (null)
>>>
>>>
>>>
>>