Please add this to the next commitfest, so that we don't forget it. On Wed, Feb 1, 2017 at 3:58 PM, Ashutosh Bapat <ashutosh.ba...@enterprisedb.com> wrote: > On Tue, Jan 31, 2017 at 9:53 AM, Higuchi, Daisuke > <higuchi.dais...@jp.fujitsu.com> wrote: >> Hello, >> >> This this is my first posting to the mailing list. >> >> I am interested in multiple hosts of libpq [1], then I found the bug in this >> feature. >> When I set "target_session_attrs" to "any" and call PQsendQuery, my >> application is succeeded. >> However, when I set "target_session_attrs" to "read-write" and call >> PQsendQuery, "another command is already in progress" is occurred. >> I attached the test application to reproduce this problem. >> >> I think this is because PQgetResult is not called until PQgetResult has >> returned a null pointer. >> So, I attached the patch for fix this. >> >> [1] >> https://www.postgresql.org/message-id/flat/20150818041850.ga5...@wagner.pp.ru#20150818041850.ga5...@wagner.pp.ru >> > Interestingly, when I don't set PGPORT, PGHOST I get the same error > with the C program. The patch fixes the problem. > > Per the documentation [1], "PQgetResult must be called repeatedly > until it returns a null pointer, indicating that the command is > done.". The code in PQgetResult() under CONNECTION_CHECK_WRITABLE > case, violates that. The patch fixes it. The patch however jumps to > keep_going without changing conn->status, which means that it will end > up again in the same case. While that's fine, may be we should use a > local loop on PQgetResult() to keep the code readable. > > I would have added a test with the patch, but it seems we don't have > much tests in interfaces/libpq. The bug is pretty trivial and would > have been caught easily had we had any tests. > > [1] https://www.postgresql.org/docs/devel/static/libpq-async.html > > -- > Best Wishes, > Ashutosh Bapat > EnterpriseDB Corporation > The Postgres Database Company
-- Best Wishes, Ashutosh Bapat EnterpriseDB Corporation The Postgres Database Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
