From: Alvaro Herrera Date: Wed, 8 Nov 2023 15:44:08 +0000 (+0100) Subject: Call pqPipelineFlush from PQsendFlushRequest X-Git-Tag: REL_17_BETA1~1519 X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=1a5594b95762a3c1d3a670881ee7f3c5679a1642;p=postgresql.git Call pqPipelineFlush from PQsendFlushRequest When PQsendFlushRequest() was added by commit 69cf1d5429d4, we argued against adding a PQflush() call in it[1]. This is still the right decision: if the user wants a flush to occur, they can just call that. However, we failed to realize that the message bytes could still be given to the kernel for transmitting when this can be made without blocking. That's what pqPipelineFlush() does, and it is done for every single other message type sent by libpq, so do that. (When the socket is in blocking mode this may indeed block, but that's what all the other libpq message-sending routines do, too.) [1] https://www.postgresql.org/message-id/202106252352.5ca4byasfun5%40alvherre.pgsql Author: Jelte Fennema-Nio Discussion: https://postgr.es/m/CAGECzQTxZRevRWkKodE-SnJk1Yfm4eKT+8E4Cyq3MJ9YKTnNew@mail.gmail.com --- diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c index c6d80ec3968..04610ccf5e8 100644 --- a/src/interfaces/libpq/fe-exec.c +++ b/src/interfaces/libpq/fe-exec.c @@ -3316,6 +3316,14 @@ PQsendFlushRequest(PGconn *conn) return 0; } + /* + * Give the data a push (in pipeline mode, only if we're past the size + * threshold). In nonblock mode, don't complain if we're unable to send + * it all; PQgetResult() will do any additional flushing needed. + */ + if (pqPipelineFlush(conn) < 0) + return 0; + return 1; }