CURLMOPT_PIPELINING(3)     curl_multi_setopt options    CURLMOPT_PIPELINING(3)

NAME
       CURLMOPT_PIPELINING - enable HTTP pipelining and multiplexing

SYNOPSIS
       #include <curl/curl.h>

       CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_PIPELINING, long
       bitmask);

DESCRIPTION
       Pass in the bitmask parameter to instruct libcurl to enable HTTP
       pipelining and/or HTTP/2 multiplexing for this multi handle.

       When enabled, libcurl will attempt to use those protocol features when
       doing parallel requests to the same hosts.

       For pipelining, this means that if you add a second request that can
       use an already existing connection, the second request will be "piped"
       on the same connection rather than being executed in parallel.

       For multiplexing, this means that follow-up requests can re-use an
       existing connection and send the new request multiplexed over that at
       the same time as other transfers are already using that single
       connection.

       There are several other related options that are interesting to tweak
       and adjust to alter how libcurl spreads out requests on different
       connections or not etc.

       Before 7.43.0, this option was set to 1 and 0 to enable and disable
       HTTP/1.1 pipelining.

       Starting in 7.43.0, bitmask's second bit also has a meaning, and you
       can ask for pipelining and multiplexing independently of each other by
       toggling the correct bits.

       CURLPIPE_NOTHING
              Default, which means doing no attempts at pipelining or
              multiplexing.

       CURLPIPE_HTTP1
              If this bit is set, libcurl will try to pipeline HTTP/1.1
              requests on connections that are already established and in use
              to hosts.

              This bit is deprecated and has no effect since version 7.62.0.

       CURLPIPE_MULTIPLEX
              If this bit is set, libcurl will try to multiplex the new
              transfer over an existing connection if possible. This requires
              HTTP/2.

DEFAULT
       Since 7.62.0, CURLPIPE_MULTIPLEX is enabled by default.

       Before that, default was CURLPIPE_NOTHING.

PROTOCOLS
       HTTP(S)

EXAMPLE
       CURLM *m = curl_multi_init();
       /* try HTTP/2 multiplexing */
       curl_multi_setopt(m, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);

AVAILABILITY
       Added in 7.16.0. Multiplex support bit added in 7.43.0. HTTP/1
       Pipelining support was disabled in 7.62.0.

RETURN VALUE
       Returns CURLM_OK if the option is supported, and CURLM_UNKNOWN_OPTION
       if not.

SEE ALSO
       CURLMOPT_MAX_PIPELINE_LENGTH(3),  CURLMOPT_PIPELINING_SITE_BL(3),
       CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE(3),
       CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE(3),
       CURLMOPT_MAX_HOST_CONNECTIONS(3),  CURLMOPT_MAXCONNECTS(3),
       CURLMOPT_MAX_HOST_CONNECTIONS(3),

libcurl 7.77.0                 November 4, 2020         CURLMOPT_PIPELINING(3)