CURLMOPT_PIPELINING.3: extended and clarified

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.TH CURLMOPT_PIPELINING 3 "17 Jun 2014" "libcurl 7.37.0" "curl_multi_setopt options"

.SH NAME

CURLMOPT_PIPELINING \- enable/disable HTTP pipelining

CURLMOPT_PIPELINING \- enable HTTP pipelining and multiplexing

.SH SYNOPSIS

#include <curl/curl.h>

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

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

.SH DESCRIPTION

Set the \fBbits\fP parameter to 1 to make libcurl use HTTP pipelining for

HTTP/1.1 transfers done using this multi handle, as far as possible. 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.

Pass in the \fBbitmask\fP parameter to instruct libcurl to enable HTTP

pipelining and/or HTTP/2 multiplexing for this multi handle.

When using pipelining, there are also several other related options that are

interesting to tweak and adjust to alter how libcurl spreads out requests on

different connections or not etc.

When enabled, libcurl will attempt to use those protocol features when doing

parallel requests to the same hosts.

Starting in 7.43.0, the \fBbits\fP parameter's bit 1 also has a meaning and

libcurl is now offering symbol names for the bits:

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 done of 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, \fBbitmask\fP's second bit also has a meaning, and you can

ask for pipelining and multiplexing independently of each other by toggling

the correct bits.

.IP CURLPIPE_NOTHING (0)

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

.IP CURLPIPE_HTTP1 (1)

If this bit is set, libcurl will try to multiplex the new transfer over an

existing connection if possible. This requires HTTP/2.

.SH DEFAULT

0 (off)

0 (both pipeline and multiplexing are off)

.SH PROTOCOLS

HTTP(S)

.SH EXAMPLE