Go to main content

man pages section 3: Library Interfaces and Headers

Exit Print View

Updated: Wednesday, July 27, 2022
 
 

CURLMOPT_MAX_HOST_CONNECTIONS (3)

Name

CURLMOPT_MAX_HOST_CONNECTIONS - max number of connections to a single host

Synopsis

#include <curl/curl.h>

CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_MAX_HOST_CONNECTIONS,
long max);

Description

curl_multi_setopt options                     CURLMOPT_MAX_HOST_CONNECTIONS(3)



NAME
       CURLMOPT_MAX_HOST_CONNECTIONS  -  max number of connections to a single
       host

SYNOPSIS
       #include <curl/curl.h>

       CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_MAX_HOST_CONNECTIONS,
                                   long max);

DESCRIPTION
       Pass a long to indicate max. The set number will be used as the maximum
       amount  of  simultaneously  open  connections  to a single host (a host
       being the same as a host name + port number pair). For each new session
       to  a  host,  libcurl will open a new connection up to the limit set by
       CURLMOPT_MAX_HOST_CONNECTIONS(3). When the limit is reached,  the  ses-
       sions  will  be  pending until a connection becomes available. If CURL-
       MOPT_PIPELINING(3) is enabled, libcurl will try to pipeline if the host
       is capable of it.

       The default max value is 0, unlimited.  However, for backwards compati-
       bility, setting it to 0 when CURLMOPT_PIPELINING(3) is 1  will  not  be
       treated as unlimited. Instead it will open only 1 connection and try to
       pipeline on it.

       This set limit is also used for proxy connections, and then  the  proxy
       is considered to be the host for which this limit counts.

       When more transfers are added to the multi handle than what can be per-
       formed due to the set limit, they will be queued up waiting  for  their
       chance.  When  that  happens, the CURLOPT_TIMEOUT_MS(3) timeout will be
       counted inclusive of the waiting time, meaning that if you  set  a  too
       narrow  timeout  in  such  a  case  the transfer might never even start
       before it times out.

       Even in the queued up situation, the CURLOPT_CONNECTTIMEOUT_MS(3) time-
       out is however treated as a per-connect timeout.

DEFAULT
       0

PROTOCOLS
       HTTP(S)

EXAMPLE
       CURLM *m = curl_multi_init();
       /* do no more than 2 connections per host */
       curl_multi_setopt(m, CURLMOPT_MAX_HOST_CONNECTIONS, 2L);

AVAILABILITY
       Added in 7.30.0

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


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+------------------+
       |ATTRIBUTE TYPE | ATTRIBUTE VALUE  |
       +---------------+------------------+
       |Availability   | web/curl         |
       +---------------+------------------+
       |Stability      | Uncommitted      |
       +---------------+------------------+

SEE ALSO
       CURLMOPT_MAXCONNECTS(3), CURLMOPT_MAX_TOTAL_CONNECTIONS(3),



NOTES
       Source code for open source software components in Oracle  Solaris  can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-
       code-downloads.html.

       This    software    was    built    from    source     available     at
       https://github.com/oracle/solaris-userland.    The  original  community
       source      was      downloaded       from        https://curl.se/down-
       load/curl-7.83.1.tar.bz2.

       Further information about this software can be found on the open source
       community website at http://curl.haxx.se/.



libcurl 7.83.1                 November 26, 2021
                                              CURLMOPT_MAX_HOST_CONNECTIONS(3)