curl_multi_add_handle.3

.\" **************************************************************************
.\" *                                  _   _ ____  _
.\" *  Project                     ___| | | |  _ \| |
.\" *                             / __| | | | |_) | |
.\" *                            | (__| |_| |  _ <| |___
.\" *                             \___|\___/|_| \_\_____|
.\" *
.\" * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
.\" *
.\" * This software is licensed as described in the file COPYING, which
.\" * you should have received as part of this distribution. The terms
.\" * are also available at https://curl.se/docs/copyright.html.
.\" *
.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
.\" * copies of the Software, and permit persons to whom the Software is
.\" * furnished to do so, under the terms of the COPYING file.
.\" *
.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
.\" * KIND, either express or implied.
.\" *
.\" **************************************************************************
.TH curl_multi_add_handle 3 "4 March 2002" "libcurl 7.9.5" "libcurl Manual"
.SH NAME
curl_multi_add_handle - add an easy handle to a multi session
.SH SYNOPSIS
#include <curl/curl.h>

CURLMcode curl_multi_add_handle(CURLM *multi_handle, CURL *easy_handle);
.ad
.SH DESCRIPTION
Adds a standard easy handle to the multi stack. This function call will make
this \fImulti_handle\fP control the specified \fIeasy_handle\fP.

While an easy handle is added to a multi stack, you cannot and you must not
use \fIcurl_easy_perform(3)\fP on that handle. After having removed the easy
handle from the multi stack again, it is perfectly fine to use it with the
easy interface again.

If the easy handle is not set to use a shared (\fICURLOPT_SHARE(3)\fP) or
global DNS cache (\fICURLOPT_DNS_USE_GLOBAL_CACHE(3)\fP), it will be made to
use the DNS cache that is shared between all easy handles within the multi
handle when \fIcurl_multi_add_handle(3)\fP is called.

When an easy interface is added to a multi handle, it will use a shared
connection cache owned by the multi handle. Removing and adding new easy
handles will not affect the pool of connections or the ability to do
connection re-use.

If you have \fICURLMOPT_TIMERFUNCTION(3)\fP set in the multi handle (and you
really should if you're working event-based with
\fIcurl_multi_socket_action(3)\fP and friends), that callback will be called
from within this function to ask for an updated timer so that your main event
loop will get the activity on this handle to get started.

The easy handle will remain added to the multi handle until you remove it
again with \fIcurl_multi_remove_handle(3)\fP - even when a transfer with that
specific easy handle is completed.

You should remove the easy handle from the multi stack before you terminate
first the easy handle and then the multi handle:

1 - \fIcurl_multi_remove_handle(3)\fP

2 - \fIcurl_easy_cleanup(3)\fP

3 - \fIcurl_multi_cleanup(3)\fP
.SH RETURN VALUE
CURLMcode type, general libcurl multi interface error code.
.SH "SEE ALSO"
.BR curl_multi_cleanup "(3)," curl_multi_init "(3), "
.BR curl_multi_setopt "(3), " curl_multi_socket_action "(3) "