1---
2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
3SPDX-License-Identifier: curl
4Title: curl_multi_add_handle
5Section: 3
6Source: libcurl
7See-also:
8  - curl_multi_cleanup (3)
9  - curl_multi_get_handles (3)
10  - curl_multi_init (3)
11  - curl_multi_setopt (3)
12  - curl_multi_socket_action (3)
13Protocol:
14  - All
15---
16
17# NAME
18
19curl_multi_add_handle - add an easy handle to a multi session
20
21# SYNOPSIS
22
23~~~c
24#include <curl/curl.h>
25
26CURLMcode curl_multi_add_handle(CURLM *multi_handle, CURL *easy_handle);
27~~~
28
29# DESCRIPTION
30
31Adds the *easy handle* to the *multi_handle*.
32
33While an easy handle is added to a multi stack, you cannot and you must not
34use curl_easy_perform(3) on that handle. After having removed the easy
35handle from the multi stack again, it is perfectly fine to use it with the
36easy interface again.
37
38If the easy handle is not set to use a shared (CURLOPT_SHARE(3)) cache,
39it is made to use a DNS cache that is shared between all easy handles within
40the multi handle when curl_multi_add_handle(3) is called.
41
42When an easy interface is added to a multi handle, it is set to use a shared
43connection cache owned by the multi handle. Removing and adding new easy
44handles does not affect the pool of connections or the ability to do
45connection reuse.
46
47If you have CURLMOPT_TIMERFUNCTION(3) set in the multi handle (as you
48should if you are working event-based with curl_multi_socket_action(3)
49and friends), that callback is called from within this function to ask for an
50updated timer so that your main event loop gets the activity on this handle to
51get started.
52
53The easy handle remains added to the multi handle until you remove it again
54with curl_multi_remove_handle(3) - even when a transfer with that
55specific easy handle is completed.
56
57You should remove the easy handle from the multi stack before you terminate
58first the easy handle and then the multi handle:
59
601 - curl_multi_remove_handle(3)
61
622 - curl_easy_cleanup(3)
63
643 - curl_multi_cleanup(3)
65
66# EXAMPLE
67
68~~~c
69int main(void)
70{
71  /* init a multi stack */
72  CURLM *multi = curl_multi_init();
73
74  /* create two easy handles */
75  CURL *http_handle = curl_easy_init();
76  CURL *http_handle2 = curl_easy_init();
77
78  /* add individual transfers */
79  curl_multi_add_handle(multi, http_handle);
80  curl_multi_add_handle(multi, http_handle2);
81}
82~~~
83
84# AVAILABILITY
85
86Added in 7.9.6
87
88# RETURN VALUE
89
90CURLMcode type, general libcurl multi interface error code.
91