table of contents
- bookworm 7.88.1-10+deb12u12
- bookworm-backports 8.12.1-3~bpo12+1
- testing 8.13.0~rc2-2
- unstable 8.13.0~rc3-1
CURLSHOPT_SHARE(3) | Library Functions Manual | CURLSHOPT_SHARE(3) |
NAME¶
CURLSHOPT_SHARE - add data to share
SYNOPSIS¶
#include <curl/curl.h> CURLSHcode curl_share_setopt(CURLSH *share, CURLSHOPT_SHARE, long type);
DESCRIPTION¶
The type parameter specifies what specific data that should be shared and kept in the share object that was created with curl_share_init(3). The given type must be one of the values described below. You can set CURLSHOPT_SHARE(3) multiple times with different data arguments to have the share object share multiple types of data. Unset a type again by setting CURLSHOPT_UNSHARE(3).
- CURL_LOCK_DATA_COOKIE
- Cookie data is shared across the easy handles using this shared object.
Note that this does not activate an easy handle's cookie handling. You can
do that separately by using CURLOPT_COOKIEFILE(3) for example.
It is not supported to share cookies between multiple concurrent threads.
- CURL_LOCK_DATA_DNS
- Cached DNS hosts are shared across the easy handles using this shared object. Note that when you use the multi interface, all easy handles added to the same multi handle share the DNS cache by default without using this option.
- CURL_LOCK_DATA_SSL_SESSION
- SSL sessions are shared across the easy handles using this shared object.
This reduces the time spent in the SSL handshake when reconnecting to the
same server. This symbol was added in 7.10.3 but was not implemented until
7.23.0.
Note that when you use the multi interface, all easy handles added to the same multi handle share the SSL session cache by default without using this option.
- CURL_LOCK_DATA_CONNECT
- Put the connection cache in the share object and make all easy handles
using this share object share the connection cache.
It is not supported to share connections between multiple concurrent threads.
Connections that are used for HTTP/2 or HTTP/3 multiplexing only get additional transfers added to them if the existing connection is held by the same multi or easy handle. libcurl does not support doing multiplexed streams in different threads using a shared connection.
Support for CURL_LOCK_DATA_CONNECT was added in 7.57.0, but the symbol existed before this.
Note that when you use the multi interface, all easy handles added to the same multi handle share the connection cache by default without using this option.
- CURL_LOCK_DATA_PSL
- The Public Suffix List stored in the share object is made available to all
easy handle bound to the later. Since the Public Suffix List is
periodically refreshed, this avoids updates in too many different
contexts.
Added in 7.61.0.
Note that when you use the multi interface, all easy handles added to the same multi handle share the PSL cache by default without using this option.
- CURL_LOCK_DATA_HSTS
- The in-memory HSTS cache.
It is not supported to share the HSTS between multiple concurrent threads.
Added in 7.88.0
PROTOCOLS¶
This functionality affects all supported protocols
EXAMPLE¶
int main(void) {
CURLSHcode sh;
CURLSH *share = curl_share_init();
sh = curl_share_setopt(share, CURLSHOPT_SHARE, CURL_LOCK_DATA_COOKIE);
if(sh)
printf("Error: %s\n", curl_share_strerror(sh)); }
AVAILABILITY¶
Added in curl 7.10.3
RETURN VALUE¶
CURLSHE_OK (zero) means that the option was set properly, non-zero means an error occurred. See libcurl-errors(3) for the full list with descriptions.
SEE ALSO¶
CURLSHOPT_UNSHARE(3), curl_share_cleanup(3), curl_share_init(3), curl_share_setopt(3)
2025-03-26 | libcurl |