Ubuntu Manpage: CURLSHOPT_SHARE

Provided by: libcurl4-doc_8.14.1-2ubuntu1_all

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.