.\" ************************************************************************** .\" * _ _ ____ _ .\" * Project ___| | | | _ \| | .\" * / __| | | | |_) | | .\" * | (__| |_| | _ <| |___ .\" * \___|\___/|_| \_\_____| .\" * .\" * Copyright (C) 1998 - 2017, 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.haxx.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_share_setopt 3 "December 05, 2017" "libcurl 7.58.0" "libcurl Manual" .SH NAME curl_share_setopt - Set options for a shared object .SH SYNOPSIS .B #include <curl/curl.h> .sp CURLSHcode curl_share_setopt(CURLSH *share, CURLSHoption option, parameter); .ad .SH DESCRIPTION Set the \fIoption\fP to \fIparameter\fP for the given \fIshare\fP. .SH OPTIONS .IP CURLSHOPT_LOCKFUNC The \fIparameter\fP must be a pointer to a function matching the following prototype: void lock_function(CURL *handle, curl_lock_data data, curl_lock_access access, void *userptr); \fIdata\fP defines what data libcurl wants to lock, and you must make sure that only one lock is given at any time for each kind of data. \fIaccess\fP defines what access type libcurl wants, shared or single. \fIuserptr\fP is the pointer you set with \fICURLSHOPT_USERDATA\fP. .IP CURLSHOPT_UNLOCKFUNC The \fIparameter\fP must be a pointer to a function matching the following prototype: void unlock_function(CURL *handle, curl_lock_data data, void *userptr); \fIdata\fP defines what data libcurl wants to unlock, and you must make sure that only one lock is given at any time for each kind of data. \fIuserptr\fP is the pointer you set with \fICURLSHOPT_USERDATA\fP. .IP CURLSHOPT_SHARE The \fIparameter\fP specifies a type of data that should be shared. This may be set to one of the values described below. .RS .IP CURL_LOCK_DATA_COOKIE Cookie data will be shared across the easy handles using this shared object. .IP CURL_LOCK_DATA_DNS Cached DNS hosts will be 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 will share DNS cache by default without this having to be used! .IP CURL_LOCK_DATA_SSL_SESSION SSL session IDs will be shared across the easy handles using this shared object. This will reduce the time spent in the SSL handshake when reconnecting to the same server. Note SSL session IDs are reused within the same easy handle by default. Note this symbol was added in 7.10.3 but was not implemented until 7.23.0. .IP 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. Using this, you can for example do multi-threaded libcurl use with one handle in each thread, and yet have a shared pool of unused connections and this way get way better connection re-use than if you use one separate pool in each thread. Connections that are used for HTTP/1.1 Pipelining or HTTP/2 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 HTTP/2 streams in different threads using a shared connection. Support for \fBCURL_LOCK_DATA_CONNECT\fP was added in 7.57.0, but the symbol existed before this. .RE .IP CURLSHOPT_UNSHARE This option does the opposite of \fICURLSHOPT_SHARE\fP. It specifies that the specified \fIparameter\fP will no longer be shared. Valid values are the same as those for \fICURLSHOPT_SHARE\fP. .IP CURLSHOPT_USERDATA The \fIparameter\fP allows you to specify a pointer to data that will be passed to the lock_function and unlock_function each time it is called. .SH RETURN VALUE CURLSHE_OK (zero) means that the option was set properly, non-zero means an error occurred as \fI<curl/curl.h>\fP defines. See the \fIlibcurl-errors.3\fP man page for the full list with descriptions. .SH "SEE ALSO" .BR curl_share_cleanup "(3), " curl_share_init "(3)"