curl_share_setopt man page

curl_share_setopt ā€” Set options for a shared object

Synopsis

#include <curl/curl.h>

CURLSHcode curl_share_setopt(CURLSH *share, CURLSHoption option, parameter);

Description

Set the option to parameter for the given share.

Options

CURLSHOPT_LOCKFUNC

The parameter 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);

data 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.

access defines what access type libcurl wants, shared or single.

userptr is the pointer you set with CURLSHOPT_USERDATA.

CURLSHOPT_UNLOCKFUNC

The parameter must be a pointer to a function matching the following prototype:

void unlock_function(CURL *handle, curl_lock_data data, void *userptr);

data 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.

userptr is the pointer you set with CURLSHOPT_USERDATA.

CURLSHOPT_SHARE

The parameter specifies a type of data that should be shared. This may be set to one of the values described below.

CURL_LOCK_DATA_COOKIE

Cookie data will be shared across the easy handles using this shared object.

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!

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.

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. Support for this was added in 7.57.0, but the symbol existed long before this.

CURLSHOPT_UNSHARE

This option does the opposite of CURLSHOPT_SHARE. It specifies that the specified parameter will no longer be shared. Valid values are the same as those for CURLSHOPT_SHARE.

CURLSHOPT_USERDATA

The parameter allows you to specify a pointer to data that will be passed to the lock_function and unlock_function each time it is called.

Return Value

CURLSHE_OK (zero) means that the option was set properly, non-zero means an error occurred as <curl/curl.h> defines. See the libcurl-errors.3 man page for the full list with descriptions.

See Also

curl_share_cleanup(3), curl_share_init(3)

Referenced By

CURLOPT_SHARE(3), curl_share_cleanup(3), curl_share_init(3), libcurl-share(3), libcurl-thread(3).

November 09, 2017 libcurl 7.57.0 libcurl Manual