1--- 2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 3SPDX-License-Identifier: curl 4Title: libcurl-share 5Section: 3 6Source: libcurl 7See-also: 8 - curl_share_cleanup (3) 9 - curl_share_init (3) 10 - curl_share_setopt (3) 11 - libcurl-easy (3) 12 - libcurl-errors (3) 13 - libcurl-multi (3) 14Protocol: 15 - All 16--- 17 18# NAME 19 20libcurl-share - how to use the share interface 21 22# DESCRIPTION 23 24This is an overview on how to use the libcurl share interface in your C 25programs. There are specific man pages for each function mentioned in 26here. 27 28All functions in the share interface are prefixed with curl_share. 29 30# OBJECTIVES 31 32The share interface was added to enable sharing of data between curl handles. 33 34# ONE SET OF DATA - MANY TRANSFERS 35 36You can have multiple easy handles share data between them. Have them update 37and use the **same** cookie database, DNS cache, TLS session cache and/or 38connection cache! This way, each single transfer takes advantage from data 39updates made by the other transfer(s). 40 41# SHARE OBJECT 42 43You create a shared object with curl_share_init(3). It returns a handle 44for a newly created one. 45 46You tell the shared object what data you want it to share by using 47curl_share_setopt(3). 48 49Since you can use this share from multiple threads, and libcurl has no 50internal thread synchronization, you must provide mutex callbacks if you are 51using this multi-threaded. You set lock and unlock functions with 52curl_share_setopt(3) too. 53 54Then, you make an easy handle to use this share, you set the 55CURLOPT_SHARE(3) option with curl_easy_setopt(3), and pass in 56share handle. You can make any number of easy handles share the same share 57handle. 58 59To make an easy handle stop using that particular share, you set 60CURLOPT_SHARE(3) to NULL for that easy handle. To make a handle stop 61sharing a particular data, you can CURLSHOPT_UNSHARE(3) it. 62 63When you are done using the share, make sure that no easy handle is still using 64it, and call curl_share_cleanup(3) on the handle. 65
