libcurl-share.md (1991B)
1 --- 2 c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 3 SPDX-License-Identifier: curl 4 Title: libcurl-share 5 Section: 3 6 Source: libcurl 7 See-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) 14 Protocol: 15 - All 16 Added-in: n/a 17 --- 18 19 # NAME 20 21 libcurl-share - how to use the share interface 22 23 # DESCRIPTION 24 25 This is an overview on how to use the libcurl share interface in your C 26 programs. There are specific man pages for each function mentioned in 27 here. 28 29 All functions in the share interface are prefixed with curl_share. 30 31 # OBJECTIVES 32 33 The share interface was added to enable sharing of data between curl handles. 34 35 # ONE SET OF DATA - MANY TRANSFERS 36 37 You can have multiple easy handles share data between them. Have them update 38 and use the **same** cookie database, DNS cache, TLS session cache and/or 39 connection cache. This way, each single transfer takes advantage from data 40 updates made by the other transfer(s). 41 42 # SHARE OBJECT 43 44 You create a shared object with curl_share_init(3). It returns a handle 45 for a newly created one. 46 47 You tell the shared object what data you want it to share by using 48 curl_share_setopt(3). 49 50 Since you can use this share from multiple threads, and libcurl has no 51 internal thread synchronization, you must provide mutex callbacks if you are 52 using this multi-threaded. You set lock and unlock functions with 53 curl_share_setopt(3) too. 54 55 Then, you make an easy handle to use this share, you set the 56 CURLOPT_SHARE(3) option with curl_easy_setopt(3), and pass in 57 share handle. You can make any number of easy handles share the same share 58 handle. 59 60 To make an easy handle stop using that particular share, you set 61 CURLOPT_SHARE(3) to NULL for that easy handle. To make a handle stop 62 sharing a particular data, you can CURLSHOPT_UNSHARE(3) it. 63 64 When you are done using the share, make sure that no easy handle is still using 65 it, and call curl_share_cleanup(3) on the handle.