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Diffstat (limited to 'docs/libcurl/opts/CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS.3')
| -rw-r--r-- | docs/libcurl/opts/CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS.3 | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/docs/libcurl/opts/CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS.3 b/docs/libcurl/opts/CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS.3 new file mode 100644 index 00000000..8510d3e9 --- /dev/null +++ b/docs/libcurl/opts/CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS.3 @@ -0,0 +1,60 @@ +.\" ************************************************************************** +.\" * _ _ ____ _ +.\" * Project ___| | | | _ \| | +.\" * / __| | | | |_) | | +.\" * | (__| |_| | _ <| |___ +.\" * \___|\___/|_| \_\_____| +.\" * +.\" * Copyright (C) 1998 - 2015, 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 CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS 3 "February 21, 2018" "libcurl 7.59.0" "curl_easy_setopt options" + +.SH NAME +CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS \- head start for ipv6 for happy eyeballs +.SH SYNOPSIS +#include <curl/curl.h> + +CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS, long timeout); +.SH DESCRIPTION +Happy eyeballs is an algorithm that attempts to connect to both IPv4 and IPv6 +addresses for dual-stack hosts, preferring IPv6 first for \fItimeout\fP +milliseconds. If the IPv6 address cannot be connected to within that time then +a connection attempt is made to the IPv4 address in parallel. The first +connection to be established is the one that is used. + +The range of suggested useful values for \fItimeout\fP is limited. Happy +Eyeballs RFC 6555 says "It is RECOMMENDED that connection attempts be paced +150-250 ms apart to balance human factors against network load." libcurl +currently defaults to 200 ms. Firefox and Chrome currently default to 300 ms. +.SH DEFAULT +CURL_HET_DEFAULT (currently defined as 200L) +.SH EXAMPLE +.nf +CURL *curl = curl_easy_init(); +if(curl) { + curl_easy_setopt(curl, CURLOPT_URL, "https://example.com"); + curl_easy_setopt(curl, CURLOPT_HAPPY_EYEBALLS_TIMEOUT_MS, 300L); + + curl_easy_perform(curl); + + /* always cleanup */ + curl_easy_cleanup(curl); +} +.fi +.SH AVAILABILITY +Added in 7.59.0 +.SH RETURN VALUE +Returns CURLE_OK |