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Diffstat (limited to 'docs/libcurl/opts/CURLOPT_CONN_UPKEEP_INTERVAL_MS.3')
| -rw-r--r-- | docs/libcurl/opts/CURLOPT_CONN_UPKEEP_INTERVAL_MS.3 | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/docs/libcurl/opts/CURLOPT_CONN_UPKEEP_INTERVAL_MS.3 b/docs/libcurl/opts/CURLOPT_CONN_UPKEEP_INTERVAL_MS.3 new file mode 100644 index 000000000..e2545a5c8 --- /dev/null +++ b/docs/libcurl/opts/CURLOPT_CONN_UPKEEP_INTERVAL_MS.3 @@ -0,0 +1,73 @@ +.\" ************************************************************************** +.\" * _ _ ____ _ +.\" * Project ___| | | | _ \| | +.\" * / __| | | | |_) | | +.\" * | (__| |_| | _ <| |___ +.\" * \___|\___/|_| \_\_____| +.\" * +.\" * Copyright (C) 1998 - 2018, 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_CONN_UPKEEP_INTERVAL_MS 3 "31 Oct 2018" "libcurl 7.62.0" "curl_easy_setopt options" +.SH NAME +CURLOPT_CONN_UPKEEP_INTERVAL_MS \- connection upkeep interval +.SH SYNOPSIS +#include <curl/curl.h> + +CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CONN_UPKEEP_INTERVAL_MS, long upkeep_interval_ms); +.SH DESCRIPTION +Some protocols have "connection upkeep" mechanisms. These mechanisms usually +send some traffic on existing connections in order to keep them alive; this +can prevent connections from being closed due to overzealous firewalls, for +example. + +The user needs to explicitly call \fIcurl_easy_conn_upkeep(3)\fP in order to +perform the upkeep work. + +Currently the only protocol with a connection upkeep mechanism is HTTP/2: when +the connection upkeep interval is exceeded and \fIcurl_easy_conn_upkeep(3)\fP +is called, an HTTP/2 PING frame is sent on the connection. + +.SH DEFAULT +CURL_UPKEEP_INTERVAL_DEFAULT (currently defined as 60000L, which is 60 seconds) +.SH EXAMPLE +.nf +CURL *curl = curl_easy_init(); +if(curl) { + /* Make a connection to an HTTP/2 server. */ + curl_easy_setopt(curl, CURLOPT_URL, "https://example.com"); + + /* Set the interval to 30000ms / 30s */ + curl_easy_setopt(curl, CURLOPT_CONN_UPKEEP_INTERVAL_MS, 30000L); + + curl_easy_perform(curl); + + /* Perform more work here. */ + + /* While the connection is being held open, curl_easy_conn_upkeep() can be + called. If curl_easy_conn_upkeep() is called and the time since the last + upkeep exceeds the interval, then an HTTP/2 PING is sent. */ + curl_easy_conn_upkeep(curl); + + /* Perform more work here. */ + + /* always cleanup */ + curl_easy_cleanup(curl); +} +.fi +.SH AVAILABILITY +Added in 7.62.0 +.SH RETURN VALUE +Returns CURLE_OK |