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Diffstat (limited to 'docs/libcurl/opts/CURLMOPT_TIMERFUNCTION.3')
| -rw-r--r-- | docs/libcurl/opts/CURLMOPT_TIMERFUNCTION.3 | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/docs/libcurl/opts/CURLMOPT_TIMERFUNCTION.3 b/docs/libcurl/opts/CURLMOPT_TIMERFUNCTION.3 new file mode 100644 index 00000000..f509b453 --- /dev/null +++ b/docs/libcurl/opts/CURLMOPT_TIMERFUNCTION.3 @@ -0,0 +1,101 @@ +.\" ************************************************************************** +.\" * _ _ ____ _ +.\" * Project ___| | | | _ \| | +.\" * / __| | | | |_) | | +.\" * | (__| |_| | _ <| |___ +.\" * \___|\___/|_| \_\_____| +.\" * +.\" * Copyright (C) 1998 - 2014, 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 http://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 CURLMOPT_TIMERFUNCTION 3 "17 Jun 2014" "libcurl 7.37.0" "curl_multi_setopt options" +.SH NAME +CURLMOPT_TIMERFUNCTION \- set callback to receive timeout values +.SH SYNOPSIS +.nf +#include <curl/curl.h> + +int timer_callback(CURLM *multi, /* multi handle */ + long timeout_ms, /* see above */ + void *userp); /* private callback pointer */ + +CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_TIMERFUNCTION, timer_callback); +.SH DESCRIPTION +Pass a pointer to your callback function, which should match the prototype +shown above. + +Certain features, such as timeouts and retries, require you to call libcurl +even when there is no activity on the file descriptors. + +Your callback function \fBtimer_callback\fP should install a non-repeating +timer with an interval of \fBtimeout_ms\fP. Each time that timer fires, call +either \fIcurl_multi_socket_action(3)\fP or \fIcurl_multi_perform(3)\fP, +depending on which interface you use. + +A \fBtimeout_ms\fP value of -1 means you should delete your timer. + +A \fBtimeout_ms\fP value of 0 means you should call +\fIcurl_multi_socket_action(3)\fP or \fIcurl_multi_perform(3)\fP (once) as soon +as possible. + +\fBtimer_callback\fP will only be called when the \fBtimeout_ms\fP changes. + +The \fBuserp\fP pointer is set with \fICURLMOPT_TIMERDATA(3)\fP. + +The timer callback should return 0 on success, and -1 on error. This callback +can be used instead of, or in addition to, \fIcurl_multi_timeout(3)\fP. +.SH DEFAULT +NULL +.SH PROTOCOLS +All +.SH EXAMPLE +.nf +static gboolean timeout_cb(gpointer user_data) { + if (user_data) { + g_free(user_data); + curl_multi_setopt(curl_handle, CURLMOPT_TIMERDATA, NULL); + } + int running; + curl_multi_socket_action(multi, CURL_SOCKET_TIMEOUT, 0, &running); + return G_SOURCE_REMOVE; +} + +static int timerfunc(CURLM *multi, long timeout_ms, void *userp) { + guint *id = userp; + + if (id) + g_source_remove(*id); + + // -1 means we should just delete our timer. + if (timeout_ms == -1) { + g_free(id); + id = NULL; + } else { + if (!id) + id = g_new(guint, 1); + *id = g_timeout_add(timeout_ms, timeout_cb, id); + } + curl_multi_setopt(multi, CURLMOPT_TIMERDATA, id); + return 0; +} + +curl_multi_setopt(multi, CURLMOPT_TIMERFUNCTION, timerfunc); +.fi +.SH AVAILABILITY +Added in 7.16.0 +.SH RETURN VALUE +Returns CURLM_OK if the option is supported, and CURLM_UNKNOWN_OPTION if not. +.SH "SEE ALSO" +.BR CURLMOPT_TIMERDATA "(3), " CURLMOPT_SOCKETFUNCTION "(3), " |