<title>CURLMOPT_TIMERFUNCTION man page</title>
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<p class="level0"><a name="NAME"></a><h2 class="nroffsh">NAME</h2>
<p class="level0">CURLMOPT_TIMERFUNCTION - set callback to receive timeout values <a name="SYNOPSIS"></a><h2 class="nroffsh">SYNOPSIS</h2>
-<p class="level0"><pre class="level0">
-#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);
-</pre>
+<p class="level0"><pre>
+<p class="level0">#include <curl/curl.h>
+ <p class="level0">int timer_callback(CURLM *multi, /* multi handle */
+ long timeout_ms, /* see above */
+ void *userp); /* private callback pointer */
+ <p class="level0">CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_TIMERFUNCTION, timer_callback);
+ </pre>
<a name="DESCRIPTION"></a><h2 class="nroffsh">DESCRIPTION</h2>
<p class="level0">Pass a pointer to your callback function, which should match the prototype shown above.
-<p class="level0">Certain features, such as timeouts and retries, require you to call libcurl even when there is no activity on the file descriptors.
-<p class="level0">Your callback function <span Class="bold">timer_callback</span> should install a non-repeating timer with an interval of <span Class="bold">timeout_ms</span>. Each time that timer fires, call either <span Class="emphasis">curl_multi_socket_action(3)</span> or <span Class="emphasis">curl_multi_perform(3)</span>, depending on which interface you use.
-<p class="level0">A <span Class="bold">timeout_ms</span> value of -1 means you should delete your timer.
-<p class="level0">A <span Class="bold">timeout_ms</span> value of 0 means you should call <span Class="emphasis">curl_multi_socket_action(3)</span> or <span Class="emphasis">curl_multi_perform(3)</span> (once) as soon as possible.
-<p class="level0"><span Class="bold">timer_callback</span> will only be called when the <span Class="bold">timeout_ms</span> changes.
+<p class="level0">This callback function will be called when the timeout value changes. The <span Class="bold">timeout_ms</span> value is at what latest time the application should call one of the "performing" functions of the multi interface (<span Class="emphasis">curl_multi_socket_action(3)</span> and <span Class="emphasis">curl_multi_perform(3)</span>) - to allow libcurl to keep timeouts and retries etc to work. A <span Class="bold">timeout_ms</span> value of -1 means that there is no timeout at all, and 0 means that the timeout is already expired. libcurl attempts to limit calling this only when the fixed future timeout time actually changes.
<p class="level0">The <span Class="bold">userp</span> pointer is set with <a Class="emphasis" href="./CURLMOPT_TIMERDATA.html">CURLMOPT_TIMERDATA</a>.
<p class="level0">The timer callback should return 0 on success, and -1 on error. This callback can be used instead of, or in addition to, <span Class="emphasis">curl_multi_timeout(3)</span>. <a name="DEFAULT"></a><h2 class="nroffsh">DEFAULT</h2>
<p class="level0">NULL <a name="PROTOCOLS"></a><h2 class="nroffsh">PROTOCOLS</h2>
<p class="level0">All <a name="EXAMPLE"></a><h2 class="nroffsh">EXAMPLE</h2>
-<p class="level0"><pre class="level0">
-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);
-</pre>
-
-<p class="level0"><a name="AVAILABILITY"></a><h2 class="nroffsh">AVAILABILITY</h2>
+<p class="level0">TODO <a name="AVAILABILITY"></a><h2 class="nroffsh">AVAILABILITY</h2>
<p class="level0">Added in 7.16.0 <a name="RETURN"></a><h2 class="nroffsh">RETURN VALUE</h2>
<p class="level0">Returns CURLM_OK if the option is supported, and CURLM_UNKNOWN_OPTION if not. <a name="SEE"></a><h2 class="nroffsh">SEE ALSO</h2>
<p class="level0"><a Class="manpage" href="./CURLMOPT_TIMERDATA.html">CURLMOPT_TIMERDATA</a>, <a Class="manpage" href="./CURLMOPT_SOCKETFUNCTION.html">CURLMOPT_SOCKETFUNCTION</a>, <span Class="manpage"> </span> <p class="roffit">