.\" generated by cd2nroff 0.1 from curl_multi_wakeup.md
.TH curl_multi_wakeup 3 "2025-06-27" libcurl
.SH NAME
curl_multi_wakeup \- wake up a sleeping curl_multi_poll call
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLMcode curl_multi_wakeup(CURLM *multi_handle);
.fi
.SH DESCRIPTION
This function can be called from any thread and it wakes up a sleeping
\fIcurl_multi_poll(3)\fP call that is currently (or is about to be) waiting
for activity or a timeout.

If the function is called when there is no \fIcurl_multi_poll(3)\fP call, it
causes the next call to return immediately.

Calling this function only guarantees to wake up the current (or the next if
there is no current) \fIcurl_multi_poll(3)\fP call, which means it is possible
that multiple calls to this function wake up the same waiting operation.

This function has no effect on \fIcurl_multi_wait(3)\fP calls.
.SH PROTOCOLS
This functionality affects all supported protocols
.SH EXAMPLE
.nf
extern int time_to_die(void);
extern int set_something_to_signal_thread_1_to_exit(void);
extern int decide_to_stop_thread1();

int main(void)
{
  CURL *easy;
  CURLM *multi = curl_multi_init();
  int still_running;

  easy = curl_easy_init();

  /* add the individual easy handle */
  curl_multi_add_handle(multi, easy);

  /* this is thread 1 */
  do {
    CURLMcode mc;
    int numfds;

    mc = curl_multi_perform(multi, &still_running);

    if(mc == CURLM_OK) {
      /* wait for activity, timeout or wakeup */
      mc = curl_multi_poll(multi, NULL, 0, 10000, &numfds);
    }

    if(time_to_die())
      return 1;

  } while(still_running);

  curl_multi_remove_handle(multi, easy);

  /* this is thread 2 */

  if(decide_to_stop_thread1()) {

    set_something_to_signal_thread_1_to_exit();

    curl_multi_wakeup(multi);
  }
}
.fi
.SH AVAILABILITY
Added in curl 7.68.0
.SH RETURN VALUE
This function returns a CURLMcode indicating success or error.

CURLM_OK (0) means everything was OK, non\-zero means an error occurred, see
\fIlibcurl\-errors(3)\fP.
.SH SEE ALSO
.BR curl_multi_poll (3),
.BR curl_multi_wait (3)