curl_multi_wakeup(3)       Library Functions Manual       curl_multi_wakeup(3)

NAME
       curl_multi_wakeup - wake up a sleeping curl_multi_poll call

SYNOPSIS
       #include <curl/curl.h>

       CURLMcode curl_multi_wakeup(CURLM *multi_handle);

DESCRIPTION
       This function can be called from any thread and it wakes up a sleeping
       curl_multi_poll(3) call that is currently (or is about to be) waiting
       for activity or a timeout.

       If the function is called when there is no curl_multi_poll(3) 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) curl_multi_poll(3) call, which means it is
       possible that multiple calls to this function wake up the same waiting
       operation.

       This function has no effect on curl_multi_wait(3) calls.

PROTOCOLS
       This functionality affects all supported protocols

EXAMPLE
       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);
         }
       }

AVAILABILITY
       Added in curl 7.68.0

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 libcurl-errors(3).

SEE ALSO
       curl_multi_poll(3), curl_multi_wait(3)

libcurl                           2025-06-04              curl_multi_wakeup(3)