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).