---
name: "curl_multi_wakeup"
section: "3"
platform: "linux"
package: "curl"
version: "8.23.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/curl_multi_wakeup"
---

# curl\_multi\_wakeup(3)

wake up a sleeping curl\_multi\_poll call

## 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)](/curl_multi_poll/3.md)* 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)](/curl_multi_poll/3.md)* 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)](/curl_multi_poll/3.md)* 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)](/curl_multi_wait/3.md)* 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(void);
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 mresult;
    int numfds;
    mresult = curl_multi_perform(multi, &still_running);
    if(mresult == CURLM_OK) {
      /* wait for activity, timeout or wakeup */
      mresult = 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)](/libcurl-errors/3.md)*.

## SEE ALSO

[**curl\_multi\_poll**(3)](/curl_multi_poll/3.md), [**curl\_multi\_wait**(3)](/curl_multi_wait/3.md)