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curl_multi_timeout(3)               libcurl              curl_multi_timeout(3)


NAME

       curl_multi_timeout - how long to wait for action before proceeding


SYNOPSIS

       #include <curl/curl.h>

       CURLMcode curl_multi_timeout(CURLM *multi_handle, long *timeout);


DESCRIPTION

       An application using the libcurl multi interface should call
       curl_multi_timeout(3) to figure out how long it should wait for socket
       actions - at most - before proceeding.

       Proceeding means either doing the socket-style timeout action: call the
       curl_multi_socket_action(3) function with the sockfd argument set to
       CURL_SOCKET_TIMEOUT, or call curl_multi_perform(3) if you are using the
       simpler and older multi interface approach.

       The timeout value returned in the long timeout points to, is in number
       of milliseconds at this moment. If 0, it means you should proceed
       immediately without waiting for anything. If it returns -1, there's no
       timeout at all set.

       An application that uses the multi_socket API SHOULD NOT use this
       function, but SHOULD instead use the CURLMOPT_TIMERFUNCTION(3) option
       for proper and desired behavior.

       Note: if libcurl returns a -1 timeout here, it just means that libcurl
       currently has no stored timeout value. You must not wait too long (more
       than a few seconds perhaps) before you call curl_multi_perform() again.


EXAMPLE

       struct timeval timeout;
       long timeo;

       curl_multi_timeout(multi_handle, &timeo);
       if(timeo < 0)
         /* no set timeout, use a default */
         timeo = 980;

       timeout.tv_sec = timeo / 1000;
       timeout.tv_usec = (timeo % 1000) * 1000;

       /* wait for activities no longer than the set timeout */
       select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout);


TYPICAL USAGE

       Call curl_multi_timeout(3), then wait for action on the sockets. Figure
       out which sockets to wait for by calling curl_multi_fdset(3).

       When there is activity or timeout, call curl_multi_perform(3) and then
       loop - until all transfers are complete.


AVAILABILITY

       This function was added in libcurl 7.15.4.


RETURN VALUE

       The standard CURLMcode for multi interface error codes.


SEE ALSO

       curl_multi_fdset(3), curl_multi_info_read(3),  curl_multi_socket(3),
       curl_multi_setopt(3)

libcurl 8.1.2                   April 26, 2023           curl_multi_timeout(3)

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