curl_multi_perform(3) 맨 페이지 - 윈디하나의 솔라나라

개요

섹션
맨 페이지 이름
검색(S)

curl_multi_perform(3)

curl_multi_perform(3)           libcurl Manual           curl_multi_perform(3)



NAME
       curl_multi_perform - reads/writes available data from easy handles

SYNOPSIS
       #include <curl/curl.h>

       CURLMcode curl_multi_perform(CURLM *multi_handle, int *running_handles);

DESCRIPTION
       This  function  performs  transfers  on all the added handles that need
       attention in a non-blocking fashion. The easy handles  have  previously
       been added to the multi handle with curl_multi_add_handle(3).

       When  an  application  has  found  out  there's  data available for the
       multi_handle or a timeout has elapsed, the application should call this
       function  to  read/write  whatever  there is to read or write right now
       etc.  curl_multi_perform(3) returns as soon  as  the  reads/writes  are
       done.  This  function  does not require that there actually is any data
       available for reading or that data can be written,  it  can  be  called
       just  in  case. It will store the number of handles that still transfer
       data in the second argument's integer-pointer.

       If the amount of running_handles is changed from the previous call  (or
       is  less  than  the  amount of easy handles you have added to the multi
       handle), you know that there is one or more transfers  less  "running".
       You can then call curl_multi_info_read(3) to get information about each
       individual completed transfer, and that returned info includes CURLcode
       and  more. If an added handle fails quickly, it may never be counted as
       a running_handle. You could use curl_multi_info_read(3) to track actual
       status of the added handles in that case.

       When running_handles is set to zero (0) on the return of this function,
       there is no longer any transfers in progress.

       When this function returns error, the state of all transfers are uncer‐
       tain  and they cannot be continued. curl_multi_perform(3) should not be
       called again on the same multi handle after an error has been returned,
       unless first removing all the handles and adding new ones.

EXAMPLE
       int still_running;
       do {
         CURLMcode mc = curl_multi_perform(multi_handle, &still_running);

         if(!mc && still_running)
           /* wait for activity, timeout or "nothing" */
           mc = curl_multi_poll(multi_handle, NULL, 0, 1000, NULL);

         if(mc) {
           fprintf(stderr, "curl_multi_poll() failed, code %d.\n", (int)mc);
           break;
         }

       /* if there are still transfers, loop! */
       } while(still_running);

AVAILABILITY
       Added in 7.9.6

RETURN VALUE
       CURLMcode type, general libcurl multi interface error code.

       This  function returns errors regarding the whole multi stack. Problems
       on individual transfers may  have  occurred  even  when  this  function
       returns  CURLM_OK.  Use curl_multi_info_read(3) to figure out how indi‐
       vidual transfers did.

TYPICAL USAGE
       Most applications will use curl_multi_poll(3) to make libcurl wait  for
       activity  on  any of the ongoing transfers. As soon as one or more file
       descriptor has activity or the  function  times  out,  the  application
       calls curl_multi_perform(3).

SEE ALSO
       curl_multi_cleanup(3),      curl_multi_init(3),     curl_multi_wait(3),
       curl_multi_add_handle(3), curl_multi_fdset(3), curl_multi_info_read(3),
       libcurl-errors(3)



libcurl 7.86.0                  August 15, 2022          curl_multi_perform(3)
맨 페이지 내용의 저작권은 맨 페이지 작성자에게 있습니다.
RSS ATOM XHTML 5 CSS3