CURLOPT_STREAM_DEPENDS_E(3)                           curl_easy_setopt options

NAME
       CURLOPT_STREAM_DEPENDS_E - set stream this transfer depends on
       exclusively

SYNOPSIS
       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_STREAM_DEPENDS_E, CURL
       *dephandle);

DESCRIPTION
       Pass a CURL * pointer in dephandle to identify the stream within the
       same connection that this stream is depending upon exclusively. That
       means it depends on it and sets the Exclusive bit.

       The spec says "Including a dependency expresses a preference to
       allocate resources to the identified stream rather than to the
       dependent stream."

       Setting a dependency with the exclusive flag for a reprioritized stream
       causes all the dependencies of the new parent stream to become
       dependent on the reprioritized stream.

       This option can be set during transfer.

       dephandle must not be the same as handle, that will cause this function
       to return an error. It must be another easy handle, and it also needs
       to be a handle of a transfer that will be sent over the same HTTP/2
       connection for this option to have an actual effect.

DEFAULT
       NULL

PROTOCOLS
       HTTP/2

EXAMPLE
       CURL *curl = curl_easy_init();
       CURL *curl2 = curl_easy_init(); /* a second handle */
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/one");

         /* the second depends on the first */
         curl_easy_setopt(curl2, CURLOPT_URL, "https://example.com/two");
         curl_easy_setopt(curl2, CURLOPT_STREAM_DEPENDS_E, curl);

         /* then add both to a multi handle and transfer them! */
       }

AVAILABILITY
       Added in 7.46.0

RETURN VALUE
       Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION
       if not.

SEE ALSO
       CURLOPT_STREAM_WEIGHT(3), CURLOPT_STREAM_DEPENDS(3),

libcurl 7.77.0                 November 4, 2020    CURLOPT_STREAM_DEPENDS_E(3)