1--- 2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 3SPDX-License-Identifier: curl 4Title: CURLOPT_STREAM_DEPENDS_E 5Section: 3 6Source: libcurl 7See-also: 8 - CURLMOPT_PIPELINING (3) 9 - CURLOPT_HTTP_VERSION (3) 10 - CURLOPT_STREAM_DEPENDS (3) 11 - CURLOPT_STREAM_WEIGHT (3) 12Protocol: 13 - HTTP 14--- 15 16# NAME 17 18CURLOPT_STREAM_DEPENDS_E - stream this transfer depends on exclusively 19 20# SYNOPSIS 21 22~~~c 23#include <curl/curl.h> 24 25CURLcode curl_easy_setopt(CURL *handle, CURLOPT_STREAM_DEPENDS_E, 26 CURL *dephandle); 27~~~ 28 29# DESCRIPTION 30 31Pass a CURL pointer in *dephandle* to identify the stream within the same 32connection that this stream is depending upon exclusively. That means it 33depends on it and sets the Exclusive bit. 34 35The spec says "Including a dependency expresses a preference to allocate 36resources to the identified stream rather than to the dependent stream." 37 38Setting a dependency with the exclusive flag for a reprioritized stream causes 39all the dependencies of the new parent stream to become dependent on the 40reprioritized stream. 41 42This option can be set during transfer. 43 44*dephandle* must not be the same as *handle*, that makes this function return 45an error. It must be another easy handle, and it also needs to be a handle of 46a transfer that is about to be sent over the same HTTP/2 connection for this 47option to have an actual effect. 48 49# DEFAULT 50 51NULL 52 53# EXAMPLE 54 55~~~c 56int main(void) 57{ 58 CURL *curl = curl_easy_init(); 59 CURL *curl2 = curl_easy_init(); /* a second handle */ 60 if(curl) { 61 curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/one"); 62 63 /* the second depends on the first */ 64 curl_easy_setopt(curl2, CURLOPT_URL, "https://example.com/two"); 65 curl_easy_setopt(curl2, CURLOPT_STREAM_DEPENDS_E, curl); 66 67 /* then add both to a multi handle and transfer them! */ 68 } 69} 70~~~ 71 72# AVAILABILITY 73 74Added in 7.46.0 75 76# RETURN VALUE 77 78Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not. 79