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| author | Daniel Stenberg <daniel@haxx.se> | 2019-07-29 13:41:00 +0200 |
|---|---|---|
| committer | Daniel Stenberg <daniel@haxx.se> | 2019-08-06 09:33:29 +0200 |
| commit | 02346abc32a3995299fa9c2f35b9f0a1d091b045 (patch) | |
| tree | de504a328c326fc2ebef7265ddf4de7456fd56be /include | |
| parent | cee7639b790f29113759f69c4a955c2ead8bff31 (diff) | |
| download | curl-02346abc32a3995299fa9c2f35b9f0a1d091b045.tar.gz | |
curl_multi_poll: a sister to curl_multi_wait() that waits more
Repeatedly we see problems where using curl_multi_wait() is difficult or
just awkward because if it has no file descriptor to wait for
internally, it returns immediately and leaves it to the caller to wait
for a small amount of time in order to avoid occasional busy-looping.
This is often missed or misunderstood, leading to underperforming
applications.
This change introduces curl_multi_poll() as a replacement drop-in
function that accepts the exact same set of arguments. This function
works identically to curl_multi_wait() - EXCEPT - for the case when
there's nothing to wait for internally, as then this function will by
itself wait for a "suitable" short time before it returns. This
effectiely avoids all risks of busy-looping and should also make it less
likely that apps "over-wait".
This also changes the curl tool to use this funtion internally when
doing parallel transfers and changes curl_easy_perform() to use it
internally.
Closes #4163
Diffstat (limited to 'include')
| -rw-r--r-- | include/curl/multi.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/include/curl/multi.h b/include/curl/multi.h index b19dbaf79..6777b446f 100644 --- a/include/curl/multi.h +++ b/include/curl/multi.h @@ -7,7 +7,7 @@ * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * - * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al. + * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al. * * This software is licensed as described in the file COPYING, which * you should have received as part of this distribution. The terms @@ -173,6 +173,20 @@ CURL_EXTERN CURLMcode curl_multi_wait(CURLM *multi_handle, int timeout_ms, int *ret); +/* + * Name: curl_multi_poll() + * + * Desc: Poll on all fds within a CURLM set as well as any + * additional fds passed to the function. + * + * Returns: CURLMcode type, general multi error code. + */ +CURL_EXTERN CURLMcode curl_multi_poll(CURLM *multi_handle, + struct curl_waitfd extra_fds[], + unsigned int extra_nfds, + int timeout_ms, + int *ret); + /* * Name: curl_multi_perform() * |