curl_multi_wait(3) libcurl Manual curl_multi_wait(3)NAMEcurl_multi_wait - polls on all easy handles in a multi handle
SYNOPSIS
#include <curl/curl.h>
CURLMcode curl_multi_wait(CURLM *multi_handle,
struct curl_waitfd extra_fds[],
unsigned int extra_nfds,
int timeout_ms,
int *numfds);
DESCRIPTION
This function polls on all file descriptors used by the curl easy han‐
dles contained in the given multi handle set. It will block until
activity is detected on at least one of the handles or timeout_ms has
passed. Alternatively, if the multi handle has a pending internal
timeout that has a shorter expiry time than timeout_ms, that shorter
time will be used instead to make sure timeout accuracy is reasonably
kept.
The calling application may pass additional curl_waitfd structures
which are similar to poll(2)'s pollfd structure to be waited on in the
same call.
On completion, if numfds is supplied, it will be populated with the
total number of file descriptors on which interesting events occured.
This number can include both libcurl internal descriptors as well as
descriptors provided in extra_fds.
If no extra file descriptors are provided and libcurl has no file
descriptor to offer to wait for, this function will return immediately.
This function is encouraged to be used instead of select(3) when using
the multi interface to allow applications to easier circumvent the com‐
mon problem with 1024 maximum file descriptors.
curl_waitfd
struct curl_waitfd {
curl_socket_t fd;
short events;
short revents;
};
CURL_WAIT_POLLIN
Bit flag to curl_waitfd.events indicating the socket should poll
on read events such as new data received.
CURL_WAIT_POLLPRI
Bit flag to curl_waitfd.events indicating the socket should poll
on high priority read events such as out of band data.
CURL_WAIT_POLLOUT
Bit flag to curl_waitfd.events indicating the socket should poll
on write events such as the socket being clear to write without
blocking.
RETURN VALUE
CURLMcode type, general libcurl multi interface error code. See
libcurl-errors(3)AVAILABILITY
This function was added in libcurl 7.28.0.
SEE ALSOcurl_multi_fdset(3), curl_multi_perform(3)libcurl 7.28.0 12 Jul 2012 curl_multi_wait(3)