updated docs with the new parameter

.SH SYNOPSIS

#include <curl/curl.h>

CURLMcode curl_multi_socket(CURLM * multi_handle, curl_socket_t sockfd);

CURLMcode curl_multi_socket(CURLM * multi_handle, curl_socket_t sockfd,

                            int *running_handles);

CURLMcode curl_multi_socket_all(CURLM *multi_handle);

CURLMcode curl_multi_socket_all(CURLM *multi_handle,

                                int *running_handles);

.SH DESCRIPTION

Alternative versions of \fIcurl_multi_perform()\fP that allows the application

to pass in one of the file descriptors/sockets that have been detected to have

\&"action" on them and let libcurl perform. This allows libcurl to not have to

scan through all possible file descriptors to check for action. When the

application has detected action on a socket handled by libcurl, it should call

\fIcurl_multi_perform()\fP with the \fBsockfd\fP argument set to the socket

with the action.

These functions inform the application about updates in the socket (file

descriptor) status by doing none, one or multiple calls to the callback

function set with the CURLMOPT_SOCKETFUNCTION option to

Alternative versions of \fIcurl_multi_perform(3)\fP that allows the

application to pass in one of the file descriptors/sockets that have been

detected to have \&"action" on them and let libcurl perform. This allows

libcurl to not have to scan through all possible file descriptors to check for

action. When the application has detected action on a socket handled by

libcurl, it should call \fIcurl_multi_socket(3)\fP with the \fBsockfd\fP

argument set to the socket with the action.

At return, the int \fBrunning_handles\fP points to will contain the number of

still running easy handles within the multi handle. When this number reaches

zero, all transfers are complete/done. Note that when you call

\fIcurl_multi_socket(3)\fP on a specific socket and the counter decreases by

one, it DOES NOT necessarily mean that this exact socket/transfer is the one

that completed. Use \fIcurl_multi_info_read(3)\fP to figure out which easy

handle that completed.

The curl_multi_socket functions inform the application about updates in the

socket (file descriptor) status by doing none, one or multiple calls to the

socket callback function set with the CURLMOPT_SOCKETFUNCTION option to

\fIcurl_multi_setopt(3)\fP. They update the status with changes since the

previous time this function was called.

To force libcurl to (re-)check all its internal sockets and transfers instead

of just a single one, you call \fBcurl_multi_socket_all(3)\fP.

of just a single one, you call \fBcurl_multi_socket_all(3)\fP. This is

typically done as the first function call before the application has any

knowledge about what sockets libcurl uses.

Applications should call \fBcurl_multi_timeout(3)\fP to figure out how long to

wait for socket actions \- at most \- before doing the timeout action: call