mirror of
https://codeberg.org/kiss-community/repo
synced 2024-08-20 13:16:19 +00:00
106 lines
3.4 KiB
Groff
106 lines
3.4 KiB
Groff
.\" generated by cd2nroff 0.1 from curl_multi_poll.md
|
|
.TH curl_multi_poll 3 "2024-06-01" libcurl
|
|
.SH NAME
|
|
curl_multi_poll \- polls on all easy handles in a multi handle
|
|
.SH SYNOPSIS
|
|
.nf
|
|
#include <curl/curl.h>
|
|
|
|
CURLMcode curl_multi_poll(CURLM *multi_handle,
|
|
struct curl_waitfd extra_fds[],
|
|
unsigned int extra_nfds,
|
|
int timeout_ms,
|
|
int *numfds);
|
|
.fi
|
|
.SH DESCRIPTION
|
|
\fIcurl_multi_poll(3)\fP polls all file descriptors used by the curl easy
|
|
handles contained in the given multi handle set. It blocks until activity is
|
|
detected on at least one of the handles or \fItimeout_ms\fP has passed.
|
|
Alternatively, if the multi handle has a pending internal timeout that has a
|
|
shorter expiry time than \fItimeout_ms\fP, that shorter time is used instead
|
|
to make sure timeout accuracy is reasonably kept.
|
|
|
|
The calling application may pass additional curl_waitfd structures which are
|
|
similar to \fIpoll(2)\fP\(aqs \fIpollfd\fP structure to be waited on in the same
|
|
call.
|
|
|
|
On completion, if \fInumfds\fP is non\-NULL, it gets populated with the total
|
|
number of file descriptors on which interesting events occurred. This number
|
|
can include both libcurl internal descriptors as well as descriptors provided
|
|
in \fIextra_fds\fP.
|
|
|
|
The \fIcurl_multi_wakeup(3)\fP function can be used from another thread to
|
|
wake up this function and return faster. This is one of the details
|
|
that makes this function different than \fIcurl_multi_wait(3)\fP which cannot
|
|
be woken up this way.
|
|
|
|
If no extra file descriptors are provided and libcurl has no file descriptor
|
|
to offer to wait for, this function instead waits during \fItimeout_ms\fP
|
|
milliseconds (or shorter if an internal timer indicates so). This is the other
|
|
detail that makes this function different than \fIcurl_multi_wait(3)\fP.
|
|
|
|
This function is encouraged to be used instead of select(3) when using the
|
|
multi interface to allow applications to easier circumvent the common problem
|
|
with 1024 maximum file descriptors.
|
|
.SH curl_waitfd
|
|
.nf
|
|
struct curl_waitfd {
|
|
curl_socket_t fd;
|
|
short events;
|
|
short revents;
|
|
};
|
|
.fi
|
|
.IP CURL_WAIT_POLLIN
|
|
Bit flag to curl_waitfd.events indicating the socket should poll on read
|
|
events such as new data received.
|
|
.IP 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.
|
|
.IP 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.
|
|
.SH PROTOCOLS
|
|
All
|
|
.SH EXAMPLE
|
|
.nf
|
|
int main(void)
|
|
{
|
|
CURL *easy_handle;
|
|
CURLM *multi_handle;
|
|
int still_running = 0;
|
|
|
|
/* add the individual easy handle */
|
|
curl_multi_add_handle(multi_handle, easy_handle);
|
|
|
|
do {
|
|
CURLMcode mc;
|
|
int numfds;
|
|
|
|
mc = curl_multi_perform(multi_handle, &still_running);
|
|
|
|
if(mc == CURLM_OK) {
|
|
/* wait for activity or timeout */
|
|
mc = curl_multi_poll(multi_handle, NULL, 0, 1000, &numfds);
|
|
}
|
|
|
|
if(mc != CURLM_OK) {
|
|
fprintf(stderr, "curl_multi failed, code %d.\\n", mc);
|
|
break;
|
|
}
|
|
|
|
} while(still_running);
|
|
|
|
curl_multi_remove_handle(multi_handle, easy_handle);
|
|
}
|
|
.fi
|
|
.SH AVAILABILITY
|
|
Added in 7.66.0.
|
|
.SH RETURN VALUE
|
|
CURLMcode type, general libcurl multi interface error code. See
|
|
\fIlibcurl\-errors(3)\fP
|
|
.SH SEE ALSO
|
|
.BR curl_multi_fdset (3),
|
|
.BR curl_multi_perform (3),
|
|
.BR curl_multi_wait (3),
|
|
.BR curl_multi_wakeup (3)
|