mingw/share/man/man3/curl_multi_socket.3 - external/msysgit/msysgit - Git at Google

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 .\" * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
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 .\" * furnished to do so, under the terms of the COPYING file.
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 .\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 .\" * KIND, either express or implied.
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 .\" **************************************************************************
 .TH curl_multi_socket 3 "9 Jul 2006" "libcurl 7.16.0" "libcurl Manual"
 .SH NAME
 curl_multi_socket \- reads/writes available data
 .SH SYNOPSIS
 .nf
 #include <curl/curl.h>
 CURLMcode curl_multi_socket(CURLM * multi_handle, curl_socket_t sockfd,
                             int *running_handles);

 CURLMcode curl_multi_socket_all(CURLM *multi_handle,
                                 int *running_handles);
 .fi
 .SH DESCRIPTION
 These functions are deprecated. Do not use! See
 \fIcurl_multi_socket_action(3)\fP instead!

 At return, the integer \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_action(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 \fBcurl_multi_socket_action(3)\fP 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 the callback was called.

 Get the timeout time by setting the \fICURLMOPT_TIMERFUNCTION\fP option with
 \fIcurl_multi_setopt(3)\fP. Your application will then get called with
 information on how long to wait for socket actions at most before doing the
 timeout action: call the \fBcurl_multi_socket_action(3)\fP function with the
 \fBsockfd\fP argument set to CURL_SOCKET_TIMEOUT. You can also use the
 \fIcurl_multi_timeout(3)\fP function to poll the value at any given time, but
 for an event-based system using the callback is far better than relying on
 polling the timeout value.

 Usage of \fIcurl_multi_socket(3)\fP is deprecated, whereas the function is
 equivalent to \fIcurl_multi_socket_action(3)\fP with \fBev_bitmask\fP set to
 0.

 Force libcurl to (re-)check all its internal sockets and transfers instead of
 just a single one by calling \fBcurl_multi_socket_all(3)\fP. Note that there
 should not be any reason to use this function!
 .SH "CALLBACK DETAILS"

 The socket \fBcallback\fP function uses a prototype like this
 .nf

   int curl_socket_callback(CURL *easy,      /* easy handle */
                            curl_socket_t s, /* socket */
                            int action,      /* see values below */
                            void *userp,    /* private callback pointer */
                            void *socketp); /* private socket pointer */

 .fi
 The callback MUST return 0.

 The \fIeasy\fP argument is a pointer to the easy handle that deals with this
 particular socket. Note that a single handle may work with several sockets
 simultaneously.

 The \fIs\fP argument is the actual socket value as you use it within your
 system.

 The \fIaction\fP argument to the callback has one of five values:
 .RS
 .IP "CURL_POLL_NONE (0)"
 register, not interested in readiness (yet)
 .IP "CURL_POLL_IN (1)"
 register, interested in read readiness
 .IP "CURL_POLL_OUT (2)"
 register, interested in write readiness
 .IP "CURL_POLL_INOUT (3)"
 register, interested in both read and write readiness
 .IP "CURL_POLL_REMOVE (4)"
 unregister
 .RE

 The \fIsocketp\fP argument is a private pointer you have previously set with
 \fIcurl_multi_assign(3)\fP to be associated with the \fIs\fP socket. If no
 pointer has been set, socketp will be NULL. This argument is of course a
 service to applications that want to keep certain data or structs that are
 strictly associated to the given socket.

 The \fIuserp\fP argument is a private pointer you have previously set with
 \fIcurl_multi_setopt(3)\fP and the CURLMOPT_SOCKETDATA option.
 .SH "RETURN VALUE"
 CURLMcode type, general libcurl multi interface error code.

 Legacy: If you receive \fICURLM_CALL_MULTI_PERFORM\fP, this basically means
 that you should call \fIcurl_multi_socket(3)\fP again, before you wait for
 more actions on libcurl's sockets. You don't have to do it immediately, but
 the return code means that libcurl may have more data available to return or
 that there may be more data to send off before it is "satisfied".

 In modern libcurls, \fICURLM_CALL_MULTI_PERFORM\fP or
 \fICURLM_CALL_MULTI_SOKCET\fP should not be returned and no application needs
 to care about them.

 NOTE that the return code is for the whole multi stack. Problems still might have
 occurred on individual transfers even when one of these functions
 return OK.
 .SH "TYPICAL USAGE"
 1. Create a multi handle

 2. Set the socket callback with CURLMOPT_SOCKETFUNCTION

 3. Set the timeout callback with CURLMOPT_TIMERFUNCTION, to get to know what
 timeout value to use when waiting for socket activities.

 4. Add easy handles with curl_multi_add_handle()

 5. Provide some means to manage the sockets libcurl is using, so you can check
 them for activity. This can be done through your application code, or by way
 of an external library such as libevent or glib.

 6. Wait for activity on any of libcurl's sockets, use the timeout value your
 callback has been told

 7, When activity is detected, call curl_multi_socket_action() for the
 socket(s) that got action. If no activity is detected and the timeout expires,
 call \fIcurl_multi_socket_action(3)\fP with \fICURL_SOCKET_TIMEOUT\fP

 8. Go back to step 6.
 .SH AVAILABILITY
 This function was added in libcurl 7.15.4, and is deemed stable since
 7.16.0.

 \fIcurl_multi_socket(3)\fP is deprecated, use
 \fIcurl_multi_socket_action(3)\fP instead!
 .SH "SEE ALSO"
 .BR curl_multi_cleanup "(3), " curl_multi_init "(3), "
 .BR curl_multi_fdset "(3), " curl_multi_info_read "(3), "
 .BR "the hiperfifo.c example"
	.\" **************************************************************************
	.\" * _ _ ____ _
	.\" * Project ___\| \| \| \| _ \\| \|
	.\" * / __\| \| \| \| \|_) \| \|
	.\" * \| (__\| \|_\| \| _ <\| \|___
	.\" * \___\|\___/\|_\| \_\_____\|
	.\" *
	.\" * Copyright (C) 1998 - 2011, 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
	.\" * are also available at http://curl.haxx.se/docs/copyright.html.
	.\" *
	.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
	.\" * copies of the Software, and permit persons to whom the Software is
	.\" * furnished to do so, under the terms of the COPYING file.
	.\" *
	.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
	.\" * KIND, either express or implied.
	.\" *
	.\" **************************************************************************
	.TH curl_multi_socket 3 "9 Jul 2006" "libcurl 7.16.0" "libcurl Manual"
	.SH NAME
	curl_multi_socket \- reads/writes available data
	.SH SYNOPSIS
	.nf
	#include <curl/curl.h>
	CURLMcode curl_multi_socket(CURLM * multi_handle, curl_socket_t sockfd,
	int *running_handles);

	CURLMcode curl_multi_socket_all(CURLM *multi_handle,
	int *running_handles);
	.fi
	.SH DESCRIPTION
	These functions are deprecated. Do not use! See
	\fIcurl_multi_socket_action(3)\fP instead!

	At return, the integer \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_action(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 \fBcurl_multi_socket_action(3)\fP 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 the callback was called.

	Get the timeout time by setting the \fICURLMOPT_TIMERFUNCTION\fP option with
	\fIcurl_multi_setopt(3)\fP. Your application will then get called with
	information on how long to wait for socket actions at most before doing the
	timeout action: call the \fBcurl_multi_socket_action(3)\fP function with the
	\fBsockfd\fP argument set to CURL_SOCKET_TIMEOUT. You can also use the
	\fIcurl_multi_timeout(3)\fP function to poll the value at any given time, but
	for an event-based system using the callback is far better than relying on
	polling the timeout value.

	Usage of \fIcurl_multi_socket(3)\fP is deprecated, whereas the function is
	equivalent to \fIcurl_multi_socket_action(3)\fP with \fBev_bitmask\fP set to
	0.

	Force libcurl to (re-)check all its internal sockets and transfers instead of
	just a single one by calling \fBcurl_multi_socket_all(3)\fP. Note that there
	should not be any reason to use this function!
	.SH "CALLBACK DETAILS"

	The socket \fBcallback\fP function uses a prototype like this
	.nf

	int curl_socket_callback(CURL easy, / easy handle */
	curl_socket_t s, /* socket */
	int action, /* see values below */
	void userp, / private callback pointer */
	void socketp); / private socket pointer */

	.fi
	The callback MUST return 0.

	The \fIeasy\fP argument is a pointer to the easy handle that deals with this
	particular socket. Note that a single handle may work with several sockets
	simultaneously.

	The \fIs\fP argument is the actual socket value as you use it within your
	system.

	The \fIaction\fP argument to the callback has one of five values:
	.RS
	.IP "CURL_POLL_NONE (0)"
	register, not interested in readiness (yet)
	.IP "CURL_POLL_IN (1)"
	register, interested in read readiness
	.IP "CURL_POLL_OUT (2)"
	register, interested in write readiness
	.IP "CURL_POLL_INOUT (3)"
	register, interested in both read and write readiness
	.IP "CURL_POLL_REMOVE (4)"
	unregister
	.RE

	The \fIsocketp\fP argument is a private pointer you have previously set with
	\fIcurl_multi_assign(3)\fP to be associated with the \fIs\fP socket. If no
	pointer has been set, socketp will be NULL. This argument is of course a
	service to applications that want to keep certain data or structs that are
	strictly associated to the given socket.

	The \fIuserp\fP argument is a private pointer you have previously set with
	\fIcurl_multi_setopt(3)\fP and the CURLMOPT_SOCKETDATA option.
	.SH "RETURN VALUE"
	CURLMcode type, general libcurl multi interface error code.

	Legacy: If you receive \fICURLM_CALL_MULTI_PERFORM\fP, this basically means
	that you should call \fIcurl_multi_socket(3)\fP again, before you wait for
	more actions on libcurl's sockets. You don't have to do it immediately, but
	the return code means that libcurl may have more data available to return or
	that there may be more data to send off before it is "satisfied".

	In modern libcurls, \fICURLM_CALL_MULTI_PERFORM\fP or
	\fICURLM_CALL_MULTI_SOKCET\fP should not be returned and no application needs
	to care about them.

	NOTE that the return code is for the whole multi stack. Problems still might have
	occurred on individual transfers even when one of these functions
	return OK.
	.SH "TYPICAL USAGE"
	1. Create a multi handle

	2. Set the socket callback with CURLMOPT_SOCKETFUNCTION

	3. Set the timeout callback with CURLMOPT_TIMERFUNCTION, to get to know what
	timeout value to use when waiting for socket activities.

	4. Add easy handles with curl_multi_add_handle()

	5. Provide some means to manage the sockets libcurl is using, so you can check
	them for activity. This can be done through your application code, or by way
	of an external library such as libevent or glib.

	6. Wait for activity on any of libcurl's sockets, use the timeout value your
	callback has been told

	7, When activity is detected, call curl_multi_socket_action() for the
	socket(s) that got action. If no activity is detected and the timeout expires,
	call \fIcurl_multi_socket_action(3)\fP with \fICURL_SOCKET_TIMEOUT\fP

	8. Go back to step 6.
	.SH AVAILABILITY
	This function was added in libcurl 7.15.4, and is deemed stable since
	7.16.0.

	\fIcurl_multi_socket(3)\fP is deprecated, use
	\fIcurl_multi_socket_action(3)\fP instead!
	.SH "SEE ALSO"
	.BR curl_multi_cleanup "(3), " curl_multi_init "(3), "
	.BR curl_multi_fdset "(3), " curl_multi_info_read "(3), "
	.BR "the hiperfifo.c example"