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diff --git a/docs/libcurl/gnurl_multi_socket.3 b/docs/libcurl/gnurl_multi_socket.3 new file mode 100644 index 000000000..3ca76e668 --- /dev/null +++ b/docs/libcurl/gnurl_multi_socket.3 @@ -0,0 +1,159 @@ +.\" ************************************************************************** +.\" * _ _ ____ _ +.\" * Project ___| | | | _ \| | +.\" * / __| | | | |_) | | +.\" * | (__| |_| | _ <| |___ +.\" * \___|\___/|_| \_\_____| +.\" * +.\" * Copyright (C) 1998 - 2018, 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 https://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 gnurl_multi_socket 3 "9 Jul 2006" "libcurl 7.16.0" "libgnurl Manual" +.SH NAME +curl_multi_socket \- reads/writes available data +.SH SYNOPSIS +.nf +#include <gnurl/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 \fIcurl_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 +\fICURLMOPT_SOCKETFUNCTION(3)\fP 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(3)\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 \fIcurl_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 \fIcurl_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 \fICURLMOPT_SOCKETDATA(3)\fP 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_SOCKET\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 \fICURLMOPT_SOCKETFUNCTION(3)\fP + +3. Set the timeout callback with \fICURLMOPT_TIMERFUNCTION(3)\fP, 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" |