added more info

docs/libcurl/libcurl-multi.3

@@ -2,7 +2,7 @@
 .\" nroff -man [file]
 .\" $Id$
 .\"
-.TH libcurl-multi 5 "20 March 2001" "libcurl 7.9.5" "libcurl multi interface"
+.TH libcurl-multi 5 "13 Oct 2001" "libcurl 7.10.1" "libcurl multi interface"
 .SH NAME
 libcurl-multi \- how to use the multi interface
 .SH DESCRIPTION
@@ -37,7 +37,7 @@ curl_multi_* functions.
 
 Each single transfer is built up with an easy handle. You must create them,
 and setup the appropriate options for each easy handle, as outlined in the
-\fIlibcurl(3)\fP man page.
+\fIlibcurl(3)\fP man page, using \fIcurl_easy_setopt(3)\fP.
 
 When the easy handle is setup for a transfer, then instead of using
 \fIcurl_easy_perform\fP (as when using the easy interface for transfers), you
@@ -49,11 +49,11 @@ handles.
 Should you change your mind, the easy handle is again removed from the multi
 stack using \fIcurl_multi_remove_handle\fP. Once removed from the multi
 handle, you can again use other easy interface functions like
-curl_easy_perform or whatever you think is necessary.
+\fIcurl_easy_perform\fP on the handle or whatever you think is necessary.
 
-Adding the easy handles to the multi handle does not start any
-transfer. Remember that one of the main ideas with this interface is to let
-your application drive. You drive the transfers by invoking
+Adding the easy handle to the multi handle does not start the transfer.
+Remember that one of the main ideas with this interface is to let your
+application drive. You drive the transfers by invoking
 \fIcurl_multi_perform\fP. libcurl will then transfer data if there is anything
 available to transfer. It'll use the callbacks and everything else you have
 setup in the individual easy handles. It'll transfer data on all current
@@ -62,24 +62,39 @@ all, it may be none.
 
 Your application can acquire knowledge from libcurl when it would like to get
 invoked to transfer data, so that you don't have to busy-loop and call that
-\fIcurl_multi_perform\fP like a mad man! \fIcurl_multi_fdset\fP offers an
+\fIcurl_multi_perform\fP like crazy. \fIcurl_multi_fdset\fP offers an
 interface using which you can extract fd_sets from libcurl to use in select()
 or poll() calls in order to get to know when the transfers in the multi stack
 might need attention. This also makes it very easy for your program to wait
 for input on your own private file descriptors at the same time or perhaps
 timeout every now and then, should you want that.
 
+A little note here about the return codes from the multi functions, and
+especially the \fIcurl_multi_perform\fP: if you receive
+\fICURLM_CALL_MULTI_PERFORM\fP, this basicly means that you should call
+\fIcurlm_call_multi_perform\fP again, before you select() on more actions. 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".
+
 \fIcurl_multi_perform\fP stores the number of still running transfers in one
 of its input arguments, and by reading that you can figure out when all the
 transfers in the multi handles are done. 'done' does not mean successful. One
-or more of the transfers may have failed.
+or more of the transfers may have failed. Tracking when this number changes,
+you know when one or more transfers are done.
 
 To get information about completed transfers, to figure out success or not and
 similar, \fIcurl_multi_info_read\fP should be called. It can return a message
 about a current or previous transfer. Repeated invokes of the function get
-more messages until the message queue is empty.
+more messages until the message queue is empty. The information you receive
+there includes an easy handle pointer which you may use to identify which easy
+handle the information regards.
 
 When all transfers in the multi stack are done, cleanup the multi handle with
 \fIcurl_multi_cleanup\fP. Be careful and please note that you \fBMUST\fP
 invoke separate \fIcurl_easy_cleanup\fP calls on every single easy handle to
 clean them up properly.
+
+If you want to re-use an easy handle that was added to the multi handle for
+transfer, you must first remove it from the multi stack and then re-add it
+again (possbily after having altered some options at your own choice).