2 .TH conn 3 "23 May 1999" "Straylight/Edgeware" "mLib utilities library"
7 conn \- selector for nonblocking connections
10 .B "#include <mLib/conn.h>"
12 .B "typedef struct { ...\& } conn;"
14 .ta \w'\fBint conn_fd('u
15 .BI "int conn_fd(conn *" c ", sel_state *" s ", int " fd ,
16 .BI " void (*" func ")(int " fd ", void *" p ),
19 .ta \w'\fBint conn_init('u
20 .BI "int conn_init(conn *" c ", sel_state *" s ", int " fd ,
21 .BI " struct sockaddr *" dst ", int " dsz ,
22 .BI " void (*" func ")(int " fd ", void *" p ),
25 .BI "void conn_kill(conn *" c );
30 selector manages a nonblocking connection to a remote socket. The
31 selector's state is maintained in an object of type
36 selector must be initialized. This requires a call to
38 with a fairly large number of arguments:
43 object which needs to be initialized.
46 Pointer to a multiplexor object (type
48 to which this selector should be attached. See
50 for more details about multiplexors, and how this whole system works.
53 File descriptor for the socket you want to connect. This becomes the
56 selector until the connection attempt finishes. For example, if there's
57 an error, the descriptor will be closed.
59 .BI "struct sockaddr *" dst
60 Pointer to destination socket address for the connection. Make sure
61 that the address has the right family.
64 Size of the destination socket address.
66 .BI "void (*" func ")(int " fd ", void *" p )
67 A function to call when the connection is complete. It is passed the
68 file descriptor of the connected socket, and the pointer passed
76 An arbitrary pointer whose value is passed to the handler function when
77 the connection finishes.
79 A few words are in order about
81 detailed behaviour and return value. If it returns \-1, the connection
82 attempt has failed immediately, an error code is stored in the global
85 the file descriptor has been
87 and the connection function will
89 be called. If it returns zero, then there has been no immediate
90 failure; the connection function
92 have been called, if the connection succeeded immediately, but it will
93 certainly be called some time, unless the connector is killed (see
95 below). When the connection function is called, it will either be
96 passed the file descriptor of the new-connected socket (to indicate
97 success) or the value \-1 for failure; in the latter case, an
98 appropriate error code is stored in
101 Alternatively, if you have a socket with a pending connection (i.e., a
110 Its arguments are the same as for
112 except that since the socket knows its a peer address the
116 arguments are not given, and it can't fail.
118 If you want to cancel the connection attempt before it finishes, call
120 with the address of the selector. The file descriptor is closed, and
121 the selector becomes safe to be discarded.
127 Mark Wooding, <mdw@distorted.org.uk>