Tcl Source Code

    if (stickyError != 0) {
	Tcl_SetErrno(stickyError);
	if (interp != NULL) {
	    Tcl_SetObjResult(interp,
			     Tcl_NewStringObj(Tcl_PosixError(interp), -1));
	}
	return TCL_ERROR;
    }
    /*
     * Bug 97069ea11a: set error message if a flush code is set and no error
     * message set up to now.
     */
    if (flushcode != 0 && interp != NULL
	    && 0 == Tcl_GetCharLength(Tcl_GetObjResult(interp)) ) {
	Tcl_SetErrno(flushcode);
	Tcl_SetObjResult(interp,
		Tcl_NewStringObj(Tcl_PosixError(interp), -1));
    }
    if ((flushcode != 0) || (result != 0)) {
	return TCL_ERROR;
    }
    return TCL_OK;
}


fconfigure $s1 -buffering line
fconfigure $s2 -buffering line
set t1 [clock milliseconds]
puts $s2 test1; gets $s1
puts $s2 test2; gets $s1
close $s1; close $s2
set t2 [clock milliseconds]
set lat1 [expr {($t2-$t1)*2}]; # doubled as a safety margin

# Test the latency of failed connection attempts over the loopback
# interface. They can take more than a second under Windowos and requres
# additional [after]s in some tests that are not needed on systems that fail
# immediately.
set t1 [clock milliseconds]
catch {socket 127.0.0.1 [randport]}
set t2 [clock milliseconds]
set lat2 [expr {($t2-$t1)*3}]

# Use the maximum of the two latency calculations, but at least 100ms
set latency [expr {$lat1 > $lat2 ? $lat1 : $lat2}]
set latency [expr {$latency > 100 ? $latency : 100}]
unset t1 t2 s1 s2 lat1 lat2 server

# If remoteServerIP or remoteServerPort are not set, check in the environment
# variables for externally set values.
#

if {![info exists remoteServerIP]} {
    if {[info exists env(remoteServerIP)]} {

	puts $f testing
	flush $f
        exit
    }
    close $f
    # If the socket doesn't hit end-of-file in 10 seconds, the script1 process
    # must have inherited the client.
    set timeout 0
    set after [after 10000 {set x "client socket was inherited"}]
} -constraints [list socket supported_$af stdio exec] -body {
    # Create the server socket
    set server [socket -server accept -myaddr $localhost 0]
    proc accept { file host port } {
	# When the client connects, establish the read handler
	global server
	close $server
	fileevent $file readable [list getdata $file]
	fconfigure $file -buffering line -blocking 0
        set ::f $file
    }
    proc getdata { file } {
	# Read handler on the accepted socket.
	global x
	set status [catch {read $file} data]
	if {$status != 0} {
	    set x "read failed, error was $data"

	} elseif {$data ne ""} {
	} elseif {[fblocked $file]} {
	} elseif {[eof $file]} {



            set x "client socket was not inherited"


	} else {
	    set x "impossible case"

	}
    }
    # Launch the script2 process
    ### exec [interpreter] script2 &
    set p [open "|[list [interpreter] $path(script2)]" w]
    puts $p [lindex [fconfigure $server -sockname] 2] ; flush $p
    vwait x
    return $x
} -cleanup {
    fconfigure $f -blocking 1
    close $f
    after cancel $after
    close $p
} -result {client socket was not inherited}
test socket_$af-12.3 {testing inheritance of accepted sockets} -setup {
    file delete $path(script1)
    file delete $path(script2)
    set f [open $path(script1) w]

    gets $p listen
    set f [socket $localhost $listen]
    fconfigure $f -buffering full -blocking 0
    fileevent $f readable [list getdata $f]
    # If the socket is still open after 5 seconds, the script1 process must
    # have inherited the accepted socket.
    set failed 0
    set after [after 5000 [list set x "accepted socket was inherited"]]
    proc getdata { file } {
	# Read handler on the client socket.
	global x
	global failed
	set status [catch {read $file} data]
	if {$status != 0} {
	    set x "read failed, error was $data"

	} elseif {[string compare {} $data]} {
	} elseif {[fblocked $file]} {
	} elseif {[eof $file]} {



            set x "accepted socket was not inherited"


	} else {
	    set x "impossible case"

	}
	return
    }
    vwait x
    set x
} -cleanup {
    fconfigure $f -blocking 1
    close $f
    after cancel $after
    close $p
} -result {accepted socket was not inherited}

test socket_$af-13.1 {Testing use of shared socket between two threads} -body {
    # create a thread
    set serverthread [thread::create -preserved [string map [list @localhost@ $localhost] {
        set f [socket -server accept -myaddr @localhost@ 0]
        set listen [lindex [fconfigure $f -sockname] 2]

if {$remoteProcChan ne ""} {
    catch {sendCommand exit}
}
catch {close $commandSocket}
catch {close $remoteProcChan}
}
unset ::tcl::unsupported::socketAF
test socket-14.0.0 {[socket -async] when server only listens on IPv4} \
    -constraints [list socket supported_any localhost_v4] \
    -setup {
        proc accept {s a p} {
            global x
            puts $s bye
            close $s
            set x ok
        }
        set server [socket -server accept -myaddr 127.0.0.1 0]
        set port [lindex [fconfigure $server -sockname] 2]
    } -body {
        set client [socket -async localhost $port]
        set after [after $latency {set x [fconfigure $client -error]}]
        vwait x
        set x
    } -cleanup {
        after cancel $after
        close $server
        close $client
        unset x
    } -result ok
test socket-14.0.1 {[socket -async] when server only listens on IPv6} \
    -constraints [list socket supported_any localhost_v6] \
    -setup {
        proc accept {s a p} {
            global x
            puts $s bye
            close $s
            set x ok
        }
        set server [socket -server accept -myaddr ::1 0]
        set port [lindex [fconfigure $server -sockname] 2]
    } -body {
        set client [socket -async localhost $port]
        set after [after $latency {set x [fconfigure $client -error]}]
        vwait x
        set x
    } -cleanup {
        after cancel $after
        close $server
        close $client
        unset x

        set x ""
    } -body {
        set client [socket -async localhost $port]
        fileevent $client writable {
            lappend x [fconfigure $client -error]
	    fileevent $client writable {}
        }
        set after [after $latency {lappend x timeout}]
        while {[llength $x] < 2 && "timeout" ni $x} {
            vwait x
        }
        lsort $x; # we only want to see both events, the order doesn't matter
    } -cleanup {
        after cancel $after
        close $server
        close $client
        unset x
    } -result {{} ok}
test socket-14.2 {[socket -async] fileevent connection refused} \
    -constraints [list socket supported_any] \
    -body {
        set client [socket -async localhost [randport]]


        fileevent $client writable {set x ok}
        set after [after $latency {set x timeout}]
        vwait x
        after cancel $after

        lappend x [fconfigure $client -error]
    } -cleanup {
        after cancel $after
        close $client



        unset x after client
    } -result {ok {connection refused}}
test socket-14.3 {[socket -async] when server only listens on IPv6} \
    -constraints [list socket supported_any localhost_v6] \
    -setup {
        proc accept {s a p} {
            global x
            puts $s bye
            close $s
            set x ok
        }
        set server [socket -server accept -myaddr ::1 0]
        set port [lindex [fconfigure $server -sockname] 2]
    } -body {
        set client [socket -async localhost $port]
        set after [after $latency {set x [fconfigure $client -error]}]
        vwait x
        set x
    } -cleanup {
        after cancel $after
        close $server
        close $client
        unset x

    } -body {
        set client [socket -async localhost $port]
        fileevent $client writable {
            lappend x [fconfigure $client -error]
            fileevent $client writable {}
        }
        fileevent $client readable {lappend x [gets $client]}
        set after [after $latency {lappend x timeout}]
        while {[llength $x] < 2 && "timeout" ni $x} {
            vwait x
        }
        lsort $x
    } -cleanup {
        after cancel $after
        close $client
        close $server
        unset x
    } -result {{} bye}
test socket-14.5 {[socket -async] which fails before any connect() can be made} \
    -constraints [list socket supported_any] \
    -body {
        # address from rfc5737
        socket -async -myaddr 192.0.2.42 127.0.0.1 [randport]
    } \
    -returnCodes 1 \
    -result {couldn't open socket: cannot assign requested address}
test socket-14.6.0 {[socket -async] with no event loop and server listening on IPv4} \
    -constraints [list socket supported_inet supported_inet6] \
    -setup {
        proc accept {s a p} {
            global x
            puts $s bye
            close $s
            set x ok
        }
        set server [socket -server accept -myaddr 127.0.0.1 0]
        set port [lindex [fconfigure $server -sockname] 2]
        set x ""
    } \
    -body {
        set client [socket -async localhost $port]
        for {set i 0} {$i < 50} {incr i } {


            update
            if {$x ne ""} {
                lappend x [gets $client]
                break
            }
            after 100
        }
        set x
    } \
    -cleanup {
        close $server
        close $client
        unset x
    } \
    -result {ok bye}
test socket-14.6.1 {[socket -async] with no event loop and server listening on IPv6} \
    -constraints [list socket supported_inet supported_inet6] \
    -setup {
        proc accept {s a p} {
            global x
            puts $s bye
            close $s
            set x ok
        }
        set server [socket -server accept -myaddr ::1 0]
        set port [lindex [fconfigure $server -sockname] 2]
        set x ""
    } \
    -body {
        set client [socket -async localhost $port]
        for {set i 0} {$i < 50} {incr i } {
            update
            if {$x ne ""} {
                lappend x [gets $client]
                break
            }
            after 100
        }
        set x
    } \
    -cleanup {
        close $server
        close $client
        unset x
    } \
    -result {ok bye}
test socket-14.7.0 {pending [socket -async] and blocking [gets], server is IPv4} \
    -constraints {socket supported_inet supported_inet6} \
    -setup {
        makeFile {
            set server [socket -server accept -myaddr 127.0.0.1 0]
            proc accept {s h p} {puts $s ok; close $s; set ::x 1}
            puts [lindex [fconfigure $server -sockname] 2]
            flush stdout
            vwait x
        } script
        set fd [open |[list [interpreter] script] RDWR]
        set port [gets $fd]
    } -body {
        set sock [socket -async localhost $port]
        list [fconfigure $sock -error] [gets $sock] [fconfigure $sock -error]
    } -cleanup {
        # make sure the server exits
        catch {socket 127.0.0.1 $port}
        close $sock
        close $fd
    } -result {{} ok {}}
test socket-14.7.1 {pending [socket -async] and blocking [gets], server is IPv6} \
    -constraints {socket supported_inet supported_inet6} \
    -setup {
        makeFile {
            set server [socket -server accept -myaddr ::1 0]
            proc accept {s h p} {puts $s ok; close $s; set ::x 1}
            puts [lindex [fconfigure $server -sockname] 2]
            flush stdout
            vwait x
        } script
        set fd [open |[list [interpreter] script] RDWR]
        set port [gets $fd]
    } -body {
        set sock [socket -async localhost $port]
        list [fconfigure $sock -error] [gets $sock] [fconfigure $sock -error]
    } -cleanup {
        # make sure the server exits
        catch {socket ::1 $port}
        close $sock
        close $fd
    } -result {{} ok {}}
test socket-14.7.2 {pending [socket -async] and blocking [gets], no listener} \
    -constraints {socket supported_inet supported_inet6} \
    -body {
        set sock [socket -async localhost [randport]]
        catch {gets $sock} x
        list $x [fconfigure $sock -error] [fconfigure $sock -error]
    } -cleanup {
        close $sock
    } -match glob -result {{error reading "sock*": socket is not connected} {connection refused} {}}
test socket-14.8.0 {pending [socket -async] and nonblocking [gets], server is IPv4} \
    -constraints {socket supported_inet supported_inet6} \
    -setup {
        makeFile {
            set server [socket -server accept -myaddr 127.0.0.1 0]
            proc accept {s h p} {puts $s ok; close $s; set ::x 1}
            puts [lindex [fconfigure $server -sockname] 2]
            flush stdout
            vwait x
        } script
        set fd [open |[list [interpreter] script] RDWR]
        set port [gets $fd]
    } -body {
        set sock [socket -async localhost $port]
        fconfigure $sock -blocking 0
        for {set i 0} {$i < 50} {incr i } {
            if {[catch {gets $sock} x] || $x ne "" || ![fblocked $sock]} break
            after 200
        }
        set x
    } -cleanup {
        # make sure the server exits
        catch {socket 127.0.0.1 $port}
        close $sock
        close $fd
    } -result {ok}
test socket-14.8.1 {pending [socket -async] and nonblocking [gets], server is IPv6} \
    -constraints {socket supported_inet supported_inet6} \
    -setup {
        makeFile {
            set server [socket -server accept -myaddr ::1 0]
            proc accept {s h p} {puts $s ok; close $s; set ::x 1}
            puts [lindex [fconfigure $server -sockname] 2]
            flush stdout
            vwait x
        } script
        set fd [open |[list [interpreter] script] RDWR]
        set port [gets $fd]
    } -body {
        set sock [socket -async localhost $port]
        fconfigure $sock -blocking 0
        for {set i 0} {$i < 50} {incr i } {
            if {[catch {gets $sock} x] || $x ne "" || ![fblocked $sock]} break
            after 200
        }
        set x
    } -cleanup {
        # make sure the server exits
        catch {socket ::1 $port}
        close $sock
        close $fd
    } -result {ok}
test socket-14.8.2 {pending [socket -async] and nonblocking [gets], no listener} \
    -constraints {socket supported_inet supported_inet6} \
    -body {
        set sock [socket -async localhost [randport]]
        fconfigure $sock -blocking 0
        for {set i 0} {$i < 50} {incr i } {
            if {[catch {gets $sock} x] || $x ne "" || ![fblocked $sock]} break
            after 200
        }
        list $x [fconfigure $sock -error] [fconfigure $sock -error]
    } -cleanup {
        close $sock
    } -match glob -result {{error reading "sock*": socket is not connected} {connection refused} {}}
test socket-14.9.0 {pending [socket -async] and blocking [puts], server is IPv4} \
    -constraints {socket supported_inet supported_inet6} \
    -setup {
        makeFile {
            set server [socket -server accept -myaddr 127.0.0.1 0]
            proc accept {s h p} {set ::x $s}
            puts [lindex [fconfigure $server -sockname] 2]
            flush stdout
            vwait x
            puts [gets $x]
        } script
        set fd [open |[list [interpreter] script] RDWR]
        set port [gets $fd]
    } -body {
        set sock [socket -async localhost $port]
        puts $sock ok
        flush $sock
        list [fconfigure $sock -error] [gets $fd]
    } -cleanup {
        # make sure the server exits
        catch {socket 127.0.0.1 $port}
        close $sock
        close $fd
    } -result {{} ok}
test socket-14.9.1 {pending [socket -async] and blocking [puts], server is IPv6} \
    -constraints {socket supported_inet supported_inet6} \
    -setup {
        makeFile {
            set server [socket -server accept -myaddr ::1 0]
            proc accept {s h p} {set ::x $s}
            puts [lindex [fconfigure $server -sockname] 2]
            flush stdout
            vwait x
            puts [gets $x]
        } script
        set fd [open |[list [interpreter] script] RDWR]
        set port [gets $fd]
    } -body {
        set sock [socket -async localhost $port]
        puts $sock ok
        flush $sock
        list [fconfigure $sock -error] [gets $fd]
    } -cleanup {
        # make sure the server exits
        catch {socket ::1 $port}
        close $sock
        close $fd
    } -result {{} ok}
test socket-14.10.0 {pending [socket -async] and blocking [puts], server is IPv4} \
    -constraints {socket supported_inet supported_inet6} \
    -setup {
        makeFile {
            set server [socket -server accept -myaddr 127.0.0.1 0]
            proc accept {s h p} {set ::x $s}
            puts [lindex [fconfigure $server -sockname] 2]
            flush stdout
            vwait x
            puts [gets $x]
        } script
        set fd [open |[list [interpreter] script] RDWR]
        set port [gets $fd]
    } -body {
        set sock [socket -async localhost $port]
        fconfigure $sock -blocking 0
        puts $sock ok
        flush $sock
        fileevent $fd readable {set x 1}
        vwait x
        list [fconfigure $sock -error] [gets $fd]
    } -cleanup {
        # make sure the server exits
        catch {socket 127.0.0.1 $port}
        close $sock
        close $fd
    } -result {{} ok}
test socket-14.10.1 {pending [socket -async] and blocking [puts], server is IPv6} \
    -constraints {socket supported_inet supported_inet6} \
    -setup {
        makeFile {
            set server [socket -server accept -myaddr ::1 0]
            proc accept {s h p} {set ::x $s}
            puts [lindex [fconfigure $server -sockname] 2]
            flush stdout
            vwait x
            puts [gets $x]
        } script
        set fd [open |[list [interpreter] script] RDWR]
        set port [gets $fd]
    } -body {
        set sock [socket -async localhost $port]
        fconfigure $sock -blocking 0
        puts $sock ok
        flush $sock
        fileevent $fd readable {set x 1}
        vwait x
        list [fconfigure $sock -error] [gets $fd]
    } -cleanup {
        # make sure the server exits
        catch {socket ::1 $port}
        close $sock
        close $fd
    } -result {{} ok}
test socket-14.11.0 {pending [socket -async] and blocking [puts], no listener, no flush} \
    -constraints {socket supported_inet supported_inet6} \
    -body {
        set sock [socket -async localhost [randport]]
        fconfigure $sock -blocking 0
        puts $sock ok
        fileevent $sock writable {set x 1}
        vwait x
        close $sock
    } -cleanup {
        catch {close $sock}
        unset x
    } -result {socket is not connected} -returnCodes 1
test socket-14.11.1 {pending [socket -async] and blocking [puts], no listener, flush} \
    -constraints {socket supported_inet supported_inet6} \
    -body {
        set sock [socket -async localhost [randport]]
        fconfigure $sock -blocking 0
        puts $sock ok
        flush $sock
        fileevent $sock writable {set x 1}
        vwait x
        close $sock
    } -cleanup {
        catch {close $sock}
        unset x
    } -result {socket is not connected} -returnCodes 1
test socket-14.12 {[socket -async] background progress triggered by [fconfigure -error]} \
    -constraints {socket supported_inet supported_inet6} \
    -body {
        set s [socket -async localhost [randport]]
        for {set i 0} {$i < 50} {incr i} {
            set x [fconfigure $s -error]
            if {$x != ""} break
            after 200
        }
        set x
    } -cleanup {
        close $s
        unset x s
    } -result {connection refused}

test socket-14.13 {testing writable event when quick failure} -constraints {socket win supported_inet} -body {
    # Test for bug 336441ed59 where a quick background fail was ignored
    
    # Test only for windows as socket -async 255.255.255.255 fails
    # directly on unix
    
    # The following connect should fail very quickly
    set a1 [after 2000 {set x timeout}]
    set s [socket -async 255.255.255.255 43434]
    fileevent $s writable {set x writable}
    vwait x
    set x
} -cleanup {
    catch {close $s}
    after cancel $a1
} -result writable

test socket-14.14 {testing fileevent readable on failed async socket connect} -constraints [list socket] -body {
    # Test for bug 581937ab1e
    
    set a1 [after 5000 {set x timeout}]
    # This connect should fail
    set s [socket -async localhost [randport]]
    fileevent $s readable {set x readable}
    vwait x
    set x
} -cleanup {
    catch {close $s}
    after cancel $a1
} -result readable

test socket-14.15 {blocking read on async socket should not trigger event handlers} \
    -constraints socket -body {
        set s [socket -async localhost [randport]]
        set x ok
        fileevent $s writable {set x fail}
        catch {read $s}
        set x
    } -result ok

set num 0
foreach servip {127.0.0.1 ::1 localhost} {
    foreach cliip {127.0.0.1 ::1 localhost} {
        if {$servip eq $cliip || "localhost" in [list $servip $cliip]} {
            set result {-result "sock*" -match glob}
        } else {
            set result {
                -result {couldn't open socket: connection refused}
                -returnCodes 1
            }
        }
        test socket-15.1.$num "Connect to $servip from $cliip" \
            -constraints {socket supported_inet supported_inet6} -setup {
                set server [socket -server accept -myaddr $servip 0]
                proc accept {s h p} { close $s }
                set port [lindex [fconfigure $server -sockname] 2]
            } -body {
                set s [socket $cliip $port]
            } -cleanup {
                close $server
                catch {close $s}
            } {*}$result
        incr num
    }
}

::tcltest::cleanupTests
flush stdout
return

# Local Variables:
# mode: tcl
# fill-column: 78
# End:

    struct addrinfo *addrlist;	/* Addresses to connect to. */
    struct addrinfo *addr;	/* Iterator over addrlist. */
    struct addrinfo *myaddrlist;/* Local address. */
    struct addrinfo *myaddr;	/* Iterator over myaddrlist. */
    int filehandlers;           /* Caches FileHandlers that get set up while
                                 * an async socket is not yet connected. */
    int connectError;           /* Cache SO_ERROR of async socket. */
    int cachedBlocking;         /* Cache blocking mode of async socket. */
};

/*
 * These bits may be ORed together into the "flags" field of a TcpState
 * structure.
 */

#define TCP_NONBLOCKING		(1<<0)	/* Socket with non-blocking I/O */
#define TCP_ASYNC_CONNECT	(1<<1)	/* Async connect in progress. */
#define TCP_ASYNC_PENDING	(1<<4)	/* TcpConnect was called to
					 * process an async connect. This
					 * flag indicates that reentry is
					 * still pending */
#define TCP_ASYNC_FAILED	(1<<5)	/* An async connect finally failed */

/*
 * The following defines the maximum length of the listen queue. This is the
 * number of outstanding yet-to-be-serviced requests for a connection on a
 * server socket, more than this number of outstanding requests and the
 * connection request will fail.
 */

#define SOCKET_BUFSIZE	4096

/*
 * Static routines for this file:
 */

static int		TcpConnect(Tcl_Interp *interp,
                                           TcpState *state);
static void		TcpAccept(ClientData data, int mask);
static int		TcpBlockModeProc(ClientData data, int mode);
static int		TcpCloseProc(ClientData instanceData,
			    Tcl_Interp *interp);
static int		TcpClose2Proc(ClientData instanceData,
			    Tcl_Interp *interp, int flags);

 * The following variable holds the network name of this host.
 */

static TclInitProcessGlobalValueProc InitializeHostName;
static ProcessGlobalValue hostName =
	{0, 0, NULL, NULL, InitializeHostName, NULL, NULL};

#if 0
/* printf debugging */
void printaddrinfo(struct addrinfo *addrlist, char *prefix)
{
    char host[NI_MAXHOST], port[NI_MAXSERV];
    struct addrinfo *ai;
    for (ai = addrlist; ai != NULL; ai = ai->ai_next) {
	getnameinfo(ai->ai_addr, ai->ai_addrlen,
		    host, sizeof(host),
		    port, sizeof(port),
		    NI_NUMERICHOST|NI_NUMERICSERV);
	fprintf(stderr,"%s: %s:%s\n", prefix, host, port);
    }
}
#endif
/*
 *----------------------------------------------------------------------
 *
 * InitializeHostName --
 *
 * 	This routine sets the process global value of the name of the local
 * 	host on which the process is running.

    int mode)			/* The mode to set. Can be one of
				 * TCL_MODE_BLOCKING or
				 * TCL_MODE_NONBLOCKING. */
{
    TcpState *statePtr = instanceData;

    if (mode == TCL_MODE_BLOCKING) {
	CLEAR_BITS(statePtr->flags, TCP_NONBLOCKING);
    } else {
	SET_BITS(statePtr->flags, TCP_NONBLOCKING);
    }
    if (statePtr->flags & TCP_ASYNC_CONNECT) {
        statePtr->cachedBlocking = mode;
        return 0;
    }
    if (TclUnixSetBlockingMode(statePtr->fds.fd, mode) < 0) {
	return errno;
    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * WaitForConnect --
 *
 *	Check the state of an async connect process. If a connection
 *	attempt terminated, process it, which may finalize it or may
 *	start the next attempt. If a connect error occures, it is saved
 *	in statePtr->connectError to be reported by 'fconfigure -error'.
 *
 *	There are two modes of operation, defined by errorCodePtr:
 *	 *  non-NULL: Called by explicite read/write command. block if
 *	    socket is blocking.
 *	    May return two error codes:
 *	     *	EWOULDBLOCK: if connect is still in progress
 *	     *	ENOTCONN: if connect failed. This would be the error
 *		message of a rect or sendto syscall so this is
 *		emulated here.
 *	 *  NULL: Called by a backround operation. Do not block and
 *	    don't return any error code.
 *
 * Results:
 * 	0 if the connection has completed, -1 if still in progress
 * 	or there is an error.
 *
 * Side effects:
 *	Processes socket events off the system queue.
 *	May process asynchroneous connect.
 *
 *----------------------------------------------------------------------
 */

static int
WaitForConnect(
    TcpState *statePtr,		/* State of the socket. */
    int *errorCodePtr)
{
    int timeout;


    /*
     * Check if an async connect failed already and error reporting is demanded,
     * return the error ENOTCONN
     */

    if (errorCodePtr != NULL && (statePtr->flags & TCP_ASYNC_FAILED)) {
	*errorCodePtr = ENOTCONN;
	return -1;
    }

    /*
     * Check if an async connect is running. If not return ok
     */
     
    if (!(statePtr->flags & TCP_ASYNC_PENDING)) {
	return 0;
    }
    
    if (errorCodePtr == NULL || (statePtr->flags & TCP_NONBLOCKING)) {
        timeout = 0;
    } else {
        timeout = -1;
    }
    do {
        if (TclUnixWaitForFile(statePtr->fds.fd,
                                TCL_WRITABLE | TCL_EXCEPTION, timeout) != 0) {
            TcpConnect(NULL, statePtr);

        }
        /* Do this only once in the nonblocking case and repeat it until the
         * socket is final when blocking */
    } while (timeout == -1 && statePtr->flags & TCP_ASYNC_CONNECT);

    if (errorCodePtr != NULL) {
        if (statePtr->flags & TCP_ASYNC_PENDING) {
            *errorCodePtr = EAGAIN;
            return -1;
        } else if (statePtr->connectError != 0) {
            *errorCodePtr = ENOTCONN;
            return -1;
        }
    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *

    int written;

    *errorCodePtr = 0;
    if (WaitForConnect(statePtr, errorCodePtr) != 0) {
	return -1;
    }
    written = send(statePtr->fds.fd, buf, (size_t) toWrite, 0);

    if (written > -1) {
	return written;
    }
    *errorCodePtr = errno;
    return -1;
}


				 * values. */
    Tcl_DString *dsPtr)		/* Where to store the computed value;
				 * initialized by caller. */
{
    TcpState *statePtr = instanceData;
    size_t len = 0;

    WaitForConnect(statePtr, NULL);

    if (optionName != NULL) {
	len = strlen(optionName);
    }

    if ((len > 1) && (optionName[1] == 'e') &&
	    (strncmp(optionName, "-error", len) == 0)) {
	socklen_t optlen = sizeof(int);


        if (statePtr->flags & TCP_ASYNC_CONNECT) {
            /* Suppress errors as long as we are not done */
            errno = 0;
        } else if (statePtr->connectError != 0) {
            errno = statePtr->connectError;
            statePtr->connectError = 0;
        } else {
            int err;
            getsockopt(statePtr->fds.fd, SOL_SOCKET, SO_ERROR,
                    (char *) &err, &optlen);

            errno = err;
        }
        if (errno != 0) {
	    Tcl_DStringAppend(dsPtr, Tcl_ErrnoMsg(errno), -1);
        }


	return TCL_OK;
    }


    if ((len > 1) && (optionName[1] == 'c') &&
	    (strncmp(optionName, "-connecting", len) == 0)) {

        Tcl_DStringAppend(dsPtr,
                        (statePtr->flags & TCP_ASYNC_CONNECT) ? "1" : "0", -1);
        return TCL_OK;
    }

    if ((len == 0) || ((len > 1) && (optionName[1] == 'p') &&
	    (strncmp(optionName, "-peername", len) == 0))) {
        address peername;
        socklen_t size = sizeof(peername);

	if (getpeername(statePtr->fds.fd, &peername.sa, &size) >= 0) {

         * Make sure we don't mess with server sockets since they will never
         * be readable or writable at the Tcl level. This keeps Tcl scripts
         * from interfering with the -accept behavior (bug #3394732).
         */
    	return;
    }
     
    if (statePtr->flags & TCP_ASYNC_PENDING) {
        /* Async sockets use a FileHandler internally while connecting, so we
         * need to cache this request until the connection has succeeded. */
        statePtr->filehandlers = mask;
    } else if (mask) {
        Tcl_CreateFileHandler(statePtr->fds.fd, mask,
                (Tcl_FileProc *) Tcl_NotifyChannel, statePtr->channel);
    } else {

}

/*
 *----------------------------------------------------------------------
 *
 * TcpAsyncCallback --
 *
 *	Called by the event handler that TcpConnect sets up
 *	internally for [socket -async] to get notified when the
 *	asyncronous connection attempt has succeeded or failed.
 *
 *----------------------------------------------------------------------
 */
static void
TcpAsyncCallback(
    ClientData clientData,	/* The socket state. */
    int mask)			/* Events of interest; an OR-ed combination of
				 * TCL_READABLE, TCL_WRITABLE and
				 * TCL_EXCEPTION. */
{
    TcpConnect(NULL, clientData);
}

/*
 *----------------------------------------------------------------------
 *
 * TcpConnect --
 *
 *	This function opens a new socket in client mode.
 *
 * Results:
 *      TCL_OK, if the socket was successfully connected or an asynchronous
 *      connection is in progress. If an error occurs, TCL_ERROR is returned
 *      and an error message is left in interp.

 *	return and the loops resume as if they had never been interrupted.
 *	For syncronously connecting sockets, the loops work the usual way.
 *
 *----------------------------------------------------------------------
 */

static int
TcpConnect(
    Tcl_Interp *interp,		/* For error reporting; can be NULL. */
    TcpState *statePtr)
{
    socklen_t optlen;
    int async_callback = statePtr->flags & TCP_ASYNC_PENDING;
    int ret = -1, error;
    int async = statePtr->flags & TCP_ASYNC_CONNECT;

    if (async_callback) {
        goto reenter;
    }

    for (statePtr->addr = statePtr->addrlist; statePtr->addr != NULL;
            statePtr->addr = statePtr->addr->ai_next) {


        for (statePtr->myaddr = statePtr->myaddrlist; statePtr->myaddr != NULL;
                statePtr->myaddr = statePtr->myaddr->ai_next) {
            int reuseaddr = 1;
            
	    /*
	     * No need to try combinations of local and remote addresses of
	     * different families.
	     */

	    if (statePtr->myaddr->ai_family != statePtr->addr->ai_family) {
		continue;
	    }

            /*
             * Close the socket if it is still open from the last unsuccessful
             * iteration.
             */

            if (statePtr->fds.fd >= 0) {
		close(statePtr->fds.fd);
		statePtr->fds.fd = -1;
                errno = 0;
	    }

	    statePtr->fds.fd = socket(statePtr->addr->ai_family, SOCK_STREAM, 0);
	    if (statePtr->fds.fd < 0) {
		continue;
	    }

	    /*
	     * Set the close-on-exec flag so that the socket will not get
	     * inherited by child processes.
	     */
	    
	    fcntl(statePtr->fds.fd, F_SETFD, FD_CLOEXEC);
	    
	    /*
	     * Set kernel space buffering
	     */
	    
	    TclSockMinimumBuffers(INT2PTR(statePtr->fds.fd), SOCKET_BUFSIZE);
    
	    if (async) {
                ret = TclUnixSetBlockingMode(statePtr->fds.fd,TCL_MODE_NONBLOCKING);

                if (ret < 0) {
                    continue;
                }
            }

            /* Gotta reset the error variable here, before we use it for the
             * first time in this iteration. */
            error = 0;
            
            (void) setsockopt(statePtr->fds.fd, SOL_SOCKET, SO_REUSEADDR,
                    (char *) &reuseaddr, sizeof(reuseaddr));
            ret = bind(statePtr->fds.fd, statePtr->myaddr->ai_addr,
                    statePtr->myaddr->ai_addrlen);
            if (ret < 0) {
                error = errno;
                continue;
            }

	    /*
	     * Attempt to connect. The connect may fail at present with an
	     * EINPROGRESS but at a later time it will complete. The caller
	     * will set up a file handler on the socket if she is interested
	     * in being informed when the connect completes.
	     */
	    
	    ret = connect(statePtr->fds.fd, statePtr->addr->ai_addr,
                        statePtr->addr->ai_addrlen);
            if (ret < 0) error = errno;
	    if (ret < 0 && errno == EINPROGRESS) {
                Tcl_CreateFileHandler(statePtr->fds.fd,
                        TCL_WRITABLE|TCL_EXCEPTION, TcpAsyncCallback, statePtr);
                errno = EWOULDBLOCK;
                SET_BITS(statePtr->flags, TCP_ASYNC_PENDING);
                return TCL_OK;

            reenter:
                CLEAR_BITS(statePtr->flags, TCP_ASYNC_PENDING);
                Tcl_DeleteFileHandler(statePtr->fds.fd);

                /*
                 * Read the error state from the socket to see if the async
                 * connection has succeeded or failed. As this clears the
                 * error condition, we cache the status in the socket state
                 * struct for later retrieval by [fconfigure -error].
                 */

                optlen = sizeof(int);


                getsockopt(statePtr->fds.fd, SOL_SOCKET, SO_ERROR,
                        (char *) &error, &optlen);

                errno = error;


            }

	    if (error == 0) {
		goto out;
	    }
	}
    }

out:
    statePtr->connectError = error;
    CLEAR_BITS(statePtr->flags, TCP_ASYNC_CONNECT);
    if (async_callback) {
        /*
         * An asynchonous connection has finally succeeded or failed.
         */

        TcpWatchProc(statePtr, statePtr->filehandlers);
        TclUnixSetBlockingMode(statePtr->fds.fd, statePtr->cachedBlocking);

        if (error != 0) {
            SET_BITS(statePtr->flags, TCP_ASYNC_FAILED);
        }

        /*
         * We need to forward the writable event that brought us here, bcasue
         * upon reading of getsockopt(SO_ERROR), at least some OSes clear the
         * writable state from the socket, and so a subsequent select() on
         * behalf of a script level [fileevent] would not fire. It doesn't
         * hurt that this is also called in the successful case and will save
         * the event mechanism one roundtrip through select().
         */

        /* Note: disabling this for now as it causes spurious event triggering
         * under Linux (see test socket-14.15). */
#if 0
        Tcl_NotifyChannel(statePtr->channel, TCL_WRITABLE);
#endif
    }
    if (error != 0) {
        /*
         * Failure for either a synchronous connection, or an async one that
         * failed before it could enter background mode, e.g. because an
         * invalid -myaddr was given.
         */

        if (interp != NULL) {
            errno = error;
            Tcl_SetObjResult(interp, Tcl_ObjPrintf(
                    "couldn't open socket: %s", Tcl_PosixError(interp)));
        }
        return TCL_ERROR;
    }
    return TCL_OK;
}

    const char *host,		/* Host on which to open port. */
    const char *myaddr,		/* Client-side address */
    int myport,			/* Client-side port */
    int async)			/* If nonzero, attempt to do an asynchronous
				 * connect. Otherwise we do a blocking
				 * connect. */
{
    TcpState *statePtr;
    const char *errorMsg = NULL;
    struct addrinfo *addrlist = NULL, *myaddrlist = NULL;
    char channelName[SOCK_CHAN_LENGTH];

    /*
     * Do the name lookups for the local and remote addresses.
     */

        }
        return NULL;
    }

    /*
     * Allocate a new TcpState for this socket.
     */
    statePtr = ckalloc(sizeof(TcpState));
    memset(statePtr, 0, sizeof(TcpState));
    statePtr->flags = async ? TCP_ASYNC_CONNECT : 0;
    statePtr->cachedBlocking = TCL_MODE_BLOCKING;
    statePtr->addrlist = addrlist;
    statePtr->myaddrlist = myaddrlist;
    statePtr->fds.fd = -1;

    /*
     * Create a new client socket and wrap it in a channel.
     */
    if (TcpConnect(interp, statePtr) != TCL_OK) {
        TcpCloseProc(statePtr, NULL);
        return NULL;
    }

    sprintf(channelName, SOCK_TEMPLATE, (long) statePtr);

    statePtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName, statePtr,
            (TCL_READABLE | TCL_WRITABLE));
    if (Tcl_SetChannelOption(interp, statePtr->channel, "-translation",
	    "auto crlf") == TCL_ERROR) {
	Tcl_Close(NULL, statePtr->channel);
	return NULL;
    }
    return statePtr->channel;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_MakeTcpClientChannel --
 *

#define TclpSysRealloc(ptr, size)	((void*)HeapReAlloc(GetProcessHeap(), \
					    (DWORD)0, (LPVOID)ptr, (DWORD)size))

/*
 * The following defines map from standard socket names to our internal
 * wrappers that redirect through the winSock function table (see the
 * file tclWinSock.c).
 *
 * Warning:
 *	This check was useful in times of Windows98 where WinSock may
 *	not be available. This is not the case any more.
 *	This function may be removed with TCL 9.0
 *
 */

#define getservbyname	TclWinGetServByName
#define getsockopt	TclWinGetSockOpt
#define setsockopt	TclWinSetSockOpt
/* This type is not defined in the Windows headers */
#define socklen_t       int

/*
 * tclWinSock.c --
 *
 *	This file contains Windows-specific socket related code.
 *
 * Copyright (c) 1995-1997 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * -----------------------------------------------------------------------
 * The order and naming of functions in this file should minimize
 * the file diff to tclUnixSock.c.
 * -----------------------------------------------------------------------
 *
 * General information on how this module works.
 *
 * - Each Tcl-thread with its sockets maintains an internal window to receive
 *   socket messages from the OS.
 *
 * - To ensure that message reception is always running this window is

 * use in other sections of the core, except for us.
 */

#undef getservbyname
#undef getsockopt
#undef setsockopt

/*
 * Helper macros to make parts of this file clearer. The macros do exactly
 * what they say on the tin. :-) They also only ever refer to their arguments
 * once, and so can be used without regard to side effects.
 */

#define SET_BITS(var, bits)	((var) |= (bits))
#define CLEAR_BITS(var, bits)	((var) &= ~(bits))

/* "sock" + a pointer in hex + \0 */
#define SOCK_CHAN_LENGTH        (4 + sizeof(void *) * 2 + 1)
#define SOCK_TEMPLATE           "sock%p"

/*
 * The following variable is used to tell whether this module has been
 * initialized.  If 1, initialization of sockets was successful, if -1 then
 * socket initialization failed (WSAStartup failed).
 */

static int initialized = 0;
static const TCHAR classname[] = TEXT("TclSocket");
TCL_DECLARE_MUTEX(socketMutex)










/*
 * The following defines declare the messages used on socket windows.
 */

#define SOCKET_MESSAGE		WM_USER+1
#define SOCKET_SELECT		WM_USER+2
#define SOCKET_TERMINATE	WM_USER+3

    struct sockaddr_storage sas;
} address;

#ifndef IN6_ARE_ADDR_EQUAL
#define IN6_ARE_ADDR_EQUAL IN6_ADDR_EQUAL
#endif

/*
 * This structure describes per-instance state of a tcp based channel.
 */

typedef struct TcpState TcpState;

typedef struct TcpFdList {
    TcpState *statePtr;
    SOCKET fd;
    struct TcpFdList *next;
} TcpFdList;






struct TcpState {
    Tcl_Channel channel;	/* Channel associated with this socket. */
    struct TcpFdList *sockets;	/* Windows SOCKET handle. */
    int flags;			/* Bit field comprised of the flags described
				 * below. */
    int watchEvents;		/* OR'ed combination of FD_READ, FD_WRITE,
				 * FD_CLOSE, FD_ACCEPT and FD_CONNECT that
				 * indicate which events are interesting. */
    volatile int readyEvents;	/* OR'ed combination of FD_READ, FD_WRITE,
				 * FD_CLOSE, FD_ACCEPT and FD_CONNECT that
				 * indicate which events have occurred.
				 * Set by notifier thread, access must be
				 * protected by semaphore */
    int selectEvents;		/* OR'ed combination of FD_READ, FD_WRITE,
				 * FD_CLOSE, FD_ACCEPT and FD_CONNECT that
				 * indicate which events are currently being
				 * selected. */
    volatile int acceptEventCount;
				/* Count of the current number of FD_ACCEPTs
				 * that have arrived and not yet processed.
				 * Set by notifier thread, access must be
				 * protected by semaphore */
    Tcl_TcpAcceptProc *acceptProc;
				/* Proc to call on accept. */
    ClientData acceptProcData;	/* The data for the accept proc. */

    /*
     * Only needed for client sockets
     */

    struct addrinfo *addrlist;	/* Addresses to connect to. */
    struct addrinfo *addr;	/* Iterator over addrlist. */
    struct addrinfo *myaddrlist;/* Local address. */
    struct addrinfo *myaddr;	/* Iterator over myaddrlist. */
    int connectError;		/* Cache status of async socket. */
    int cachedBlocking;         /* Cache blocking mode of async socket. */
    volatile int notifierConnectError;
				/* Async connect error set by notifier thread.
				 * This error is still a windows error code.
				 * Access must be protected by semaphore */
    struct TcpState *nextPtr;	/* The next socket on the per-thread socket
				 * list. */
};

/*
 * These bits may be ORed together into the "flags" field of a TcpState
 * structure.
 */

#define TCP_NONBLOCKING		(1<<0)	/* Socket with non-blocking I/O */
#define TCP_ASYNC_CONNECT	(1<<1)	/* Async connect in progress. */
#define SOCKET_EOF		(1<<2)	/* A zero read happened on the
					 * socket. */
#define SOCKET_PENDING		(1<<3)	/* A message has been sent for this
					 * socket */
#define TCP_ASYNC_PENDING	(1<<4)	/* TcpConnect was called to
					 * process an async connect. This
					 * flag indicates that reentry is
					 * still pending */
#define TCP_ASYNC_FAILED	(1<<5)	/* An async connect finally failed */

/*
 * The following structure is what is added to the Tcl event queue when a
 * socket event occurs.
 */

typedef struct {
    Tcl_Event header;		/* Information that is standard for all
				 * events. */
    SOCKET socket;		/* Socket descriptor that is ready. Used to
				 * find the TcpState structure for the file
				 * (can't point directly to the TcpState
				 * structure because it could go away while
				 * the event is queued). */
} SocketEvent;

/*
 * This defines the minimum buffersize maintained by the kernel.
 */

#define TCP_BUFFER_SIZE 4096













typedef struct {
    HWND hwnd;			/* Handle to window for socket messages. */
    HANDLE socketThread;	/* Thread handling the window */
    Tcl_ThreadId threadId;	/* Parent thread. */
    HANDLE readyEvent;		/* Event indicating that a socket event is
				 * ready. Also used to indicate that the
				 * socketThread has been initialized and has
				 * started. */
    HANDLE socketListLock;	/* Win32 Event to lock the socketList */
    TcpState *pendingTcpState;
				/* This socket is opened but not jet in the
				 * list. This value is also checked by
				 * the event structure. */
    TcpState *socketList;	/* Every open socket in this thread has an
				 * entry on this list. */
} ThreadSpecificData;

static Tcl_ThreadDataKey dataKey;
static WNDCLASS windowClass;

/*
 * Static routines for this file:
 */

static int		TcpConnect(Tcl_Interp *interp,
			    TcpState *state);

static void		InitSockets(void);
static TcpState *	NewSocketInfo(SOCKET socket);
static void		SocketExitHandler(ClientData clientData);
static LRESULT CALLBACK	SocketProc(HWND hwnd, UINT message, WPARAM wParam,
			    LPARAM lParam);
static int		SocketsEnabled(void);
static void		TcpAccept(TcpFdList *fds, SOCKET newSocket, address addr);
static int		WaitForConnect(TcpState *statePtr, int *errorCodePtr);
static int		WaitForSocketEvent(TcpState *statePtr, int events,
			    int *errorCodePtr);
static void		AddSocketInfoFd(TcpState *statePtr,  SOCKET socket);
static int		FindFDInList(TcpState *statePtr, SOCKET socket);
static DWORD WINAPI	SocketThread(LPVOID arg);
static void		TcpThreadActionProc(ClientData instanceData,
			    int action);

static Tcl_EventCheckProc	SocketCheckProc;
static Tcl_EventProc		SocketEventProc;
static Tcl_EventSetupProc	SocketSetupProc;
static Tcl_DriverBlockModeProc	TcpBlockModeProc;
static Tcl_DriverCloseProc	TcpCloseProc;
static Tcl_DriverClose2Proc	TcpClose2Proc;
static Tcl_DriverSetOptionProc	TcpSetOptionProc;
static Tcl_DriverGetOptionProc	TcpGetOptionProc;
static Tcl_DriverInputProc	TcpInputProc;
static Tcl_DriverOutputProc	TcpOutputProc;
static Tcl_DriverWatchProc	TcpWatchProc;
static Tcl_DriverGetHandleProc	TcpGetHandleProc;

/*
 * This structure describes the channel type structure for TCP socket
 * based IO:
 */

static const Tcl_ChannelType tcpChannelType = {
    "tcp",			/* Type name. */
    TCL_CHANNEL_VERSION_5,	/* v5 channel */
    TcpCloseProc,		/* Close proc. */
    TcpInputProc,		/* Input proc. */
    TcpOutputProc,		/* Output proc. */
    NULL,			/* Seek proc. */
    TcpSetOptionProc,		/* Set option proc. */
    TcpGetOptionProc,		/* Get option proc. */
    TcpWatchProc,		/* Initialize notifier. */
    TcpGetHandleProc,		/* Get OS handles out of channel. */
    TcpClose2Proc,		/* Close2 proc. */
    TcpBlockModeProc,		/* Set blocking or non-blocking mode.*/
    NULL,			/* flush proc. */
    NULL,			/* handler proc. */
    NULL,			/* wide seek proc. */
    TcpThreadActionProc,	/* thread action proc. */
    NULL			/* truncate proc. */
};

/*
 * The following variable holds the network name of this host.
 */


static TclInitProcessGlobalValueProc InitializeHostName;
static ProcessGlobalValue hostName =
	{0, 0, NULL, NULL, InitializeHostName, NULL, NULL};



/*
 * Address print debug functions

 */
#if 0





void printaddrinfo(struct addrinfo *ai, char *prefix)
{
    char host[NI_MAXHOST], port[NI_MAXSERV];
    getnameinfo(ai->ai_addr, ai->ai_addrlen,
		host, sizeof(host),
		port, sizeof(port),
		NI_NUMERICHOST|NI_NUMERICSERV);
}
void printaddrinfolist(struct addrinfo *addrlist, char *prefix)
{
    struct addrinfo *ai;
    for (ai = addrlist; ai != NULL; ai = ai->ai_next) {
	printaddrinfo(ai, prefix);


    }
}
#endif



/*




 *----------------------------------------------------------------------
 *





 * InitializeHostName --




 *

 *	This routine sets the process global value of the name of the local
 *	host on which the process is running.
 *
 * Results:
 *	None.


 *
 *----------------------------------------------------------------------
 */



void
InitializeHostName(
    char **valuePtr,
    int *lengthPtr,
    Tcl_Encoding *encodingPtr)
{



    TCHAR tbuf[MAX_COMPUTERNAME_LENGTH + 1];
    DWORD length = MAX_COMPUTERNAME_LENGTH + 1;
    Tcl_DString ds;


    if (GetComputerName(tbuf, &length) != 0) {
	/*


	 * Convert string from native to UTF then change to lowercase.
	 */

	Tcl_UtfToLower(Tcl_WinTCharToUtf(tbuf, -1, &ds));

    } else {
	Tcl_DStringInit(&ds);







	if (TclpHasSockets(NULL) == TCL_OK) {
	    /*

	     * The buffer size of 256 is recommended by the MSDN page that
	     * documents gethostname() as being always adequate.
	     */

	    Tcl_DString inDs;

	    Tcl_DStringInit(&inDs);
	    Tcl_DStringSetLength(&inDs, 256);
	    if (gethostname(Tcl_DStringValue(&inDs),
		    Tcl_DStringLength(&inDs)) == 0) {
		Tcl_ExternalToUtfDString(NULL, Tcl_DStringValue(&inDs), -1,
			&ds);
	    }
	    Tcl_DStringFree(&inDs);
	}





    }








    *encodingPtr = Tcl_GetEncoding(NULL, "utf-8");

    *lengthPtr = Tcl_DStringLength(&ds);
    *valuePtr = ckalloc((*lengthPtr) + 1);
    memcpy(*valuePtr, Tcl_DStringValue(&ds), (size_t)(*lengthPtr)+1);
    Tcl_DStringFree(&ds);
}





/*
 *----------------------------------------------------------------------
 *

 * Tcl_GetHostName --
 *
 *	Returns the name of the local host.
 *
 * Results:

 *	A string containing the network name for this machine, or an empty
 *	string if we can't figure out the name. The caller must not modify or
 *	free this string.

 *

 * Side effects:
 *	Caches the name to return for future calls.
 *


 *----------------------------------------------------------------------
 */

const char *

Tcl_GetHostName(void)
{



    return Tcl_GetString(TclGetProcessGlobalValue(&hostName));
}

/*
 *----------------------------------------------------------------------
 *
 * TclpHasSockets --
 *
 *	This function determines whether sockets are available on the current
 *	system and returns an error in interp if they are not. Note that
 *	interp may be NULL.
 *
 * Results:

 *	Returns TCL_OK if the system supports sockets, or TCL_ERROR with an
 *	error in interp (if non-NULL).
 *
 * Side effects:




 *	If not already prepared, initializes the TSD structure and socket





 *	message handling thread associated to the calling thread for the





 *	subsystem of the driver.
 *

 *----------------------------------------------------------------------
 */













int


TclpHasSockets(
    Tcl_Interp *interp)		/* Where to write an error message if sockets
				 * are not present, or NULL if no such message
				 * is to be written. */
{
    Tcl_MutexLock(&socketMutex);
    InitSockets();
    Tcl_MutexUnlock(&socketMutex);


    if (SocketsEnabled()) {
	return TCL_OK;

    }
    if (interp != NULL) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj(


		"sockets are not available on this system", -1));
    }
    return TCL_ERROR;
}

/*
 *----------------------------------------------------------------------
 *
 * TclpFinalizeSockets --
 *

    }
    Tcl_DeleteEventSource(SocketSetupProc, SocketCheckProc, NULL);
}

/*
 *----------------------------------------------------------------------
 *
 * TcpBlockModeProc --
 *
 *	This function is invoked by the generic IO level to set blocking and
 *	nonblocking mode on a TCP socket based channel.

 *
 * Results:


 *	0 if successful, errno when failed.
 *
 * Side effects:


 *	Sets the device into blocking or nonblocking mode.
 *
 *----------------------------------------------------------------------
 */

	/* ARGSUSED */
static int
TcpBlockModeProc(
    ClientData instanceData,	/* Socket state. */


    int mode)			/* The mode to set. Can be one of
				 * TCL_MODE_BLOCKING or
				 * TCL_MODE_NONBLOCKING. */
{



    TcpState *statePtr = instanceData;

    if (mode == TCL_MODE_NONBLOCKING) {
	statePtr->flags |= TCP_NONBLOCKING;
    } else {



	statePtr->flags &= ~(TCP_NONBLOCKING);
    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * WaitForConnect --
 *
 *	Check the state of an async connect process. If a connection
 *	attempt terminated, process it, which may finalize it or may





 *	start the next attempt. If a connect error occures, it is saved
 *	in statePtr->connectError to be reported by 'fconfigure -error'.
 *


 *	There are two modes of operation, defined by errorCodePtr:








 *	 *  non-NULL: Called by explicite read/write command. block if

 *	    socket is blocking.
 *	    May return two error codes:

 *	     *	EWOULDBLOCK: if connect is still in progress



 *	     *	ENOTCONN: if connect failed. This would be the error










 *		message of a rect or sendto syscall so this is
 *		emulated here.




 *	 *  Null: Called by a backround operation. Do not block and



 *	    don't return any error code.



 *














































 * Results:

 * 	0 if the connection has completed, -1 if still in progress

 * 	or there is an error.
 *
 * Side effects:

 *	Processes socket events off the system queue.
 *	May process asynchroneous connect.
 *
 *----------------------------------------------------------------------
 */

static int
WaitForConnect(
    TcpState *statePtr,		/* State of the socket. */
    int *errorCodePtr)		/* Where to store errors?
				 * A passed null-pointer activates background mode.
				 */
{
    int result;
    int oldMode;
    ThreadSpecificData *tsdPtr;

    /*
     * Check if an async connect failed already and error reporting is demanded,
     * return the error ENOTCONN
     */

    if (errorCodePtr != NULL && (statePtr->flags & TCP_ASYNC_FAILED)) {
	*errorCodePtr = ENOTCONN;
	return -1;
    }

    /*
     * Check if an async connect is running. If not return ok
     */
     
    if (!(statePtr->flags & TCP_ASYNC_CONNECT)) {
	return 0;
    }

    /*
     * Be sure to disable event servicing so we are truly modal.
     */

    oldMode = Tcl_SetServiceMode(TCL_SERVICE_NONE);

    /*
     * Loop in the blocking case until the connect signal is present
     */

    while (1) {

	/* get statePtr lock */
        tsdPtr = TclThreadDataKeyGet(&dataKey);
	WaitForSingleObject(tsdPtr->socketListLock, INFINITE);
	
	/* Check for connect event */
	if (statePtr->readyEvents & FD_CONNECT) {

	    /* Consume the connect event */
	    statePtr->readyEvents &= ~(FD_CONNECT);

	    /*
	     * For blocking sockets and foreground processing
	     * disable async connect as we continue now synchoneously
	     */
	    if ( errorCodePtr != NULL &&
		    ! (statePtr->flags & TCP_NONBLOCKING) ) {
		CLEAR_BITS(statePtr->flags, TCP_ASYNC_CONNECT);
	    }

	    /* Free list lock */
	    SetEvent(tsdPtr->socketListLock);

	    /*
	     * Continue connect.
	     * If switched to synchroneous connect, the connect is terminated.
	     */
	    result = TcpConnect(NULL, statePtr);

	    /* Restore event service mode */
	    (void) Tcl_SetServiceMode(oldMode);

	    /*
	     * Check for Succesfull connect or async connect restart
	     */

	    if (result == TCL_OK) {
		/*
		 * Check for async connect restart
		 * (not possible for foreground blocking operation)
		 */
		if ( statePtr->flags & TCP_ASYNC_PENDING ) {
		    if (errorCodePtr != NULL) {
			*errorCodePtr = EWOULDBLOCK;
		    }
		    return -1;
		}
		return 0;
	    }

	    /*
	     * Connect finally failed.
	     * For foreground operation return ENOTCONN.
	     */

	    if (errorCodePtr != NULL) {
		*errorCodePtr = ENOTCONN;
	    }
	    return -1;
	}

        /* Free list lock */
        SetEvent(tsdPtr->socketListLock);


	/*
	 * Background operation returns with no action as there was no connect
	 * event

	 */




	if ( errorCodePtr == NULL ) {
	    return -1;
	}

	/*
	 * A non blocking socket waiting for an asyncronous connect
	 * returns directly the error EWOULDBLOCK
	 */

	if (statePtr->flags & TCP_NONBLOCKING) {
	    *errorCodePtr = EWOULDBLOCK;
	    return -1;
	}

	/*
	 * Wait until something happens.
	 */

	WaitForSingleObject(tsdPtr->readyEvent, INFINITE);




    }
}

/*


 *----------------------------------------------------------------------
 *




 * TcpInputProc --
 *

 *	This function is invoked by the generic IO level to read input from a
 *	TCP socket based channel.
 *
 * Results:

 *	The number of bytes read is returned or -1 on error. An output
 *	argument contains the POSIX error code on error, or zero if no error
 *	occurred.
 *


 * Side effects:
 *	Reads input from the input device of the channel.
 *
 *----------------------------------------------------------------------

 */


	/* ARGSUSED */
static int
TcpInputProc(
    ClientData instanceData,	/* Socket state. */
    char *buf,			/* Where to store data read. */

    int bufSize,		/* How much space is available in the





				 * buffer? */
    int *errorCodePtr)		/* Where to store error code. */
{

    TcpState *statePtr = instanceData;
    int bytesRead;
    DWORD error;
    ThreadSpecificData *tsdPtr = TclThreadDataKeyGet(&dataKey);

    *errorCodePtr = 0;

    /*
     * Check that WinSock is initialized; do not call it if not, to prevent

     * system crashes. This can happen at exit time if the exit handler for
     * WinSock ran before other exit handlers that want to use sockets.
     */


    if (!SocketsEnabled()) {
	*errorCodePtr = EFAULT;
	return -1;
    }


    /*


     * First check to see if EOF was already detected, to prevent calling the
     * socket stack after the first time EOF is detected.


     */

    if (statePtr->flags & SOCKET_EOF) {
	return 0;
    }

    /*
     * Check if there is an async connect running.
     * For blocking sockets terminate connect, otherwise do one step.
     * For a non blocking socket return EWOULDBLOCK if connect not terminated


     */




    if (WaitForConnect(statePtr, errorCodePtr) != 0) {
	return -1;
    }



    /*
     * No EOF, and it is connected, so try to read more from the socket. Note
     * that we clear the FD_READ bit because read events are level triggered

     * so a new event will be generated if there is still data available to be
     * read. We have to simulate blocking behavior here since we are always
     * using non-blocking sockets.
     */

    while (1) {
	SendMessage(tsdPtr->hwnd, SOCKET_SELECT,
		(WPARAM) UNSELECT, (LPARAM) statePtr);
	/* single fd operation: this proc is only called for a connected socket. */
	bytesRead = recv(statePtr->sockets->fd, buf, bufSize, 0);
	statePtr->readyEvents &= ~(FD_READ);


	/*







	 * Check for end-of-file condition or successful read.
	 */


	if (bytesRead == 0) {
	    statePtr->flags |= SOCKET_EOF;
	}
	if (bytesRead != SOCKET_ERROR) {
	    break;
	}

	/*
	 * If an error occurs after the FD_CLOSE has arrived, then ignore the
	 * error and report an EOF.
	 */

	if (statePtr->readyEvents & FD_CLOSE) {

	    statePtr->flags |= SOCKET_EOF;
	    bytesRead = 0;
	    break;
	}

	error = WSAGetLastError();

	/*





	 * If an RST comes, then ignore the error and report an EOF just like
	 * on unix.
	 */

	if (error == WSAECONNRESET) {
	    statePtr->flags |= SOCKET_EOF;

	    bytesRead = 0;
	    break;
	}

	/*
	 * Check for error condition or underflow in non-blocking case.
	 */



	if ((statePtr->flags & TCP_NONBLOCKING) || (error != WSAEWOULDBLOCK)) {
	    TclWinConvertError(error);
	    *errorCodePtr = Tcl_GetErrno();
	    bytesRead = -1;
	    break;


	}




	/*
	 * In the blocking case, wait until the file becomes readable or
	 * closed and try again.
	 */

	if (!WaitForSocketEvent(statePtr, FD_READ|FD_CLOSE, errorCodePtr)) {
	    bytesRead = -1;
	    break;
	}
    }



    SendMessage(tsdPtr->hwnd, SOCKET_SELECT, (WPARAM)SELECT, (LPARAM)statePtr);

    return bytesRead;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpOutputProc --
 *
 *	This function is called by the generic IO level to write data to a
 *	socket based channel.
 *
 * Results:

 *	The number of bytes written or -1 on failure.
 *
 * Side effects:
 *	Produces output on the socket.
 *
 *----------------------------------------------------------------------
 */

static int
TcpOutputProc(
    ClientData instanceData,	/* Socket state. */
    const char *buf,		/* The data buffer. */
    int toWrite,		/* How many bytes to write? */
    int *errorCodePtr)		/* Where to store error code. */
{
    TcpState *statePtr = instanceData;
    int written;
    DWORD error;
    ThreadSpecificData *tsdPtr = TclThreadDataKeyGet(&dataKey);

    *errorCodePtr = 0;

    /*
     * Check that WinSock is initialized; do not call it if not, to prevent
     * system crashes. This can happen at exit time if the exit handler for
     * WinSock ran before other exit handlers that want to use sockets.
     */

    if (!SocketsEnabled()) {
	*errorCodePtr = EFAULT;
	return -1;
    }

    /*
     * Check if there is an async connect running.
     * For blocking sockets terminate connect, otherwise do one step.
     * For a non blocking socket return EWOULDBLOCK if connect not terminated
     */

    if (WaitForConnect(statePtr, errorCodePtr) != 0) {
	return -1;
    }

    while (1) {
	SendMessage(tsdPtr->hwnd, SOCKET_SELECT,
		(WPARAM) UNSELECT, (LPARAM) statePtr);

	/* single fd operation: this proc is only called for a connected socket. */
	written = send(statePtr->sockets->fd, buf, toWrite, 0);
	if (written != SOCKET_ERROR) {
	    /*
	     * Since Windows won't generate a new write event until we hit an
	     * overflow condition, we need to force the event loop to poll
	     * until the condition changes.
	     */

	    if (statePtr->watchEvents & FD_WRITE) {
		Tcl_Time blockTime = { 0, 0 };
		Tcl_SetMaxBlockTime(&blockTime);
	    }
	    break;
	}

	/*
	 * Check for error condition or overflow. In the event of overflow, we
	 * need to clear the FD_WRITE flag so we can detect the next writable
	 * event. Note that Windows only sends a new writable event after a
	 * send fails with WSAEWOULDBLOCK.
	 */

	error = WSAGetLastError();
	if (error == WSAEWOULDBLOCK) {
	    statePtr->readyEvents &= ~(FD_WRITE);
	    if (statePtr->flags & TCP_NONBLOCKING) {
		*errorCodePtr = EWOULDBLOCK;
		written = -1;
		break;
	    }
	} else {
	    TclWinConvertError(error);
	    *errorCodePtr = Tcl_GetErrno();
	    written = -1;
	    break;
	}

	/*
	 * In the blocking case, wait until the file becomes writable or
	 * closed and try again.
	 */

	if (!WaitForSocketEvent(statePtr, FD_WRITE|FD_CLOSE, errorCodePtr)) {
	    written = -1;
	    break;
	}
    }

    SendMessage(tsdPtr->hwnd, SOCKET_SELECT, (WPARAM)SELECT, (LPARAM)statePtr);

    return written;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpCloseProc --
 *

    /* ARGSUSED */
static int
TcpCloseProc(
    ClientData instanceData,	/* The socket to close. */
    Tcl_Interp *interp)		/* Unused. */
{
    TcpState *statePtr = instanceData;
    /* TIP #218 */
    int errorCode = 0;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    /*
     * Check that WinSock is initialized; do not call it if not, to prevent
     * system crashes. This can happen at exit time if the exit handler for
     * WinSock ran before other exit handlers that want to use sockets.
     */

    if (SocketsEnabled()) {
	/*
	 * Clean up the OS socket handle. The default Windows setting for a
	 * socket is SO_DONTLINGER, which does a graceful shutdown in the
	 * background.
	 */

	while ( statePtr->sockets != NULL ) {
	    TcpFdList *thisfd = statePtr->sockets;
	    statePtr->sockets = thisfd->next;

	    if (closesocket(thisfd->fd) == SOCKET_ERROR) {
		TclWinConvertError((DWORD) WSAGetLastError());
		errorCode = Tcl_GetErrno();
	    }
	    ckfree(thisfd);
	}
    }

    if (statePtr->addrlist != NULL) {
        freeaddrinfo(statePtr->addrlist);
    }
    if (statePtr->myaddrlist != NULL) {
        freeaddrinfo(statePtr->myaddrlist);
    }

    /*
     * Clear an eventual tsd info list pointer.
     * This may be called, if an async socket connect fails or is closed
     * between connect and thread action callback.
     */
    if (tsdPtr->pendingTcpState != NULL
	    && tsdPtr->pendingTcpState == statePtr) {

	/* get infoPtr lock, because this concerns the notifier thread */
	WaitForSingleObject(tsdPtr->socketListLock, INFINITE);

	tsdPtr->pendingTcpState = NULL;

	/* Free list lock */
	SetEvent(tsdPtr->socketListLock);
    }

    /*
     * TIP #218. Removed the code removing the structure from the global
     * socket list. This is now done by the thread action callbacks, and only
     * there. This happens before this code is called. We can free without
     * fear of damaging the list.
     */

    ckfree(statePtr);
    return errorCode;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpClose2Proc --

static int
TcpClose2Proc(
    ClientData instanceData,	/* The socket to close. */
    Tcl_Interp *interp,		/* For error reporting. */
    int flags)			/* Flags that indicate which side to close. */
{
    TcpState *statePtr = instanceData;
    int errorCode = 0;
    int sd;

    /*
     * Shutdown the OS socket handle.
     */

    switch(flags) {
    case TCL_CLOSE_READ:
	sd = SD_RECEIVE;
	break;
    case TCL_CLOSE_WRITE:
	sd = SD_SEND;
	break;
    default:
	if (interp) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "socket close2proc called bidirectionally", -1));
	}
	return TCL_ERROR;
    }

    /* single fd operation: Tcl_OpenTcpServer() does not set TCL_READABLE or
     * TCL_WRITABLE so this should never be called for a server socket. */
    if (shutdown(statePtr->sockets->fd, sd) == SOCKET_ERROR) {
	TclWinConvertError((DWORD) WSAGetLastError());
	errorCode = Tcl_GetErrno();
    }

    return errorCode;
}




















































































































































































































































































































































































































































































































































































































































































































































































































































































































































































/*
 *----------------------------------------------------------------------
 *
 * TcpSetOptionProc --
 *
 *	Sets Tcp channel specific options.

TcpSetOptionProc(
    ClientData instanceData,	/* Socket state. */
    Tcl_Interp *interp,		/* For error reporting - can be NULL. */
    const char *optionName,	/* Name of the option to set. */
    const char *value)		/* New value for option. */
{
#ifdef TCL_FEATURE_KEEPALIVE_NAGLE
    TcpState *statePtr = instanceData;
    SOCKET sock;
#endif /*TCL_FEATURE_KEEPALIVE_NAGLE*/

    /*
     * Check that WinSock is initialized; do not call it if not, to prevent
     * system crashes. This can happen at exit time if the exit handler for
     * WinSock ran before other exit handlers that want to use sockets.
     */

    if (!SocketsEnabled()) {
	if (interp) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "winsock is not initialized", -1));
	}
	return TCL_ERROR;
    }

#ifdef TCL_FEATURE_KEEPALIVE_NAGLE
    #error "TCL_FEATURE_KEEPALIVE_NAGLE not reviewed for whether to treat statePtr->sockets as single fd or list"
    sock = statePtr->sockets->fd;

    if (!strcasecmp(optionName, "-keepalive")) {
	BOOL val = FALSE;
	int boolVar, rtn;

	if (Tcl_GetBoolean(interp, value, &boolVar) != TCL_OK) {
	    return TCL_ERROR;

 *	Computes an option value for a TCP socket based channel, or a list of
 *	all options and their values.
 *
 *	Note: This code is based on code contributed by John Haxby.
 *
 * Results:
 *	A standard Tcl result. The value of the specified option or a list of
 *	all options and their values is returned in the supplied DString. Sets
 *	Error message if needed.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
TcpGetOptionProc(
    ClientData instanceData,	/* Socket state. */
    Tcl_Interp *interp,		/* For error reporting - can be NULL. */
    const char *optionName,	/* Name of the option to retrieve the value
				 * for, or NULL to get all options and their
				 * values. */
    Tcl_DString *dsPtr)		/* Where to store the computed value;
				 * initialized by caller. */
{
    TcpState *statePtr = instanceData;
    char host[NI_MAXHOST], port[NI_MAXSERV];
    SOCKET sock;
    size_t len = 0;
    int errorCode = 0;
    int reverseDNS = 0;
#define SUPPRESS_RDNS_VAR "::tcl::unsupported::noReverseDNS"

    /*
     * Check that WinSock is initialized; do not call it if not, to prevent
     * system crashes. This can happen at exit time if the exit handler for
     * WinSock ran before other exit handlers that want to use sockets.
     */

    if (!SocketsEnabled()) {
	if (interp) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "winsock is not initialized", -1));
	}
	return TCL_ERROR;
    }

    /* 
     * Go one step in async connect
     * If any error is thrown save it as backround error to report eventually below
     */
    WaitForConnect(statePtr, NULL);

    sock = statePtr->sockets->fd;
    if (optionName != NULL) {
	len = strlen(optionName);
    }

    if ((len > 1) && (optionName[1] == 'e') &&
	    (strncmp(optionName, "-error", len) == 0)) {

	/*
	* Do not return any errors if async connect is running
	*/
	if ( ! (statePtr->flags & TCP_ASYNC_PENDING) ) {


	    if ( statePtr->flags & TCP_ASYNC_FAILED ) {

		/*
		 * In case of a failed async connect, eventually report the
		 * connect error only once.
		 * Do not report the system error, as this comes again and again.
		 */

		if ( statePtr->connectError != 0 ) {
		    Tcl_DStringAppend(dsPtr,
			    Tcl_ErrnoMsg(statePtr->connectError), -1);
		    statePtr->connectError = 0;
		}

	    } else {

		/*
		 * Report an eventual last error of the socket system
		 */

		int optlen;

		int ret;
		DWORD err;

		/*
		 * Populater the err Variable with a possix error
		 */
		optlen = sizeof(int);
		ret = getsockopt(sock, SOL_SOCKET, SO_ERROR,
			(char *)&err, &optlen);
		/*
		 * The error was not returned directly but should be
		 * taken from WSA
		 */
		if (ret == SOCKET_ERROR) {
		    err = WSAGetLastError();
		}
		/*
		 * Return error message
		 */
		if (err) {
		    TclWinConvertError(err);
		    Tcl_DStringAppend(dsPtr, Tcl_ErrnoMsg(Tcl_GetErrno()), -1);
		}
	    }
	}
	return TCL_OK;
    }

    if ((len > 1) && (optionName[1] == 'c') &&
	    (strncmp(optionName, "-connecting", len) == 0)) {

	Tcl_DStringAppend(dsPtr,
		(statePtr->flags & TCP_ASYNC_PENDING)
		? "1" : "0", -1);
        return TCL_OK;
    }

    if (interp != NULL && Tcl_GetVar(interp, SUPPRESS_RDNS_VAR, 0) != NULL) {
	reverseDNS = NI_NUMERICHOST;
    }

    if ((len == 0) || ((len > 1) && (optionName[1] == 'p') &&
	    (strncmp(optionName, "-peername", len) == 0))) {

	socklen_t size;
	int found = 0;

	if (len == 0) {
	    Tcl_DStringAppendElement(dsPtr, "-sockname");
	    Tcl_DStringStartSublist(dsPtr);
	}
	for (fds = statePtr->sockets; fds != NULL; fds = fds->next) {
	    sock = fds->fd;
	    size = sizeof(sockname);
	    if (getsockname(sock, &(sockname.sa), &size) >= 0) {
		int flags = reverseDNS;

		found = 1;
		getnameinfo(&sockname.sa, size, host, sizeof(host),

static void
TcpWatchProc(
    ClientData instanceData,	/* The socket state. */
    int mask)			/* Events of interest; an OR-ed combination of
				 * TCL_READABLE, TCL_WRITABLE and
				 * TCL_EXCEPTION. */
{
    TcpState *statePtr = instanceData;

    /*
     * Update the watch events mask. Only if the socket is not a server
     * socket. [Bug 557878]
     */

    if (!statePtr->acceptProc) {
	statePtr->watchEvents = 0;
	if (mask & TCL_READABLE) {
	    statePtr->watchEvents |= (FD_READ|FD_CLOSE);
	}
	if (mask & TCL_WRITABLE) {
	    statePtr->watchEvents |= (FD_WRITE|FD_CLOSE);
	}

	/*
	 * If there are any conditions already set, then tell the notifier to
	 * poll rather than block.
	 */

	if (statePtr->readyEvents & statePtr->watchEvents) {
	    Tcl_Time blockTime = { 0, 0 };

	    Tcl_SetMaxBlockTime(&blockTime);
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TcpGetHandleProc --
 *
 *	Called from Tcl_GetChannelHandle to retrieve OS handles from inside a
 *	TCP socket based channel.
 *
 * Results:
 *	Returns TCL_OK with the fd in handlePtr, or TCL_ERROR if there is no
 *	handle for the specified direction.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

	/* ARGSUSED */
static int
TcpGetHandleProc(
    ClientData instanceData,	/* The socket state. */
    int direction,		/* Not used. */
    ClientData *handlePtr)	/* Where to store the handle. */
{
    TcpState *statePtr = instanceData;

    *handlePtr = INT2PTR(statePtr->sockets->fd);
    return TCL_OK;
}



/*
 *----------------------------------------------------------------------
 *
 * TcpConnect --
 *
 *	This function opens a new socket in client mode.
 *
 *	This might be called in 3 circumstances:
 *	-   By a regular socket command
 *	-   By the event handler to continue an asynchroneous connect
 *	-   By a blocking socket function (gets/puts) to terminate the
 *	    connect synchroneously
 *
 * Results:
 *      TCL_OK, if the socket was successfully connected or an asynchronous
 *      connection is in progress. If an error occurs, TCL_ERROR is returned
 *      and an error message is left in interp.
 *
 * Side effects:
 *	Opens a socket.
 *
 * Remarks:
 *	A single host name may resolve to more than one IP address, e.g. for
 *	an IPv4/IPv6 dual stack host. For handling asyncronously connecting
 *	sockets in the background for such hosts, this function can act as a
 *	coroutine. On the first call, it sets up the control variables for the
 *	two nested loops over the local and remote addresses. Once the first
 *	connection attempt is in progress, it sets up itself as a writable
 *	event handler for that socket, and returns. When the callback occurs,
 *	control is transferred to the "reenter" label, right after the initial
 *	return and the loops resume as if they had never been interrupted.
 *	For syncronously connecting sockets, the loops work the usual way.
 *
 *----------------------------------------------------------------------
 */

static int
TcpConnect(
    Tcl_Interp *interp,		/* For error reporting; can be NULL. */
    TcpState *statePtr)
{
    DWORD error;
    u_long flag = 1;		/* Indicates nonblocking mode. */
    /*
     * We are started with async connect and the connect notification
     * was not jet received
     */
    int async_connect = statePtr->flags & TCP_ASYNC_CONNECT;
    /* We were called by the event procedure and continue our loop */
    int async_callback = statePtr->flags & TCP_ASYNC_PENDING;
    ThreadSpecificData *tsdPtr = TclThreadDataKeyGet(&dataKey);
    
    if (async_callback) {
        goto reenter;
    }
    
    for (statePtr->addr = statePtr->addrlist; statePtr->addr != NULL;
	 statePtr->addr = statePtr->addr->ai_next) {
	
        for (statePtr->myaddr = statePtr->myaddrlist; statePtr->myaddr != NULL;
	     statePtr->myaddr = statePtr->myaddr->ai_next) {

	    /*
	     * No need to try combinations of local and remote addresses
	     * of different families.
	     */

	    if (statePtr->myaddr->ai_family != statePtr->addr->ai_family) {
		continue;
	    }

            /*
             * Close the socket if it is still open from the last unsuccessful
             * iteration.
             */	    
	    if (statePtr->sockets->fd != INVALID_SOCKET) {
		closesocket(statePtr->sockets->fd);
	    }

	    /* get statePtr lock */
	    WaitForSingleObject(tsdPtr->socketListLock, INFINITE);

	    /*
	     * Reset last error from last try
	     */
	    statePtr->notifierConnectError = 0;
	    Tcl_SetErrno(0);
	    
	    statePtr->sockets->fd = socket(statePtr->myaddr->ai_family, SOCK_STREAM, 0);
	    
	    /* Free list lock */
	    SetEvent(tsdPtr->socketListLock);

	    /* continue on socket creation error */
	    if (statePtr->sockets->fd == INVALID_SOCKET) {
		TclWinConvertError((DWORD) WSAGetLastError());
		continue;
	    }

	    /*
	     * Win-NT has a misfeature that sockets are inherited in child
	     * processes by default. Turn off the inherit bit.
	     */

	    SetHandleInformation((HANDLE) statePtr->sockets->fd, HANDLE_FLAG_INHERIT, 0);

	    /*
	     * Set kernel space buffering
	     */

	    TclSockMinimumBuffers((void *) statePtr->sockets->fd, TCP_BUFFER_SIZE);

	    /*
	     * Try to bind to a local port.
	     */

	    if (bind(statePtr->sockets->fd, statePtr->myaddr->ai_addr,
			statePtr->myaddr->ai_addrlen) == SOCKET_ERROR) {
		TclWinConvertError((DWORD) WSAGetLastError());
		continue;
	    }
	    /*
	     * For asyncroneous connect set the socket in nonblocking mode
	     * and activate connect notification
	     */
	    if (async_connect) {
		TcpState *statePtr2;
		int in_socket_list = 0;
		/* get statePtr lock */
		WaitForSingleObject(tsdPtr->socketListLock, INFINITE);

		/*
		 * Bugfig for 336441ed59 to not ignore notifications until the
		 * infoPtr is in the list.
		 * Check if my statePtr is already in the tsdPtr->socketList
		 * It is set after this call by TcpThreadActionProc and is set
		 * on a second round.
		 *
		 * If not, we buffer my statePtr in the tsd memory so it is not
		 * lost by the event procedure
		 */

		for (statePtr2 = tsdPtr->socketList; statePtr2 != NULL;
			statePtr2 = statePtr->nextPtr) {
		    if (statePtr2 == statePtr) {
			in_socket_list = 1;
			break;
		    }
		}
		if (!in_socket_list) {
		    tsdPtr->pendingTcpState = statePtr;
		}
		/*
		 * Set connect mask to connect events
		 * This is activated by a SOCKET_SELECT message to the notifier
		 * thread.
		 */
		statePtr->selectEvents |= FD_CONNECT;
		
		/*
		 * Free list lock
		 */
		SetEvent(tsdPtr->socketListLock);

    		/* activate accept notification */
		SendMessage(tsdPtr->hwnd, SOCKET_SELECT, (WPARAM) SELECT,
			(LPARAM) statePtr);
	    }

	    /*
	     * Attempt to connect to the remote socket.
	     */
	    
	    connect(statePtr->sockets->fd, statePtr->addr->ai_addr,
		    statePtr->addr->ai_addrlen);

	    error = WSAGetLastError();
	    TclWinConvertError(error);

	    if (async_connect && error == WSAEWOULDBLOCK) {
		/*
		 * Asynchroneous connect
		 */

		/*
		 * Remember that we jump back behind this next round
		 */
		statePtr->flags |= TCP_ASYNC_PENDING;
		return TCL_OK;

	    reenter:
		/*
		 * Re-entry point for async connect after connect event or
		 * blocking operation
		 *
		 * Clear the reenter flag
		 */
		statePtr->flags &= ~(TCP_ASYNC_PENDING);
		/* get statePtr lock */
		WaitForSingleObject(tsdPtr->socketListLock, INFINITE);
		/* Get signaled connect error */
		TclWinConvertError((DWORD) statePtr->notifierConnectError);
		/* Clear eventual connect flag */
		statePtr->selectEvents &= ~(FD_CONNECT);
		/* Free list lock */
		SetEvent(tsdPtr->socketListLock);
	    }

	    /*
	     * Clear the tsd socket list pointer if we did not wait for
	     * the FD_CONNECT asyncroneously
	     */
	    tsdPtr->pendingTcpState = NULL;
	    
	    if (Tcl_GetErrno() == 0) {
		goto out;
	    }
	}
    }

out:
    /*
     * Socket connected or connection failed
     */

    /*
     * Async connect terminated
     */

    CLEAR_BITS(statePtr->flags, TCP_ASYNC_CONNECT);

    if ( Tcl_GetErrno() == 0 ) {
	/*
	 * Succesfully connected
	 */
	/*
	 * Set up the select mask for read/write events.
	 */
	statePtr->selectEvents = FD_READ | FD_WRITE | FD_CLOSE;
        
	/*
	 * Register for interest in events in the select mask. Note that this
	 * automatically places the socket into non-blocking mode.
	 */
        
	SendMessage(tsdPtr->hwnd, SOCKET_SELECT, (WPARAM) SELECT,
		    (LPARAM) statePtr);
    } else {
	/*
	 * Connect failed
	 */

	/*
	 * For async connect schedule a writable event to report the fail.
	 */
	if (async_callback) {
	    /*
	     * Set up the select mask for read/write events.
	     */
	    statePtr->selectEvents = FD_WRITE|FD_READ;
	    /* get statePtr lock */
	    WaitForSingleObject(tsdPtr->socketListLock, INFINITE);
	    /* Signal ready readable and writable events */
	    statePtr->readyEvents |= FD_WRITE | FD_READ;
	    /* Flag error to event routine */
	    statePtr->flags |= TCP_ASYNC_FAILED;
	    /* Save connect error to be reported by 'fconfigure -error' */
	    statePtr->connectError = Tcl_GetErrno();
	    /* Free list lock */
	    SetEvent(tsdPtr->socketListLock);
	}
	/*
	 * Error message on syncroneous connect
	 */
	if (interp != NULL) {
	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		    "couldn't open socket: %s", Tcl_PosixError(interp)));
	}
	return TCL_ERROR;
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_OpenTcpClient --
 *
 *	Opens a TCP client socket and creates a channel around it.
 *
 * Results:
 *	The channel or NULL if failed. An error message is returned in the
 *	interpreter on failure.
 *
 * Side effects:
 *	Opens a client socket and creates a new channel.
 *
 *----------------------------------------------------------------------
 */

Tcl_Channel
Tcl_OpenTcpClient(
    Tcl_Interp *interp,		/* For error reporting; can be NULL. */
    int port,			/* Port number to open. */
    const char *host,		/* Host on which to open port. */
    const char *myaddr,		/* Client-side address */
    int myport,			/* Client-side port */
    int async)			/* If nonzero, attempt to do an asynchronous
				 * connect. Otherwise we do a blocking
				 * connect. */
{
    TcpState *statePtr;
    const char *errorMsg = NULL;
    struct addrinfo *addrlist = NULL, *myaddrlist = NULL;
    char channelName[SOCK_CHAN_LENGTH];

    if (TclpHasSockets(interp) != TCL_OK) {
	return NULL;
    }

    /*
     * Check that WinSock is initialized; do not call it if not, to prevent
     * system crashes. This can happen at exit time if the exit handler for
     * WinSock ran before other exit handlers that want to use sockets.
     */

    if (!SocketsEnabled()) {
	return NULL;
    }

    /*
     * Do the name lookups for the local and remote addresses.
     */

    if (!TclCreateSocketAddress(interp, &addrlist, host, port, 0, &errorMsg)
            || !TclCreateSocketAddress(interp, &myaddrlist, myaddr, myport, 1,
                    &errorMsg)) {
        if (addrlist != NULL) {
            freeaddrinfo(addrlist);
        }
        if (interp != NULL) {
            Tcl_SetObjResult(interp, Tcl_ObjPrintf(
                    "couldn't open socket: %s", errorMsg));
        }
        return NULL;
    }

    statePtr = NewSocketInfo(INVALID_SOCKET);
    statePtr->addrlist = addrlist;
    statePtr->myaddrlist = myaddrlist;
    if (async) {
	statePtr->flags |= TCP_ASYNC_CONNECT;
    }

    /*
     * Create a new client socket and wrap it in a channel.
     */
    if (TcpConnect(interp, statePtr) != TCL_OK) {
	TcpCloseProc(statePtr, NULL);
	return NULL;
    }

    sprintf(channelName, SOCK_TEMPLATE, statePtr);

    statePtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName,
	    statePtr, (TCL_READABLE | TCL_WRITABLE));
    if (TCL_ERROR == Tcl_SetChannelOption(NULL, statePtr->channel,
	    "-translation", "auto crlf")) {
	Tcl_Close(NULL, statePtr->channel);
	return NULL;
    } else if (TCL_ERROR == Tcl_SetChannelOption(NULL, statePtr->channel,
	    "-eofchar", "")) {
	Tcl_Close(NULL, statePtr->channel);
	return NULL;
    }
    return statePtr->channel;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_MakeTcpClientChannel --
 *
 *	Creates a Tcl_Channel from an existing client TCP socket.
 *
 * Results:
 *	The Tcl_Channel wrapped around the preexisting TCP socket.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

Tcl_Channel
Tcl_MakeTcpClientChannel(
    ClientData sock)		/* The socket to wrap up into a channel. */
{
    TcpState *statePtr;
    char channelName[SOCK_CHAN_LENGTH];
    ThreadSpecificData *tsdPtr;

    if (TclpHasSockets(NULL) != TCL_OK) {
	return NULL;
    }

    tsdPtr = TclThreadDataKeyGet(&dataKey);

    /*
     * Set kernel space buffering and non-blocking.
     */

    TclSockMinimumBuffers(sock, TCP_BUFFER_SIZE);

    statePtr = NewSocketInfo((SOCKET) sock);

    /*
     * Start watching for read/write events on the socket.
     */

    statePtr->selectEvents = FD_READ | FD_CLOSE | FD_WRITE;
    SendMessage(tsdPtr->hwnd, SOCKET_SELECT, (WPARAM)SELECT, (LPARAM)statePtr);

    sprintf(channelName, SOCK_TEMPLATE, statePtr);
    statePtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName,
	    statePtr, (TCL_READABLE | TCL_WRITABLE));
    Tcl_SetChannelOption(NULL, statePtr->channel, "-translation", "auto crlf");
    return statePtr->channel;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_OpenTcpServer --
 *
 *	Opens a TCP server socket and creates a channel around it.
 *
 * Results:
 *	The channel or NULL if failed. If an error occurred, an error message
 *	is left in the interp's result if interp is not NULL.
 *
 * Side effects:
 *	Opens a server socket and creates a new channel.
 *
 *----------------------------------------------------------------------
 */

Tcl_Channel
Tcl_OpenTcpServer(
    Tcl_Interp *interp,		/* For error reporting - may be NULL. */
    int port,			/* Port number to open. */
    const char *myHost,		/* Name of local host. */
    Tcl_TcpAcceptProc *acceptProc,
				/* Callback for accepting connections from new
				 * clients. */
    ClientData acceptProcData)	/* Data for the callback. */
{
    SOCKET sock = INVALID_SOCKET;
    unsigned short chosenport = 0;
    struct addrinfo *addrlist = NULL;
    struct addrinfo *addrPtr;	/* Socket address to listen on. */
    TcpState *statePtr = NULL;	/* The returned value. */
    char channelName[SOCK_CHAN_LENGTH];
    u_long flag = 1;		/* Indicates nonblocking mode. */
    const char *errorMsg = NULL;
    ThreadSpecificData *tsdPtr = TclThreadDataKeyGet(&dataKey);

    if (TclpHasSockets(interp) != TCL_OK) {
	return NULL;
    }

    /*
     * Check that WinSock is initialized; do not call it if not, to prevent
     * system crashes. This can happen at exit time if the exit handler for
     * WinSock ran before other exit handlers that want to use sockets.
     */

    if (!SocketsEnabled()) {
	return NULL;
    }

    /*
     * Construct the addresses for each end of the socket.
     */

    if (!TclCreateSocketAddress(interp, &addrlist, myHost, port, 1, &errorMsg)) {
	goto error;
    }

    for (addrPtr = addrlist; addrPtr != NULL; addrPtr = addrPtr->ai_next) {
	sock = socket(addrPtr->ai_family, addrPtr->ai_socktype,
                addrPtr->ai_protocol);
	if (sock == INVALID_SOCKET) {
	    TclWinConvertError((DWORD) WSAGetLastError());
	    continue;
	}
	
	/*
	 * Win-NT has a misfeature that sockets are inherited in child
	 * processes by default. Turn off the inherit bit.
	 */
	
	SetHandleInformation((HANDLE) sock, HANDLE_FLAG_INHERIT, 0);
	
	/*
	 * Set kernel space buffering
	 */
	
	TclSockMinimumBuffers((void *)sock, TCP_BUFFER_SIZE);
	
	/*
	 * Make sure we use the same port when opening two server sockets
	 * for IPv4 and IPv6.
	 *
	 * As sockaddr_in6 uses the same offset and size for the port
	 * member as sockaddr_in, we can handle both through the IPv4 API.
	 */
	
	if (port == 0 && chosenport != 0) {
	    ((struct sockaddr_in *) addrPtr->ai_addr)->sin_port =
		htons(chosenport);
	}
	
	/*
	 * Bind to the specified port. Note that we must not call
	 * setsockopt with SO_REUSEADDR because Microsoft allows addresses
	 * to be reused even if they are still in use.
	 *
	 * Bind should not be affected by the socket having already been
	 * set into nonblocking mode. If there is trouble, this is one
	 * place to look for bugs.
	 */
	
	if (bind(sock, addrPtr->ai_addr, addrPtr->ai_addrlen)
	    == SOCKET_ERROR) {
	    TclWinConvertError((DWORD) WSAGetLastError());
	    closesocket(sock);
	    continue;
	}
	if (port == 0 && chosenport == 0) {
	    address sockname;
	    socklen_t namelen = sizeof(sockname);
	    
	    /*
	     * Synchronize port numbers when binding to port 0 of multiple
	     * addresses.
	     */
	    
	    if (getsockname(sock, &sockname.sa, &namelen) >= 0) {
		chosenport = ntohs(sockname.sa4.sin_port);
	    }
	}
	
	/*
	 * Set the maximum number of pending connect requests to the max
	 * value allowed on each platform (Win32 and Win32s may be
	 * different, and there may be differences between TCP/IP stacks).
	 */
	
	if (listen(sock, SOMAXCONN) == SOCKET_ERROR) {
	    TclWinConvertError((DWORD) WSAGetLastError());
	    closesocket(sock);
	    continue;
	}
	
	if (statePtr == NULL) {
	    /*
	     * Add this socket to the global list of sockets.
	     */
	    statePtr = NewSocketInfo(sock);
	} else {
	    AddSocketInfoFd( statePtr, sock );
	}
    }

error:
    if (addrlist != NULL) {
	freeaddrinfo(addrlist);
    }

    if (statePtr != NULL) {

	statePtr->acceptProc = acceptProc;
	statePtr->acceptProcData = acceptProcData;
	sprintf(channelName, SOCK_TEMPLATE, statePtr);
	statePtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName,
		statePtr, 0);
	/*
	 * Set up the select mask for connection request events.
	 */
	
	statePtr->selectEvents = FD_ACCEPT;
	
	/*
	 * Register for interest in events in the select mask. Note that this
	 * automatically places the socket into non-blocking mode.
	 */

	ioctlsocket(sock, (long) FIONBIO, &flag);
	SendMessage(tsdPtr->hwnd, SOCKET_SELECT, (WPARAM) SELECT,
		    (LPARAM) statePtr);
	if (Tcl_SetChannelOption(interp, statePtr->channel, "-eofchar", "")
	    == TCL_ERROR) {
	    Tcl_Close(NULL, statePtr->channel);
	    return NULL;
	}
	return statePtr->channel;
    }

    if (interp != NULL) {
        Tcl_SetObjResult(interp, Tcl_ObjPrintf(
		"couldn't open socket: %s",
		(errorMsg ? errorMsg : Tcl_PosixError(interp))));
    }

    if (sock != INVALID_SOCKET) {
	closesocket(sock);
    }
    return NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * TcpAccept --
 *	Accept a TCP socket connection.	 This is called by the event loop.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Creates a new connection socket. Calls the registered callback for the
 *	connection acceptance mechanism.
 *
 *----------------------------------------------------------------------
 */

	/* ARGSUSED */
static void
TcpAccept(
    TcpFdList *fds,	/* Server socket that accepted newSocket. */
    SOCKET newSocket,   /* Newly accepted socket. */
    address addr)       /* Address of new socket. */
{
    TcpState *newInfoPtr;
    TcpState *statePtr = fds->statePtr;
    int len = sizeof(addr);
    char channelName[SOCK_CHAN_LENGTH];
    char host[NI_MAXHOST], port[NI_MAXSERV];
    ThreadSpecificData *tsdPtr = TclThreadDataKeyGet(&dataKey);

    /*
     * Win-NT has a misfeature that sockets are inherited in child processes
     * by default. Turn off the inherit bit.
     */

    SetHandleInformation((HANDLE) newSocket, HANDLE_FLAG_INHERIT, 0);

    /*
     * Add this socket to the global list of sockets.
     */

    newInfoPtr = NewSocketInfo(newSocket);

    /*
     * Select on read/write events and create the channel.
     */

    newInfoPtr->selectEvents = (FD_READ | FD_WRITE | FD_CLOSE);
    SendMessage(tsdPtr->hwnd, SOCKET_SELECT, (WPARAM) SELECT,
	    (LPARAM) newInfoPtr);

    sprintf(channelName, SOCK_TEMPLATE, newInfoPtr);
    newInfoPtr->channel = Tcl_CreateChannel(&tcpChannelType, channelName,
	    newInfoPtr, (TCL_READABLE | TCL_WRITABLE));
    if (Tcl_SetChannelOption(NULL, newInfoPtr->channel, "-translation",
	    "auto crlf") == TCL_ERROR) {
	Tcl_Close(NULL, newInfoPtr->channel);
	return;
    }
    if (Tcl_SetChannelOption(NULL, newInfoPtr->channel, "-eofchar", "")
	    == TCL_ERROR) {
	Tcl_Close(NULL, newInfoPtr->channel);
	return;
    }

    /*
     * Invoke the accept callback function.
     */

    if (statePtr->acceptProc != NULL) {
	getnameinfo(&(addr.sa), len, host, sizeof(host), port, sizeof(port),
                    NI_NUMERICHOST|NI_NUMERICSERV);
	statePtr->acceptProc(statePtr->acceptProcData, newInfoPtr->channel,
			    host, atoi(port));
    }
}

/*
 *----------------------------------------------------------------------
 *
 * InitSockets --
 *
 *	Initialize the socket module.  If winsock startup is successful,
 *	registers the event window for the socket notifier code.
 *
 *	Assumes socketMutex is held.
 *
 * Warning:
 *	This check was useful in times of Windows98 where WinSock may
 *	not be available. This is not the case any more.
 *	This function may be removed with TCL 9.0.
 *	Any failures may be reported as panics.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Initializes winsock, registers a new window class and creates a
 *	window for use in asynchronous socket notification.
 *
 *----------------------------------------------------------------------
 */

static void
InitSockets(void)
{
    DWORD id, err;
    WSADATA wsaData;
    ThreadSpecificData *tsdPtr = TclThreadDataKeyGet(&dataKey);

    if (!initialized) {
	initialized = 1;
	TclCreateLateExitHandler(SocketExitHandler, NULL);

	/*
	 * Create the async notification window with a new class. We must
	 * create a new class to avoid a Windows 95 bug that causes us to get
	 * the wrong message number for socket events if the message window is
	 * a subclass of a static control.
	 */

	windowClass.style = 0;
	windowClass.cbClsExtra = 0;
	windowClass.cbWndExtra = 0;
	windowClass.hInstance = TclWinGetTclInstance();
	windowClass.hbrBackground = NULL;
	windowClass.lpszMenuName = NULL;
	windowClass.lpszClassName = classname;
	windowClass.lpfnWndProc = SocketProc;
	windowClass.hIcon = NULL;
	windowClass.hCursor = NULL;

	if (!RegisterClass(&windowClass)) {
	    TclWinConvertError(GetLastError());
	    goto initFailure;
	}

	/*
	 * Initialize the winsock library and check the interface version
	 * actually loaded. We only ask for the 1.1 interface and do require
	 * that it not be less than 1.1.
	 */

	err = WSAStartup((WORD) MAKEWORD(WSA_VERSION_MAJOR,WSA_VERSION_MINOR),
		&wsaData);
	if (err != 0) {
	    TclWinConvertError(err);
	    goto initFailure;
	}

	/*
	 * Note the byte positions ae swapped for the comparison, so that
	 * 0x0002 (2.0, MAKEWORD(2,0)) doesn't look less than 0x0101 (1.1). We
	 * want the comparison to be 0x0200 < 0x0101.
	 */

	if (MAKEWORD(HIBYTE(wsaData.wVersion), LOBYTE(wsaData.wVersion))
		< MAKEWORD(WSA_VERSION_MINOR, WSA_VERSION_MAJOR)) {
	    TclWinConvertError(WSAVERNOTSUPPORTED);
	    WSACleanup();
	    goto initFailure;
	}
    }

    /*
     * Check for per-thread initialization.
     */

    if (tsdPtr != NULL) {
	return;
    }

    /*
     * OK, this thread has never done anything with sockets before.  Construct
     * a worker thread to handle asynchronous events related to sockets
     * assigned to _this_ thread.
     */

    tsdPtr = TCL_TSD_INIT(&dataKey);
    tsdPtr->pendingTcpState = NULL;
    tsdPtr->socketList = NULL;
    tsdPtr->hwnd       = NULL;
    tsdPtr->threadId   = Tcl_GetCurrentThread();
    tsdPtr->readyEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
    if (tsdPtr->readyEvent == NULL) {
	goto initFailure;
    }
    tsdPtr->socketListLock = CreateEvent(NULL, FALSE, TRUE, NULL);
    if (tsdPtr->socketListLock == NULL) {
	goto initFailure;
    }
    tsdPtr->socketThread = CreateThread(NULL, 256, SocketThread, tsdPtr, 0,
	    &id);
    if (tsdPtr->socketThread == NULL) {
	goto initFailure;
    }

    SetThreadPriority(tsdPtr->socketThread, THREAD_PRIORITY_HIGHEST);

    /*
     * Wait for the thread to signal when the window has been created and if
     * it is ready to go.
     */

    WaitForSingleObject(tsdPtr->readyEvent, INFINITE);

    if (tsdPtr->hwnd == NULL) {
	goto initFailure;	/* Trouble creating the window. */
    }

    Tcl_CreateEventSource(SocketSetupProc, SocketCheckProc, NULL);
    return;

  initFailure:
    TclpFinalizeSockets();
    initialized = -1;
    return;
}

/*
 *----------------------------------------------------------------------
 *
 * SocketsEnabled --
 *
 *	Check that the WinSock was successfully initialized.
 *
 * Warning:
 *	This check was useful in times of Windows98 where WinSock may
 *	not be available. This is not the case any more.
 *	This function may be removed with TCL 9.0
 *
 * Results:
 *	1 if it is.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

    /* ARGSUSED */
static int
SocketsEnabled(void)
{
    int enabled;

    Tcl_MutexLock(&socketMutex);
    enabled = (initialized == 1);
    Tcl_MutexUnlock(&socketMutex);
    return enabled;
}


/*
 *----------------------------------------------------------------------
 *
 * SocketExitHandler --
 *
 *	Callback invoked during exit clean up to delete the socket
 *	communication window and to release the WinSock DLL.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

    /* ARGSUSED */
static void
SocketExitHandler(
    ClientData clientData)		/* Not used. */
{
    Tcl_MutexLock(&socketMutex);

    /*
     * Make sure the socket event handling window is cleaned-up for, at
     * most, this thread.
     */

    TclpFinalizeSockets();
    UnregisterClass(classname, TclWinGetTclInstance());
    WSACleanup();
    initialized = 0;
    Tcl_MutexUnlock(&socketMutex);
}

/*
 *----------------------------------------------------------------------
 *
 * SocketSetupProc --
 *
 *	This function is invoked before Tcl_DoOneEvent blocks waiting for an
 *	event.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Adjusts the block time if needed.
 *
 *----------------------------------------------------------------------
 */

void
SocketSetupProc(
    ClientData data,		/* Not used. */
    int flags)			/* Event flags as passed to Tcl_DoOneEvent. */
{
    TcpState *statePtr;
    Tcl_Time blockTime = { 0, 0 };
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    if (!(flags & TCL_FILE_EVENTS)) {
	return;
    }

    /*
     * Check to see if there is a ready socket.	 If so, poll.
     */
    WaitForSingleObject(tsdPtr->socketListLock, INFINITE);
    for (statePtr = tsdPtr->socketList; statePtr != NULL;
	    statePtr = statePtr->nextPtr) {
	if (statePtr->readyEvents &
	    (statePtr->watchEvents | FD_CONNECT | FD_ACCEPT)
	) {
	    Tcl_SetMaxBlockTime(&blockTime);
	    break;
	}
    }
    SetEvent(tsdPtr->socketListLock);
}

/*
 *----------------------------------------------------------------------
 *
 * SocketCheckProc --
 *
 *	This function is called by Tcl_DoOneEvent to check the socket event
 *	source for events.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	May queue an event.
 *
 *----------------------------------------------------------------------
 */

static void
SocketCheckProc(
    ClientData data,		/* Not used. */
    int flags)			/* Event flags as passed to Tcl_DoOneEvent. */
{
    TcpState *statePtr;
    SocketEvent *evPtr;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    if (!(flags & TCL_FILE_EVENTS)) {
	return;
    }

    /*
     * Queue events for any ready sockets that don't already have events
     * queued (caused by persistent states that won't generate WinSock
     * events).
     */

    WaitForSingleObject(tsdPtr->socketListLock, INFINITE);
    for (statePtr = tsdPtr->socketList; statePtr != NULL;
	    statePtr = statePtr->nextPtr) {
	if ((statePtr->readyEvents &
		(statePtr->watchEvents | FD_CONNECT | FD_ACCEPT))
	    && !(statePtr->flags & SOCKET_PENDING)
	) {
	    statePtr->flags |= SOCKET_PENDING;
	    evPtr = ckalloc(sizeof(SocketEvent));
	    evPtr->header.proc = SocketEventProc;
	    evPtr->socket = statePtr->sockets->fd;
	    Tcl_QueueEvent((Tcl_Event *) evPtr, TCL_QUEUE_TAIL);
	}
    }
    SetEvent(tsdPtr->socketListLock);
}

/*
 *----------------------------------------------------------------------
 *
 * SocketEventProc --
 *
 *	This function is called by Tcl_ServiceEvent when a socket event
 *	reaches the front of the event queue. This function is responsible for
 *	notifying the generic channel code.
 *
 * Results:
 *	Returns 1 if the event was handled, meaning it should be removed from
 *	the queue. Returns 0 if the event was not handled, meaning it should
 *	stay on the queue. The only time the event isn't handled is if the
 *	TCL_FILE_EVENTS flag bit isn't set.
 *
 * Side effects:
 *	Whatever the channel callback functions do.
 *
 *----------------------------------------------------------------------
 */

static int
SocketEventProc(
    Tcl_Event *evPtr,		/* Event to service. */
    int flags)			/* Flags that indicate what events to handle,
				 * such as TCL_FILE_EVENTS. */
{
    TcpState *statePtr;
    SocketEvent *eventPtr = (SocketEvent *) evPtr;
    int mask = 0, events;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
    TcpFdList *fds;
    SOCKET newSocket;
    address addr;
    int len;

    if (!(flags & TCL_FILE_EVENTS)) {
	return 0;
    }

    /*
     * Find the specified socket on the socket list.
     */

    WaitForSingleObject(tsdPtr->socketListLock, INFINITE);
    for (statePtr = tsdPtr->socketList; statePtr != NULL;
	    statePtr = statePtr->nextPtr) {
	if (statePtr->sockets->fd == eventPtr->socket) {
	    break;
	}
    }

    /*
     * Discard events that have gone stale.
     */

    if (!statePtr) {
        SetEvent(tsdPtr->socketListLock);
	return 1;
    }

    /*
     * Clear flag that (this) event is pending
     */

    statePtr->flags &= ~SOCKET_PENDING;

    /*
     * Continue async connect if pending and ready
     */

    if ( statePtr->readyEvents & FD_CONNECT ) {
	if ( statePtr->flags & TCP_ASYNC_PENDING ) {

	    /*
	     * Do one step and save eventual connect error
	     */

	    SetEvent(tsdPtr->socketListLock);
	    WaitForConnect(statePtr,NULL);

	} else {
	    
	    /*
	     * No async connect reenter pending. Just clear event.
	     */

	    statePtr->readyEvents &= ~(FD_CONNECT);
	    SetEvent(tsdPtr->socketListLock);
	}
	return 1;
    }

    /*
     * Handle connection requests directly.
     */
    if (statePtr->readyEvents & FD_ACCEPT) {
	for (fds = statePtr->sockets; fds != NULL; fds = fds->next) {

	    /*
	    * Accept the incoming connection request.
	    */
	    len = sizeof(address);

	    newSocket = accept(fds->fd, &(addr.sa), &len);

	    /* On Tcl server sockets with multiple OS fds we loop over the fds trying
	     * an accept() on each, so we expect INVALID_SOCKET.  There are also other
	     * network stack conditions that can result in FD_ACCEPT but a subsequent
	     * failure on accept() by the time we get around to it.
	     * Access to sockets (acceptEventCount, readyEvents) in socketList
	     * is still protected by the lock (prevents reintroduction of 
	     * SF Tcl Bug 3056775.
	     */

	    if (newSocket == INVALID_SOCKET) {
		/* int err = WSAGetLastError(); */
		continue;
	    }

	    /*
	     * It is possible that more than one FD_ACCEPT has been sent, so an extra
	     * count must be kept. Decrement the count, and reset the readyEvent bit
	     * if the count is no longer > 0.
	     */
	    statePtr->acceptEventCount--;

	    if (statePtr->acceptEventCount <= 0) {
		statePtr->readyEvents &= ~(FD_ACCEPT);
	    }

	    SetEvent(tsdPtr->socketListLock);

	    /* Caution: TcpAccept() has the side-effect of evaluating the server
	     * accept script (via AcceptCallbackProc() in tclIOCmd.c), which can
	     * close the server socket and invalidate statePtr and fds.
	     * If TcpAccept() accepts a socket we must return immediately and let
	     * SocketCheckProc queue additional FD_ACCEPT events.
	     */
	    TcpAccept(fds, newSocket, addr);
	    return 1;
	}

	/* Loop terminated with no sockets accepted; clear the ready mask so 
	 * we can detect the next connection request. Note that connection 
	 * requests are level triggered, so if there is a request already 
	 * pending, a new event will be generated.
	 */
	statePtr->acceptEventCount = 0;
	statePtr->readyEvents &= ~(FD_ACCEPT);

	SetEvent(tsdPtr->socketListLock);
	return 1;
    }

    SetEvent(tsdPtr->socketListLock);

    /*
     * Mask off unwanted events and compute the read/write mask so we can
     * notify the channel.
     */

    events = statePtr->readyEvents & statePtr->watchEvents;

    if (events & FD_CLOSE) {
	/*
	 * If the socket was closed and the channel is still interested in
	 * read events, then we need to ensure that we keep polling for this
	 * event until someone does something with the channel. Note that we
	 * do this before calling Tcl_NotifyChannel so we don't have to watch
	 * out for the channel being deleted out from under us. This may cause
	 * a redundant trip through the event loop, but it's simpler than
	 * trying to do unwind protection.
	 */

	Tcl_Time blockTime = { 0, 0 };

	Tcl_SetMaxBlockTime(&blockTime);
	mask |= TCL_READABLE|TCL_WRITABLE;
    } else if (events & FD_READ) {

	/*
	 * Throw the readable event if an async connect failed.
	 */

	if ( statePtr->flags & TCP_ASYNC_FAILED ) {

	    mask |= TCL_READABLE;
	    
	} else {
	    fd_set readFds;
	    struct timeval timeout;

	    /*
	     * We must check to see if data is really available, since someone
	     * could have consumed the data in the meantime. Turn off async
	     * notification so select will work correctly. If the socket is
	     * still readable, notify the channel driver, otherwise reset the
	     * async select handler and keep waiting.
	     */

	    SendMessage(tsdPtr->hwnd, SOCKET_SELECT,
		    (WPARAM) UNSELECT, (LPARAM) statePtr);

	    FD_ZERO(&readFds);
	    FD_SET(statePtr->sockets->fd, &readFds);
	    timeout.tv_usec = 0;
	    timeout.tv_sec = 0;

	    if (select(0, &readFds, NULL, NULL, &timeout) != 0) {
		mask |= TCL_READABLE;
	    } else {
		statePtr->readyEvents &= ~(FD_READ);
		SendMessage(tsdPtr->hwnd, SOCKET_SELECT,
			(WPARAM) SELECT, (LPARAM) statePtr);
	    }
	}
    }

    /*
     * writable event
     */

    if (events & FD_WRITE) {
	mask |= TCL_WRITABLE;
    }
    
    /*
     * Call registered event procedures
     */
     
    if (mask) {
	Tcl_NotifyChannel(statePtr->channel, mask);
    }
    return 1;
}

/*
 *----------------------------------------------------------------------
 *
 * AddSocketInfoFd --
 *
 *	This function adds a SOCKET file descriptor to the 'sockets' linked 
 *	list of a TcpState structure.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None, except for allocation of memory.
 *
 *----------------------------------------------------------------------
 */

static void
AddSocketInfoFd(
    TcpState *statePtr, 
    SOCKET socket)
{
    TcpFdList *fds = statePtr->sockets;

    if ( fds == NULL ) {
	/* Add the first FD */
	statePtr->sockets = ckalloc(sizeof(TcpFdList));
	fds = statePtr->sockets;
    } else {
	/* Find end of list and append FD */
	while ( fds->next != NULL ) {
	    fds = fds->next;
	}
    
	fds->next = ckalloc(sizeof(TcpFdList));
	fds = fds->next;
    }

    /* Populate new FD */
    fds->fd = socket;
    fds->statePtr = statePtr;
    fds->next = NULL;
}

    
/*
 *----------------------------------------------------------------------
 *
 * NewSocketInfo --
 *
 *	This function allocates and initializes a new TcpState structure.
 *
 * Results:
 *	Returns a newly allocated TcpState.
 *
 * Side effects:
 *	None, except for allocation of memory.
 *
 *----------------------------------------------------------------------
 */

static TcpState *
NewSocketInfo(SOCKET socket)
{
    TcpState *statePtr = ckalloc(sizeof(TcpState));

    memset(statePtr, 0, sizeof(TcpState));

    /*
     * TIP #218. Removed the code inserting the new structure into the global
     * list. This is now handled in the thread action callbacks, and only
     * there.
     */

    AddSocketInfoFd(statePtr, socket);

    return statePtr;
}

/*
 *----------------------------------------------------------------------
 *
 * WaitForSocketEvent --
 *
 *	Waits until one of the specified events occurs on a socket.
 *	For event FD_CONNECT use WaitForConnect.
 *
 * Results:
 *	Returns 1 on success or 0 on failure, with an error code in
 *	errorCodePtr.
 *
 * Side effects:
 *	Processes socket events off the system queue.
 *
 *----------------------------------------------------------------------
 */

static int
WaitForSocketEvent(
    TcpState *statePtr,	/* Information about this socket. */
    int events,			/* Events to look for. May be one of
				 * FD_READ or FD_WRITE.
				 */
    int *errorCodePtr)		/* Where to store errors? */
{
    int result = 1;
    int oldMode;
    ThreadSpecificData *tsdPtr = TclThreadDataKeyGet(&dataKey);
    /*
     * Be sure to disable event servicing so we are truly modal.
     */

    oldMode = Tcl_SetServiceMode(TCL_SERVICE_NONE);

    /*
     * Reset WSAAsyncSelect so we have a fresh set of events pending.
     */

    SendMessage(tsdPtr->hwnd, SOCKET_SELECT, (WPARAM) UNSELECT,
	    (LPARAM) statePtr);
    SendMessage(tsdPtr->hwnd, SOCKET_SELECT, (WPARAM) SELECT,
	    (LPARAM) statePtr);

    while (1) {
	int event_found;

	/* get statePtr lock */
	WaitForSingleObject(tsdPtr->socketListLock, INFINITE);
	
	/* Check if event occured */
	event_found = (statePtr->readyEvents & events);

	/* Free list lock */
	SetEvent(tsdPtr->socketListLock);

	/* exit loop if event occured */
	if (event_found) {
	    break;
	}
	
	/* Exit loop if event did not occur but this is a non-blocking channel */
	if (statePtr->flags & TCP_NONBLOCKING) {
	    *errorCodePtr = EWOULDBLOCK;
	    result = 0;
	    break;
	}

	/*
	 * Wait until something happens.
	 */

	WaitForSingleObject(tsdPtr->readyEvent, INFINITE);
    }

    (void) Tcl_SetServiceMode(oldMode);
    return result;
}

/*
 *----------------------------------------------------------------------
 *
 * SocketThread --
 *
 *	Helper thread used to manage the socket event handling window.

    HWND hwnd,
    UINT message,
    WPARAM wParam,
    LPARAM lParam)
{
    int event, error;
    SOCKET socket;
    TcpState *statePtr;
    int info_found = 0;
    TcpFdList *fds = NULL;
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)
#ifdef _WIN64
	    GetWindowLongPtr(hwnd, GWLP_USERDATA);
#else
	    GetWindowLong(hwnd, GWL_USERDATA);
#endif

	break;

    case SOCKET_MESSAGE:
	event = WSAGETSELECTEVENT(lParam);
	error = WSAGETSELECTERROR(lParam);
	socket = (SOCKET) wParam;

	WaitForSingleObject(tsdPtr->socketListLock, INFINITE);

	/*
	 * Find the specified socket on the socket list and update its
	 * eventState flag.
	 */


	for (statePtr = tsdPtr->socketList; statePtr != NULL;
		statePtr = statePtr->nextPtr) {
	    if ( FindFDInList(statePtr,socket) ) {
		info_found = 1;
		break;
	    }
	}
	/*
	 * Check if there is a pending info structure not jet in the
	 * list
	 */
	if ( !info_found
		&& tsdPtr->pendingTcpState != NULL
		&& FindFDInList(tsdPtr->pendingTcpState,socket) ) {
	    statePtr = tsdPtr->pendingTcpState;
	    info_found = 1;
	}
	if (info_found) {

	    /*
	     * Update the socket state.
	     *
	     * A count of FD_ACCEPTS is stored, so if an FD_CLOSE event
	     * happens, then clear the FD_ACCEPT count. Otherwise,
	     * increment the count if the current event is an FD_ACCEPT.
	     */

	    if (event & FD_CLOSE) {
		statePtr->acceptEventCount = 0;
		statePtr->readyEvents &= ~(FD_WRITE|FD_ACCEPT);
	    } else if (event & FD_ACCEPT) {
		statePtr->acceptEventCount++;
	    }

	    if (event & FD_CONNECT) {
		/*







		 * Remember any error that occurred so we can report
		 * connection failures.
		 */

		if (error != ERROR_SUCCESS) {

		    statePtr->notifierConnectError = error;
		}
	    }
	    /*






	     * Inform main thread about signaled events

	     */
	    statePtr->readyEvents |= event;

	    /*
	     * Wake up the Main Thread.
	     */

	    SetEvent(tsdPtr->readyEvent);
	    Tcl_ThreadAlert(tsdPtr->threadId);



	}
	SetEvent(tsdPtr->socketListLock);
	break;

    case SOCKET_SELECT:
	statePtr = (TcpState *) lParam;
	for (fds = statePtr->sockets; fds != NULL; fds = fds->next) {

	    if (wParam == SELECT) {
		WSAAsyncSelect(fds->fd, hwnd,
			SOCKET_MESSAGE, statePtr->selectEvents);
	    } else {
		/*
		 * Clear the selection mask
		 */

		WSAAsyncSelect(fds->fd, hwnd, 0, 0);
	    }

    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * FindFDInList --
 *
 *	Return true, if the given file descriptior is contained in the
 *	file descriptor list.
 *
 * Results:

 *	true if found.
 *
 * Side effects:

 *
 *----------------------------------------------------------------------
 */






























static int




FindFDInList(

    TcpState *statePtr,


    SOCKET socket)




{
    TcpFdList *fds;
    for (fds = statePtr->sockets; fds != NULL; fds = fds->next) {





	if (fds->fd == socket) {

	    return 1;
	}
    }
    return 0;





}

/*
 *----------------------------------------------------------------------
 *
 * TclWinGetSockOpt, et al. --
 *
 *	These functions are wrappers that let us bind the WinSock API
 *	dynamically so we can run on systems that don't have the wsock32.dll.
 *	We need wrappers for these interfaces because they are called from the
 *	generic Tcl code.
 *	Those functions are exported by the stubs table.
 *
 * Warning:
 *	Those functions are depreciated and will be removed with TCL 9.0.
 *
 * Results:
 *	As defined for each function.
 *
 * Side effects:
 *	As defined for each function.
 *

static void
TcpThreadActionProc(
    ClientData instanceData,
    int action)
{
    ThreadSpecificData *tsdPtr;
    TcpState *statePtr = instanceData;
    int notifyCmd;

    if (action == TCL_CHANNEL_THREAD_INSERT) {
	/*
	 * Ensure that socket subsystem is initialized in this thread, or else
	 * sockets will not work.
	 */

	Tcl_MutexLock(&socketMutex);
	InitSockets();
	Tcl_MutexUnlock(&socketMutex);

	tsdPtr = TCL_TSD_INIT(&dataKey);

	WaitForSingleObject(tsdPtr->socketListLock, INFINITE);
	statePtr->nextPtr = tsdPtr->socketList;
	tsdPtr->socketList = statePtr;
	
	if (statePtr == tsdPtr->pendingTcpState) {
	    tsdPtr->pendingTcpState = NULL;
	}
	
	SetEvent(tsdPtr->socketListLock);

	notifyCmd = SELECT;
    } else {
	TcpState **nextPtrPtr;
	int removed = 0;

	tsdPtr = TCL_TSD_INIT(&dataKey);

	/*
	 * TIP #218, Bugfix: All access to socketList has to be protected by
	 * the lock.
	 */

	WaitForSingleObject(tsdPtr->socketListLock, INFINITE);
	for (nextPtrPtr = &(tsdPtr->socketList); (*nextPtrPtr) != NULL;
		nextPtrPtr = &((*nextPtrPtr)->nextPtr)) {
	    if ((*nextPtrPtr) == statePtr) {
		(*nextPtrPtr) = statePtr->nextPtr;
		removed = 1;
		break;
	    }
	}
	SetEvent(tsdPtr->socketListLock);

	/*

    /*
     * Ensure that, or stop, notifications for the socket occur in this
     * thread.
     */

    SendMessage(tsdPtr->hwnd, SOCKET_SELECT,
	    (WPARAM) notifyCmd, (LPARAM) statePtr);
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 */