Windows support and minor touchups to the documentation.

2 files changed, 14 insertions, 5 deletions

diff --git a/doc/socket.n b/doc/socket.n
index 532ea2e..823dbd5 100644
--- a/doc/socket.n
+++ b/doc/socket.n
@@ -140,7 +140,7 @@ actively listening on it. This is the default on Windows.
 \fB\-reuseport\fI boolean\fR
 .
 Tells the kernel whether to allow the binding of multiple sockets to the same
-address and port as long as all of them specify the \fB-reuseport\fR option.
+address and port.
 .PP
 Server channels cannot be used for input or output; their sole use is to
 accept new client connections. The channels created for each incoming
diff --git a/win/tclWinSock.c b/win/tclWinSock.c
index b228730..af22cf8 100644
--- a/win/tclWinSock.c
+++ b/win/tclWinSock.c
@@ -2039,7 +2039,7 @@ Tcl_OpenTcpServerEx(
     Tcl_Interp *interp,		/* For error reporting - may be NULL. */
     int port,			/* Port number to open. */
     const char *myHost,		/* Name of local host. */
-    unsigned int flags,		/* Flags (not used) */
+    unsigned int flags,		/* Flags. */
     Tcl_TcpAcceptProc *acceptProc,
 				/* Callback for accepting connections from new
 				 * clients. */
@@ -2053,6 +2053,7 @@ Tcl_OpenTcpServerEx(
     char channelName[SOCK_CHAN_LENGTH];
     u_long flag = 1;		/* Indicates nonblocking mode. */
     const char *errorMsg = NULL;
+    int optvalue;
 
     if (TclpHasSockets(interp) != TCL_OK) {
 	return NULL;
@@ -2111,9 +2112,17 @@ Tcl_OpenTcpServerEx(
 	}
 
 	/*
-	 * Bind to the specified port. Note that we must not call
-	 * setsockopt with SO_REUSEADDR or SO_REUSEPORT because Microsoft
-	 * allows addresses and ports to be reused even if they are still in use.
+	 * The SO_REUSEADDR option on Windows behaves like SO_REUSEPORT on unix
+	 * systems.
+	 */
+	if (flags & TCL_TCPSERVER_REUSEPORT) {
+	    optvalue = 1;
+	    (void) setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
+			      (char *) &optvalue, sizeof(optvalue));
+	}
+
+	/*
+	 * Bind to the specified port.
 	 *
 	 * Bind should not be affected by the socket having already been
 	 * set into nonblocking mode. If there is trouble, this is one