Patch #1003700: Add socketpair function to socket module.

Doc/lib/libsocket.tex

@@ -303,6 +303,14 @@ success, a new \class{SSLObject} is returned.
 \warning{This does not do any certificate verification!}
 \end{funcdesc}
 
+\begin{funcdesc}{socketpair}{\optional{family\optional{, type\optional{, proto}}}}
+Build a pair of connected socket objects using the given address
+family, socket type and protocol number.  Address family, socket type
+and protocol number are as for the \function{socket()} function above.
+Availability: \UNIX.
+\versionadded{2.3}
+\end{funcdesc}
+
 \begin{funcdesc}{fromfd}{fd, family, type\optional{, proto}}
 Build a socket object from an existing file descriptor (an integer as
 returned by a file object's \method{fileno()} method).  Address family,

Lib/socket.py

@@ -10,6 +10,7 @@ socket are available as methods of the socket object.
 Functions:
 
 socket() -- create a new socket object
+socketpair() -- create a pair of new socket objects [*]
 fromfd() -- create a socket object from an open file descriptor [*]
 gethostname() -- return the current hostname
 gethostbyname() -- map a hostname to its IP number

Lib/test/test_socket.py

@@ -187,6 +187,28 @@ class SocketConnectedTest(ThreadedTCPSocketTest):
         self.serv_conn = None
         ThreadedTCPSocketTest.clientTearDown(self)
 
+class SocketPairTest(unittest.TestCase, ThreadableTest):
+
+    def __init__(self, methodName='runTest'):
+        unittest.TestCase.__init__(self, methodName=methodName)
+        ThreadableTest.__init__(self)
+
+    def setUp(self):
+        self.serv, self.cli = socket.socketpair()
+
+    def tearDown(self):
+        self.serv.close()
+        self.serv = None
+
+    def clientSetUp(self):
+        pass
+
+    def clientTearDown(self):
+        self.cli.close()
+        self.cli = None
+        ThreadableTest.clientTearDown(self)
+
+    
 #######################################################################
 ## Begin Tests
 
@@ -541,6 +563,25 @@ class BasicUDPTest(ThreadedUDPSocketTest):
     def _testRecvFrom(self):
         self.cli.sendto(MSG, 0, (HOST, PORT))
 
+class BasicSocketPairTest(SocketPairTest):
+
+    def __init__(self, methodName='runTest'):
+        SocketPairTest.__init__(self, methodName=methodName)
+
+    def testRecv(self):
+        msg = self.serv.recv(1024)
+        self.assertEqual(msg, MSG)
+
+    def _testRecv(self):
+        self.cli.send(MSG)
+
+    def testSend(self):
+        self.serv.send(MSG)
+
+    def _testSend(self):
+        msg = self.cli.recv(1024)
+        self.assertEqual(msg, MSG)
+
 class NonBlockingTCPTests(ThreadedTCPSocketTest):
 
     def __init__(self, methodName='runTest'):
@@ -786,6 +827,8 @@ def test_main():
         LineBufferedFileObjectClassTestCase,
         SmallBufferedFileObjectClassTestCase
     ])
+    if hasattr(socket, "socketpair"):
+        tests.append(BasicSocketPairTest)
     test_support.run_unittest(*tests)
 
 if __name__ == "__main__":

Misc/NEWS

@@ -24,6 +24,8 @@ Core and builtins
 Extension modules
 -----------------
 
+- Added socket.socketpair().
+
 Library
 -------
 

Modules/socketmodule.c

@@ -28,6 +28,7 @@ Module interface:
 - socket.getservbyname(servicename[, protocolname]) --> port number
 - socket.getservbyport(portnumber[, protocolname]) --> service name
 - socket.socket([family[, type [, proto]]]) --> new socket object
+- socket.socketpair([family[, type [, proto]]]) --> (socket, socket)
 - socket.ntohs(16 bit value) --> new int object
 - socket.ntohl(32 bit value) --> new int object
 - socket.htons(16 bit value) --> new int object
@@ -3009,6 +3010,63 @@ PyDoc_STRVAR(getprotobyname_doc,
 Return the protocol number for the named protocol.  (Rarely used.)");
 
 
+#ifdef HAVE_SOCKETPAIR
+/* Create a pair of sockets using the socketpair() function.
+   Arguments as for socket(). */
+
+/*ARGSUSED*/
+static PyObject *
+socket_socketpair(PyObject *self, PyObject *args)
+{
+	PySocketSockObject *s0 = NULL, *s1 = NULL;
+	SOCKET_T sv[2];
+	int family, type = SOCK_STREAM, proto = 0;
+	PyObject *res = NULL;
+
+#if defined(AF_UNIX)
+	family = AF_UNIX;
+#else
+	family = AF_INET;
+#endif
+	if (!PyArg_ParseTuple(args, "|iii:socketpair",
+			      &family, &type, &proto))
+		return NULL;
+	/* Create a pair of socket fds */
+	if (socketpair(family, type, proto, sv) < 0)
+		return set_error();
+#ifdef SIGPIPE
+	(void) signal(SIGPIPE, SIG_IGN);
+#endif
+	s0 = new_sockobject(sv[0], family, type, proto);
+	if (s0 == NULL)
+		goto finally;
+	s1 = new_sockobject(sv[1], family, type, proto);
+	if (s1 == NULL)
+		goto finally;
+	res = PyTuple_Pack(2, s0, s1);
+
+finally:
+	if (res == NULL) {
+		if (s0 == NULL)
+			SOCKETCLOSE(sv[0]);
+		if (s1 == NULL)
+			SOCKETCLOSE(sv[1]);
+	}
+	Py_XDECREF(s0);
+	Py_XDECREF(s1);
+	return res;
+}
+
+PyDoc_STRVAR(socketpair_doc,
+"socketpair([family[, type[, proto]]]) -> (socket object, socket object)\n\
+\n\
+Create a pair of socket objects from the sockets returned by the platform\n\
+socketpair() function.\n\
+The arguments are the same as for socket().");
+
+#endif /* HAVE_SOCKETPAIR */
+
+
 #ifndef NO_DUP
 /* Create a socket object from a numeric file description.
    Useful e.g. if stdin is a socket.
@@ -3607,6 +3665,10 @@ static PyMethodDef socket_methods[] = {
 #ifndef NO_DUP
 	{"fromfd",		socket_fromfd,
 	 METH_VARARGS, fromfd_doc},
+#endif
+#ifdef HAVE_SOCKETPAIR
+	{"socketpair",		socket_socketpair,
+	 METH_VARARGS, socketpair_doc},
 #endif
 	{"ntohs",		socket_ntohs,
 	 METH_VARARGS, ntohs_doc},

configure.in

@@ -2468,6 +2468,17 @@ int foo(int x, ...) {
 ])
 AC_MSG_RESULT($works)
 
+# check for socketpair
+AC_MSG_CHECKING(for socketpair)
+AC_TRY_COMPILE([
+#include <sys/types.h>
+#include <sys/socket.h>
+], void *x=socketpair,
+  AC_DEFINE(HAVE_SOCKETPAIR, 1, Define if you have the 'socketpair' function.)
+  AC_MSG_RESULT(yes),
+  AC_MSG_RESULT(no)
+)
+
 # check if sockaddr has sa_len member
 AC_MSG_CHECKING(if sockaddr has sa_len member)
 AC_TRY_COMPILE([#include <sys/types.h>

pyconfig.h.in

@@ -428,6 +428,9 @@
 /* Define to 1 if you have the `snprintf' function. */
 #undef HAVE_SNPRINTF
 
+/* Define to 1 if you have the `socketpair' function. */
+#undef HAVE_SOCKETPAIR
+
 /* Define if sockaddr has sa_len member */
 #undef HAVE_SOCKADDR_SA_LEN