Python socket.MSG_DONTWAIT Examples

def test_flags(self):
        """
        The C{flags} argument to L{send1msg} is passed on to the underlying
        C{sendmsg} call, to affect it in whatever way is defined by those
        flags.
        """
        # Just exercise one flag with simple, well-known behavior. MSG_DONTWAIT
        # makes the send a non-blocking call, even if the socket is in blocking
        # mode.  See also test_flags in RecvmsgTests
        for i in range(8 * 1024):
            try:
                send1msg(self.input.fileno(), "x" * 1024, MSG_DONTWAIT)
            except error as e:
                self.assertEqual(e.args[0], errno.EAGAIN)
                break
        else:
            self.fail(
                "Failed to fill up the send buffer, "
                "or maybe send1msg blocked for a while") 

def _read(self):
        #read until the client is stopped or the client disconnects
        while self._connected:
            #read data from Bluetooth socket
            try:
                data = self._client_sock.recv(1024, socket.MSG_DONTWAIT)
            except IOError as e:
                self._handle_bt_error(e)
                data = b""
            if data:
                #print("received [%s]" % data)
                if self._data_received_callback:
                    if self._encoding:
                        data = data.decode(self._encoding)
                    self.data_received_callback(data)
            if self._conn_thread.stopping.wait(BLUETOOTH_TIMEOUT):
                break 

def _read(self):
        #read until the server is stopped or the client disconnects
        while self._client_connected:
            #read data from Bluetooth socket
            try:
                data = self._client_sock.recv(1024, socket.MSG_DONTWAIT)
            except IOError as e:
                self._handle_bt_error(e)
                data = b""
            if data:
                if self._data_received_callback:
                    if self._encoding:
                        data = data.decode(self._encoding)
                    self.data_received_callback(data)
            if self._conn_thread.stopping.wait(BLUETOOTH_TIMEOUT):
                break

        #close the client socket
        self._client_sock.close()
        self._client_sock = None
        self._client_info = None
        self._client_connected = False 

def test_flags(self):
        """
        The C{flags} argument to L{sendmsg} is passed on to the underlying
        C{sendmsg} call, to affect it in whatever way is defined by those
        flags.
        """
        # Just exercise one flag with simple, well-known behavior. MSG_DONTWAIT
        # makes the send a non-blocking call, even if the socket is in blocking
        # mode.  See also test_flags in RecvmsgTests
        for i in range(8 * 1024):
            try:
                sendmsg(self.input, b"x" * 1024, flags=MSG_DONTWAIT)
            except error as e:
                self.assertEqual(e.args[0], errno.EAGAIN)
                break
        else:
            self.fail(
                "Failed to fill up the send buffer, "
                "or maybe send1msg blocked for a while") 

def test_flags(self):
        """
        The C{flags} argument to L{sendmsg} is passed on to the underlying
        C{sendmsg} call, to affect it in whatever way is defined by those
        flags.
        """
        # Just exercise one flag with simple, well-known behavior. MSG_DONTWAIT
        # makes the send a non-blocking call, even if the socket is in blocking
        # mode.  See also test_flags in RecvmsgTests
        for i in range(1024):
            try:
                sendmsg(self.input, b"x" * 1024, flags=MSG_DONTWAIT)
            except error as e:
                self.assertEqual(e.args[0], errno.EAGAIN)
                break
        else:
            self.fail(
                "Failed to fill up the send buffer, "
                "or maybe send1msg blocked for a while") 

def test_flags(self):
        """
        The C{flags} argument to L{send1msg} is passed on to the underlying
        C{sendmsg} call, to affect it in whatever way is defined by those
        flags.
        """
        # Just exercise one flag with simple, well-known behavior. MSG_DONTWAIT
        # makes the send a non-blocking call, even if the socket is in blocking
        # mode.  See also test_flags in RecvmsgTests
        for i in range(1024):
            try:
                send1msg(self.input.fileno(), "x" * 1024, MSG_DONTWAIT)
            except error as e:
                self.assertEqual(e.args[0], errno.EAGAIN)
                break
        else:
            self.fail(
                "Failed to fill up the send buffer, "
                "or maybe send1msg blocked for a while") 

def sendto(self, msg, address):
        if (self.sock.getsockname(), address) not in self.isolations:
            self.lg.debug("{} - [{}] --> {}".format(self.sock.getsockname(), msg, address))
            try:
                return self.sock.sendto(msg, socket.MSG_DONTWAIT, address)
            except ConnectionRefusedError:
                self.lg.warning(
                    "simulator_stuff.sendto: the message {} has not been \
                     delivered because the destination {} left the team".format(
                        msg, address))
            except KeyboardInterrupt:
                self.lg.warning("simulator_stuff.sendto: send_packet {} to {}".format(msg, address))
                raise
            except FileNotFoundError:
                self.lg.error("simulator_stuff.sendto: {}".format(address))
                raise
            except BlockingIOError:
                raise
        else:
            self.lg.warning("{} not sent from {} to {} (isolated)".format(msg, self.sock.getsockname(), address)) 

def _testSendmsgTimeout(self):
        try:
            self.cli_sock.settimeout(0.03)
            with self.assertRaises(socket.timeout):
                while True:
                    self.sendmsgToServer([b"a"*512])
        finally:
            self.misc_event.set()

    # XXX: would be nice to have more tests for sendmsg flags argument.

    # Linux supports MSG_DONTWAIT when sending, but in general, it
    # only works when receiving.  Could add other platforms if they
    # support it too. 

def testSendmsgDontWait(self):
        # Check that MSG_DONTWAIT in flags causes non-blocking behaviour.
        self.assertEqual(self.serv_sock.recv(512), b"a"*512)
        self.assertTrue(self.misc_event.wait(timeout=self.fail_timeout)) 

def _testSendmsgDontWait(self):
        try:
            with self.assertRaises(OSError) as cm:
                while True:
                    self.sendmsgToServer([b"a"*512], [], socket.MSG_DONTWAIT)
            self.assertIn(cm.exception.errno,
                          (errno.EAGAIN, errno.EWOULDBLOCK))
        finally:
            self.misc_event.set() 

def process(self):
    """Without blocking, read available packets and invoke their callbacks."""
    data = self.socket.recv(BUFFER_SIZE, socket.MSG_DONTWAIT)
    buf = ctypes.create_string_buffer(data)
    nfq.nfq_handle_packet(self.handle, buf, len(data)) 

def read_ha_proxy_stats(haproxy_stats_socket):
    conn = socket(AF_UNIX, SOCK_STREAM)
    try:
        conn.connect(haproxy_stats_socket)
        conn.sendall(b'show stat\r\n')
        data = conn.recv(BUFFER_SIZE)
        while len(data) % BUFFER_SIZE == 0:
            try:
                data += conn.recv(BUFFER_SIZE, MSG_DONTWAIT)
            except socket.error:
                break
        return data
    finally:
        conn.close() 

def test_flags(self):
        """
        The C{flags} argument to L{recv1msg} is passed on to the underlying
        C{recvmsg} call, to affect it in whatever way is defined by those
        flags.
        """
        # See test_flags in SendmsgTests
        reader, writer = socketpair(AF_UNIX)
        exc = self.assertRaises(
            error, recv1msg, reader.fileno(), MSG_DONTWAIT)
        self.assertEqual(exc.args[0], errno.EAGAIN) 

def _send(self, sock, data):
        sock.sendall(data, socket.MSG_DONTWAIT) 

def _testSendmsgTimeout(self):
        try:
            self.cli_sock.settimeout(0.03)
            with self.assertRaises(socket.timeout):
                while True:
                    self.sendmsgToServer([b"a"*512])
        finally:
            self.misc_event.set()

    # XXX: would be nice to have more tests for sendmsg flags argument.

    # Linux supports MSG_DONTWAIT when sending, but in general, it
    # only works when receiving.  Could add other platforms if they
    # support it too. 

def testSendmsgDontWait(self):
        # Check that MSG_DONTWAIT in flags causes non-blocking behaviour.
        self.assertEqual(self.serv_sock.recv(512), b"a"*512)
        self.assertTrue(self.misc_event.wait(timeout=self.fail_timeout)) 

def _testSendmsgDontWait(self):
        try:
            with self.assertRaises(OSError) as cm:
                while True:
                    self.sendmsgToServer([b"a"*512], [], socket.MSG_DONTWAIT)
            self.assertIn(cm.exception.errno,
                          (errno.EAGAIN, errno.EWOULDBLOCK))
        finally:
            self.misc_event.set() 

def try_recv(self):
        """Return None immediately if nothing is waiting"""
        try:
            lenstr = self.sock.recv(4, socket.MSG_DONTWAIT)
        except socket.error:
            return None
        if len(lenstr) < 4:
            raise EOFError("Socket closed")
        length = struct.unpack("<I", lenstr)[0]
        return self._get_next_obj(length) 

def _testSendmsgTimeout(self):
        try:
            self.cli_sock.settimeout(0.03)
            with self.assertRaises(socket.timeout):
                while True:
                    self.sendmsgToServer([b"a"*512])
        finally:
            self.misc_event.set()

    # XXX: would be nice to have more tests for sendmsg flags argument.

    # Linux supports MSG_DONTWAIT when sending, but in general, it
    # only works when receiving.  Could add other platforms if they
    # support it too. 

def testSendmsgDontWait(self):
        # Check that MSG_DONTWAIT in flags causes non-blocking behaviour.
        self.assertEqual(self.serv_sock.recv(512), b"a"*512)
        self.assertTrue(self.misc_event.wait(timeout=self.fail_timeout)) 

def _testSendmsgDontWait(self):
        try:
            with self.assertRaises(OSError) as cm:
                while True:
                    self.sendmsgToServer([b"a"*512], [], socket.MSG_DONTWAIT)
            self.assertIn(cm.exception.errno,
                          (errno.EAGAIN, errno.EWOULDBLOCK))
        finally:
            self.misc_event.set() 

def test_flags(self):
        """
        The C{flags} argument to L{recv1msg} is passed on to the underlying
        C{recvmsg} call, to affect it in whatever way is defined by those
        flags.
        """
        # See test_flags in SendmsgTests
        reader, writer = socketpair(AF_UNIX)
        exc = self.assertRaises(
            error, recv1msg, reader.fileno(), MSG_DONTWAIT)
        self.assertEqual(exc.args[0], errno.EAGAIN) 

def sendto(self, msg, address):

        self.lg.debug(f"{self.sock.getsockname()} - [{msg}] --> {address}")
        try:
            return self.sock.sendto(msg, socket.MSG_DONTWAIT, address)
        except ConnectionRefusedError:
            self.lg.error("sendto: connection refused from {address}")
        except KeyboardInterrupt:
            self.lg.warning("sendto: keyboard interrupt")
            raise
        except FileNotFoundError:
            self.lg.error("sendto: file not found")
            raise
        except BlockingIOError:
            raise