except ImportError:
import Queue as queue
import logging
+from . import vpp_papi
class VppTransportSocketIOError(IOError):
+ # TODO: Document different values of error number (first numeric argument).
pass
self.server_address = server_address
self.header = struct.Struct('>QII')
self.message_table = {}
+ # These queues can be accessed async.
+ # They are always up, but replaced on connect.
+ # TODO: Use multiprocessing.Pipe instead of multiprocessing.Queue
+ # if possible.
self.sque = multiprocessing.Queue()
self.q = multiprocessing.Queue()
- self.message_thread = threading.Thread(target=self.msg_thread_func)
+ # The following fields are set in connect().
+ self.message_thread = None
+ self.socket = None
def msg_thread_func(self):
while True:
2, 'Unknown response from select')
def connect(self, name, pfx, msg_handler, rx_qlen):
+ # TODO: Reorder the actions and add "roll-backs",
+ # to restore clean disconnect state when failure happens durng connect.
+
+ if self.message_thread is not None:
+ raise VppTransportSocketIOError(
+ 1, "PAPI socket transport connect: Need to disconnect first.")
# Create a UDS socket
self.socket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
raise
self.connected = True
+
+ # Queues' feeder threads from previous connect may still be sending.
+ # Close and join to avoid any errors.
+ self.sque.close()
+ self.q.close()
+ self.sque.join_thread()
+ self.q.join_thread()
+ # Finally safe to replace.
+ self.sque = multiprocessing.Queue()
+ self.q = multiprocessing.Queue()
+ self.message_thread = threading.Thread(target=self.msg_thread_func)
+
# Initialise sockclnt_create
sockclnt_create = self.parent.messages['sockclnt_create']
sockclnt_create_reply = self.parent.messages['sockclnt_create_reply']
msg = self._read()
hdr, length = self.parent.header.unpack(msg, 0)
if hdr.msgid != 16:
+ # TODO: Add first numeric argument.
raise VppTransportSocketIOError('Invalid reply message')
r, length = sockclnt_create_reply.unpack(msg)
self.socket_index = r.index
for m in r.message_table:
- n = m.name.rstrip(b'\x00\x13')
+ n = m.name
self.message_table[n] = m.index
self.message_thread.daemon = True
return 0
def disconnect(self):
+ # TODO: Support repeated disconnect calls, recommend users to call
+ # disconnect when they are not sure what the state is after failures.
+ # TODO: Any volunteer for comprehensive docstrings?
rv = 0
- try: # Might fail, if VPP closes socket before packet makes it out
+ try:
+ # Might fail, if VPP closes socket before packet makes it out,
+ # or if there was a failure during connect().
rv = self.parent.api.sockclnt_delete(index=self.socket_index)
- except IOError:
+ except (IOError, vpp_papi.VPPApiError):
pass
self.connected = False
- self.socket.close()
- self.sque.put(True) # Terminate listening thread
- self.message_thread.join()
+ if self.socket is not None:
+ self.socket.close()
+ if self.sque is not None:
+ self.sque.put(True) # Terminate listening thread
+ if self.message_thread is not None and self.message_thread.is_alive():
+ # Allow additional connect() calls.
+ self.message_thread.join()
+ # Wipe message table, VPP can be restarted with different plugins.
+ self.message_table = {}
+ # Collect garbage.
+ self.message_thread = None
+ self.socket = None
+ # Queues will be collected after connect replaces them.
return rv
def suspend(self):
# Send header
header = self.header.pack(0, len(buf), 0)
- n = self.socket.send(header)
- n = self.socket.send(buf)
+ try:
+ self.socket.sendall(header)
+ self.socket.sendall(buf)
+ except socket.error as err:
+ raise VppTransportSocketIOError(1, 'Sendall error: {err!r}'.format(
+ err=err))
+
+ def _read_fixed(self, size):
+ """Repeat receive until fixed size is read. Return empty on error."""
+ buf = bytearray(size)
+ view = memoryview(buf)
+ left = size
+ while 1:
+ got = self.socket.recv_into(view, left)
+ if got <= 0:
+ # Read error.
+ return ""
+ if got >= left:
+ # TODO: Raise if got > left?
+ break
+ left -= got
+ view = view[got:]
+ return buf
def _read(self):
- hdr = self.socket.recv(16)
+ """Read single complete message, return it or empty on error."""
+ hdr = self._read_fixed(16)
if not hdr:
return
- (_, l, _) = self.header.unpack(hdr) # If at head of message
+ (_, hdrlen, _) = self.header.unpack(hdr) # If at head of message
# Read rest of message
- msg = self.socket.recv(l)
- if l > len(msg):
- nbytes = len(msg)
- buf = bytearray(l)
- view = memoryview(buf)
- view[:nbytes] = msg
- view = view[nbytes:]
- left = l - nbytes
- while left:
- nbytes = self.socket.recv_into(view, left)
- view = view[nbytes:]
- left -= nbytes
- return buf
- if l == len(msg):
+ msg = self._read_fixed(hdrlen)
+ if hdrlen == len(msg):
return msg
- raise VPPTransportSocketIOError(1, 'Unknown socket read error')
+ raise VppTransportSocketIOError(1, 'Unknown socket read error')
- def read(self):
+ def read(self, timeout=None):
if not self.connected:
raise VppTransportSocketIOError(1, 'Not connected')
+ if timeout is None:
+ timeout = self.read_timeout
try:
- return self.q.get(True, self.read_timeout)
+ return self.q.get(True, timeout)
except queue.Empty:
return None
Code Review / vpp.git / blobdiff