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Commit 29660883 authored by Jim Fulton's avatar Jim Fulton
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Removed unneeded zrpc.client 

Removed an odd test that tested for an implementation-specific
(afaict) regression.
parent 07d258d1
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src/ZEO/tests/testZEO.py
View file @ 29660883
......@@ -1488,31 +1488,6 @@ def quick_close_doesnt_kill_server():
>>> db.close()
"""
def sync_connect_doesnt_hang():
r"""
>>> import threading
>>> import ZEO.zrpc.client
>>> ConnectThread = ZEO.zrpc.client.ConnectThread
>>> ZEO.zrpc.client.ConnectThread = lambda *a, **kw: threading.Thread()
>>> class CM(ZEO.zrpc.client.ConnectionManager):
... sync_wait = 1
... _start_asyncore_loop = lambda self: None
>>> cm = CM(('', 0), object())
Calling connect results in an exception being raised, instead of hanging
indefinitely when the thread dies without setting up the connection.
>>> cm.connect(sync=1)
Traceback (most recent call last):
...
AssertionError
>>> cm.thread.isAlive()
False
>>> ZEO.zrpc.client.ConnectThread = ConnectThread
"""
def can_use_empty_string_for_local_host_on_client():
"""We should be able to spell localhost with ''.
......
src/ZEO/zrpc/client.py deleted 100644 → 0
View file @ 07d258d1
##############################################################################
#
# Copyright (c) 2001, 2002 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE
#
##############################################################################
import asyncore
import errno
import logging
import select
import socket
import sys
import threading
import time
import ZEO.zrpc.trigger
from ZEO.zrpc.connection import ManagedClientConnection
from ZEO.zrpc.log import log
from ZEO.zrpc.error import DisconnectedError
from ZODB.POSException import ReadOnlyError
from ZODB.loglevels import BLATHER
from six.moves import map
from six.moves import zip
def client_timeout():
return 30.0
def client_loop(map):
read = asyncore.read
write = asyncore.write
_exception = asyncore._exception
while map:
try:
# The next two lines intentionally don't use
# iterators. Other threads can close dispatchers, causeing
# the socket map to shrink.
r = e = map.keys()
w = [fd for (fd, obj) in map.items() if obj.writable()]
try:
r, w, e = select.select(r, w, e, client_timeout())
except select.error as err:
# Python >= 3.3 makes select.error an alias of OSError,
# which is not subscriptable but does have the 'errno' attribute
err_errno = getattr(err, 'errno', None) or err[0]
if err_errno != errno.EINTR:
if err_errno == errno.EBADF:
# If a connection is closed while we are
# calling select on it, we can get a bad
# file-descriptor error. We'll check for this
# case by looking for entries in r and w that
# are not in the socket map.
if [fd for fd in r if fd not in map]:
continue
if [fd for fd in w if fd not in map]:
continue
raise
else:
continue
if not map:
break
if not (r or w or e):
# The line intentionally doesn't use iterators. Other
# threads can close dispatchers, causeing the socket
# map to shrink.
for obj in map.values():
if isinstance(obj, ManagedClientConnection):
# Send a heartbeat message as a reply to a
# non-existent message id.
try:
obj.send_reply(-1, None)
except DisconnectedError:
pass
continue
for fd in r:
obj = map.get(fd)
if obj is None:
continue
read(obj)
for fd in w:
obj = map.get(fd)
if obj is None:
continue
write(obj)
for fd in e:
obj = map.get(fd)
if obj is None:
continue
_exception(obj)
except:
if map:
try:
logging.getLogger(__name__+'.client_loop').critical(
'A ZEO client loop failed.',
exc_info=sys.exc_info())
except:
pass
for fd, obj in map.items():
if not hasattr(obj, 'mgr'):
continue
try:
obj.mgr.client.close()
except:
map.pop(fd, None)
try:
logging.getLogger(__name__+'.client_loop'
).critical(
"Couldn't close a dispatcher.",
exc_info=sys.exc_info())
except:
pass
class ConnectionManager(object):
"""Keeps a connection up over time"""
sync_wait = 30
def __init__(self, addrs, client, tmin=1, tmax=180):
self.client = client
self._start_asyncore_loop()
self.addrlist = self._parse_addrs(addrs)
self.tmin = min(tmin, tmax)
self.tmax = tmax
self.cond = threading.Condition(threading.Lock())
self.connection = None # Protected by self.cond
self.closed = 0
# If thread is not None, then there is a helper thread
# attempting to connect.
self.thread = None # Protected by self.cond
def new_addrs(self, addrs):
self.addrlist = self._parse_addrs(addrs)
def _start_asyncore_loop(self):
self.map = {}
self.trigger = ZEO.zrpc.trigger.trigger(self.map)
self.loop_thread = threading.Thread(
name="%s zeo client networking thread" % self.client.__name__,
target=client_loop, args=(self.map,))
self.loop_thread.setDaemon(True)
self.loop_thread.start()
def __repr__(self):
return "<%s for %s>" % (self.__class__.__name__, self.addrlist)
def _parse_addrs(self, addrs):
# Return a list of (addr_type, addr) pairs.
# For backwards compatibility (and simplicity?) the
# constructor accepts a single address in the addrs argument --
# a string for a Unix domain socket or a 2-tuple with a
# hostname and port. It can also accept a list of such addresses.
addr_type = self._guess_type(addrs)
if addr_type is not None:
return [(addr_type, addrs)]
else:
addrlist = []
for addr in addrs:
addr_type = self._guess_type(addr)
if addr_type is None:
raise ValueError("unknown address in list: %s" % repr(addr))
addrlist.append((addr_type, addr))
return addrlist
def _guess_type(self, addr):
if isinstance(addr, str):
return socket.AF_UNIX
if (len(addr) == 2
and isinstance(addr[0], str)
and isinstance(addr[1], int)):
return socket.AF_INET # also denotes IPv6
# not anything I know about
return None
def close(self):
"""Prevent ConnectionManager from opening new connections"""
self.closed = 1
self.cond.acquire()
try:
t = self.thread
self.thread = None
finally:
self.cond.release()
if t is not None:
log("CM.close(): stopping and joining thread")
t.stop()
t.join(30)
if t.isAlive():
log("CM.close(): self.thread.join() timed out",
level=logging.WARNING)
for fd, obj in list(self.map.items()):
if obj is not self.trigger:
try:
obj.close()
except:
logging.getLogger(__name__+'.'+self.__class__.__name__
).critical(
"Couldn't close a dispatcher.",
exc_info=sys.exc_info())
self.map.clear()
self.trigger.pull_trigger()
try:
self.loop_thread.join(9)
except RuntimeError:
pass # we are the thread :)
self.trigger.close()
def attempt_connect(self):
"""Attempt a connection to the server without blocking too long.
There isn't a crisp definition for too long. When a
ClientStorage is created, it attempts to connect to the
server. If the server isn't immediately available, it can
operate from the cache. This method will start the background
connection thread and wait a little while to see if it
finishes quickly.
"""
# Will a single attempt take too long?
# Answer: it depends -- normally, you'll connect or get a
# connection refused error very quickly. Packet-eating
# firewalls and other mishaps may cause the connect to take a
# long time to time out though. It's also possible that you
# connect quickly to a slow server, and the attempt includes
# at least one roundtrip to the server (the register() call).
# But that's as fast as you can expect it to be.
self.connect()
self.cond.acquire()
try:
t = self.thread
conn = self.connection
finally:
self.cond.release()
if t is not None and conn is None:
event = t.one_attempt
event.wait()
self.cond.acquire()
try:
conn = self.connection
finally:
self.cond.release()
return conn is not None
def connect(self, sync=0):
self.cond.acquire()
try:
if self.connection is not None:
return
t = self.thread
if t is None:
log("CM.connect(): starting ConnectThread")
self.thread = t = ConnectThread(self, self.client)
t.setDaemon(1)
t.start()
if sync:
while self.connection is None and t.isAlive():
self.cond.wait(self.sync_wait)
if self.connection is None:
log("CM.connect(sync=1): still waiting...")
assert self.connection is not None
finally:
self.cond.release()
def connect_done(self, conn, preferred):
# Called by ConnectWrapper.notify_client() after notifying the client
log("CM.connect_done(preferred=%s)" % preferred)
self.cond.acquire()
try:
self.connection = conn
if preferred:
self.thread = None
self.cond.notifyAll() # Wake up connect(sync=1)
finally:
self.cond.release()
def close_conn(self, conn):
# Called by the connection when it is closed
self.cond.acquire()
try:
if conn is not self.connection:
# Closing a non-current connection
log("CM.close_conn() non-current", level=BLATHER)
return
log("CM.close_conn()")
self.connection = None
finally:
self.cond.release()
self.client.notifyDisconnected()
if not self.closed:
self.connect()
def is_connected(self):
self.cond.acquire()
try:
return self.connection is not None
finally:
self.cond.release()
# When trying to do a connect on a non-blocking socket, some outcomes
# are expected. Set _CONNECT_IN_PROGRESS to the errno value(s) expected
# when an initial connect can't complete immediately. Set _CONNECT_OK
# to the errno value(s) expected if the connect succeeds *or* if it's
# already connected (our code can attempt redundant connects).
if hasattr(errno, "WSAEWOULDBLOCK"): # Windows
# Caution: The official Winsock docs claim that WSAEALREADY should be
# treated as yet another "in progress" indicator, but we've never
# seen this.
_CONNECT_IN_PROGRESS = (errno.WSAEWOULDBLOCK,)
# Win98: WSAEISCONN; Win2K: WSAEINVAL
_CONNECT_OK = (0, errno.WSAEISCONN, errno.WSAEINVAL)
else: # Unix
_CONNECT_IN_PROGRESS = (errno.EINPROGRESS,)
_CONNECT_OK = (0, errno.EISCONN)
class ConnectThread(threading.Thread):
"""Thread that tries to connect to server given one or more addresses.
The thread is passed a ConnectionManager and the manager's client
as arguments. It calls testConnection() on the client when a
socket connects; that should return 1 or 0 indicating whether this
is a preferred or a fallback connection. It may also raise an
exception, in which case the connection is abandoned.
The thread will continue to run, attempting connections, until a
preferred connection is seen and successfully handed over to the
manager and client.
As soon as testConnection() finds a preferred connection, or after
all sockets have been tried and at least one fallback connection
has been seen, notifyConnected(connection) is called on the client
and connect_done() on the manager. If this was a preferred
connection, the thread then exits; otherwise, it keeps trying
until it gets a preferred connection, and then reconnects the
client using that connection.
"""
__super_init = threading.Thread.__init__
# We don't expect clients to call any methods of this Thread other
# than close() and those defined by the Thread API.
def __init__(self, mgr, client):
self.__super_init(name="Connect(%s)" % mgr.addrlist)
self.mgr = mgr
self.client = client
self.stopped = 0
self.one_attempt = threading.Event()
# A ConnectThread keeps track of whether it has finished a
# call to try_connecting(). This allows the ConnectionManager
# to make an attempt to connect right away, but not block for
# too long if the server isn't immediately available.
def stop(self):
self.stopped = 1
def run(self):
delay = self.mgr.tmin
success = 0
# Don't wait too long the first time.
# TODO: make timeout configurable?
attempt_timeout = 5
while not self.stopped:
success = self.try_connecting(attempt_timeout)
if not self.one_attempt.isSet():
self.one_attempt.set()
attempt_timeout = 75
if success > 0:
break
time.sleep(delay)
if self.mgr.is_connected():
log("CT: still trying to replace fallback connection",
level=logging.INFO)
delay = min(delay*2, self.mgr.tmax)
log("CT: exiting thread: %s" % self.getName())
def try_connecting(self, timeout):
"""Try connecting to all self.mgr.addrlist addresses.
Return 1 if a preferred connection was found; 0 if no
connection was found; and -1 if a fallback connection was
found.
If no connection is found within timeout seconds, return 0.
"""
log("CT: attempting to connect on %d sockets" % len(self.mgr.addrlist))
deadline = time.time() + timeout
wrappers = self._create_wrappers()
for wrap in wrappers.keys():
if wrap.state == "notified":
return 1
try:
if time.time() > deadline:
return 0
r = self._connect_wrappers(wrappers, deadline)
if r is not None:
return r
if time.time() > deadline:
return 0
r = self._fallback_wrappers(wrappers, deadline)
if r is not None:
return r
# Alas, no luck.
assert not wrappers
finally:
for wrap in wrappers.keys():
wrap.close()
del wrappers
return 0
def _expand_addrlist(self):
for domain, addr in self.mgr.addrlist:
# AF_INET really means either IPv4 or IPv6, possibly
# indirected by DNS. By design, DNS lookup is deferred
# until connections get established, so that DNS
# reconfiguration can affect failover
if domain == socket.AF_INET:
host, port = addr
for (family, socktype, proto, cannoname, sockaddr
) in socket.getaddrinfo(host or 'localhost', port):
# we only speak TCP, so let's skip UDP and RAW sockets
# otherwise we'll try to connect to the same address
# three times in a row
if socktype != socket.SOCK_STREAM:
continue
# for IPv6, drop flowinfo, and restrict addresses
# to [host]:port
yield family, sockaddr[:2]
else:
yield domain, addr
def _create_wrappers(self):
# Create socket wrappers
wrappers = {} # keys are active wrappers
for domain, addr in self._expand_addrlist():
wrap = ConnectWrapper(domain, addr, self.mgr, self.client)
wrap.connect_procedure()
if wrap.state == "notified":
for w in wrappers.keys():
w.close()
return {wrap: wrap}
if wrap.state != "closed":
wrappers[wrap] = wrap
return wrappers
def _connect_wrappers(self, wrappers, deadline):
# Next wait until they all actually connect (or fail)
# The deadline is necessary, because we'd wait forever if a
# sockets never connects or fails.
while wrappers:
if self.stopped:
for wrap in wrappers.keys():
wrap.close()
return 0
# Select connecting wrappers
connecting = [wrap
for wrap in wrappers.keys()
if wrap.state == "connecting"]
if not connecting:
break
if time.time() > deadline:
break
try:
r, w, x = select.select([], connecting, connecting, 1.0)
log("CT: select() %d, %d, %d" % tuple(map(len, (r,w,x))))
except select.error as msg:
log("CT: select failed; msg=%s" % str(msg),
level=logging.WARNING)
continue
# Exceptable wrappers are in trouble; close these suckers
for wrap in x:
log("CT: closing troubled socket %s" % str(wrap.addr))
del wrappers[wrap]
wrap.close()
# Writable sockets are connected
for wrap in w:
wrap.connect_procedure()
if wrap.state == "notified":
del wrappers[wrap] # Don't close this one
for wrap in wrappers.keys():
wrap.close()
return 1
if wrap.state == "closed":
del wrappers[wrap]
def _fallback_wrappers(self, wrappers, deadline):
# If we've got wrappers left at this point, they're fallback
# connections. Try notifying them until one succeeds.
for wrap in list(wrappers.keys()):
assert wrap.state == "tested" and wrap.preferred == 0
if self.mgr.is_connected():
wrap.close()
else:
wrap.notify_client()
if wrap.state == "notified":
del wrappers[wrap] # Don't close this one
for wrap in wrappers.keys():
wrap.close()
return -1
assert wrap.state == "closed"
del wrappers[wrap]
# TODO: should check deadline
class ConnectWrapper:
"""An object that handles the connection procedure for one socket.
This is a little state machine with states:
closed
opened
connecting
connected
tested
notified
"""
def __init__(self, domain, addr, mgr, client):
"""Store arguments and create non-blocking socket."""
self.domain = domain
self.addr = addr
self.mgr = mgr
self.client = client
# These attributes are part of the interface
self.state = "closed"
self.sock = None
self.conn = None
self.preferred = 0
log("CW: attempt to connect to %s" % repr(addr))
try:
self.sock = socket.socket(domain, socket.SOCK_STREAM)
except socket.error as err:
log("CW: can't create socket, domain=%s: %s" % (domain, err),
level=logging.ERROR)
self.close()
return
self.sock.setblocking(0)
self.state = "opened"
def connect_procedure(self):
"""Call sock.connect_ex(addr) and interpret result."""
if self.state in ("opened", "connecting"):
try:
err = self.sock.connect_ex(self.addr)
except socket.error as msg:
log("CW: connect_ex(%r) failed: %s" % (self.addr, msg),
level=logging.ERROR)
self.close()
return
log("CW: connect_ex(%s) returned %s" %
(self.addr, errno.errorcode.get(err) or str(err)))
if err in _CONNECT_IN_PROGRESS:
self.state = "connecting"
return
if err not in _CONNECT_OK:
log("CW: error connecting to %s: %s" %
(self.addr, errno.errorcode.get(err) or str(err)),
level=logging.WARNING)
self.close()
return
self.state = "connected"
if self.state == "connected":
self.test_connection()
def test_connection(self):
"""Establish and test a connection at the zrpc level.
Call the client's testConnection(), giving the client a chance
to do app-level check of the connection.
"""
self.conn = ManagedClientConnection(self.sock, self.addr, self.mgr)
self.sock = None # The socket is now owned by the connection
try:
self.preferred = self.client.testConnection(self.conn)
self.state = "tested"
except ReadOnlyError:
log("CW: ReadOnlyError in testConnection (%s)" % repr(self.addr))
self.close()
return
except:
log("CW: error in testConnection (%s)" % repr(self.addr),
level=logging.ERROR, exc_info=True)
self.close()
return
if self.preferred:
self.notify_client()
def notify_client(self):
"""Call the client's notifyConnected().
If this succeeds, call the manager's connect_done().
If the client is already connected, we assume it's a fallback
connection, and the new connection must be a preferred
connection. The client will close the old connection.
"""
try:
self.client.notifyConnected(self.conn)
except:
log("CW: error in notifyConnected (%s)" % repr(self.addr),
level=logging.ERROR, exc_info=True)
self.close()
return
self.state = "notified"
self.mgr.connect_done(self.conn, self.preferred)
def close(self):
"""Close the socket and reset everything."""
self.state = "closed"
self.mgr = self.client = None
self.preferred = 0
if self.conn is not None:
# Closing the ZRPC connection will eventually close the
# socket, somewhere in asyncore. Guido asks: Why do we care?
self.conn.close()
self.conn = None
if self.sock is not None:
self.sock.close()
self.sock = None
def fileno(self):
return self.sock.fileno()
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