Design and code by Eric S. Raymond <esr@thyrsus.com>. See the project
resource page at <http://www.catb.org/~esr/irker/>.
-Requires Python 2.6 and the irc client library at version >= 2.0.2: see
+Requires Python 2.6 or 2.5 with the simplejson library installed, and
+the irc client library at version >= 2.0.2: see
http://pypi.python.org/pypi/irc/
"""
CHANNEL_MAX = 18 # Max channels open per socket (default)
ANTI_FLOOD_DELAY = 0.5 # Anti-flood delay after transmissions, seconds
ANTI_BUZZ_DELAY = 0.09 # Anti-buzz delay after queue-empty check
+CONNECTION_MAX = 200 # To avoid hitting a thread limit
# No user-serviceable parts below this line
-version = "1.7"
+version = "1.10"
-# This black magic imports support for green threads (coroutines),
-# then has kinky sex with the import library internals, replacing
-# "threading" with a coroutine-using imposter. Threads then become
-# ultra-light-weight and cooperatively scheduled.
-try:
- import eventlet
- eventlet.monkey_patch()
- green_threads = True
- # With greenlets we don't worry about thread exhaustion, only the
- # file descriptor limit (typically 1024 on modern Unixes). Thus we
- # can handle a lot more concurrent sessions and generate less
- # join/leave spam under heavy load.
- CONNECTION_MAX = 1000
-except ImportError:
- # Threads are more expensive if we have to use OS-level ones
- # rather than greenlets. We need to avoid pushing thread limits
- # as well as fd limits. See security.txt for discussion.
- CONNECTION_MAX = 200
- green_threads = False
-
-import sys, getopt, urlparse, time, random, socket
+import sys, getopt, urlparse, time, random, socket, signal
import threading, Queue, SocketServer
import irc.client, logging
try:
# even if the queue is nonempty but efforts to connect have failed for
# a long time.
#
-# There are multiple threads. One accepts incoming traffic from all servers.
-# Each Connection also has a consumer thread and a thread-safe message queue.
-# The program main appends messages to queues as JSON requests are received;
-# the consumer threads try to ship them to servers. When a socket write
-# stalls, it only blocks an individual consumer thread; if it stalls long
-# enough, the session will be timed out.
+# There are multiple threads. One accepts incoming traffic from all
+# servers. Each Connection also has a consumer thread and a
+# thread-safe message queue. The program main appends messages to
+# queues as JSON requests are received; the consumer threads try to
+# ship them to servers. When a socket write stalls, it only blocks an
+# individual consumer thread; if it stalls long enough, the session
+# will be timed out. This solves the biggest problem with a
+# single-threaded implementation, which is that you can't count on a
+# single stalled write not hanging all other traffic - you're at the
+# mercy of the length of the buffers in the TCP/IP layer.
#
# Message delivery is thus not reliable in the face of network stalls,
# but this was considered acceptable because IRC (notoriously) has the
# same problem - there is little point in reliable delivery to a relay
# that is down or unreliable.
#
-# This code uses only NICK, JOIN, MODE, and PRIVMSG. It is strictly
+# This code uses only NICK, JOIN, PART, MODE, and PRIVMSG. It is strictly
# compliant to RFC1459, except for the interpretation and use of the
# DEAF and CHANLIMIT and (obsolete) MAXCHANNELS features. CHANLIMIT
# is as described in the Internet RFC draft
# the connection rather than holding a socket open in
# the server forever.
now = time.time()
- if (now > self.last_xmit + XMIT_TTL \
- or now > self.last_ping + PING_TTL) \
- and self.status != "disconnected":
- self.irker.debug(1, "timing out inactive connection to %s at %s" % (self.servername, time.asctime()))
- self.connection.context = None
- self.connection.quit("transmission timeout")
- self.connection.close()
- self.connection = None
+ xmit_timeout = now > self.last_xmit + XMIT_TTL
+ ping_timeout = now > self.last_ping + PING_TTL
+ if self.status == "disconnected":
+ # If the queue is empty, we can drop this connection.
+ self.status = "expired"
+ break
+ elif xmit_timeout or ping_timeout:
+ self.irker.debug(1, "timing out connection to %s at %s (ping_timeout=%s, xmit_timeout=%s)" % (self.servername, time.asctime(), ping_timeout, xmit_timeout))
+ with self.irker.library_lock:
+ self.connection.context = None
+ self.connection.quit("transmission timeout")
+ self.connection = None
self.status = "disconnected"
else:
# Prevent this thread from hogging the CPU by pausing
# reflex arc it is highly unlikely any human will ever
# notice.
time.sleep(ANTI_BUZZ_DELAY)
+ elif self.status == "disconnected" \
+ and time.time() > self.last_xmit + DISCONNECT_TTL:
+ # Queue is nonempty, but the IRC server might be
+ # down. Letting failed connections retain queue
+ # space forever would be a memory leak.
+ self.status = "expired"
+ break
elif not self.connection:
# Queue is nonempty but server isn't connected.
- self.connection = self.irker.irc.server()
- self.connection.context = self
- # Try to avoid colliding with other instances
- self.nick_trial = random.randint(1, 990)
- self.channels_joined = {}
- # This will throw irc.client.ServerConnectionError on failure
- try:
- self.connection.connect(self.servername,
- self.port,
- nickname=self.nickname(),
- username="irker",
- ircname="irker relaying client")
- self.status = "handshaking"
- self.irker.debug(1, "XMIT_TTL bump (%s connection) at %s" % (self.servername, time.asctime()))
- self.last_xmit = time.time()
- except irc.client.ServerConnectionError:
- self.status = "disconnected"
+ with self.irker.library_lock:
+ self.connection = self.irker.irc.server()
+ self.connection.context = self
+ # Try to avoid colliding with other instances
+ self.nick_trial = random.randint(1, 990)
+ self.channels_joined = {}
+ try:
+ # This will throw
+ # irc.client.ServerConnectionError on failure
+ self.connection.connect(self.servername,
+ self.port,
+ nickname=self.nickname(),
+ username="irker",
+ ircname="irker relaying client")
+ self.status = "handshaking"
+ self.irker.debug(1, "XMIT_TTL bump (%s connection) at %s" % (self.servername, time.asctime()))
+ self.last_xmit = time.time()
+ self.last_ping = time.time()
+ except irc.client.ServerConnectionError:
+ self.status = "disconnected"
elif self.status == "handshaking":
if time.time() > self.last_xmit + HANDSHAKE_TTL:
self.status = "expired"
# Don't buzz on the empty-queue test while we're
# handshaking
time.sleep(ANTI_BUZZ_DELAY)
- elif self.status == "disconnected" \
- and time.time() > self.last_xmit + DISCONNECT_TTL:
- # Queue is nonempty, but the IRC server might be
- # down. Letting failed connections retain queue
- # space forever would be a memory leak.
- self.status = "expired"
- break
elif self.status == "unseen" \
and time.time() > self.last_xmit + UNSEEN_TTL:
# Nasty people could attempt a denial-of-service
self.status = "expired"
break
elif self.status == "ready":
- (channel, message) = self.queue.get()
- if channel not in self.channels_joined:
- self.connection.join(channel)
- self.irker.debug(1, "joining %s on %s." % (channel, self.servername))
- for segment in message.split("\n"):
- self.connection.privmsg(channel, segment)
- time.sleep(ANTI_FLOOD_DELAY)
- self.last_xmit = self.channels_joined[channel] = time.time()
- self.irker.debug(1, "XMIT_TTL bump (%s transmission) at %s" % (self.servername, time.asctime()))
- self.queue.task_done()
+ with self.irker.library_lock:
+ (channel, message) = self.queue.get()
+ if channel not in self.channels_joined:
+ self.connection.join(channel)
+ self.irker.debug(1, "joining %s on %s." % (channel, self.servername))
+ for segment in message.split("\n"):
+ self.connection.privmsg(channel, segment)
+ time.sleep(ANTI_FLOOD_DELAY)
+ self.last_xmit = self.channels_joined[channel] = time.time()
+ self.irker.debug(1, "XMIT_TTL bump (%s transmission) at %s" % (self.servername, time.asctime()))
+ self.queue.task_done()
except:
(exc_type, _exc_value, exc_traceback) = sys.exc_info()
self.irker.logerr("exception %s in thread for %s" % \
# This is so we can see tracebacks for errors inside the thread
# when we need to be able to for debugging purposes.
if debuglvl > 0:
- raise exc_type, exc_value, exc_traceback
+ raise exc_type, _exc_value, exc_traceback
def live(self):
"Should this connection not be scavenged?"
return self.status != "expired"
if self.channel_limits:
match_count = 0
for already in self.channels_joined:
+ # This obscure code is because the RFCs allow separate limits
+ # by channel type (indicated by the first character of the name)
+ # a feature that is almost never actually used.
if already[0] == channel[0]:
match_count += 1
return match_count < self.channel_limits.get(channel[0], CHANNEL_MAX)
return len(self.connections) > 0
def last_xmit(self):
"Return the time of the most recent transmission."
- return max([x.last_xmit for x in self.connections])
+ return max(x.last_xmit for x in self.connections)
class Irker:
"Persistent IRC multiplexer."
self.irc.add_global_handler("featurelist", self._handle_features)
self.irc.add_global_handler("disconnect", self._handle_disconnect)
self.irc.add_global_handler("kick", self._handle_kick)
- thread = threading.Thread(target=self.irc.process_forever)
+ self.library_lock = threading.Lock()
+ thread = threading.Thread(target=self._process_forever)
thread.setDaemon(True)
self.irc._thread = thread
thread.start()
"Debugging information."
if self.debuglevel >= level:
sys.stderr.write("irkerd: %s\n" % errmsg)
+ def _process_forever(self):
+ "IRC library process_forever with mutex."
+ self.debug(1, "process_forever()")
+ while True:
+ with self.library_lock:
+ self.irc.process_once(ANTI_BUZZ_DELAY)
def _handle_ping(self, connection, _event):
"PING arrived, bump the last-received time for the connection."
if connection.context:
def _handle_disconnect(self, connection, _event):
"Server hung up the connection."
self.debug(1, "server %s disconnected" % connection.server)
+ connection.close()
if connection.context:
connection.context.handle_disconnect()
def _handle_kick(self, connection, event):
# choose the one longest idle on the
# assumption that message activity is likely
# to be clumpy.
- oldest = None
- oldtime = float("inf")
if len(self.servers) >= CONNECTION_MAX:
- for (name, server) in self.servers.items():
- if server.last_xmit() < oldtime:
- oldest = name
- oldtime = server.last_xmit()
+ oldest = min(self.servers.keys(), key=lambda name: self.servers[name].last_xmit())
del self.servers[oldest]
except ValueError:
self.logerr("can't recognize JSON on input: %r" % line)
server.setDaemon(True)
server.start()
try:
- while True:
- time.sleep(10)
+ signal.pause()
except KeyboardInterrupt:
raise SystemExit(1)
except socket.error, e: