#!/usr/bin/env python
"""
AppServer
The WebKit app server is a TCP/IP server that accepts requests, hands them
off to the Application and sends the request back over the connection.
The fact that the app server stays resident is what makes it so much quicker
than traditional CGI programming. Everything gets cached.
FUTURE
* Implement the additional settings that are commented out below.
"""
from Common import *
from AutoReloadingAppServer import AutoReloadingAppServer as AppServer
from MiscUtils.Funcs import timestamp
from marshal import dumps, loads
import os, sys
from threading import Lock, Thread, Event
import threading
import Queue
import select
import socket
import threading
import time
import errno
import traceback
from WebUtils import Funcs
debug = 0
DefaultConfig = {
'Port': 8086,
'MaxServerThreads': 20,
'MinServerThreads': 5,
'StartServerThreads': 10,
# @@ 2000-04-27 ce: None of the following settings are implemented
# 'RequestQueueSize': 16,# 'RequestBufferSize': 64*1024,
# 'SocketType': 'inet', # inet, unix
}
#Need to know this value for communications
#Note that this limits the size of the dictionary we receive from the AppServer to 2,147,483,647 bytes
intLength = len(dumps(int(1)))
server = None
class ThreadedAppServer(AppServer):
"""
"""
## Init ##
def __init__(self, path=None):
AppServer.__init__(self, path)
threadCount = self.setting('StartServerThreads')
self._maxServerThreads = self.setting('MaxServerThreads')
self._minServerThreads = self.setting('MinServerThreads')
self._threadPool = []
self._threadCount = 0
self._threadUseCounter = []
# twice the number of threads we have:
self._requestQueue = Queue.Queue(self._maxServerThreads * 2)
self._addr = None
self._requestID = 1
out = sys.stdout
out.write('Creating %d threads' % threadCount)
for i in range(threadCount):
self.spawnThread()
out.write(".")
out.flush()
out.write("\n")
self.recordPID()
self._socketHandlers = {}
self._handlerCache = {}
self._sockets = {}
self.addSocketHandler(self.address(), AdapterHandler)
self.readyForRequests()
def addSocketHandler(self, serverAddress, handlerClass):
self._socketHandlers[serverAddress] = handlerClass
self._handlerCache[serverAddress] = []
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
try:
sock.bind(serverAddress)
sock.listen(1024)
except:
if self.running:
self.initiateShutdown()
self._closeThread.join()
raise
print "Listening on", serverAddress
f = open(self.serverSidePath(
'%s.text' % handlerClass.protocolName), 'w')
f.write('%s:%d' % (serverAddress[0], serverAddress[1]))
f.close()
self._sockets[serverAddress] = sock
def isPersistent(self):
return 1
def mainloop(self, timeout=1):
from errno import EINTR
threadCheckInterval = self._maxServerThreads*2
threadUpdateDivisor = 5 #grabstat interval
threadCheck=0
while 1:
if not self.running:
return
#block for timeout seconds waiting for connections
try:
input, output, exc = select.select(
self._sockets.values(), [], [], timeout)
except select.error, v:
if v[0] == EINTR or v[0]==0: break
else: raise
for sock in input:
print sock.getsockname()
self._requestID += 1
client, addr = sock.accept()
serverAddress = sock.getsockname()
try:
handler = self._handlerCache[serverAddress].pop()
except IndexError:
handler = self._socketHandlers[serverAddress](self, serverAddress)
handler.activate(client, self._requestID)
self._requestQueue.put(handler)
if threadCheck % threadUpdateDivisor == 0:
self.updateThreadUsage()
if threadCheck > threadCheckInterval:
threadCheck=0
self.manageThreadCount()
else:
threadCheck = threadCheck + 1
self.restartIfNecessary()
def activeThreadCount(self):
"""
Get a snapshot of the number of threads currently in use.
"""
count = 0
for i in self._threadPool:
if i._processing:
count = count + 1
return count
def updateThreadUsage(self):
"""
Update the threadUseCounter list.
"""
count = self.activeThreadCount()
if len(self._threadUseCounter) > self._maxServerThreads:
self._threadUseCounter.pop(0)
self._threadUseCounter.append(count)
def manageThreadCount(self):
"""
Adjust the number of threads in use. This algorithm
needs work. The edges (ie at the minserverthreads)
are tricky. When working with this, remember thread
creation is CHEAP
"""
average = 0
max = 0
debug = 0
if debug: print "ThreadUse Samples=%s" % str(self._threadUseCounter)
for i in self._threadUseCounter:
average += i
if i > max:
max = i
average = average / len(self._threadUseCounter)
if debug: print "Average Thread Use: ", avg
if debug: print "Max Thread Use: ", max
if debug: print "ThreadCount: ", self.threadCount
if len(self._threadUseCounter) < self._maxServerThreads:
return #not enough samples
margin = self._threadCount / 2 #smoothing factor
if debug: print "margin=", margin
if average > self._threadCount - margin and \
self._threadCount < self._maxServerThreads:
# Running low: double thread count
n = min(self._threadCount,
self._maxServerThreads - self._threadCount)
if debug: print "Adding %s threads" % n
for i in range(n):
self.spawnThread()
elif average < self._threadCount - margin and \
self._threadCount > self._minServerThreads:
n=min(self._threadCount - self._minServerThreads,
self._threadCount - max)
self.absorbThread(n)
else:
#cleanup any stale threads that we killed but haven't joined
self.absorbThread(0)
def spawnThread(self):
debug=0
if debug: print "Spawning new thread"
t = Thread(target=self.threadloop)
t._processing = 0
t.start()
self._threadPool.append(t)
self._threadCount += 1
if debug: print "New Thread Spawned, threadCount=", self._threadCount
#self.threadUseCounter=[] #reset
def absorbThread(self, count=1):
"""
Absorb a thread. We do this by putting a None on the
Queue. When a thread gets it, that tells it to exit.
BUT, even though we put it on, the thread may not have
retrieved it before we exit this function. So we need
to decrement the thread count even if we didn't find a
thread that isn't alive. We'll get it the next time
through.
"""
debug = 0
if debug: print "Absorbing %s Threads" % count
for i in range(count):
self._requestQueue.put(None)
self._threadCount -= 1
for i in self._threadPool:
if not i.isAlive():
rv = i.join() #Don't need a timeout, it isn't alive
self._threadPool.remove(i)
if debug: print "Thread Absorbed, Real Thread Count=", len(self.threadPool)
#self.threadUseCounter=[] #reset
def threadloop(self):
self.initThread()
t=threading.currentThread()
t.processing=0
try:
while 1:
try:
handler = self._requestQueue.get()
if handler is None: #None means time to quit
if debug: print "Thread retrieved None, quitting"
break
t.processing=1
try:
handler.handleRequest()
except:
traceback.print_exc(file=sys.stderr)
t.processing=0
handler.close()
except Queue.Empty:
pass
finally:
self.delThread()
if debug: print threading.currentThread(), "Quitting"
def initThread(self):
"""
Invoked immediately by threadloop() as a hook for
subclasses. This implementation does nothing and
subclasses need not invoke super.
"""
pass
def delThread(self):
"""
Invoked immediately by threadloop() as a hook for
subclasses. This implementation does nothing and
subclasses need not invoke super.
"""
pass
def awakeSelect(self):
""" Send a connect to ourself to pop the select() call
out of it's loop safely """
for addr in self._sockets.keys():
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
sock.connect(addr)
sock.close()
except:
pass
def shutDown(self):
self.running=0
self.awakeSelect()
self._shuttingdown=1 #jsl-is this used anywhere?
print "ThreadedAppServer: Shutting Down"
for sock in self._sockets.values():
sock.close()
for i in range(self._threadCount):
self._requestQueue.put(None)#kill all threads
for i in self._threadPool:
try:
i.join()
except:
pass
AppServer.shutDown(self)
## Network Server ##
def address(self):
if self._addr is None:
self._addr = (self.setting('Host'), self.setting('Port'))
return self._addr
class Handler:
def __init__(self, server, serverAddress):
self._server = server
self._serverAddress = serverAddress
def activate(self, sock, requestID):
"""
Activates the handler for processing the request.
Number is the number of the request, mostly used to identify
verbose output. Each request should be given a unique,
incremental number.
"""
self._requestID = requestID
self._sock = sock
def close(self):
self._sock = None
self._server._handlerCache[self._serverAddress].append(self)
def handleRequest(self):
pass
def receiveDict(self):
"""
Utility function to receive a marshalled dictionary.
"""
chunk = ''
missing = intLength
while missing > 0:
block = self._sock.recv(missing)
if not block:
self._sock.close()
raise NotEnoughDataError, 'received only %d of %d bytes when receiving dictLength' % (len(chunk), intLength)
chunk += block
missing = intLength - len(chunk)
dictLength = loads(chunk)
if type(dictLength) != type(1):
self._sock.close()
raise ProtocolError, "Invalid AppServer protocol"
chunk = ''
missing = dictLength
while missing > 0:
block = self._sock.recv(missing)
if not block:
self._sock.close()
raise NotEnoughDataError, 'received only %d of %d bytes when receiving dict' % (len(chunk), dictLength)
chunk += block
missing = dictLength - len(chunk)
return loads(chunk)
class MonitorHandler(Handler):
protcolName = 'monitor'
def handleRequest(self):
verbose = self.server._verbose
startTime = time.time()
if verbose:
print 'BEGIN REQUEST'
print time.asctime(time.localtime(startTime))
conn = self._sock
if verbose:
print 'receiving request from', conn
BUFSIZE = 8*1024
dict = self.receiveDict()
if dict['format'] == "STATUS":
conn.send(str(self.server._reqCount))
if dict['format'] == 'QUIT':
conn.send("OK")
conn.close()
self.server.shutDown()
from WebKit.ASStreamOut import ASStreamOut
class TASASStreamOut(ASStreamOut):
def __init__(self, sock):
ASStreamOut.__init__(self)
self._socket = sock
def flush(self):
debug=0
result = ASStreamOut.flush(self)
if result: ##a true return value means we can send
reslen = len(self._buffer)
sent = 0
while sent < reslen:
try:
sent = sent + self._socket.send(self._buffer[sent:sent+8192])
except socket.error, e:
if e[0]==errno.EPIPE: #broken pipe
pass
else:
print "StreamOut Error: ", e
break
self.pop(sent)
class AdapterHandler(Handler):
protocolName = 'address'
def handleRequest(self):
verbose = self._server._verbose
self._startTime = time.time()
if verbose:
print '%5i %s ' % (self._requestID, timestamp()['pretty']),
data = []
dict = self.receiveDict()
if dict and verbose and dict.has_key('environ'):
requestURI = Funcs.requestURI(dict['environ'])
print requestURI
else:
requestURI = None
dict['input'] = self.makeInput()
streamOut = TASASStreamOut(self._sock)
transaction = self._server._app.dispatchRawRequest(dict, streamOut)
streamOut.close()
try:
self._sock.shutdown(1)
self._sock.close()
except:
pass
if self._server._verbose:
duration = '%0.2f secs' % (time.time() - self._startTime)
duration = string.ljust(duration, 19)
print '%5i %s %s' % (self._requestID, duration, requestURI)
print
transaction._application=None
transaction.die()
del transaction
def makeInput(self):
return self._sock.makefile("rb",8012)
def run(useMonitor = 0, http=0, workDir=None):
global server
global monitor
monitor = useMonitor
try:
server = None
server = ThreadedAppServer(workDir)
if useMonitor:
addr = server.address()
server.addSocketHandler((addr[0], addr[1]-1),
MonitorHandler)
if http:
from WebKit.HTTPServer import HTTPAppServerHandler
addr = ('127.0.0.1', 8080)
server.addSocketHandler(addr, HTTPAppServerHandler)
# On NT, run mainloop in a different thread because
# it's not safe for Ctrl-C to be caught while
# manipulating the queues. It's not safe on Linux
# either, but there, it appears that Ctrl-C will
# trigger an exception in ANY thread, so this fix
# doesn't help.
if os.name == 'nt':
# catch the exception raised by sys.exit so
# that we can re-call it in the main thread.
global exitStatus
exitStatus = None
def windowsmainloop(server):
global exitStatus
try:
server.mainloop()
except SystemExit, e:
exitStatus = e.code
# Run the server thread
t = threading.Thread(target=windowsmainloop, args=(server,))
t.start()
try:
while server.running:
time.sleep(1.0)
except KeyboardInterrupt:
pass
server.running = 0
t.join()
# re-call sys.exit if necessary
if exitStatus:
sys.exit(exitStatus)
else:
try:
server.mainloop()
except KeyboardInterrupt, e:
server.shutDown()
except Exception, e:
if not isinstance(e, SystemExit):
import traceback
traceback.print_exc(file=sys.stderr)
print
print "Exiting AppServer"
if server:
if server.running:
server.initiateShutdown()
server._closeThread.join()
# if we're here as a result of exit() being called,
# exit with that return code.
if isinstance(e,SystemExit):
sys.exit(e)
sys.exit()
def shutDown(arg1,arg2):
global server
print "Shutdown Called", time.asctime(time.localtime(time.time()))
if server:
server.initiateShutdown()
else:
print 'WARNING: No server reference to shutdown.'
import signal
signal.signal(signal.SIGINT, shutDown)
signal.signal(signal.SIGTERM, shutDown)
usage = """
The AppServer is the main process of WebKit. It handles requests for
servlets from webservers. ThreadedAppServer takes the following
command line arguments: stop: Stop the currently running Apperver.
daemon: run as a daemon If AppServer is called with no arguments, it
will start the AppServer and record the pid of the process in
appserverpid.txt
"""
import re
settingRE = re.compile(r'^--([a-zA-Z][a-zA-Z0-9]*\.[a-zA-Z][a-zA-Z0-9]*)=')
from MiscUtils import Configurable
def main(args):
monitor = 0
http = 0
function = run
daemon = 0
workDir = None
for i in args[:]:
if settingRE.match(i):
match = settingRE.match(i)
name = match.group(1)
value = i[match.end():]
Configurable.addCommandLineSetting(name, value)
elif i == "monitor":
print "Enabling Monitoring"
monitor=1
elif i == "stop":
import AppServer
function=AppServer.stop
elif i == "daemon":
daemon=1
elif i == "start":
pass
elif i[:8] == "workdir=":
workDir = i[8:]
elif i == "http":
http = 1
else:
print usage
if daemon:
if os.name == "posix":
pid=os.fork()
if pid:
sys.exit()
else:
print "daemon mode not available on your OS"
function(useMonitor=monitor, http=http, workDir=workDir)