#!/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
}
#Below used with the RestartApplication function
#ReStartLock=Lock()
#ReqCount=0
#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
int_length = len(dumps(int(1)))
server = None
class ThreadedAppServer(AppServer):
"""
"""
## Init ##
def __init__(self, path=None):
AppServer.__init__(self, path)
self._addr = None
threadCount = self.setting('StartServerThreads')
self.maxServerThreads = self.setting('MaxServerThreads')
self.minServerThreads = self.setting('MinServerThreads')
self.monitorPort = None
self.threadPool = []
self.threadCount=0
self.threadUseCounter=[]
self.requestQueue = Queue.Queue(self.maxServerThreads * 2) # twice the number of threads we have
self.rhCache = [] # This will grow to a limit of the number of
# threads plus the size of the requestQueue plus one.
# It used to be a Queue but since we don't make
# use of the blocking behavior and because of problems
# with Queue.Empty being raised on .get_nowait()
# when the queue isn't in fact empty, we have switched
# to using a list instead.
self.mainsocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# Must use SO_REUSEADDR to avoid problems restarting the app server
# This was discussed on Webware-devel in Oct 2001, and this solution
# was found by Jeff Johnson
self.mainsocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
addr = self.address()
try:
self.mainsocket.bind(addr)
except:
if self.running:
self.initiateShutdown()
self._closeThread.join()
raise
print "Listening on", addr
open(self.serverSidePath('address.text'), 'w').write('%s:%d' % (addr[0], addr[1]))
self.monitorPort = addr[1]-1
out = sys.stdout
out.write('Creating %d threads' % threadCount)
for i in range(threadCount):
self.spawnThread()
out.write(".")
out.flush()
out.write("\n")
# @@ 2001-05-30 ce: another hard coded number: @@jsl- not everything needs to be configurable....
self.mainsocket.listen(1024)
self.recordPID()
self.readyForRequests()
def isPersistent(self):
return 1
def mainloop(self, monitor=None, timeout=1):
from errno import EINTR
inputsockets = [self.mainsocket,]
if monitor:
inputsockets.append(monitor.insock)
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(inputsockets,[],[],timeout)
except select.error, v:
# if the error is EINTR/interrupt, then self.running should be set to 0 and
# we'll exit on the next loop
if v[0] == EINTR or v[0]==0: break
else: raise
# @@ gat 2002-03-20: I found through heavy testing of restart behavior that WebKit
# dropped fewer requests on restart by removing this test.
## if not self.running:
## return
for sock in input:
if sock.getsockname()[1] == self.monitorPort:
client,addr = sock.accept()
monitor.activate(client)
self.requestQueue.put(monitor)
else:
self._reqCount = self._reqCount+1
rh = None
client,addr = sock.accept()
try:
rh = self.rhCache.pop()
except IndexError:
rh = RequestHandler(self)
rh.activate(client, self._reqCount)
self.requestQueue.put(rh)
if threadCheck % threadUpdateDivisor == 0:
self.updateThreadUsage()
if threadCheck > threadCheckInterval:
if debug: print "\nBusy Threads: ", self.activeThreadCount()
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
"""
avg=0
max=0
debug=0
if debug: print "ThreadUse Samples=%s" % str(self.threadUseCounter)
for i in self.threadUseCounter:
avg = avg + i
if i > max:
max = i
avg = avg / 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 avg > 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 avg < 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 = 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 = 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:
rh=self.requestQueue.get()
if rh == None: #None means time to quit
if debug: print "Thread retrieved None, quitting"
break
# @@ gat 2002-03-21: we don't want to drop a request that we've
# already received from the adapter; therefore, I removed the
# test of self.running. Now, once a request gets put into the
# request queue, it WILL be processed, never dropped. This
# might slow down shutdown a bit if many requests are currently
# being processed, but it makes restarting the appserver work
# better.
## if self.running:
## t.processing=1
## try:
## rh.handleRequest()
## except:
## traceback.print_exc(file=sys.stderr)
## t.processing=0
t.processing=1
try:
rh.handleRequest()
except:
traceback.print_exc(file=sys.stderr)
t.processing=0
rh.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
"""
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
addr = self.address()
try:
sock.connect(addr)
sock.close()
except:
pass
return
def shutDown(self):
self.running=0
self.awakeSelect()
self._shuttingdown=1 #jsl-is this used anywhere?
print "ThreadedAppServer: Shutting Down"
self.mainsocket.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
## Misc ##
def setRequestQueueSize(self, value):
assert value>=1
self.__class__.request_queue_size = value
class Monitor:
def __init__(self, server):
self.server = server
self.port = server.monitorPort
self.insock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.insock.bind((server.address()[0],server.address()[1]-1))
self.insock.listen(1)
print "******** Listening to Monitor Socket ************"
def activate(self, socket):
self.sock = socket
def close(self):
self.sock = None
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
chunk = ''
missing = int_length
while missing > 0:
block = conn.recv(missing)
if not block:
conn.close()
raise NotEnoughDataError, 'received only %d out of %d bytes when receiving dict_length' % (len(chunk), int_length)
chunk = chunk + block
missing = int_length - len(chunk)
dict_length = loads(chunk)
if type(dict_length) != type(1):
conn.close()
print "Error: Invalid AppServer protocol"
return 0
chunk = ''
missing = dict_length
while missing > 0:
block = conn.recv(missing)
if not block:
conn.close()
raise NotEnoughDataError, 'received only %d out of %d bytes when receiving dict' % (len(chunk), dict_length)
chunk = chunk + block
missing = dict_length - len(chunk)
dict = loads(chunk)
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)
if debug: print "TASASStreamout is sending %s bytes" % reslen
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 RequestHandler:
def __init__(self, server):
self.server = server
def activate(self, sock, number):
"""
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.sock = sock
# self._strmOut = TASASStreamOut(sock)
self._number = number
def close(self):
self.sock = None
# self._strmOut = None
self.server.rhCache.append(self)
def handleRequest(self):
verbose = self.server._verbose
startTime = time.time()
if verbose:
print '%5i %s ' % (self._number, timestamp()['pretty']),
conn = self.sock
# @@ 2001-05-30 ce: Ack! Look at this hard coding.
BUFSIZE = 8*1024
data = []
chunk = ''
missing = int_length
while missing > 0:
block = conn.recv(missing)
if not block:
conn.close()
if len(chunk) == 0:
# We probably awakened due to awakeSelect being called.
return 0
else:
# We got a partial request -- something went wrong.
raise NotEnoughDataError, 'received only %d out of %d bytes when receiving dict_length' % (len(chunk), int_length)
chunk = chunk + block
missing = int_length - len(chunk)
dict_length = loads(chunk)
if type(dict_length) != type(1):
conn.close()
print
print "Error: Invalid AppServer protocol"
return 0
chunk = ''
missing = dict_length
while missing > 0:
block = conn.recv(missing)
if not block:
conn.close()
raise NotEnoughDataError, 'received only %d out of %d bytes when receiving dict' % (len(chunk), dict_length)
chunk = chunk + block
missing = dict_length - len(chunk)
dict = loads(chunk)
#if verbose: print "Comm Delay=%s" % (time.time() - dict['time'])
if dict:
if verbose:
if dict.has_key('environ'):
requestURI = Funcs.requestURI(dict['environ'])
else:
requestURI = None
print requestURI
dict['input'] = conn.makefile("rb",8012)
strmOut = TASASStreamOut(self.sock)
transaction = self.server._app.dispatchRawRequest(dict, strmOut)
strmOut.close()
try:
conn.shutdown(1)
conn.close()
except:
pass
if verbose:
duration = '%0.2f secs' % (time.time() - startTime)
duration = string.ljust(duration, 19)
print '%5i %s %s' % (self._number, duration, requestURI)
print
transaction._application=None
transaction.die()
del transaction
def restartApp(self):
"""
Not used
"""
if self.server.num_requests> 200:
print "Trying to get lock"
ReStartLock.acquire()
if self.server.num_requests> 200: #check again to make sure another thread didn't do it
print "Restarting Application"
currApp=self.server.wkApp
wkAppServer=currApp._server
newApp = wkAppServer.createApplication()
newApp._sessions = currApp._sessions
wkAppServer._app=newApp
self.server.wkApp=newApp
for i in currApp._factoryList:
currApp._factoryList.remove(i)
for i in currApp._factoryByExt.keys():
currApp._factoryByExt[i]=None
currApp._canFactory=None
wkAppServer._plugIns=[]
wkAppServer.loadPlugIns()
self.server.num_requests=0
print "Refs to old App=",sys.getrefcount(currApp)
currApp=None
ReStartLock.release()
# This will be thrown when less data arrived on the socket than we were expecting.
class NotEnoughDataError(Exception):
pass
def run(useMonitor = 0, workDir=None):
global server
global monitor
monitor = useMonitor
try:
server = None
server = ThreadedAppServer(workDir)
if useMonitor:
monitor_socket = Monitor(server)
else:
monitor_socket = None
# 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, monitor):
global exitStatus
try:
server.mainloop(monitor)
except SystemExit, e:
exitStatus = e.code
# Run the server thread
t = threading.Thread(target=windowsmainloop, args=(server, monitor_socket))
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(monitor_socket)
except KeyboardInterrupt, e:
server.shutDown()
except Exception, e:
if not isinstance(e, SystemExit):
import traceback
traceback.print_exc(file=sys.stderr)
#print e
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
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:]
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(monitor, workDir)