172 lines
7 KiB
Python
172 lines
7 KiB
Python
|
"""An ISAPI extension base class implemented using a thread-pool."""
|
||
|
|
# $Id$
|
||
|
|
|
||
|
|
import sys
|
||
|
|
import time
|
||
|
|
from isapi import isapicon, ExtensionError
|
||
|
|
import isapi.simple
|
||
|
|
from win32file import GetQueuedCompletionStatus, CreateIoCompletionPort, \
|
||
|
|
PostQueuedCompletionStatus, CloseHandle
|
||
|
|
from win32security import SetThreadToken
|
||
|
|
from win32event import INFINITE
|
||
|
|
from pywintypes import OVERLAPPED
|
||
|
|
|
||
|
|
import threading
|
||
|
|
import traceback
|
||
|
|
|
||
|
|
ISAPI_REQUEST = 1
|
||
|
|
ISAPI_SHUTDOWN = 2
|
||
|
|
|
||
|
|
class WorkerThread(threading.Thread):
|
||
|
|
def __init__(self, extension, io_req_port):
|
||
|
|
self.running = False
|
||
|
|
self.io_req_port = io_req_port
|
||
|
|
self.extension = extension
|
||
|
|
threading.Thread.__init__(self)
|
||
|
|
# We wait 15 seconds for a thread to terminate, but if it fails to,
|
||
|
|
# we don't want the process to hang at exit waiting for it...
|
||
|
|
self.setDaemon(True)
|
||
|
|
|
||
|
|
def run(self):
|
||
|
|
self.running = True
|
||
|
|
while self.running:
|
||
|
|
errCode, bytes, key, overlapped = \
|
||
|
|
GetQueuedCompletionStatus(self.io_req_port, INFINITE)
|
||
|
|
if key == ISAPI_SHUTDOWN and overlapped is None:
|
||
|
|
break
|
||
|
|
|
||
|
|
# Let the parent extension handle the command.
|
||
|
|
dispatcher = self.extension.dispatch_map.get(key)
|
||
|
|
if dispatcher is None:
|
||
|
|
raise RuntimeError("Bad request '%s'" % (key,))
|
||
|
|
|
||
|
|
dispatcher(errCode, bytes, key, overlapped)
|
||
|
|
|
||
|
|
def call_handler(self, cblock):
|
||
|
|
self.extension.Dispatch(cblock)
|
||
|
|
|
||
|
|
# A generic thread-pool based extension, using IO Completion Ports.
|
||
|
|
# Sub-classes can override one method to implement a simple extension, or
|
||
|
|
# may leverage the CompletionPort to queue their own requests, and implement a
|
||
|
|
# fully asynch extension.
|
||
|
|
class ThreadPoolExtension(isapi.simple.SimpleExtension):
|
||
|
|
"Base class for an ISAPI extension based around a thread-pool"
|
||
|
|
max_workers = 20
|
||
|
|
worker_shutdown_wait = 15000 # 15 seconds for workers to quit...
|
||
|
|
def __init__(self):
|
||
|
|
self.workers = []
|
||
|
|
# extensible dispatch map, for sub-classes that need to post their
|
||
|
|
# own requests to the completion port.
|
||
|
|
# Each of these functions is called with the result of
|
||
|
|
# GetQueuedCompletionStatus for our port.
|
||
|
|
self.dispatch_map = {
|
||
|
|
ISAPI_REQUEST: self.DispatchConnection,
|
||
|
|
}
|
||
|
|
|
||
|
|
def GetExtensionVersion(self, vi):
|
||
|
|
isapi.simple.SimpleExtension.GetExtensionVersion(self, vi)
|
||
|
|
# As per Q192800, the CompletionPort should be created with the number
|
||
|
|
# of processors, even if the number of worker threads is much larger.
|
||
|
|
# Passing 0 means the system picks the number.
|
||
|
|
self.io_req_port = CreateIoCompletionPort(-1, None, 0, 0)
|
||
|
|
# start up the workers
|
||
|
|
self.workers = []
|
||
|
|
for i in range(self.max_workers):
|
||
|
|
worker = WorkerThread(self, self.io_req_port)
|
||
|
|
worker.start()
|
||
|
|
self.workers.append(worker)
|
||
|
|
|
||
|
|
def HttpExtensionProc(self, control_block):
|
||
|
|
overlapped = OVERLAPPED()
|
||
|
|
overlapped.object = control_block
|
||
|
|
PostQueuedCompletionStatus(self.io_req_port, 0, ISAPI_REQUEST, overlapped)
|
||
|
|
return isapicon.HSE_STATUS_PENDING
|
||
|
|
|
||
|
|
def TerminateExtension(self, status):
|
||
|
|
for worker in self.workers:
|
||
|
|
worker.running = False
|
||
|
|
for worker in self.workers:
|
||
|
|
PostQueuedCompletionStatus(self.io_req_port, 0, ISAPI_SHUTDOWN, None)
|
||
|
|
# wait for them to terminate - pity we aren't using 'native' threads
|
||
|
|
# as then we could do a smart wait - but now we need to poll....
|
||
|
|
end_time = time.time() + self.worker_shutdown_wait/1000
|
||
|
|
alive = self.workers
|
||
|
|
while alive:
|
||
|
|
if time.time() > end_time:
|
||
|
|
# xxx - might be nice to log something here.
|
||
|
|
break
|
||
|
|
time.sleep(0.2)
|
||
|
|
alive = [w for w in alive if w.isAlive()]
|
||
|
|
self.dispatch_map = {} # break circles
|
||
|
|
CloseHandle(self.io_req_port)
|
||
|
|
|
||
|
|
# This is the one operation the base class supports - a simple
|
||
|
|
# Connection request. We setup the thread-token, and dispatch to the
|
||
|
|
# sub-class's 'Dispatch' method.
|
||
|
|
def DispatchConnection(self, errCode, bytes, key, overlapped):
|
||
|
|
control_block = overlapped.object
|
||
|
|
# setup the correct user for this request
|
||
|
|
hRequestToken = control_block.GetImpersonationToken()
|
||
|
|
SetThreadToken(None, hRequestToken)
|
||
|
|
try:
|
||
|
|
try:
|
||
|
|
self.Dispatch(control_block)
|
||
|
|
except:
|
||
|
|
self.HandleDispatchError(control_block)
|
||
|
|
finally:
|
||
|
|
# reset the security context
|
||
|
|
SetThreadToken(None, None)
|
||
|
|
|
||
|
|
def Dispatch(self, ecb):
|
||
|
|
"""Overridden by the sub-class to handle connection requests.
|
||
|
|
|
||
|
|
This class creates a thread-pool using a Windows completion port,
|
||
|
|
and dispatches requests via this port. Sub-classes can generally
|
||
|
|
implement each connection request using blocking reads and writes, and
|
||
|
|
the thread-pool will still provide decent response to the end user.
|
||
|
|
|
||
|
|
The sub-class can set a max_workers attribute (default is 20). Note
|
||
|
|
that this generally does *not* mean 20 threads will all be concurrently
|
||
|
|
running, via the magic of Windows completion ports.
|
||
|
|
|
||
|
|
There is no default implementation - sub-classes must implement this.
|
||
|
|
"""
|
||
|
|
raise NotImplementedError("sub-classes should override Dispatch")
|
||
|
|
|
||
|
|
def HandleDispatchError(self, ecb):
|
||
|
|
"""Handles errors in the Dispatch method.
|
||
|
|
|
||
|
|
When a Dispatch method call fails, this method is called to handle
|
||
|
|
the exception. The default implementation formats the traceback
|
||
|
|
in the browser.
|
||
|
|
"""
|
||
|
|
ecb.HttpStatusCode = isapicon.HSE_STATUS_ERROR
|
||
|
|
#control_block.LogData = "we failed!"
|
||
|
|
exc_typ, exc_val, exc_tb = sys.exc_info()
|
||
|
|
limit = None
|
||
|
|
try:
|
||
|
|
try:
|
||
|
|
import cgi
|
||
|
|
ecb.SendResponseHeaders("200 OK", "Content-type: text/html\r\n\r\n",
|
||
|
|
False)
|
||
|
|
print(file=ecb)
|
||
|
|
print("<H3>Traceback (most recent call last):</H3>", file=ecb)
|
||
|
|
list = traceback.format_tb(exc_tb, limit) + \
|
||
|
|
traceback.format_exception_only(exc_typ, exc_val)
|
||
|
|
print("<PRE>%s<B>%s</B></PRE>" % (
|
||
|
|
cgi.escape("".join(list[:-1])), cgi.escape(list[-1]),), file=ecb)
|
||
|
|
except ExtensionError:
|
||
|
|
# The client disconnected without reading the error body -
|
||
|
|
# its probably not a real browser at the other end, ignore it.
|
||
|
|
pass
|
||
|
|
except:
|
||
|
|
print("FAILED to render the error message!")
|
||
|
|
traceback.print_exc()
|
||
|
|
print("ORIGINAL extension error:")
|
||
|
|
traceback.print_exception(exc_typ, exc_val, exc_tb)
|
||
|
|
finally:
|
||
|
|
# holding tracebacks in a local of a frame that may itself be
|
||
|
|
# part of a traceback used to be evil and cause leaks!
|
||
|
|
exc_tb = None
|
||
|
|
ecb.DoneWithSession()
|