Current File : //opt/alt/python37/lib/python3.7/site-packages/paste/httpserver.py
# (c) 2005 Ian Bicking and contributors; written for Paste (http://pythonpaste.org)
# Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php
# (c) 2005 Clark C. Evans
# This module is part of the Python Paste Project and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
# This code was written with funding by http://prometheusresearch.com
"""
WSGI HTTP Server
This is a minimalistic WSGI server using Python's built-in BaseHTTPServer;
if pyOpenSSL is installed, it also provides SSL capabilities.
"""
# @@: add in protection against HTTP/1.0 clients who claim to
# be 1.1 but do not send a Content-Length
# @@: add support for chunked encoding, this is not a 1.1 server
# till this is completed.
import atexit
import traceback
import socket, sys, threading, urlparse, Queue, urllib
import posixpath
import time
import thread
import os
from itertools import count
from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
from SocketServer import ThreadingMixIn
from paste.util import converters
import logging
try:
from paste.util import killthread
except ImportError:
# Not available, probably no ctypes
killthread = None
__all__ = ['WSGIHandlerMixin', 'WSGIServer', 'WSGIHandler', 'serve']
__version__ = "0.5"
class ContinueHook(object):
"""
When a client request includes a 'Expect: 100-continue' header, then
it is the responsibility of the server to send 100 Continue when it
is ready for the content body. This allows authentication, access
levels, and other exceptions to be detected *before* bandwith is
spent on the request body.
This is a rfile wrapper that implements this functionality by
sending 100 Continue to the client immediately after the user
requests the content via a read() operation on the rfile stream.
After this response is sent, it becomes a pass-through object.
"""
def __init__(self, rfile, write):
self._ContinueFile_rfile = rfile
self._ContinueFile_write = write
for attr in ('close', 'closed', 'fileno', 'flush',
'mode', 'bufsize', 'softspace'):
if hasattr(rfile, attr):
setattr(self, attr, getattr(rfile, attr))
for attr in ('read', 'readline', 'readlines'):
if hasattr(rfile, attr):
setattr(self, attr, getattr(self, '_ContinueFile_' + attr))
def _ContinueFile_send(self):
self._ContinueFile_write("HTTP/1.1 100 Continue\r\n\r\n")
rfile = self._ContinueFile_rfile
for attr in ('read', 'readline', 'readlines'):
if hasattr(rfile, attr):
setattr(self, attr, getattr(rfile, attr))
def _ContinueFile_read(self, size=-1):
self._ContinueFile_send()
return self._ContinueFile_rfile.read(size)
def _ContinueFile_readline(self, size=-1):
self._ContinueFile_send()
return self._ContinueFile_rfile.readline(size)
def _ContinueFile_readlines(self, sizehint=0):
self._ContinueFile_send()
return self._ContinueFile_rfile.readlines(sizehint)
class WSGIHandlerMixin:
"""
WSGI mix-in for HTTPRequestHandler
This class is a mix-in to provide WSGI functionality to any
HTTPRequestHandler derivative (as provided in Python's BaseHTTPServer).
This assumes a ``wsgi_application`` handler on ``self.server``.
"""
lookup_addresses = True
def log_request(self, *args, **kwargs):
""" disable success request logging
Logging transactions should not be part of a WSGI server,
if you want logging; look at paste.translogger
"""
pass
def log_message(self, *args, **kwargs):
""" disable error message logging
Logging transactions should not be part of a WSGI server,
if you want logging; look at paste.translogger
"""
pass
def version_string(self):
""" behavior that BaseHTTPServer should have had """
if not self.sys_version:
return self.server_version
else:
return self.server_version + ' ' + self.sys_version
def wsgi_write_chunk(self, chunk):
"""
Write a chunk of the output stream; send headers if they
have not already been sent.
"""
if not self.wsgi_headers_sent and not self.wsgi_curr_headers:
raise RuntimeError(
"Content returned before start_response called")
if not self.wsgi_headers_sent:
self.wsgi_headers_sent = True
(status, headers) = self.wsgi_curr_headers
code, message = status.split(" ", 1)
self.send_response(int(code), message)
#
# HTTP/1.1 compliance; either send Content-Length or
# signal that the connection is being closed.
#
send_close = True
for (k, v) in headers:
lk = k.lower()
if 'content-length' == lk:
send_close = False
if 'connection' == lk:
if 'close' == v.lower():
self.close_connection = 1
send_close = False
self.send_header(k, v)
if send_close:
self.close_connection = 1
self.send_header('Connection', 'close')
self.end_headers()
self.wfile.write(chunk)
def wsgi_start_response(self, status, response_headers, exc_info=None):
if exc_info:
try:
if self.wsgi_headers_sent:
raise exc_info[0], exc_info[1], exc_info[2]
else:
# In this case, we're going to assume that the
# higher-level code is currently handling the
# issue and returning a resonable response.
# self.log_error(repr(exc_info))
pass
finally:
exc_info = None
elif self.wsgi_curr_headers:
assert 0, "Attempt to set headers a second time w/o an exc_info"
self.wsgi_curr_headers = (status, response_headers)
return self.wsgi_write_chunk
def wsgi_setup(self, environ=None):
"""
Setup the member variables used by this WSGI mixin, including
the ``environ`` and status member variables.
After the basic environment is created; the optional ``environ``
argument can be used to override any settings.
"""
(scheme, netloc, path, query, fragment) = urlparse.urlsplit(self.path)
path = urllib.unquote(path)
endslash = path.endswith('/')
path = posixpath.normpath(path)
if endslash and path != '/':
# Put the slash back...
path += '/'
(server_name, server_port) = self.server.server_address[:2]
rfile = self.rfile
# We can put in the protection to keep from over-reading the
# file
try:
content_length = int(self.headers.get('Content-Length', '0'))
except ValueError:
content_length = 0
if '100-continue' == self.headers.get('Expect','').lower():
rfile = LimitedLengthFile(ContinueHook(rfile, self.wfile.write), content_length)
else:
if not hasattr(self.connection, 'get_context'):
# @@: LimitedLengthFile is currently broken in connection
# with SSL (sporatic errors that are diffcult to trace, but
# ones that go away when you don't use LimitedLengthFile)
rfile = LimitedLengthFile(rfile, content_length)
remote_address = self.client_address[0]
self.wsgi_environ = {
'wsgi.version': (1,0)
,'wsgi.url_scheme': 'http'
,'wsgi.input': rfile
,'wsgi.errors': sys.stderr
,'wsgi.multithread': True
,'wsgi.multiprocess': False
,'wsgi.run_once': False
# CGI variables required by PEP-333
,'REQUEST_METHOD': self.command
,'SCRIPT_NAME': '' # application is root of server
,'PATH_INFO': path
,'QUERY_STRING': query
,'CONTENT_TYPE': self.headers.get('Content-Type', '')
,'CONTENT_LENGTH': self.headers.get('Content-Length', '0')
,'SERVER_NAME': server_name
,'SERVER_PORT': str(server_port)
,'SERVER_PROTOCOL': self.request_version
# CGI not required by PEP-333
,'REMOTE_ADDR': remote_address
}
if scheme:
self.wsgi_environ['paste.httpserver.proxy.scheme'] = scheme
if netloc:
self.wsgi_environ['paste.httpserver.proxy.host'] = netloc
if self.lookup_addresses:
# @@: make lookup_addreses actually work, at this point
# it has been address_string() is overriden down in
# file and hence is a noop
if remote_address.startswith("192.168.") \
or remote_address.startswith("10.") \
or remote_address.startswith("172.16."):
pass
else:
address_string = None # self.address_string()
if address_string:
self.wsgi_environ['REMOTE_HOST'] = address_string
if hasattr(self.server, 'thread_pool'):
# Now that we know what the request was for, we should
# tell the thread pool what its worker is working on
self.server.thread_pool.worker_tracker[thread.get_ident()][1] = self.wsgi_environ
self.wsgi_environ['paste.httpserver.thread_pool'] = self.server.thread_pool
for k, v in self.headers.items():
key = 'HTTP_' + k.replace("-","_").upper()
if key in ('HTTP_CONTENT_TYPE','HTTP_CONTENT_LENGTH'):
continue
self.wsgi_environ[key] = ','.join(self.headers.getheaders(k))
if hasattr(self.connection,'get_context'):
self.wsgi_environ['wsgi.url_scheme'] = 'https'
# @@: extract other SSL parameters from pyOpenSSL at...
# http://www.modssl.org/docs/2.8/ssl_reference.html#ToC25
if environ:
assert isinstance(environ, dict)
self.wsgi_environ.update(environ)
if 'on' == environ.get('HTTPS'):
self.wsgi_environ['wsgi.url_scheme'] = 'https'
self.wsgi_curr_headers = None
self.wsgi_headers_sent = False
def wsgi_connection_drop(self, exce, environ=None):
"""
Override this if you're interested in socket exceptions, such
as when the user clicks 'Cancel' during a file download.
"""
pass
def wsgi_execute(self, environ=None):
"""
Invoke the server's ``wsgi_application``.
"""
self.wsgi_setup(environ)
try:
result = self.server.wsgi_application(self.wsgi_environ,
self.wsgi_start_response)
try:
for chunk in result:
self.wsgi_write_chunk(chunk)
if not self.wsgi_headers_sent:
self.wsgi_write_chunk('')
finally:
if hasattr(result,'close'):
result.close()
result = None
except socket.error, exce:
self.wsgi_connection_drop(exce, environ)
return
except:
if not self.wsgi_headers_sent:
error_msg = "Internal Server Error\n"
self.wsgi_curr_headers = (
'500 Internal Server Error',
[('Content-type', 'text/plain'),
('Content-length', str(len(error_msg)))])
self.wsgi_write_chunk("Internal Server Error\n")
raise
#
# SSL Functionality
#
# This implementation was motivated by Sebastien Martini's SSL example
# http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/442473
#
try:
from OpenSSL import SSL, tsafe
SocketErrors = (socket.error, SSL.ZeroReturnError, SSL.SysCallError)
except ImportError:
# Do not require pyOpenSSL to be installed, but disable SSL
# functionality in that case.
SSL = None
SocketErrors = (socket.error,)
class SecureHTTPServer(HTTPServer):
def __init__(self, server_address, RequestHandlerClass,
ssl_context=None, request_queue_size=None):
assert not ssl_context, "pyOpenSSL not installed"
HTTPServer.__init__(self, server_address, RequestHandlerClass)
if request_queue_size:
self.socket.listen(request_queue_size)
else:
class _ConnFixer(object):
""" wraps a socket connection so it implements makefile """
def __init__(self, conn):
self.__conn = conn
def makefile(self, mode, bufsize):
return socket._fileobject(self.__conn, mode, bufsize)
def __getattr__(self, attrib):
return getattr(self.__conn, attrib)
class SecureHTTPServer(HTTPServer):
"""
Provides SSL server functionality on top of the BaseHTTPServer
by overriding _private_ members of Python's standard
distribution. The interface for this instance only changes by
adding a an optional ssl_context attribute to the constructor:
cntx = SSL.Context(SSL.SSLv23_METHOD)
cntx.use_privatekey_file("host.pem")
cntx.use_certificate_file("host.pem")
"""
def __init__(self, server_address, RequestHandlerClass,
ssl_context=None, request_queue_size=None):
# This overrides the implementation of __init__ in python's
# SocketServer.TCPServer (which BaseHTTPServer.HTTPServer
# does not override, thankfully).
HTTPServer.__init__(self, server_address, RequestHandlerClass)
self.socket = socket.socket(self.address_family,
self.socket_type)
self.ssl_context = ssl_context
if ssl_context:
class TSafeConnection(tsafe.Connection):
def settimeout(self, *args):
self._lock.acquire()
try:
return self._ssl_conn.settimeout(*args)
finally:
self._lock.release()
def gettimeout(self):
self._lock.acquire()
try:
return self._ssl_conn.gettimeout()
finally:
self._lock.release()
self.socket = TSafeConnection(ssl_context, self.socket)
self.server_bind()
if request_queue_size:
self.socket.listen(request_queue_size)
self.server_activate()
def get_request(self):
# The default SSL request object does not seem to have a
# ``makefile(mode, bufsize)`` method as expected by
# Socketserver.StreamRequestHandler.
(conn, info) = self.socket.accept()
if self.ssl_context:
conn = _ConnFixer(conn)
return (conn, info)
def _auto_ssl_context():
import OpenSSL, time, random
pkey = OpenSSL.crypto.PKey()
pkey.generate_key(OpenSSL.crypto.TYPE_RSA, 768)
cert = OpenSSL.crypto.X509()
cert.set_serial_number(random.randint(0, sys.maxint))
cert.gmtime_adj_notBefore(0)
cert.gmtime_adj_notAfter(60 * 60 * 24 * 365)
cert.get_subject().CN = '*'
cert.get_subject().O = 'Dummy Certificate'
cert.get_issuer().CN = 'Untrusted Authority'
cert.get_issuer().O = 'Self-Signed'
cert.set_pubkey(pkey)
cert.sign(pkey, 'md5')
ctx = SSL.Context(SSL.SSLv23_METHOD)
ctx.use_privatekey(pkey)
ctx.use_certificate(cert)
return ctx
class WSGIHandler(WSGIHandlerMixin, BaseHTTPRequestHandler):
"""
A WSGI handler that overrides POST, GET and HEAD to delegate
requests to the server's ``wsgi_application``.
"""
server_version = 'PasteWSGIServer/' + __version__
def handle_one_request(self):
"""Handle a single HTTP request.
You normally don't need to override this method; see the class
__doc__ string for information on how to handle specific HTTP
commands such as GET and POST.
"""
self.raw_requestline = self.rfile.readline()
if not self.raw_requestline:
self.close_connection = 1
return
if not self.parse_request(): # An error code has been sent, just exit
return
self.wsgi_execute()
def handle(self):
# don't bother logging disconnects while handling a request
try:
BaseHTTPRequestHandler.handle(self)
except SocketErrors, exce:
self.wsgi_connection_drop(exce)
def address_string(self):
"""Return the client address formatted for logging.
This is overridden so that no hostname lookup is done.
"""
return ''
class LimitedLengthFile(object):
def __init__(self, file, length):
self.file = file
self.length = length
self._consumed = 0
if hasattr(self.file, 'seek'):
self.seek = self._seek
def __repr__(self):
base_repr = repr(self.file)
return base_repr[:-1] + ' length=%s>' % self.length
def read(self, length=None):
left = self.length - self._consumed
if length is None:
length = left
else:
length = min(length, left)
# next two lines are hnecessary only if read(0) blocks
if not left:
return ''
data = self.file.read(length)
self._consumed += len(data)
return data
def readline(self, *args):
max_read = self.length - self._consumed
if len(args):
max_read = min(args[0], max_read)
data = self.file.readline(max_read)
self._consumed += len(data)
return data
def readlines(self, hint=None):
data = self.file.readlines(hint)
for chunk in data:
self._consumed += len(chunk)
return data
def __iter__(self):
return self
def next(self):
if self.length - self._consumed <= 0:
raise StopIteration
return self.readline()
## Optional methods ##
def _seek(self, place):
self.file.seek(place)
self._consumed = place
def tell(self):
if hasattr(self.file, 'tell'):
return self.file.tell()
else:
return self._consumed
class ThreadPool(object):
"""
Generic thread pool with a queue of callables to consume.
Keeps a notion of the status of its worker threads:
idle: worker thread with nothing to do
busy: worker thread doing its job
hung: worker thread that's been doing a job for too long
dying: a hung thread that has been killed, but hasn't died quite
yet.
zombie: what was a worker thread that we've tried to kill but
isn't dead yet.
At any time you can call track_threads, to get a dictionary with
these keys and lists of thread_ids that fall in that status. All
keys will be present, even if they point to emty lists.
hung threads are threads that have been busy more than
hung_thread_limit seconds. Hung threads are killed when they live
longer than kill_thread_limit seconds. A thread is then
considered dying for dying_limit seconds, if it is still alive
after that it is considered a zombie.
When there are no idle workers and a request comes in, another
worker *may* be spawned. If there are less than spawn_if_under
threads in the busy state, another thread will be spawned. So if
the limit is 5, and there are 4 hung threads and 6 busy threads,
no thread will be spawned.
When there are more than max_zombie_threads_before_die zombie
threads, a SystemExit exception will be raised, stopping the
server. Use 0 or None to never raise this exception. Zombie
threads *should* get cleaned up, but killing threads is no
necessarily reliable. This is turned off by default, since it is
only a good idea if you've deployed the server with some process
watching from above (something similar to daemontools or zdaemon).
Each worker thread only processes ``max_requests`` tasks before it
dies and replaces itself with a new worker thread.
"""
SHUTDOWN = object()
def __init__(
self, nworkers, name="ThreadPool", daemon=False,
max_requests=100, # threads are killed after this many requests
hung_thread_limit=30, # when a thread is marked "hung"
kill_thread_limit=1800, # when you kill that hung thread
dying_limit=300, # seconds that a kill should take to go into effect (longer than this and the thread is a "zombie")
spawn_if_under=5, # spawn if there's too many hung threads
max_zombie_threads_before_die=0, # when to give up on the process
hung_check_period=100, # every 100 requests check for hung workers
logger=None, # Place to log messages to
error_email=None, # Person(s) to notify if serious problem occurs
):
"""
Create thread pool with `nworkers` worker threads.
"""
self.nworkers = nworkers
self.max_requests = max_requests
self.name = name
self.queue = Queue.Queue()
self.workers = []
self.daemon = daemon
if logger is None:
logger = logging.getLogger('paste.httpserver.ThreadPool')
if isinstance(logger, basestring):
logger = logging.getLogger(logger)
self.logger = logger
self.error_email = error_email
self._worker_count = count()
assert (not kill_thread_limit
or kill_thread_limit >= hung_thread_limit), (
"kill_thread_limit (%s) should be higher than hung_thread_limit (%s)"
% (kill_thread_limit, hung_thread_limit))
if not killthread:
kill_thread_limit = 0
self.logger.info(
"Cannot use kill_thread_limit as ctypes/killthread is not available")
self.kill_thread_limit = kill_thread_limit
self.dying_limit = dying_limit
self.hung_thread_limit = hung_thread_limit
assert spawn_if_under <= nworkers, (
"spawn_if_under (%s) should be less than nworkers (%s)"
% (spawn_if_under, nworkers))
self.spawn_if_under = spawn_if_under
self.max_zombie_threads_before_die = max_zombie_threads_before_die
self.hung_check_period = hung_check_period
self.requests_since_last_hung_check = 0
# Used to keep track of what worker is doing what:
self.worker_tracker = {}
# Used to keep track of the workers not doing anything:
self.idle_workers = []
# Used to keep track of threads that have been killed, but maybe aren't dead yet:
self.dying_threads = {}
# This is used to track when we last had to add idle workers;
# we shouldn't cull extra workers until some time has passed
# (hung_thread_limit) since workers were added:
self._last_added_new_idle_workers = 0
if not daemon:
atexit.register(self.shutdown)
for i in range(self.nworkers):
self.add_worker_thread(message='Initial worker pool')
def add_task(self, task):
"""
Add a task to the queue
"""
self.logger.debug('Added task (%i tasks queued)', self.queue.qsize())
if self.hung_check_period:
self.requests_since_last_hung_check += 1
if self.requests_since_last_hung_check > self.hung_check_period:
self.requests_since_last_hung_check = 0
self.kill_hung_threads()
if not self.idle_workers and self.spawn_if_under:
# spawn_if_under can come into effect...
busy = 0
now = time.time()
self.logger.debug('No idle workers for task; checking if we need to make more workers')
for worker in self.workers:
if not hasattr(worker, 'thread_id'):
# Not initialized
continue
time_started, info = self.worker_tracker.get(worker.thread_id,
(None, None))
if time_started is not None:
if now - time_started < self.hung_thread_limit:
busy += 1
if busy < self.spawn_if_under:
self.logger.info(
'No idle tasks, and only %s busy tasks; adding %s more '
'workers', busy, self.spawn_if_under-busy)
self._last_added_new_idle_workers = time.time()
for i in range(self.spawn_if_under - busy):
self.add_worker_thread(message='Response to lack of idle workers')
else:
self.logger.debug(
'No extra workers needed (%s busy workers)',
busy)
if (len(self.workers) > self.nworkers
and len(self.idle_workers) > 3
and time.time()-self._last_added_new_idle_workers > self.hung_thread_limit):
# We've spawned worers in the past, but they aren't needed
# anymore; kill off some
self.logger.info(
'Culling %s extra workers (%s idle workers present)',
len(self.workers)-self.nworkers, len(self.idle_workers))
self.logger.debug(
'Idle workers: %s', self.idle_workers)
for i in range(len(self.workers) - self.nworkers):
self.queue.put(self.SHUTDOWN)
self.queue.put(task)
def track_threads(self):
"""
Return a dict summarizing the threads in the pool (as
described in the ThreadPool docstring).
"""
result = dict(idle=[], busy=[], hung=[], dying=[], zombie=[])
now = time.time()
for worker in self.workers:
if not hasattr(worker, 'thread_id'):
# The worker hasn't fully started up, we should just
# ignore it
continue
time_started, info = self.worker_tracker.get(worker.thread_id,
(None, None))
if time_started is not None:
if now - time_started > self.hung_thread_limit:
result['hung'].append(worker)
else:
result['busy'].append(worker)
else:
result['idle'].append(worker)
for thread_id, (time_killed, worker) in self.dying_threads.items():
if not self.thread_exists(thread_id):
# Cull dying threads that are actually dead and gone
self.logger.info('Killed thread %s no longer around',
thread_id)
try:
del self.dying_threads[thread_id]
except KeyError:
pass
continue
if now - time_killed > self.dying_limit:
result['zombie'].append(worker)
else:
result['dying'].append(worker)
return result
def kill_worker(self, thread_id):
"""
Removes the worker with the given thread_id from the pool, and
replaces it with a new worker thread.
This should only be done for mis-behaving workers.
"""
if killthread is None:
raise RuntimeError(
"Cannot kill worker; killthread/ctypes not available")
thread_obj = threading._active.get(thread_id)
killthread.async_raise(thread_id, SystemExit)
try:
del self.worker_tracker[thread_id]
except KeyError:
pass
self.logger.info('Killing thread %s', thread_id)
if thread_obj in self.workers:
self.workers.remove(thread_obj)
self.dying_threads[thread_id] = (time.time(), thread_obj)
self.add_worker_thread(message='Replacement for killed thread %s' % thread_id)
def thread_exists(self, thread_id):
"""
Returns true if a thread with this id is still running
"""
return thread_id in threading._active
def add_worker_thread(self, *args, **kwargs):
index = self._worker_count.next()
worker = threading.Thread(target=self.worker_thread_callback,
args=args, kwargs=kwargs,
name=("worker %d" % index))
worker.setDaemon(self.daemon)
worker.start()
def kill_hung_threads(self):
"""
Tries to kill any hung threads
"""
if not self.kill_thread_limit:
# No killing should occur
return
now = time.time()
max_time = 0
total_time = 0
idle_workers = 0
starting_workers = 0
working_workers = 0
killed_workers = 0
for worker in self.workers:
if not hasattr(worker, 'thread_id'):
# Not setup yet
starting_workers += 1
continue
time_started, info = self.worker_tracker.get(worker.thread_id,
(None, None))
if time_started is None:
# Must be idle
idle_workers += 1
continue
working_workers += 1
max_time = max(max_time, now-time_started)
total_time += now-time_started
if now - time_started > self.kill_thread_limit:
self.logger.warning(
'Thread %s hung (working on task for %i seconds)',
worker.thread_id, now - time_started)
try:
import pprint
info_desc = pprint.pformat(info)
except:
out = StringIO()
traceback.print_exc(file=out)
info_desc = 'Error:\n%s' % out.getvalue()
self.notify_problem(
"Killing worker thread (id=%(thread_id)s) because it has been \n"
"working on task for %(time)s seconds (limit is %(limit)s)\n"
"Info on task:\n"
"%(info)s"
% dict(thread_id=worker.thread_id,
time=now - time_started,
limit=self.kill_thread_limit,
info=info_desc))
self.kill_worker(worker.thread_id)
killed_workers += 1
if working_workers:
ave_time = float(total_time) / working_workers
ave_time = '%.2fsec' % ave_time
else:
ave_time = 'N/A'
self.logger.info(
"kill_hung_threads status: %s threads (%s working, %s idle, %s starting) "
"ave time %s, max time %.2fsec, killed %s workers"
% (idle_workers + starting_workers + working_workers,
working_workers, idle_workers, starting_workers,
ave_time, max_time, killed_workers))
self.check_max_zombies()
def check_max_zombies(self):
"""
Check if we've reached max_zombie_threads_before_die; if so
then kill the entire process.
"""
if not self.max_zombie_threads_before_die:
return
found = []
now = time.time()
for thread_id, (time_killed, worker) in self.dying_threads.items():
if not self.thread_exists(thread_id):
# Cull dying threads that are actually dead and gone
try:
del self.dying_threads[thread_id]
except KeyError:
pass
continue
if now - time_killed > self.dying_limit:
found.append(thread_id)
if found:
self.logger.info('Found %s zombie threads', found)
if len(found) > self.max_zombie_threads_before_die:
self.logger.fatal(
'Exiting process because %s zombie threads is more than %s limit',
len(found), self.max_zombie_threads_before_die)
self.notify_problem(
"Exiting process because %(found)s zombie threads "
"(more than limit of %(limit)s)\n"
"Bad threads (ids):\n"
" %(ids)s\n"
% dict(found=len(found),
limit=self.max_zombie_threads_before_die,
ids="\n ".join(map(str, found))),
subject="Process restart (too many zombie threads)")
self.shutdown(10)
print 'Shutting down', threading.currentThread()
raise ServerExit(3)
def worker_thread_callback(self, message=None):
"""
Worker thread should call this method to get and process queued
callables.
"""
thread_obj = threading.currentThread()
thread_id = thread_obj.thread_id = thread.get_ident()
self.workers.append(thread_obj)
self.idle_workers.append(thread_id)
requests_processed = 0
add_replacement_worker = False
self.logger.debug('Started new worker %s: %s', thread_id, message)
try:
while True:
if self.max_requests and self.max_requests < requests_processed:
# Replace this thread then die
self.logger.debug('Thread %s processed %i requests (limit %s); stopping thread'
% (thread_id, requests_processed, self.max_requests))
add_replacement_worker = True
break
runnable = self.queue.get()
if runnable is ThreadPool.SHUTDOWN:
self.logger.debug('Worker %s asked to SHUTDOWN', thread_id)
break
try:
self.idle_workers.remove(thread_id)
except ValueError:
pass
self.worker_tracker[thread_id] = [time.time(), None]
requests_processed += 1
try:
try:
runnable()
except:
# We are later going to call sys.exc_clear(),
# removing all remnants of any exception, so
# we should log it now. But ideally no
# exception should reach this level
print >> sys.stderr, (
'Unexpected exception in worker %r' % runnable)
traceback.print_exc()
if thread_id in self.dying_threads:
# That last exception was intended to kill me
break
finally:
try:
del self.worker_tracker[thread_id]
except KeyError:
pass
sys.exc_clear()
self.idle_workers.append(thread_id)
finally:
try:
del self.worker_tracker[thread_id]
except KeyError:
pass
try:
self.idle_workers.remove(thread_id)
except ValueError:
pass
try:
self.workers.remove(thread_obj)
except ValueError:
pass
try:
del self.dying_threads[thread_id]
except KeyError:
pass
if add_replacement_worker:
self.add_worker_thread(message='Voluntary replacement for thread %s' % thread_id)
def shutdown(self, force_quit_timeout=0):
"""
Shutdown the queue (after finishing any pending requests).
"""
self.logger.info('Shutting down threadpool')
# Add a shutdown request for every worker
for i in range(len(self.workers)):
self.queue.put(ThreadPool.SHUTDOWN)
# Wait for each thread to terminate
hung_workers = []
for worker in self.workers:
worker.join(0.5)
if worker.isAlive():
hung_workers.append(worker)
zombies = []
for thread_id in self.dying_threads:
if self.thread_exists(thread_id):
zombies.append(thread_id)
if hung_workers or zombies:
self.logger.info("%s workers didn't stop properly, and %s zombies",
len(hung_workers), len(zombies))
if hung_workers:
for worker in hung_workers:
self.kill_worker(worker.thread_id)
self.logger.info('Workers killed forcefully')
if force_quit_timeout:
hung = []
timed_out = False
need_force_quit = bool(zombies)
for workers in self.workers:
if not timed_out and worker.isAlive():
timed_out = True
worker.join(force_quit_timeout)
if worker.isAlive():
print "Worker %s won't die" % worker
need_force_quit = True
if need_force_quit:
import atexit
# Remove the threading atexit callback
for callback in list(atexit._exithandlers):
func = getattr(callback[0], 'im_func', None)
if not func:
continue
globs = getattr(func, 'func_globals', {})
mod = globs.get('__name__')
if mod == 'threading':
atexit._exithandlers.remove(callback)
atexit._run_exitfuncs()
print 'Forcefully exiting process'
os._exit(3)
else:
self.logger.info('All workers eventually killed')
else:
self.logger.info('All workers stopped')
def notify_problem(self, msg, subject=None, spawn_thread=True):
"""
Called when there's a substantial problem. msg contains the
body of the notification, subject the summary.
If spawn_thread is true, then the email will be send in
another thread (so this doesn't block).
"""
if not self.error_email:
return
if spawn_thread:
t = threading.Thread(
target=self.notify_problem,
args=(msg, subject, False))
t.start()
return
from_address = 'errors@localhost'
if not subject:
subject = msg.strip().splitlines()[0]
subject = subject[:50]
subject = '[http threadpool] %s' % subject
headers = [
"To: %s" % self.error_email,
"From: %s" % from_address,
"Subject: %s" % subject,
]
try:
system = ' '.join(os.uname())
except:
system = '(unknown)'
body = (
"An error has occurred in the paste.httpserver.ThreadPool\n"
"Error:\n"
" %(msg)s\n"
"Occurred at: %(time)s\n"
"PID: %(pid)s\n"
"System: %(system)s\n"
"Server .py file: %(file)s\n"
% dict(msg=msg,
time=time.strftime("%c"),
pid=os.getpid(),
system=system,
file=os.path.abspath(__file__),
))
message = '\n'.join(headers) + "\n\n" + body
import smtplib
server = smtplib.SMTP('localhost')
error_emails = [
e.strip() for e in self.error_email.split(",")
if e.strip()]
server.sendmail(from_address, error_emails, message)
server.quit()
print 'email sent to', error_emails, message
class ThreadPoolMixIn(object):
"""
Mix-in class to process requests from a thread pool
"""
def __init__(self, nworkers, daemon=False, **threadpool_options):
# Create and start the workers
self.running = True
assert nworkers > 0, "ThreadPoolMixIn servers must have at least one worker"
self.thread_pool = ThreadPool(
nworkers,
"ThreadPoolMixIn HTTP server on %s:%d"
% (self.server_name, self.server_port),
daemon,
**threadpool_options)
def process_request(self, request, client_address):
"""
Queue the request to be processed by on of the thread pool threads
"""
# This sets the socket to blocking mode (and no timeout) since it
# may take the thread pool a little while to get back to it. (This
# is the default but since we set a timeout on the parent socket so
# that we can trap interrupts we need to restore this,.)
request.setblocking(1)
# Queue processing of the request
self.thread_pool.add_task(
lambda: self.process_request_in_thread(request, client_address))
def handle_error(self, request, client_address):
exc_class, exc, tb = sys.exc_info()
if exc_class is ServerExit:
# This is actually a request to stop the server
raise
return super(ThreadPoolMixIn, self).handle_error(request, client_address)
def process_request_in_thread(self, request, client_address):
"""
The worker thread should call back here to do the rest of the
request processing. Error handling normaller done in 'handle_request'
must be done here.
"""
try:
self.finish_request(request, client_address)
self.close_request(request)
except:
self.handle_error(request, client_address)
self.close_request(request)
exc = sys.exc_info()[1]
if isinstance(exc, (MemoryError, KeyboardInterrupt)):
raise
def serve_forever(self):
"""
Overrides `serve_forever` to shut the threadpool down cleanly.
"""
try:
while self.running:
try:
self.handle_request()
except socket.timeout:
# Timeout is expected, gives interrupts a chance to
# propogate, just keep handling
pass
finally:
self.thread_pool.shutdown()
def server_activate(self):
"""
Overrides server_activate to set timeout on our listener socket.
"""
# We set the timeout here so that we can trap interrupts on windows
self.socket.settimeout(1)
def server_close(self):
"""
Finish pending requests and shutdown the server.
"""
self.running = False
self.socket.close()
self.thread_pool.shutdown(60)
class WSGIServerBase(SecureHTTPServer):
def __init__(self, wsgi_application, server_address,
RequestHandlerClass=None, ssl_context=None,
request_queue_size=None):
SecureHTTPServer.__init__(self, server_address,
RequestHandlerClass, ssl_context,
request_queue_size=request_queue_size)
self.wsgi_application = wsgi_application
self.wsgi_socket_timeout = None
def get_request(self):
# If there is a socket_timeout, set it on the accepted
(conn,info) = SecureHTTPServer.get_request(self)
if self.wsgi_socket_timeout:
conn.settimeout(self.wsgi_socket_timeout)
return (conn, info)
class WSGIServer(ThreadingMixIn, WSGIServerBase):
daemon_threads = False
class WSGIThreadPoolServer(ThreadPoolMixIn, WSGIServerBase):
def __init__(self, wsgi_application, server_address,
RequestHandlerClass=None, ssl_context=None,
nworkers=10, daemon_threads=False,
threadpool_options=None, request_queue_size=None):
WSGIServerBase.__init__(self, wsgi_application, server_address,
RequestHandlerClass, ssl_context,
request_queue_size=request_queue_size)
if threadpool_options is None:
threadpool_options = {}
ThreadPoolMixIn.__init__(self, nworkers, daemon_threads,
**threadpool_options)
class ServerExit(SystemExit):
"""
Raised to tell the server to really exit (SystemExit is normally
caught)
"""
def serve(application, host=None, port=None, handler=None, ssl_pem=None,
ssl_context=None, server_version=None, protocol_version=None,
start_loop=True, daemon_threads=None, socket_timeout=None,
use_threadpool=None, threadpool_workers=10,
threadpool_options=None, request_queue_size=5):
"""
Serves your ``application`` over HTTP(S) via WSGI interface
``host``
This is the ipaddress to bind to (or a hostname if your
nameserver is properly configured). This defaults to
127.0.0.1, which is not a public interface.
``port``
The port to run on, defaults to 8080 for HTTP, or 4443 for
HTTPS. This can be a string or an integer value.
``handler``
This is the HTTP request handler to use, it defaults to
``WSGIHandler`` in this module.
``ssl_pem``
This an optional SSL certificate file (via OpenSSL). You can
supply ``*`` and a development-only certificate will be
created for you, or you can generate a self-signed test PEM
certificate file as follows::
$ openssl genrsa 1024 > host.key
$ chmod 400 host.key
$ openssl req -new -x509 -nodes -sha1 -days 365 \\
-key host.key > host.cert
$ cat host.cert host.key > host.pem
$ chmod 400 host.pem
``ssl_context``
This an optional SSL context object for the server. A SSL
context will be automatically constructed for you if you supply
``ssl_pem``. Supply this to use a context of your own
construction.
``server_version``
The version of the server as reported in HTTP response line. This
defaults to something like "PasteWSGIServer/0.5". Many servers
hide their code-base identity with a name like 'Amnesiac/1.0'
``protocol_version``
This sets the protocol used by the server, by default
``HTTP/1.0``. There is some support for ``HTTP/1.1``, which
defaults to nicer keep-alive connections. This server supports
``100 Continue``, but does not yet support HTTP/1.1 Chunked
Encoding. Hence, if you use HTTP/1.1, you're somewhat in error
since chunked coding is a mandatory requirement of a HTTP/1.1
server. If you specify HTTP/1.1, every response *must* have a
``Content-Length`` and you must be careful not to read past the
end of the socket.
``start_loop``
This specifies if the server loop (aka ``server.serve_forever()``)
should be called; it defaults to ``True``.
``daemon_threads``
This flag specifies if when your webserver terminates all
in-progress client connections should be droppped. It defaults
to ``False``. You might want to set this to ``True`` if you
are using ``HTTP/1.1`` and don't set a ``socket_timeout``.
``socket_timeout``
This specifies the maximum amount of time that a connection to a
given client will be kept open. At this time, it is a rude
disconnect, but at a later time it might follow the RFC a bit
more closely.
``use_threadpool``
Server requests from a pool of worker threads (``threadpool_workers``)
rather than creating a new thread for each request. This can
substantially reduce latency since there is a high cost associated
with thread creation.
``threadpool_workers``
Number of worker threads to create when ``use_threadpool`` is true. This
can be a string or an integer value.
``threadpool_options``
A dictionary of options to be used when instantiating the
threadpool. See paste.httpserver.ThreadPool for specific
options (``threadpool_workers`` is a specific option that can
also go here).
``request_queue_size``
The 'backlog' argument to socket.listen(); specifies the
maximum number of queued connections.
"""
is_ssl = False
if ssl_pem or ssl_context:
assert SSL, "pyOpenSSL is not installed"
is_ssl = True
port = int(port or 4443)
if not ssl_context:
if ssl_pem == '*':
ssl_context = _auto_ssl_context()
else:
ssl_context = SSL.Context(SSL.SSLv23_METHOD)
ssl_context.use_privatekey_file(ssl_pem)
ssl_context.use_certificate_chain_file(ssl_pem)
host = host or '127.0.0.1'
if port is None:
if ':' in host:
host, port = host.split(':', 1)
else:
port = 8080
server_address = (host, int(port))
if not handler:
handler = WSGIHandler
if server_version:
handler.server_version = server_version
handler.sys_version = None
if protocol_version:
assert protocol_version in ('HTTP/0.9', 'HTTP/1.0', 'HTTP/1.1')
handler.protocol_version = protocol_version
if use_threadpool is None:
use_threadpool = True
if converters.asbool(use_threadpool):
server = WSGIThreadPoolServer(application, server_address, handler,
ssl_context, int(threadpool_workers),
daemon_threads,
threadpool_options=threadpool_options,
request_queue_size=request_queue_size)
else:
server = WSGIServer(application, server_address, handler, ssl_context,
request_queue_size=request_queue_size)
if daemon_threads:
server.daemon_threads = daemon_threads
if socket_timeout:
server.wsgi_socket_timeout = int(socket_timeout)
if converters.asbool(start_loop):
protocol = is_ssl and 'https' or 'http'
host, port = server.server_address[:2]
if host == '0.0.0.0':
print 'serving on 0.0.0.0:%s view at %s://127.0.0.1:%s' % \
(port, protocol, port)
else:
print "serving on %s://%s:%s" % (protocol, host, port)
try:
server.serve_forever()
except KeyboardInterrupt:
# allow CTRL+C to shutdown
pass
return server
# For paste.deploy server instantiation (egg:Paste#http)
# Note: this gets a separate function because it has to expect string
# arguments (though that's not much of an issue yet, ever?)
def server_runner(wsgi_app, global_conf, **kwargs):
from paste.deploy.converters import asbool
for name in ['port', 'socket_timeout', 'threadpool_workers',
'threadpool_hung_thread_limit',
'threadpool_kill_thread_limit',
'threadpool_dying_limit', 'threadpool_spawn_if_under',
'threadpool_max_zombie_threads_before_die',
'threadpool_hung_check_period',
'threadpool_max_requests', 'request_queue_size']:
if name in kwargs:
kwargs[name] = int(kwargs[name])
for name in ['use_threadpool', 'daemon_threads']:
if name in kwargs:
kwargs[name] = asbool(kwargs[name])
threadpool_options = {}
for name, value in kwargs.items():
if name.startswith('threadpool_') and name != 'threadpool_workers':
threadpool_options[name[len('threadpool_'):]] = value
del kwargs[name]
if ('error_email' not in threadpool_options
and 'error_email' in global_conf):
threadpool_options['error_email'] = global_conf['error_email']
kwargs['threadpool_options'] = threadpool_options
serve(wsgi_app, **kwargs)
server_runner.__doc__ = (serve.__doc__ or '') + """
You can also set these threadpool options:
``threadpool_max_requests``:
The maximum number of requests a worker thread will process
before dying (and replacing itself with a new worker thread).
Default 100.
``threadpool_hung_thread_limit``:
The number of seconds a thread can work on a task before it is
considered hung (stuck). Default 30 seconds.
``threadpool_kill_thread_limit``:
The number of seconds a thread can work before you should kill it
(assuming it will never finish). Default 600 seconds (10 minutes).
``threadpool_dying_limit``:
The length of time after killing a thread that it should actually
disappear. If it lives longer than this, it is considered a
"zombie". Note that even in easy situations killing a thread can
be very slow. Default 300 seconds (5 minutes).
``threadpool_spawn_if_under``:
If there are no idle threads and a request comes in, and there are
less than this number of *busy* threads, then add workers to the
pool. Busy threads are threads that have taken less than
``threadpool_hung_thread_limit`` seconds so far. So if you get
*lots* of requests but they complete in a reasonable amount of time,
the requests will simply queue up (adding more threads probably
wouldn't speed them up). But if you have lots of hung threads and
one more request comes in, this will add workers to handle it.
Default 5.
``threadpool_max_zombie_threads_before_die``:
If there are more zombies than this, just kill the process. This is
only good if you have a monitor that will automatically restart
the server. This can clean up the mess. Default 0 (disabled).
`threadpool_hung_check_period``:
Every X requests, check for hung threads that need to be killed,
or for zombie threads that should cause a restart. Default 100
requests.
``threadpool_logger``:
Logging messages will go the logger named here.
``threadpool_error_email`` (or global ``error_email`` setting):
When threads are killed or the process restarted, this email
address will be contacted (using an SMTP server on localhost).
"""
if __name__ == '__main__':
from paste.wsgilib import dump_environ
#serve(dump_environ, ssl_pem="test.pem")
serve(dump_environ, server_version="Wombles/1.0",
protocol_version="HTTP/1.1", port="8888")
Mini Shell