########################################
#
# The MIT License (MIT)
#
# Copyright (c) typedef int GmbH
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# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software'), to deal
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# The above copyright notice and this permission notice shall be included in
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# THE SOFTWARE IS PROVIDED "AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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########################################
import sys
import traceback
import txaio
txaio.use_twisted()
from twisted.internet.error import ReactorAlreadyInstalledError
from twisted.python import reflect
__all__ = ("current_reactor_klass", "install_optimal_reactor", "install_reactor")
[docs]
def current_reactor_klass():
"""
Return class name of currently installed Twisted reactor or None.
"""
if "twisted.internet.reactor" in sys.modules:
current_reactor = reflect.qual(
sys.modules["twisted.internet.reactor"].__class__
).split(".")[-1]
else:
current_reactor = None
return current_reactor
[docs]
def install_optimal_reactor(require_optimal_reactor=True):
"""
Try to install the optimal Twisted reactor for this platform:
- Linux: epoll
- BSD/OSX: kqueue
- Windows: iocp
- Other: select
Notes:
- This function exists, because the reactor types selected based on platform
in `twisted.internet.default` are different from here.
- The imports are inlined, because the Twisted code base is notorious for
importing the reactor as a side-effect of merely importing. Hence we postpone
all importing.
See: http://twistedmatrix.com/documents/current/core/howto/choosing-reactor.html#reactor-functionality
:param require_optimal_reactor: If ``True`` and the desired reactor could not be installed,
raise ``ReactorAlreadyInstalledError``, else fallback to another reactor.
:type require_optimal_reactor: bool
:returns: The Twisted reactor in place (`twisted.internet.reactor`).
"""
log = txaio.make_logger()
# determine currently installed reactor, if any
#
current_reactor = current_reactor_klass()
# depending on platform, install optimal reactor
#
if "bsd" in sys.platform or sys.platform.startswith("darwin"):
# *BSD and MacOSX
#
if current_reactor != "KQueueReactor":
if current_reactor is None:
try:
from twisted.internet import kqreactor
kqreactor.install()
except:
log.warn(
"Running on *BSD or MacOSX, but cannot install kqueue Twisted reactor: {tb}",
tb=traceback.format_exc(),
)
else:
log.debug(
"Running on *BSD or MacOSX and optimal reactor (kqueue) was installed."
)
else:
log.warn(
"Running on *BSD or MacOSX, but cannot install kqueue Twisted reactor, because another reactor ({klass}) is already installed.",
klass=current_reactor,
)
if require_optimal_reactor:
raise ReactorAlreadyInstalledError()
else:
log.debug(
"Running on *BSD or MacOSX and optimal reactor (kqueue) already installed."
)
elif sys.platform in ["win32"]:
# Windows
#
if current_reactor != "IOCPReactor":
if current_reactor is None:
try:
from twisted.internet.iocpreactor import reactor as iocpreactor
iocpreactor.install()
except:
log.warn(
"Running on Windows, but cannot install IOCP Twisted reactor: {tb}",
tb=traceback.format_exc(),
)
else:
log.debug(
"Running on Windows and optimal reactor (ICOP) was installed."
)
else:
log.warn(
"Running on Windows, but cannot install IOCP Twisted reactor, because another reactor ({klass}) is already installed.",
klass=current_reactor,
)
if require_optimal_reactor:
raise ReactorAlreadyInstalledError()
else:
log.debug(
"Running on Windows and optimal reactor (ICOP) already installed."
)
elif sys.platform.startswith("linux"):
# Linux
#
if current_reactor != "EPollReactor":
if current_reactor is None:
try:
from twisted.internet import epollreactor
epollreactor.install()
except:
log.warn(
"Running on Linux, but cannot install Epoll Twisted reactor: {tb}",
tb=traceback.format_exc(),
)
else:
log.debug(
"Running on Linux and optimal reactor (epoll) was installed."
)
else:
log.warn(
"Running on Linux, but cannot install Epoll Twisted reactor, because another reactor ({klass}) is already installed.",
klass=current_reactor,
)
if require_optimal_reactor:
raise ReactorAlreadyInstalledError()
else:
log.debug("Running on Linux and optimal reactor (epoll) already installed.")
else:
# Other platform
#
if current_reactor != "SelectReactor":
if current_reactor is None:
try:
from twisted.internet import selectreactor
selectreactor.install()
# from twisted.internet import default as defaultreactor
# defaultreactor.install()
except:
log.warn(
'Running on "{platform}", but cannot install Select Twisted reactor: {tb}',
tb=traceback.format_exc(),
platform=sys.platform,
)
else:
log.debug(
'Running on "{platform}" and optimal reactor (Select) was installed.',
platform=sys.platform,
)
else:
log.warn(
'Running on "{platform}", but cannot install Select Twisted reactor, because another reactor ({klass}) is already installed.',
klass=current_reactor,
platform=sys.platform,
)
if require_optimal_reactor:
raise ReactorAlreadyInstalledError()
else:
log.debug(
'Running on "{platform}" and optimal reactor (Select) already installed.',
platform=sys.platform,
)
from twisted.internet import reactor
txaio.config.loop = reactor
return reactor
[docs]
def install_reactor(
explicit_reactor=None, verbose=False, log=None, require_optimal_reactor=True
):
"""
Install Twisted reactor.
:param explicit_reactor: If provided, install this reactor. Else, install
the optimal reactor.
:type explicit_reactor: obj
:param verbose: If ``True``, log (at level "info") the reactor that is
in place afterwards.
:type verbose: bool
:param log: Explicit logging to this txaio logger object.
:type log: obj
:param require_optimal_reactor: If ``True`` and the desired reactor could not be installed,
raise ``ReactorAlreadyInstalledError``, else fallback to another reactor.
:type require_optimal_reactor: bool
:returns: The Twisted reactor in place (`twisted.internet.reactor`).
"""
if not log:
log = txaio.make_logger()
if explicit_reactor:
# install explicitly given reactor
#
from twisted.application.reactors import installReactor
if verbose:
log.info(
'Trying to install explicitly specified Twisted reactor "{reactor}" ..',
reactor=explicit_reactor,
)
try:
installReactor(explicit_reactor)
except:
log.failure(
"Could not install Twisted reactor {reactor}\n{log_failure.value}",
reactor=explicit_reactor,
)
sys.exit(1)
else:
# automatically choose optimal reactor
#
if verbose:
log.info("Automatically choosing optimal Twisted reactor ..")
install_optimal_reactor(require_optimal_reactor)
# now the reactor is installed, import it
from twisted.internet import reactor
txaio.config.loop = reactor
if verbose:
from twisted.python.reflect import qual
log.info(
"Running on Twisted reactor {reactor}", reactor=qual(reactor.__class__)
)
return reactor