U lu f ã@s2dZddlZddlmZmZmZGdd„dƒZdS)zWin32 compatibility utilities.éN)ÚAnyÚCallableÚOptionalc@sFeZdZdZd eegefddœdd„Zdd„Zdd „Z d d „Z dS) Úallow_interruptaDUtility for fixing CTRL-C events on Windows. On Windows, the Python interpreter intercepts CTRL-C events in order to translate them into ``KeyboardInterrupt`` exceptions. It (presumably) does this by setting a flag in its "console control handler" and checking it later at a convenient location in the interpreter. However, when the Python interpreter is blocked waiting for the ZMQ poll operation to complete, it must wait for ZMQ's ``select()`` operation to complete before translating the CTRL-C event into the ``KeyboardInterrupt`` exception. The only way to fix this seems to be to add our own "console control handler" and perform some application-defined operation that will unblock the ZMQ polling operation in order to force ZMQ to pass control back to the Python interpreter. This context manager performs all that Windows-y stuff, providing you with a hook that is called when a CTRL-C event is intercepted. This hook allows you to unblock your ZMQ poll operation immediately, which will then result in the expected ``KeyboardInterrupt`` exception. Without this context manager, your ZMQ-based application will not respond normally to CTRL-C events on Windows. If a CTRL-C event occurs while blocked on ZMQ socket polling, the translation to a ``KeyboardInterrupt`` exception will be delayed until the I/O completes and control returns to the Python interpreter (this may never happen if you use an infinite timeout). A no-op implementation is provided on non-Win32 systems to avoid the application from having to conditionally use it. Example usage: .. sourcecode:: python def stop_my_application(): # ... with allow_interrupt(stop_my_application): # main polling loop. In a typical ZMQ application, you would use the "self pipe trick" to send message to a ``PAIR`` socket in order to interrupt your blocking socket polling operation. In a Tornado event loop, you can use the ``IOLoop.stop`` method to unblock your I/O loop. N)ÚactionÚreturncCstjdkrdS| |¡dS)aTranslate ``action`` into a CTRL-C handler. ``action`` is a callable that takes no arguments and returns no value (returned value is ignored). It must *NEVER* raise an exception. If unspecified, a no-op will be used. ÚntN)ÚosÚnameÚ _init_action)Úselfr©r ú3/tmp/pip-unpacked-wheel-h6ekxre8/zmq/utils/win32.pyÚ__init__?s zallow_interrupt.__init__c s€ddlm}m}ddlm}m}| d¡}|||ƒ}|j}|_||f|_ ||_ ˆdkr`dd„‰ˆ|_ |‡fdd„ƒ} | |_ dS) Nr)Ú WINFUNCTYPEÚwindll)ÚBOOLÚDWORDÚkernel32cSsdS)Nr r r r rÚ[óz.allow_interrupt._init_action..cs|dkrˆƒdS)Nrr )Úevent©rr rÚhandle^sz,allow_interrupt._init_action..handle) ÚctypesrrZctypes.wintypesrrÚ LoadLibraryÚSetConsoleCtrlHandlerÚ_SetConsoleCtrlHandlerÚargtypesÚrestyperr) r rrrrrrZPHANDLER_ROUTINErrr rrr Ls  þ  zallow_interrupt._init_actioncCs.tjdkrdS| |jd¡}|dkr*tƒ‚dS)z"Install the custom CTRL-C handler.rNér©r r rrÚOSError)r Úresultr r rÚ __enter__ls  zallow_interrupt.__enter__cGs.tjdkrdS| |jd¡}|dkr*tƒ‚dS)z!Remove the custom CTRL-C handler.rNrr!)r Úargsr#r r rÚ__exit__vs  zallow_interrupt.__exit__)N) Ú__name__Ú __module__Ú __qualname__Ú__doc__rrrrr r$r&r r r rr s 2   r)r*r Útypingrrrrr r r rÚs