twisted.application.runner._pidfile.NonePIDFile

Method	`__enter__`	Enter a context using this PIDFile.
Method	`__exit__`	Exit a context using this PIDFile.
Method	`__init__`	Undocumented
Method	`isRunning`	Determine whether there is a running process corresponding to the PID in this PID file.
Method	`read`	Read the process ID stored in this PID file.
Method	`remove`	Remove this PID file.
Method	`writeRunningPID`	Store the PID of the current process in this PID file.
Method	`_write`	Store a PID in this PID file.

def __enter__(self): (source)

from twisted.application.runner._pidfile.IPIDFile

Enter a context using this PIDFile.

Writes the PID file with the PID of the running process.

Returns
`NonePIDFile`	Undocumented
Raises
`AlreadyRunningError`	A process corresponding to the PID in this PID file is already running.

def __exit__(self, excType, excValue, traceback): (source)

from twisted.application.runner._pidfile.IPIDFile

Exit a context using this PIDFile.

Removes the PID file.

Parameters
excType:`Optional[Type[BaseException]]`	Undocumented
excValue:`Optional[BaseException]`	Undocumented
traceback:`Optional[TracebackType]`	Undocumented

def __init__(self): (source)

Undocumented

def isRunning(self): (source)

from twisted.application.runner._pidfile.IPIDFile

Determine whether there is a running process corresponding to the PID in this PID file.

Returns
`bool`	True if this PID file contains a PID and a process with that PID is currently running; false otherwise.
Raises
`EnvironmentError`	If this PID file cannot be read.
`InvalidPIDFileError`	If this PID file's content is invalid.
`StalePIDFileError`	If this PID file's content refers to a PID for which there is no corresponding running process.

def read(self): (source)

from twisted.application.runner._pidfile.IPIDFile

Read the process ID stored in this PID file.

Returns
`int`	The contained process ID.
Raises
`NoPIDFound`	If this PID file does not exist.
`EnvironmentError`	If this PID file cannot be read.
`ValueError`	If this PID file's content is invalid.

def remove(self): (source)

from twisted.application.runner._pidfile.IPIDFile

Remove this PID file.

Raises
`EnvironmentError`	If this PID file cannot be removed.

def writeRunningPID(self): (source)

from twisted.application.runner._pidfile.IPIDFile

Store the PID of the current process in this PID file.

Raises
`EnvironmentError`	If this PID file cannot be written.

def _write(self, pid): (source)

Store a PID in this PID file.

Parameters
pid:`int`	A PID to store.
Raises
`EnvironmentError`	If this PID file cannot be written.
Note
This implementation always raises an `EnvironmentError`.