twisted.application.runner._pidfile.PIDFile

class documentation

class PIDFile: (source)

Constructor: PIDFile(filePath)

Implements interfaces: twisted.application.runner._pidfile.IPIDFile

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Concrete implementation of IPIDFile.

This implementation is presently not supported on non-POSIX platforms. Specifically, calling PIDFile.isRunning will raise NotImplementedError.

Method	`__enter__`	Enter a context using this PIDFile.
Method	`__exit__`	Exit a context using this PIDFile.
Method	`__init__`	No summary
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.
Instance Variable	`filePath`	Undocumented
Static Method	`_format`	Format a PID file's content.
Static Method	`_pidIsRunningPOSIX`	POSIX implementation for running process check.
Method	`_write`	Store a PID in this PID file.
Class Variable	`_log`	Undocumented

def __enter__(self) -> PIDFile: (source) ¶

from twisted.application.runner._pidfile.IPIDFile

Enter a context using this PIDFile.

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

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

def __exit__(self, excType: Optional[Type[BaseException]], excValue: Optional[BaseException], traceback: Optional[TracebackType]): (source) ¶

from twisted.application.runner._pidfile.IPIDFile

Exit a context using this PIDFile.

Removes the PID file.

def __init__(self, filePath: FilePath[Any]): (source) ¶

Parameters
filePath:`FilePath[Any]`	The path to the PID file on disk.

def isRunning(self) -> bool: (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) -> int: (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.

filePath = (source) ¶

Undocumented

@staticmethod
def _format(pid: int) -> bytes: (source) ¶

Format a PID file's content.

Parameters
pid:`int`	A process ID.
Returns
`bytes`	Formatted PID file contents.

@staticmethod
def _pidIsRunningPOSIX(pid: int) -> bool: (source) ¶

POSIX implementation for running process check.

Determine whether there is a running process corresponding to the given PID.

Parameters
pid:`int`	The PID to check.
Returns
`bool`	True if the given 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 _write(self, pid: int): (source) ¶

Store a PID in this PID file.

Parameters
pid:`int`	A PID to store.
Raises
`EnvironmentError`	If this PID file cannot be written.

_log = (source) ¶

Undocumented