class documentation

class PIDFile: (source)

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__
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): (source)

Enter a context using this PIDFile.

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

Returns
PIDFileUndocumented
Raises
AlreadyRunningErrorA process corresponding to the PID in this PID file is already running.
def __exit__(self, excType, excValue, traceback): (source)

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, filePath): (source)
Parameters
filePath:FilePathThe path to the PID file on disk.
def isRunning(self): (source)
Determine whether there is a running process corresponding to the PID in this PID file.
Returns
boolTrue if this PID file contains a PID and a process with that PID is currently running; false otherwise.
Raises
EnvironmentErrorIf this PID file cannot be read.
InvalidPIDFileErrorIf this PID file's content is invalid.
StalePIDFileErrorIf this PID file's content refers to a PID for which there is no corresponding running process.
def read(self): (source)
Read the process ID stored in this PID file.
Returns
intThe contained process ID.
Raises
NoPIDFoundIf this PID file does not exist.
EnvironmentErrorIf this PID file cannot be read.
ValueErrorIf this PID file's content is invalid.
def remove(self): (source)
Remove this PID file.
Raises
EnvironmentErrorIf this PID file cannot be removed.
def writeRunningPID(self): (source)
Store the PID of the current process in this PID file.
Raises
EnvironmentErrorIf this PID file cannot be written.
filePath = (source)

Undocumented

@staticmethod
def _format(pid): (source)
Format a PID file's content.
Parameters
pid:intA process ID.
Returns
bytesFormatted PID file contents.
@staticmethod
def _pidIsRunningPOSIX(pid): (source)

POSIX implementation for running process check.

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

Parameters
pid:intThe PID to check.
Returns
boolTrue if the given PID is currently running; false otherwise.
Raises
EnvironmentErrorIf this PID file cannot be read.
InvalidPIDFileErrorIf this PID file's content is invalid.
StalePIDFileErrorIf this PID file's content refers to a PID for which there is no corresponding running process.
def _write(self, pid): (source)
Store a PID in this PID file.
Parameters
pid:intA PID to store.
Raises
EnvironmentErrorIf this PID file cannot be written.
_log = (source)

Undocumented