# -*- test-case-name: twisted.test.test_process -*-
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.

"""
Cross-platform process-related functionality used by different
L{IReactorProcess} implementations.
"""

from twisted.python.reflect import qual
from twisted.python.deprecate import getWarningMethod
from twisted.python.failure import Failure
from twisted.python.log import err
from twisted.persisted.styles import Ephemeral

_missingProcessExited = ("Since Twisted 8.2, IProcessProtocol.processExited "
"is required. %s must implement it.")

class BaseProcess(Ephemeral):
pid = None
status = None
lostProcess = 0
proto = None

def __init__(self, protocol):
self.proto = protocol


def _callProcessExited(self, reason):
default = object()
processExited = getattr(self.proto, 'processExited', default)
if processExited is default:
getWarningMethod()(
_missingProcessExited % (qual(self.proto.__class__),),
DeprecationWarning, stacklevel=0)
else:
processExited(Failure(reason))


def processEnded(self, status):
"""
This is called when the child terminates.
"""
self.status = status
self.lostProcess += 1
self.pid = None
self._callProcessExited(self._getReason(status))
self.maybeCallProcessEnded()


def maybeCallProcessEnded(self):
"""
Call processEnded on protocol after final cleanup.
"""
if self.proto is not None:
reason = self._getReason(self.status)
proto = self.proto
self.proto = None
try:
proto.processEnded(Failure(reason))
except:
err(None, "unexpected error in processEnded")