def test__raises_exception_when_child_exits_with_non_zero_code(self):
exit_code = randint(1, 99)
expected_message = re.escape("Child exited with code %s" % exit_code)
with ExpectedException(PipeForkError, expected_message):
with pipefork() as (pid, fin, fout):
if pid == 0:
os._exit(exit_code)
def test__raises_childs_exception_when_child_crashes(self):
# If the child process exits with an exception, it is passed back to
# the parent via a pickled t.p.failure.Failure, and re-raised.
with ExpectedException(ZeroDivisionError):
with pipefork() as (pid, fin, fout):
if pid == 0:
# Child.
raise ZeroDivisionError()
def test__SystemExit_in_child_is_not_raised_in_parent(self):
# All exceptions are pickled and passed back to the parent process,
# except for SystemExit. It instead results in a call to os._exit().
exit_code = randint(1, 99)
expected_message = re.escape("Child exited with code %s" % exit_code)
with ExpectedException(PipeForkError, expected_message):
with pipefork() as (pid, fin, fout):
if pid == 0:
raise SystemExit(exit_code)
def test__raises_parents_exception_when_parent_crashes(self):
# If the parent raises an exception, it is propagated. During
# tear-down of the pipefork's context the child is reaped, but any
# exceptions (via the crash file, or raised on behalf of the child
# because of a non-zero exit code or non-zero signal) propagating back
# from the child are masked by the exception in the parent.
with ExpectedException(ZeroDivisionError):
with pipefork() as (pid, fin, fout):
if pid != 0:
# Parent.
raise ZeroDivisionError()
def test__raises_exception_when_child_killed_by_signal(self):
expected_message = re.escape("Child killed by signal 15 (SIGTERM)")
with ExpectedException(PipeForkError, expected_message):
with pipefork() as (pid, fin, fout):
if pid == 0:
# Reset SIGTERM to the default handler; the Twisted
# reactor may have clobbered it in the parent.
signal.signal(signal.SIGTERM, signal.SIG_DFL)
# Close `fout` to signal to parent that we're running.
fout.close()
time.sleep(10)
else:
# Wait for child to close its `fout` before signalling.
fin.read()
os.kill(pid, signal.SIGTERM)
def test__forks(self):
with pipefork() as (pid, fin, fout):
if pid == 0:
# Child.
message_in = fin.read()
message_out = b"Hello %s!" % message_in
fout.write(message_out)
fout.close()
else:
# Parent.
message_out = factory.make_name("Parent").encode("ascii")
fout.write(message_out)
fout.close()
message_in = fin.read()
self.assertEqual(b"Hello %s!" % message_out, message_in)