async def test_fork_dead():
"""
Try to fork a dead scope.
"""
scope = Scope()
async with scope:
pass
with pytest.raises(AssertionError):
_ = scope.fork()
async def test_nested_cancel_wait():
"""
"""
parent = Scope()
child = parent.fork()
child << run10()
await asyncio.sleep(0.1)
child.cancel()
parent.cancel()
await asyncio.wait_for(asyncio.shield(parent), 1)
async def test_nested_cancel_join(wait):
"""
"""
parent = Scope()
child = parent.fork()
child << run10()
await asyncio.sleep(0.1)
child.cancel()
parent.cancel()
if wait:
await parent
else:
await asyncio.wait_for(parent, 1)
class Server:
"""Async TCP server using a scope to clean up everything"""
def __init__(self):
self.scope = Scope(name='TCP')
self.scope.add_done_callback(self.stop)
self.server = None
def stop(self, _):
print('scope done. closing server')
if self.server:
self.server.close()
async def run(self):
# Start TCP server
self.server = await asyncio.start_server(self.client_connected,
'0.0.0.0', 5000)
# Join the scope forever
await self.scope
async def client_connected(self, reader, writer):
peer = writer.get_extra_info('peername')
print(peer, 'connected')
async with self.scope.fork(name=peer) as ctx:
# We make one context for this connection
# Here it's overkill, but you could have to spawn many jobs!
try:
while True:
try:
data = await (ctx << reader.readline())
except OSError as ex:
print(peer, 'socket error:', ex)
break
if not data:
# Connection closed
break
txt = data.decode().strip()
print(peer, 'received:', txt)
if txt == 'stop':
# Cancel the scope and exit
print('>>> stopping server')
writer.write('Closing!\n'.encode())
self.scope.cancel()
break
# Write reply and loop
writer.write('Hello {}!\n'.format(txt).encode())
# Just for fun, print later the received message
ctx << self.print_later(txt)
finally:
# Always say goodbye
writer.write('Bye!\n'.encode())
writer.close()
print(peer, 'closed')
@staticmethod
async def print_later(txt):
await asyncio.sleep(1)
print('received earlier:', txt)
