micropython/tests/net_hosted/asyncio_start_server.py
Jim Mussared 977dc9a369 extmod/asyncio/stream.py: Fix cancellation handling of start_server.
The following code:

  server = await asyncio.start_server(...)
  async with server:
    ... code that raises ...

would lose the original exception because the server's task would not have
had a chance to be scheduled yet, and so awaiting the task in wait_closed
would raise the cancellation instead of the original exception.

Additionally, ensures that explicitly cancelling the parent task delivers
the cancellation correctly (previously was masked by the server loop), now
this only happens if the server was closed, not when the task was
cancelled.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
2023-10-02 14:11:52 +11:00

67 lines
1.8 KiB
Python

# Test basic behaviour of asyncio.start_server()
try:
import asyncio
except ImportError:
print("SKIP")
raise SystemExit
async def test():
# Test creating 2 servers using the same address
print("create server1")
server1 = await asyncio.start_server(None, "0.0.0.0", 8000)
try:
print("create server2")
await asyncio.start_server(None, "0.0.0.0", 8000)
except OSError as er:
print("OSError")
# Wait for server to close.
async with server1:
print("sleep")
await asyncio.sleep(0)
# Test that cancellation works before the server starts if
# the subsequent code raises.
print("create server3")
server3 = await asyncio.start_server(None, "0.0.0.0", 8000)
try:
async with server3:
raise OSError
except OSError as er:
print("OSError")
# Test that closing doesn't raise CancelledError.
print("create server4")
server4 = await asyncio.start_server(None, "0.0.0.0", 8000)
server4.close()
await server4.wait_closed()
print("server4 closed")
# Test that cancelling the task will still raise CancelledError, checking
# edge cases around how many times the tasks have been re-scheduled by
# sleep.
async def task(n):
print("create task server", n)
srv = await asyncio.start_server(None, "0.0.0.0", 8000)
await srv.wait_closed()
# This should be unreachable.
print("task finished")
for num_sleep in range(0, 5):
print("sleep", num_sleep)
t = asyncio.create_task(task(num_sleep))
for _ in range(num_sleep):
await asyncio.sleep(0)
t.cancel()
try:
await t
except asyncio.CancelledError:
print("CancelledError")
print("done")
asyncio.run(test())