This removes a non-idiomatic use of a "coroutine callback" in favor of
something a bit more standardized.
Signed-off-by: John Snow <js...@redhat.com>
cherry picked from commit python-qemu-qmp@commit
97f7ffa3be17a50544b52767d14b6fd478c07b9e
Signed-off-by: John Snow <js...@redhat.com>
Reviewed-by: Daniel P. Berrangé <berra...@redhat.com>
---
python/qemu/qmp/protocol.py | 35 ++++++++++++++++-------------------
1 file changed, 16 insertions(+), 19 deletions(-)
diff --git a/python/qemu/qmp/protocol.py b/python/qemu/qmp/protocol.py
index 208bdec5c89..958aeca08ac 100644
--- a/python/qemu/qmp/protocol.py
+++ b/python/qemu/qmp/protocol.py
@@ -15,6 +15,7 @@
import asyncio
from asyncio import StreamReader, StreamWriter
+from contextlib import asynccontextmanager
from enum import Enum
from functools import wraps
import logging
@@ -22,6 +23,7 @@
from ssl import SSLContext
from typing import (
Any,
+ AsyncGenerator,
Awaitable,
Callable,
Generic,
@@ -337,9 +339,8 @@ async def start_server(self, address: SocketAddrT,
This exception will wrap a more concrete one. In most cases,
the wrapped exception will be `OSError`.
"""
- await self._session_guard(
- self._do_start_server(address, ssl),
- 'Failed to establish connection')
+ async with self._session_guard('Failed to establish connection'):
+ await self._do_start_server(address, ssl)
assert self.runstate == Runstate.CONNECTING
@upper_half
@@ -362,12 +363,10 @@ async def accept(self) -> None:
"""
if self._accepted is None:
raise QMPError("Cannot call accept() before start_server().")
- await self._session_guard(
- self._do_accept(),
- 'Failed to establish connection')
- await self._session_guard(
- self._establish_session(),
- 'Failed to establish session')
+ async with self._session_guard('Failed to establish connection'):
+ await self._do_accept()
+ async with self._session_guard('Failed to establish session'):
+ await self._establish_session()
assert self.runstate == Runstate.RUNNING
@upper_half
@@ -392,12 +391,10 @@ async def connect(self, address: Union[SocketAddrT,
socket.socket],
protocol-level failure occurs while establishing a new
session, the wrapped error may also be an `QMPError`.
"""
- await self._session_guard(
- self._do_connect(address, ssl),
- 'Failed to establish connection')
- await self._session_guard(
- self._establish_session(),
- 'Failed to establish session')
+ async with self._session_guard('Failed to establish connection'):
+ await self._do_connect(address, ssl)
+ async with self._session_guard('Failed to establish session'):
+ await self._establish_session()
assert self.runstate == Runstate.RUNNING
@upper_half
@@ -418,7 +415,8 @@ async def disconnect(self) -> None:
# Section: Session machinery
# --------------------------
- async def _session_guard(self, coro: Awaitable[None], emsg: str) -> None:
+ @asynccontextmanager
+ async def _session_guard(self, emsg: str) -> AsyncGenerator[None, None]:
"""
Async guard function used to roll back to `IDLE` on any error.
@@ -435,10 +433,9 @@ async def _session_guard(self, coro: Awaitable[None],
emsg: str) -> None:
:raise ConnectError:
When any other error is encountered in the guarded block.
"""
- # Note: After Python 3.6 support is removed, this should be an
- # @asynccontextmanager instead of accepting a callback.
try:
- await coro
+ # Caller's code runs here.
+ yield
except BaseException as err:
self.logger.error("%s: %s", emsg, exception_summary(err))
self.logger.debug("%s:\n%s\n", emsg, pretty_traceback())
--
2.50.1
