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-rw-r--r--python/qemu/qmp/util.py143
1 files changed, 37 insertions, 106 deletions
diff --git a/python/qemu/qmp/util.py b/python/qemu/qmp/util.py
index ca6225e9cd..a8229e5524 100644
--- a/python/qemu/qmp/util.py
+++ b/python/qemu/qmp/util.py
@@ -1,25 +1,16 @@
 """
 Miscellaneous Utilities
 
-This module provides asyncio utilities and compatibility wrappers for
-Python 3.6 to provide some features that otherwise become available in
-Python 3.7+.
-
-Various logging and debugging utilities are also provided, such as
-`exception_summary()` and `pretty_traceback()`, used primarily for
-adding information into the logging stream.
+This module provides asyncio and various logging and debugging
+utilities, such as `exception_summary()` and `pretty_traceback()`, used
+primarily for adding information into the logging stream.
 """
 
 import asyncio
 import sys
 import traceback
-from typing import (
-    Any,
-    Coroutine,
-    Optional,
-    TypeVar,
-    cast,
-)
+from typing import TypeVar, cast
+import warnings
 
 
 T = TypeVar('T')
@@ -30,9 +21,35 @@ T = TypeVar('T')
 # --------------------------
 
 
+def get_or_create_event_loop() -> asyncio.AbstractEventLoop:
+    """
+    Return this thread's current event loop, or create a new one.
+
+    This function behaves similarly to asyncio.get_event_loop() in
+    Python<=3.13, where if there is no event loop currently associated
+    with the current context, it will create and register one. It should
+    generally not be used in any asyncio-native applications.
+    """
+    try:
+        with warnings.catch_warnings():
+            # Python <= 3.13 will trigger deprecation warnings if no
+            # event loop is set, but will create and set a new loop.
+            warnings.simplefilter("ignore")
+            loop = asyncio.get_event_loop()
+    except RuntimeError:
+        # Python 3.14+: No event loop set for this thread,
+        # create and set one.
+        loop = asyncio.new_event_loop()
+        # Set this loop as the current thread's loop, to be returned
+        # by calls to get_event_loop() in the future.
+        asyncio.set_event_loop(loop)
+
+    return loop
+
+
 async def flush(writer: asyncio.StreamWriter) -> None:
     """
-    Utility function to ensure a StreamWriter is *fully* drained.
+    Utility function to ensure an `asyncio.StreamWriter` is *fully* drained.
 
     `asyncio.StreamWriter.drain` only promises we will return to below
     the "high-water mark". This function ensures we flush the entire
@@ -72,102 +89,13 @@ def bottom_half(func: T) -> T:
 
     These methods do not, in general, have the ability to directly
     report information to a caller’s context and will usually be
-    collected as a Task result instead.
+    collected as an `asyncio.Task` result instead.
 
     They must not call upper-half functions directly.
     """
     return func
 
 
-# -------------------------------
-# Section: Compatibility Wrappers
-# -------------------------------
-
-
-def create_task(coro: Coroutine[Any, Any, T],
-                loop: Optional[asyncio.AbstractEventLoop] = None
-                ) -> 'asyncio.Future[T]':
-    """
-    Python 3.6-compatible `asyncio.create_task` wrapper.
-
-    :param coro: The coroutine to execute in a task.
-    :param loop: Optionally, the loop to create the task in.
-
-    :return: An `asyncio.Future` object.
-    """
-    if sys.version_info >= (3, 7):
-        if loop is not None:
-            return loop.create_task(coro)
-        return asyncio.create_task(coro)  # pylint: disable=no-member
-
-    # Python 3.6:
-    return asyncio.ensure_future(coro, loop=loop)
-
-
-def is_closing(writer: asyncio.StreamWriter) -> bool:
-    """
-    Python 3.6-compatible `asyncio.StreamWriter.is_closing` wrapper.
-
-    :param writer: The `asyncio.StreamWriter` object.
-    :return: `True` if the writer is closing, or closed.
-    """
-    if sys.version_info >= (3, 7):
-        return writer.is_closing()
-
-    # Python 3.6:
-    transport = writer.transport
-    assert isinstance(transport, asyncio.WriteTransport)
-    return transport.is_closing()
-
-
-async def wait_closed(writer: asyncio.StreamWriter) -> None:
-    """
-    Python 3.6-compatible `asyncio.StreamWriter.wait_closed` wrapper.
-
-    :param writer: The `asyncio.StreamWriter` to wait on.
-    """
-    if sys.version_info >= (3, 7):
-        await writer.wait_closed()
-        return
-
-    # Python 3.6
-    transport = writer.transport
-    assert isinstance(transport, asyncio.WriteTransport)
-
-    while not transport.is_closing():
-        await asyncio.sleep(0)
-
-    # This is an ugly workaround, but it's the best I can come up with.
-    sock = transport.get_extra_info('socket')
-
-    if sock is None:
-        # Our transport doesn't have a socket? ...
-        # Nothing we can reasonably do.
-        return
-
-    while sock.fileno() != -1:
-        await asyncio.sleep(0)
-
-
-def asyncio_run(coro: Coroutine[Any, Any, T], *, debug: bool = False) -> T:
-    """
-    Python 3.6-compatible `asyncio.run` wrapper.
-
-    :param coro: A coroutine to execute now.
-    :return: The return value from the coroutine.
-    """
-    if sys.version_info >= (3, 7):
-        return asyncio.run(coro, debug=debug)
-
-    # Python 3.6
-    loop = asyncio.get_event_loop()
-    loop.set_debug(debug)
-    ret = loop.run_until_complete(coro)
-    loop.close()
-
-    return ret
-
-
 # ----------------------------
 # Section: Logging & Debugging
 # ----------------------------
@@ -177,8 +105,11 @@ def exception_summary(exc: BaseException) -> str:
     """
     Return a summary string of an arbitrary exception.
 
-    It will be of the form "ExceptionType: Error Message", if the error
+    It will be of the form "ExceptionType: Error Message" if the error
     string is non-empty, and just "ExceptionType" otherwise.
+
+    This code is based on CPython's implementation of
+    `traceback.TracebackException.format_exception_only`.
     """
     name = type(exc).__qualname__
     smod = type(exc).__module__