chore: import upstream snapshot with attribution

python/ray/_private/async_compat.py

@@ -0,0 +1,54 @@
+"""
+This file should only be imported from Python 3.
+It will raise SyntaxError when importing from Python 2.
+"""
+import asyncio
+import inspect
+from functools import lru_cache
+
+from ray._private.ray_constants import env_bool
+
+try:
+    import uvloop
+except ImportError:
+    uvloop = None
+
+
+def get_new_event_loop():
+    """Construct a new event loop. Ray will use uvloop if it exists and is enabled"""
+    if uvloop and env_bool("RAY_USE_UVLOOP", True):
+        return uvloop.new_event_loop()
+    else:
+        return asyncio.new_event_loop()
+
+
+def try_install_uvloop():
+    """Installs uvloop as event-loop implementation for asyncio (if available and enabled)"""
+    if uvloop and env_bool("RAY_USE_UVLOOP", True):
+        uvloop.install()
+    else:
+        pass
+
+
+def is_async_func(func) -> bool:
+    """Return True if the function is an async or async generator method."""
+    return inspect.iscoroutinefunction(func) or inspect.isasyncgenfunction(func)
+
+
+@lru_cache(maxsize=2**10)
+def has_async_methods(cls: object) -> bool:
+    """Return True if the class has any async methods."""
+    return len(inspect.getmembers(cls, predicate=is_async_func)) > 0
+
+
+@lru_cache(maxsize=2**10)
+def sync_to_async(func):
+    """Wrap a blocking function in an async function"""
+
+    if is_async_func(func):
+        return func
+
+    async def wrapper(*args, **kwargs):
+        return func(*args, **kwargs)
+
+    return wrapper