second commit

venv/Lib/site-packages/trio/_wait_for_object.py

@@ -0,0 +1,62 @@
+import math
+from . import _timeouts
+import trio
+from ._core._windows_cffi import (
+    ffi,
+    kernel32,
+    ErrorCodes,
+    raise_winerror,
+    _handle,
+)
+
+
+async def WaitForSingleObject(obj):
+    """Async and cancellable variant of WaitForSingleObject. Windows only.
+
+    Args:
+      handle: A Win32 handle, as a Python integer.
+
+    Raises:
+      OSError: If the handle is invalid, e.g. when it is already closed.
+
+    """
+    # Allow ints or whatever we can convert to a win handle
+    handle = _handle(obj)
+
+    # Quick check; we might not even need to spawn a thread. The zero
+    # means a zero timeout; this call never blocks. We also exit here
+    # if the handle is already closed for some reason.
+    retcode = kernel32.WaitForSingleObject(handle, 0)
+    if retcode == ErrorCodes.WAIT_FAILED:
+        raise_winerror()
+    elif retcode != ErrorCodes.WAIT_TIMEOUT:
+        return
+
+    # Wait for a thread that waits for two handles: the handle plus a handle
+    # that we can use to cancel the thread.
+    cancel_handle = kernel32.CreateEventA(ffi.NULL, True, False, ffi.NULL)
+    try:
+        await trio.to_thread.run_sync(
+            WaitForMultipleObjects_sync,
+            handle,
+            cancel_handle,
+            cancellable=True,
+            limiter=trio.CapacityLimiter(math.inf),
+        )
+    finally:
+        # Clean up our cancel handle. In case we get here because this task was
+        # cancelled, we also want to set the cancel_handle to stop the thread.
+        kernel32.SetEvent(cancel_handle)
+        kernel32.CloseHandle(cancel_handle)
+
+
+def WaitForMultipleObjects_sync(*handles):
+    """Wait for any of the given Windows handles to be signaled."""
+    n = len(handles)
+    handle_arr = ffi.new("HANDLE[{}]".format(n))
+    for i in range(n):
+        handle_arr[i] = handles[i]
+    timeout = 0xFFFFFFFF  # INFINITE
+    retcode = kernel32.WaitForMultipleObjects(n, handle_arr, False, timeout)  # blocking
+    if retcode == ErrorCodes.WAIT_FAILED:
+        raise_winerror()