hub/venv/lib/python3.7/site-packages/prompt_toolkit/eventloop/win32.py

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from ctypes import pointer, windll
from ctypes.wintypes import BOOL, DWORD, HANDLE
from typing import List, Optional
from prompt_toolkit.win32_types import SECURITY_ATTRIBUTES
__all__ = ["wait_for_handles", "create_win32_event"]
WAIT_TIMEOUT = 0x00000102
INFINITE = -1
def wait_for_handles(
handles: List[HANDLE], timeout: int = INFINITE
) -> Optional[HANDLE]:
"""
Waits for multiple handles. (Similar to 'select') Returns the handle which is ready.
Returns `None` on timeout.
http://msdn.microsoft.com/en-us/library/windows/desktop/ms687025(v=vs.85).aspx
Note that handles should be a list of `HANDLE` objects, not integers. See
this comment in the patch by @quark-zju for the reason why:
''' Make sure HANDLE on Windows has a correct size
Previously, the type of various HANDLEs are native Python integer
types. The ctypes library will treat them as 4-byte integer when used
in function arguments. On 64-bit Windows, HANDLE is 8-byte and usually
a small integer. Depending on whether the extra 4 bytes are zero-ed out
or not, things can happen to work, or break. '''
This function returns either `None` or one of the given `HANDLE` objects.
(The return value can be tested with the `is` operator.)
"""
arrtype = HANDLE * len(handles)
handle_array = arrtype(*handles)
ret = windll.kernel32.WaitForMultipleObjects(
len(handle_array), handle_array, BOOL(False), DWORD(timeout)
)
if ret == WAIT_TIMEOUT:
return None
else:
return handles[ret]
def create_win32_event() -> HANDLE:
"""
Creates a Win32 unnamed Event .
http://msdn.microsoft.com/en-us/library/windows/desktop/ms682396(v=vs.85).aspx
"""
return HANDLE(
windll.kernel32.CreateEventA(
pointer(SECURITY_ATTRIBUTES()),
BOOL(True), # Manual reset event.
BOOL(False), # Initial state.
None, # Unnamed event object.
)
)