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[int], 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

"""

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:

h = handle_array[ret]

return h

def create_win32_event():

"""

Creates a Win32 unnamed Event .

http://msdn.microsoft.com/en-us/library/windows/desktop/ms682396(v=vs.85).aspx

"""

return windll.kernel32.CreateEventA(

pointer(SECURITY_ATTRIBUTES()),

BOOL(True), # Manual reset event.

BOOL(False), # Initial state.

None # Unnamed event object.

)