CreateIoCompletionPort

// KERNEL32.dll
#include <windows.h>

HANDLE CreateIoCompletionPort(
    HANDLE FileHandle,
    HANDLE ExistingCompletionPort,   // optional
    UINT_PTR CompletionKey,
    DWORD NumberOfConcurrentThreads
);

<DllImport("KERNEL32.dll", SetLastError:=True, ExactSpelling:=True)>
Public Shared Function CreateIoCompletionPort(
    FileHandle As IntPtr,   ' HANDLE
    ExistingCompletionPort As IntPtr,   ' HANDLE optional
    CompletionKey As UIntPtr,   ' UINT_PTR
    NumberOfConcurrentThreads As UInteger   ' DWORD
) As IntPtr
End Function

' FileHandle : HANDLE
' ExistingCompletionPort : HANDLE optional
' CompletionKey : UINT_PTR
' NumberOfConcurrentThreads : DWORD
Declare PtrSafe Function CreateIoCompletionPort Lib "kernel32" ( _
    ByVal FileHandle As LongPtr, _
    ByVal ExistingCompletionPort As LongPtr, _
    ByVal CompletionKey As LongPtr, _
    ByVal NumberOfConcurrentThreads As Long) As LongPtr
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

CreateIoCompletionPort = ctypes.windll.kernel32.CreateIoCompletionPort
CreateIoCompletionPort.restype = ctypes.c_void_p
CreateIoCompletionPort.argtypes = [
    wintypes.HANDLE,  # FileHandle : HANDLE
    wintypes.HANDLE,  # ExistingCompletionPort : HANDLE optional
    ctypes.c_size_t,  # CompletionKey : UINT_PTR
    wintypes.DWORD,  # NumberOfConcurrentThreads : DWORD
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('KERNEL32.dll')
CreateIoCompletionPort = Fiddle::Function.new(
  lib['CreateIoCompletionPort'],
  [
    Fiddle::TYPE_VOIDP,  # FileHandle : HANDLE
    Fiddle::TYPE_VOIDP,  # ExistingCompletionPort : HANDLE optional
    Fiddle::TYPE_UINTPTR_T,  # CompletionKey : UINT_PTR
    -Fiddle::TYPE_INT,  # NumberOfConcurrentThreads : DWORD
  ],
  Fiddle::TYPE_VOIDP)

#[link(name = "kernel32")]
extern "system" {
    fn CreateIoCompletionPort(
        FileHandle: *mut core::ffi::c_void,  // HANDLE
        ExistingCompletionPort: *mut core::ffi::c_void,  // HANDLE optional
        CompletionKey: usize,  // UINT_PTR
        NumberOfConcurrentThreads: u32  // DWORD
    ) -> *mut core::ffi::c_void;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("KERNEL32.dll", SetLastError = true)]
public static extern IntPtr CreateIoCompletionPort(IntPtr FileHandle, IntPtr ExistingCompletionPort, UIntPtr CompletionKey, uint NumberOfConcurrentThreads);
"@
$api = Add-Type -MemberDefinition $sig -Name 'KERNEL32_CreateIoCompletionPort' -Namespace Win32 -PassThru
# $api::CreateIoCompletionPort(FileHandle, ExistingCompletionPort, CompletionKey, NumberOfConcurrentThreads)

#uselib "KERNEL32.dll"
#func global CreateIoCompletionPort "CreateIoCompletionPort" sptr, sptr, sptr, sptr
; CreateIoCompletionPort FileHandle, ExistingCompletionPort, CompletionKey, NumberOfConcurrentThreads   ; 戻り値は stat
; FileHandle : HANDLE -> "sptr"
; ExistingCompletionPort : HANDLE optional -> "sptr"
; CompletionKey : UINT_PTR -> "sptr"
; NumberOfConcurrentThreads : DWORD -> "sptr"
; ※HSP3.7は #func のため戻り値はシステム変数 stat に格納されます。

#uselib "KERNEL32.dll"
#cfunc global CreateIoCompletionPort "CreateIoCompletionPort" sptr, sptr, sptr, int
; res = CreateIoCompletionPort(FileHandle, ExistingCompletionPort, CompletionKey, NumberOfConcurrentThreads)
; FileHandle : HANDLE -> "sptr"
; ExistingCompletionPort : HANDLE optional -> "sptr"
; CompletionKey : UINT_PTR -> "sptr"
; NumberOfConcurrentThreads : DWORD -> "int"

; HANDLE CreateIoCompletionPort(HANDLE FileHandle, HANDLE ExistingCompletionPort, UINT_PTR CompletionKey, DWORD NumberOfConcurrentThreads)
#uselib "KERNEL32.dll"
#cfunc global CreateIoCompletionPort "CreateIoCompletionPort" intptr, intptr, intptr, int
; res = CreateIoCompletionPort(FileHandle, ExistingCompletionPort, CompletionKey, NumberOfConcurrentThreads)
; FileHandle : HANDLE -> "intptr"
; ExistingCompletionPort : HANDLE optional -> "intptr"
; CompletionKey : UINT_PTR -> "intptr"
; NumberOfConcurrentThreads : DWORD -> "int"

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	kernel32 = windows.NewLazySystemDLL("KERNEL32.dll")
	procCreateIoCompletionPort = kernel32.NewProc("CreateIoCompletionPort")
)

// FileHandle (HANDLE), ExistingCompletionPort (HANDLE optional), CompletionKey (UINT_PTR), NumberOfConcurrentThreads (DWORD)
r1, _, err := procCreateIoCompletionPort.Call(
	uintptr(FileHandle),
	uintptr(ExistingCompletionPort),
	uintptr(CompletionKey),
	uintptr(NumberOfConcurrentThreads),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HANDLE

function CreateIoCompletionPort(
  FileHandle: THandle;   // HANDLE
  ExistingCompletionPort: THandle;   // HANDLE optional
  CompletionKey: NativeUInt;   // UINT_PTR
  NumberOfConcurrentThreads: DWORD   // DWORD
): THandle; stdcall;
  external 'KERNEL32.dll' name 'CreateIoCompletionPort';

result := DllCall("KERNEL32\CreateIoCompletionPort"
    , "Ptr", FileHandle   ; HANDLE
    , "Ptr", ExistingCompletionPort   ; HANDLE optional
    , "UPtr", CompletionKey   ; UINT_PTR
    , "UInt", NumberOfConcurrentThreads   ; DWORD
    , "Ptr")   ; return: HANDLE

●CreateIoCompletionPort(FileHandle, ExistingCompletionPort, CompletionKey, NumberOfConcurrentThreads) = DLL("KERNEL32.dll", "void* CreateIoCompletionPort(void*, void*, int, dword)")
# 呼び出し: CreateIoCompletionPort(FileHandle, ExistingCompletionPort, CompletionKey, NumberOfConcurrentThreads)
# FileHandle : HANDLE -> "void*"
# ExistingCompletionPort : HANDLE optional -> "void*"
# CompletionKey : UINT_PTR -> "int"
# NumberOfConcurrentThreads : DWORD -> "dword"
# なでしこ1は32bit・ANSI(Shift_JIS)。文字列=char*(ANSI)、ポインタ/ハンドル=void*(4byte)。