#ifndef _NTIOAPI_H

/**
 * Posts a caller-defined packet to an I/O completion port, without issuing file I/O.
 * Useful for notifying workers through the same queue used for I/O completions.
 *
 * \param[in] IoCompletionHandle Handle with IO_COMPLETION_MODIFY_STATE (0x2).
 * \param[in, optional] KeyContext Opaque pointer-sized value returned to the consumer.
 * \param[in, optional] ApcContext Opaque pointer-sized value returned to the consumer;
 * it is not an APC routine and this call does not dispatch a user callback.
 * \param[in] IoStatus Status value stored in the packet, independent of this call's status.
 * \param[in] IoStatusInformation Pointer-sized packet information, often a byte count.
 * \return NTSTATUS describing posting, not the supplied IoStatus. A negative
 * IoStatus can be posted successfully and later dequeued with STATUS_SUCCESS.
 * \remarks Context values may be NULL and are not dereferenced or copied as buffers.
 * The call does not require prior file association. Use NtSetIoCompletionEx with a
 * separately allocated memory reserve when a reusable packet allocation is needed.
 * \sa https://learn.microsoft.com/en-us/windows/win32/api/ioapiset/nf-ioapiet-postqueuedcompletionstatus
 */
_Kernel_entry_
NTSYSCALLAPI
NTSTATUS
NTAPI
NtSetIoCompletion(
    _In_ HANDLE IoCompletionHandle,
    _In_opt_ PVOID KeyContext,
    _In_opt_ PVOID ApcContext,
    _In_ NTSTATUS IoStatus,
    _In_ ULONG_PTR IoStatusInformation
    );

#endif
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#ifndef _NTZWAPI_H

_Kernel_entry_
NTSYSCALLAPI
NTSTATUS
NTAPI
ZwSetIoCompletion(
    _In_ HANDLE IoCompletionHandle,
    _In_opt_ PVOID KeyContext,
    _In_opt_ PVOID ApcContext,
    _In_ NTSTATUS IoStatus,
    _In_ ULONG_PTR IoStatusInformation
    );

#endif
View code on GitHub