NtCancelWaitCompletionPacket - NtDoc

#ifndef _NTIOAPI_H
// Wait completion packet
#if (PHNT_VERSION >= PHNT_WIN8)

NTSYSCALLAPI
NTSTATUS
NTAPI
NtCancelWaitCompletionPacket(
    _In_ HANDLE WaitCompletionPacketHandle,
    _In_ BOOLEAN RemoveSignaledPacket
    );

#endif
#endif
View code on GitHub

#ifndef _NTZWAPI_H

NTSYSCALLAPI
NTSTATUS
NTAPI
ZwCancelWaitCompletionPacket(
    _In_ HANDLE WaitCompletionPacketHandle,
    _In_ BOOLEAN RemoveSignaledPacket
    );

#endif
View code on GitHub