#ifndef _NTLPCAPI_H
// begin_private

NTSYSCALLAPI
NTSTATUS
NTAPI
NtAlpcDeleteSecurityContext(
    _In_ HANDLE PortHandle,
    _Reserved_ ULONG Flags,
    _In_ ALPC_HANDLE ContextHandle
    );

// end_private
#endif
View code on GitHub

#ifndef _NTZWAPI_H

NTSYSCALLAPI
NTSTATUS
NTAPI
ZwAlpcDeleteSecurityContext(
    _In_ HANDLE PortHandle,
    _Reserved_ ULONG Flags,
    _In_ ALPC_HANDLE ContextHandle
    );

#endif
View code on GitHub