#ifndef _NTEXAPI_H
#if (PHNT_MODE != PHNT_MODE_KERNEL)

//
// Thread execution
//

/**
 * The NtDelayExecution routine delays the calling thread until a deadline or an allowed interruption. 
 * This is a scheduling delay, not a wait for an object's signal and not a precision clock.
 *
 * \param Alertable TRUE permits an alert or ordinary user APC to interrupt the
 * delay; the APC runs on this thread. Retrying after an interruption is the caller's
 * responsibility, including recomputing remaining time for a relative interval.
 * \param DelayInterval Required readable LARGE_INTEGER; NULL does not mean an
 * infinite delay. Units are 100 nanoseconds: negative values are relative intervals,
 * positive values are absolute times since January 1, 1601 (UTC), and zero requests
 * a scheduling yield. User input must be 4-byte aligned on x64 and its WoW64 forwarding path. 
 * The captured input is not updated with remaining time.
 * \return STATUS_SUCCESS (0) on elapsed nonzero delay, STATUS_USER_APC (0xC0) or
 * STATUS_ALERTED (0x101) for interruption. A zero interval can return either
 * STATUS_SUCCESS or STATUS_NO_YIELD_PERFORMED (0x40000024). This also applies to
 * an alertable zero interval when no APC or alert terminates it first.
 * \remarks Expiration makes execution eligible, not necessarily immediate; other
 * scheduling work can delay return. A yield does not prove another thread ran or
 * completed useful work, and is not a replacement for synchronization. Do not
 * treat STATUS_NO_YIELD_PERFORMED as failure or as a count of ready threads.
 * \see https://learn.microsoft.com/en-us/windows/win32/api/synchapi/nf-synchapi-sleepex
 * \see RtlDelayExecution
 */
_Kernel_entry_
NTSYSCALLAPI
NTSTATUS
NTAPI
NtDelayExecution(
    _In_ BOOLEAN Alertable,
    _In_ PLARGE_INTEGER DelayInterval
    );

#endif
#endif
View code on GitHub

#ifndef _NTZWAPI_H

_Kernel_entry_
NTSYSCALLAPI
NTSTATUS
NTAPI
ZwDelayExecution(
    _In_ BOOLEAN Alertable,
    _In_ PLARGE_INTEGER DelayInterval
    );

#endif
View code on GitHub