RtlSetThreadIsCritical - NtDoc

#ifndef _NTRTL_H

/**
 * The RtlSetThreadIsCritical function sets or clears the critical status of the current thread.
 *
 * \param NewValue TRUE to mark the thread as critical, FALSE to clear.
 * \param OldValue Optional pointer to receive the previous critical status.
 * \param CheckFlag If TRUE, checks for certain conditions before setting.
 * \return NTSTATUS Successful or errant status.
 * \remarks A critical thread will cause a system bugcheck if terminated.
 */
NTSYSAPI
NTSTATUS
STDAPIVCALLTYPE
RtlSetThreadIsCritical(
    _In_ BOOLEAN NewValue,
    _Out_opt_ PBOOLEAN OldValue,
    _In_ BOOLEAN CheckFlag
    );

#endif
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