KiTryToAcquireThreadLock

UINT8 __stdcall KiTryToAcquireThreadLock(_ETHREAD *Thread, UINT8 *CheckLockOrder){
  if( _interlockedbittestandset64((volatile signed __int32 *)&Thread->Tcb.ThreadLock, 0i64) )
    return 0;
  if( CheckLockOrder )
    *CheckLockOrder = 1;
  return 1;
}

Referenced by:

KeTryToInsertQueueApc
KiDeferredReadySingleThread
KiMonitorCacheErrata
KiQueueReadyThread
KiTryToUpdateVPBackingThreadPriority
KiUpdateGlobalCpuSetConfiguration