Callers of KeWaitForSingleObject must be running at IRQL <= DISPATCH_LEVEL. However, if Timeout = NULL or *Timeout != 0, the caller must be running at IRQL <= APC_LEVEL and in a nonarbitrary thread context. (If Timeout != NULL and *Timeout = 0, the caller must be running at IRQL <= DISPATCH_LEVEL.)
Callers of KeWaitForSingleObject must be running at IRQL <= DISPATCH_LEVEL. However, if Timeout = NULL or *Timeout != 0, the caller must be running at IRQL <= APC_LEVEL and in a nonarbitrary thread context. (If Timeout != NULL and *Timeout = 0, the caller must be running at IRQL <= DISPATCH_LEVEL.)
