If there is an architectural difference, I will note it. Windows NT is a multithreaded, micro-kernel-based [ 11 ] operating system. The term micro-kernel implies that the kernel component is very small, and provides only basic functions such as thread dispatching and hardware exception handling. The core operating system code runs in privileged processor mode.
This mode is also known as protected mode when referring to the CPU , or kernel mode when referring to a process or thread. Protected mode provides direct access to system memory and other hardware. Applications run in a nonprivileged processor mode known as user mode and have no direct hardware access. Applications have to use the system calls — the API Application Programming Interface — in the underlying operating system to perform tasks such as reading or writing to memory or to the screen.
The basic Windows NT architecture is shown in Figure 1. Operating system services are kept in discrete subsystems, some running in user mode and others in kernel mode.
There are several kernel mode subsystems in Windows NT. The kernel mode subsystems make up the Windows NT Executive , and consist of the following:. The Windows NT architecture is not strictly object-oriented, but internal structures such as shared memory segments, processes, and threads are represented as objects to provide a uniform method for handling things like access control. Objects are represented in a hierarchical namespace much like a filesystem.
Responsible for creating and terminating processes and threads using underlying kernel functions. Implements the virtual memory used to allocate a private address space to each process. Implements a fast, lightweight version of Remote Procedure Call RPC for communication between components within a computer. Enforces the access and audit policies in the system. The Security Reference Monitor provides access validation, privilege checking, and audit message generation at runtime for both user and kernel mode processes.
These components make up the kernel mode part of the Win32 subsystem. They handle user input and screen output. All of the Win32 subsystem originally ran in user mode; however, for performance reasons, a part of it was moved to kernel mode as of NT 4. In , Windows NT was upgraded to version 4, with new features and enhancements that included the following:. Kernel mode: Processes run at a higher priority than those in user mode and consist of the following:. Alerter Service is a Microsoft Windows NT service responsible for sending administrative alerts to users and computers.
The Alerter service generates an alert when potentially dangerous conditions occur, such as when disk space is running out. You can configure which users or computers receive these alerts by using Server Manager or by using the Server utility in Control Panel. Pop-up alert messages will appear if the administrator is logged on or is at the appropriate computer when the alert occurs.
The administrator can then consult the system log for information about what caused the alert. One big difference between Windows NT and Windows 95 and 98 operating systems is to share a Windows NT resource, and we should have administrative privileges. Windows NT provides security for any resource on the network. A Windows NT network domain server maintains all the account records and manages permission and user rights. To create any resource on the network, a user must have the right to complete a task and permission to use the resource.
In a Window NT Network, any client or server can function as a print server.
0コメント