The Communication Subsystem of ORDERS

• Main Authors: Shih, Ming-Yuan, 施銘原
• Other Authors: Hou Ting-Wei
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/00548992374470239481

碩士 === 國立成功大學 === 工程科學系 === 84 === ORDERS(Object-oRiented Distributed Execution environment for Real-time System)為一分散式的即時作業系統﹐需要高可靠度?高效率 且有彈性的通訊子系統。本文即陳述如何在ORDERS的微核心O2MK上實作出 一個提供物件化通訊機制的物件導向通訊子系統(Object-Oriented Communication Subsystem, OOCS)。 OOCS分為兩個部份實作﹐一個是將 實體網路封裝而抽象化的EtNet(乙太網路)系統物件﹔以及將協定軟體物 件化的 OOCP( Object-Oriented CommunicationProtocol)。為了符合可 重用性?可移植性與方便修改等因素﹐EtNet與OOCP是運用物件導向方法 分析?設計?實作出來的。 EtNet藉著PktDrv的運作而提供完整的乙太網 路通訊功能﹐包含直接應用硬體支援多點傳播 (multicast)與廣播( broadcast )﹐ 並且支援ORDERS於網路通訊方面對即時通訊的基本需求。 OOCP則利用ProtoObj來實現VMTP與EIP協定。 它們二者同樣都提供了物件 化的使用介面：EtNet的通訊代理者(CMProxy)與OOCP的快遞信差( Courier)。 目前﹐OOCS已可以在ORDERS系統中執行﹐提供完整的通訊服 務以及支援即時通訊的需求條件。本文將對OOCS之設計與實作﹐以及發展 中所遇到的問題作完整的描述。 ORDERS(Object-oRiented Distributed Execution environment for Real-time System) is a distributed real-time operating system that claimsa reliable, efficient, and flexible cmmunication subsystem. Thisthesis describes the design and implementation of Object-OrientedCommunication Subsystem (OOCS) on the O2MK , the microkernel ofORDERS. The design goal of OOCS is to support an object-orientedcommunication mechanism for other subsystems of ORDERS. OOCS consists of EtNet and OOCP ( Object-Oriented CommunicationProtocol). EtNet abstracts and encapsulates the physical network ofEthernet. OOCP implements the communication protocols. EtNet andOOCP are analyzed, designed, and implemented by objected-orientedmethodology, so that they both are reusable, portable, maintainable.EtNet implements complete Ethernet communication service by operationof PktDrv, the primary object of EtNet. EtNet efficiently supportsmulticast and broadcast by hardware. Besides, EtNet can satisfy real-time commnication requirement of ORDERS. OOCP implements VMTP and EIPby ProtoObj, an abstraction of protocol objects. EtNet and OOCP bothdeliver object-oriented communication interface: the CMProxy of EtNetand Courier of OOCP. OOCS is used by other system objects in ORDERS now. The design andimplementation of OOCS, the problems encounted during implementaion,and the approaches to solve them are all described in this thesis.