《計(jì)算機(jī)專業(yè)英語(yǔ)》課件第20章

KernelTechnology

1Applicationsputcomputerstopracticalbusinessuse,butbelowthesurfaceit’stheheartofanoperatingsystem-thekernel-thatprovidesthetechnicalwizardrytojugglemultipleprograms,connecttonetworksandstoredata.

Atraditionalkernelprovidesallthefunctionsforapplications.Thekernelmanagesmemory,I/Odevicesandparcelsoutprocessortime.

2Thekernelalsosupportssecurityandfaulttolerance,whichistheabilitytorecoverautomaticallywhenpartsofthesystemfail.

Whetherit’sasingleprogramoracollectionofexecutablefiles,allpartsofthekernelrunin“kernelmode”,whichallowsthemaccesstotheirownsectionsofmemory.

Applicationsusekernelfunctionsthroughapplicationprogramminginterfaces(API),whichareasetofstandardroutinesusedbyprograms.EachkernelcontainsitsownAPIs-whichiswhyWindowssoftwarewon’trununderUNIX,andMacintoshsoftwarewon’trunonanAS/400,eveniftheprocessoristhesame.

Systemvendorscontinuetocrammorefunctionsintokernels.Microsoft,forexample,isaddingbothadatabaseandUNIXAPIstoitsWindowsNTkernel.3Puttingsuchsupportinthekernelusuallymakesthosefunctionsfasterandmorerobust,butasmoreandmorecapabilitiesareshoehornetintothekernel,it’shardertoproduceoperatingsystems

thatcanbemaintained,enhancedanddeliveredtocustomersontime.

Italsomakeskernelshuge,complexpiecesofsoftwarethatarehardtoenhancewithoutaddingbugs.

That’swhyseveralmajorvendors—includingSunMicrosystemsInc.,DigitalEquipmentCorp.andAppleComputerInc.—aretryinganewapproachtooperatingsystemdesign:themicro-kernel.4Inamicro-kernel,onlyafewcrucialfunctions,suchasmanaginghowmemoryandprocessortimearedividedamongapplicationsandcommunicationsbetweensoftwareprocessors,runinkernelmode.

Alltherest-filesystems,networking,devicedrivers—runasapplications.5Thatkeepsthekernelsmallandsimple,makingitmucheasiertomaintain.

6Microkernelsaresuitableformassivelyparallelsystems,meaningsystemsthatusemanyprocessorstorunoneapplication.Butperformancecansuffer,becausefilesystemsanddevicedriverscan’tdirectlyaccessallthesystemdatatheapplicationneeds.

Thepathtoasmallerkernelisn’teasy.IBMtriedandfailedwithitsWorkplaceOS,andMicrosofthassteadfastlyrefusedtoshrinkWindowsNT’skernel.

Butifthemicro-kernelreallyisasflexibleandmaintainableasitsproponentssay,micro-kernelarchitecturescouldbeabighelpinhittingnewoperatingsystemreleasesoutthedoorontimeandwithfewerbugs.NewWords

wizardryn.魔術(shù)jugglev.處理multipleadj.多數(shù)的,多個(gè)的functionn.功能applicationn.應(yīng)用程序memoryn.存儲(chǔ)器securityn.安全executableadj.可執(zhí)行的hardwaren.硬件accessn.訪問,進(jìn)入routinen.例行程序runv.運(yùn)行processorn.處理器vendorn.供應(yīng)商cramv.塞入,塞進(jìn)Microsoftn.微軟公司robustadj.強(qiáng)大的capabilityn.功能,能力enhancev.升級(jí),增加maintainv.維修bugn.錯(cuò)誤approachn.方法micro-kerneln.微內(nèi)核crucialadj.關(guān)鍵的massivelyadv.大規(guī)模地paralleln.并行steadfastlyadv.堅(jiān)定不移地shrinkv.縮小flexibleadj.靈活的proponentn.支持者architecturen.體系結(jié)構(gòu)PhrasesandExpressions

connectto連接到bycontrast相反地besuitablefor適合,適應(yīng)TheExplanationofDifficultStatements

1.Applicationsputcomputerstopracticalbusinessuse,butbelowthesurfaceit’stheheartofanoperatingsystemthekernel-thatprovidesthetechnicalwizardrytojugglemultipleprograms,connecttonetworksandstoredata.

分析:此句中“thatprovidesthetechnicalwizardrytojugglemultipleprograms,connectto

networksandstoredata.”為由關(guān)系代詞that所引導(dǎo)的定語(yǔ)從句,修飾先行詞thekernel.

句意:應(yīng)用程序使計(jì)算機(jī)用于實(shí)際的商業(yè)應(yīng)用,但是,在此表層的下面,是操作系統(tǒng)的心臟——內(nèi)核,它提供了魔力般的技術(shù)來處理多個(gè)程序,連接到網(wǎng)絡(luò)和儲(chǔ)存數(shù)據(jù)。

2.Thekernelalsosupportssecurityandfaulttolerancewhichistheabilitytorecoverautomaticallywhenpartsofthesystemfail.

分析:此句中which所引導(dǎo)的從句為非限制性定語(yǔ)從句,代替先行詞faulttolerance;“whenpartsofthesystemfails”為時(shí)間狀語(yǔ)從句。

句意:內(nèi)核也支持安全和容錯(cuò)功能,容錯(cuò)是指當(dāng)部分系統(tǒng)出現(xiàn)故障時(shí)自動(dòng)恢復(fù)的能力。

3.Puttingsuchsupportinthekernelusuallymakesthosefunctionsfastenandmorerobust.

分析:“Puttingsuchsupportinthekernel”為動(dòng)名詞在句中作主語(yǔ)。

句意:把這些支持功能放進(jìn)內(nèi)核,通常會(huì)使這些功能更快、更強(qiáng)。

4.Inamicro-kernel,onlyafewcrucialfunctions,suchasmanaginghowmemoryandprocessortimearedividedamongapplicationsandcommunicationsbetweensoftwareprocesses,runinkernelmode.

分析:

此句中“suchasmanaginghowmemoryandprocessortimearedividedamongapplicationsandcommunicationsbetweensoftwareprocesses”為插入語(yǔ),句中的主干部分為“onlyafewcrucialfunctionsruninkernelmode”。句意:

在微內(nèi)核中,只有為數(shù)不多的關(guān)鍵功能以內(nèi)核方式運(yùn)行,如在幾個(gè)應(yīng)用程序之間如何分配存儲(chǔ)器和處理器時(shí)間,以及軟件進(jìn)程之間的通信等。

5.Thatkeepsthekernelsmallandsimple,makingitmucheasiertomaintain.

分析:“makingitmucheasiertomaintain”為現(xiàn)在分詞,用于此處表示伴隨情況的狀語(yǔ)。

句意:這使內(nèi)核小而簡(jiǎn)單,使它維護(hù)更容易。

6.Micro-kernelsaresuitableformassivelyparallelsystems,meaningsystemsthatusemanyprocessorstorunoneapplication.

分析:“meaningsystemsthatusemanyprocessorstorunoneapplication”為現(xiàn)在分詞作狀語(yǔ)?！皌hatusemanyprocessorstorunoneapplication”為定語(yǔ)從句,修飾先行詞systems。

句意:微內(nèi)核適合于大規(guī)模并行系統(tǒng),這意味著系統(tǒng)使用很多處理器來運(yùn)行一個(gè)應(yīng)用程序。GrammarTranslationSkills定語(yǔ)的翻譯方法(Ⅰ)

1.動(dòng)詞不定式作定語(yǔ)動(dòng)詞不定式作定語(yǔ)一般是說明句中的名詞或名詞化的形容詞及數(shù)詞,它置于其后,但翻譯時(shí),一般譯在所說明的詞之前。例如:

Thepathtoasmallerkernelisn’teasy.通向小內(nèi)核的道路是不易的。作定語(yǔ)的不定式如果為被動(dòng)形式,則含有將來的意思,翻譯時(shí)加“將要”、“應(yīng)該”、“要”、“應(yīng)”等詞。例如:

Kerneltechnologytobedescribedinthischapterisparticularlyuseful.

2.分詞及分詞短語(yǔ)作定語(yǔ)

1)譯成名詞或代詞的定語(yǔ)通常用“的”字將它譯在所說明的詞之前。例如:

Acompoundisasubstancemadeupoftwoormoreelements.化合物是由兩種或兩種以上的元素構(gòu)成的物質(zhì)。

2)譯成并列句為使譯成并列句文字更簡(jiǎn)煉、通順,通常情況是重復(fù)分詞所修飾的詞,有時(shí)還可加“這”、“這些”、“此”等或者譯成人稱代詞“他們”、“它”等。若前后的意思有所轉(zhuǎn)折還可加“但、卻、然而”等。例如:

Thesewereimportanttricksneededtoincreasethespeedofslowharddrives,ortoaddressmoreRAMthantheprocessorwasdesignedtoaccess.這些都是很重要的策略,它們對(duì)提高硬盤機(jī)的速度或?qū)Ω嗟腞AM尋址(超過處理器設(shè)計(jì)所能訪問的地址)是必需的。

3)譯成簡(jiǎn)單句的謂語(yǔ)由于英漢兩種語(yǔ)言表達(dá)方式不同,有時(shí)可以將分詞短語(yǔ)譯成謂語(yǔ)形式。例如:

Theliftforceactsthroughapointcalledthecenterofpressure.升力作用所通過的點(diǎn)叫做壓力中心。

4)譯成狀語(yǔ)從句形式如果含有明顯的條件、時(shí)間、原因、讓步等意思,通常可以分開譯。例如:

ElectronicComputerhavingmanyadvantagescannotcarryoutcreatureandreplaceman.

雖然電子計(jì)算機(jī)有很多的優(yōu)點(diǎn),但它們不能進(jìn)行創(chuàng)造性的工作,也代替不了人。

(Tobecontinued)ExercisesⅠ.Fillintheblanksaccordingtothetext:(1)Thekernelalsosupports______________whichistheabilitytorecoverautomaticallywhenpartsofthesystemfail.(2)Applicationsusekernelfunctionsthrough______________,whichareasetofstandardroutines

usedbyprograms.(3)Microsoft,forexample,isaddingboth______________toitsWindowsNTkernel.(4)Butasmoreandmorecapabilitiesareshoehornetintothekernel,it’shardertoproduce

operatingsystemsthatcanbe______________tocustomersontime.(5)______________aresuitableformassivelyparallelsystems,meaningsystemsthatusemanyprocessorstorunoneapplication.Ⅱ.Decidewhethereachofthefollowingstatementsistrueorfalseaccordingtothetext:(1)Atraditionalkernelprovidesmostofthefunctionsforapplications.(2)Allpartsofthekernelrunin“kernelmode”,whichallowsthemaccesstotheirownandother’ssectionsofmemory.(3)EachkernelcontainsitsownAPIs-whichiswhyWindowssoftwarewon’trununderUNIX,andMacintoshsoftwarewon’trunonanAS/400.(4)Inamicro-kernel,onlyafewcrucialfunctions,suchasmanaginghowmemoryandprocessortimearedividedamongapplicationsandcommunicationsbetweensoftwareprocessors,runinkernelmode.(5)Thepathtoasmallerkerneliseasy.IBMtriedandsucceededwithitsWorkplaceOS,andMicrosoftsteadfastlywantstoshrinkWindowsNT’skernel.Ⅲ.TranslatethefollowingsentencesintoChinese:(1)Hisfailuretoobservethesafetyregulationsresultedinanaccidenttothemachinery.(2)Thereisthestrongdemandforcomputerequipment.(3)Thisisamodernized,well-equippedarmyofthepeople.(4)Thepathtoasmallerkernelisn’teasy.(5)Formostusers,thelearningcurverequiredtotransformaLinuxboxintoa“personal”computeristosteep.Ⅳ.TranslatethefollowingparagraphintoChinese:

ManyorganizationsareconnectingontotheInternetandwanttodo“electroniccommerce”usingcurrentWebtechnology,however,therearestillmanyproblemsthatneedtoberesolved.Security,forexample,isone.“Howdoyoutransfersensitivefinancialinformationacrossapublicnetwork?”Thisissueiscurrentlybeingaddressedthroughthedevelopmentofsecureprotocols,suchasSHTTP,SSL,SKIPandmanyothers.RealtimedisplayofdataisalsoimpossibleinabrowserbecausetothebrowsertheWWWis“read-only”,actinglikeagiganticencyclopedia.ThisisgoingtochangewiththeintroductionofJavaandHotjavafromSunMicrosystems,theessentialingredientsneededforreal-timeinteractiveoperation.Javaisaprogramminglanguageandarun-timeenvironmentthatallowsprogramstobedownloadedoveranetwork.ReadingMaterialsNewStageofBrowserTechnology(Ⅰ)

Notsolongagotheprocessofdownloadingafilevia“anonymousftp”meaninvokingftpwiththenameofftpsite,logginginastheuser“anonymous”andthentypingapasswordthatequatedtoyouremailaddress.Oncein,youwoulduseUNIXlikecommandstonavigateandlocatethefile,typebinarytoselectbinarymode,andthenissuethegetcommandfollowedbythefilenametocopythefiletogroupyouwoulduseanotherprogram,forexampletinorrnandforsendingasimpleemailyouwouldusealocalemailclient.WhatamItryingtogetat,youmayaskwouldn’titbenicetobeabletouseonetoolforallthesetaskssuchaprogramshouldhaveaconsistentlookandfeelforalltasksandpredominantlyuseamouseratherthanthekeyboard.

Whatisthismagicalprogram?Allofyouknowthistoolasaworldwidewebbrowser.Thefirstwebbrowserwastextbasedanddevelopedtoallowresearchestoshareresearchinformation.Thesepaperscouldrefertootherrelateddocumentsthroughreferencesknownashyperlinks.Thesehyperlinksallowausertojumpfromonedocumenttoanotherrelateddocumentthroughasimplekey-press.Laterdevelopinbrowsersallowednotonlytexttobedisplayedonthescreen,butalsoin-linegraphics.ThefirstofsuchbrowserswasknownasMosaic.NewWordsandExpressionsanonymousa.匿名的equatevi.相等,等同invokev.調(diào)用ftp(filetransferprotocol)文件傳輸協(xié)議(用于向網(wǎng)絡(luò)登記、注冊(cè)、列目錄和文件拷貝的TCP/IP協(xié)議)rn(readnews)新聞閱讀器,一種閱讀文件consistentadj.一致的predominantlyadv.主要地WorldWideWebbrowser萬維網(wǎng)瀏覽器hyperlink超級(jí)鏈接Questions

(1)WhatisthefirstWebbrowser’scharacter?(2)Userscanusehyperlinkdowhat?NewStageofBrowserTechnology(Ⅱ)

Browsertechnologyisbasedontwomainstandards,“HypertextMark-upLanguage”HTML,whichisusedtocreateformatindependentcontentofthedocumentandthe“HypertextTransferProtocol”,HTTP,whichisusedtotransferdocumentsfromamachineknownasaservertothebrowser.TodaythemostpopularbrowserisNetscape’s“Navigator”developedbytheverysamepersonthatdeveloped