中科大操作系统原理与实现课件4_Threads2

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1、操作系统原理与设计第4章Threads2（线程2）陈香兰中国科学技术大学计算机学院December20,2009......提纲OSExamplesforThreadThreadSchedulingOSExamplesforThreadScheduling小结和作业......OutlineOSExamplesforThreadThreadSchedulingOSExamplesforThreadScheduling小结和作业......WindowsXPThreadsIIAnWindowsXPapplicat

2、ionrunsasaseperateprocess,andeachprocessmaycontainoneormorethreads.IImplementstheone-to-onemappingIeachuser-levelthreadmapstoanassotiatedkernelthreadIanythreadbelongingtoaprocesscanaccesstheaddressspaceoftheprocessIEachthreadcontainsIAthreadidIRegistersetISe

3、parateuserandkernelstacksIPrivatedatastorageareaITheregisterset,stacks,andprivatestorageareaareknownasthecontextofthethreads......WindowsXPThreadsIIITheprimarydatastructuresofathreadinclude:IETHREAD(executivethreadblock)IKTHREAD(kernelthreadblock)ITEB(thread

4、environmentblock)......WindowsXPThreadsIII......LinuxThreadsILinuxreferstothemastasksratherthanthreadsIThreadcreationisdonethroughclone()systemcallIclone()allowsachildtasktosharetheaddressspaceoftheparenttask(process)Iclone()VS.fork()......JavaThreadsIJava在语

5、言级提供线程创建和管理支持功能IJavathreadsaremanagedbytheJVM,notuser-levellibraryorkernelIJavathreadsmaybecreatedby:IExtendingThreadclassIImplementingtheRunnableinterfaceJava......ThreadStates......OutlineOSExamplesforThreadThreadSchedulingOSExamplesforThreadScheduling小结和作

6、业......ThreadSchedulingIuser-levelthread:kernel-levelthread(orLWP)ILocalScheduling–HowthethreadslibrarydecideswhichthreadtoputontoanavailableLWPImany-to-one,many-to-manymodelsIprocess-contentionscope,PCSIGlobalScheduling–Howthekerneldecideswhichkernelthreadt

7、orunnextImany-to-one,many-to-many&one-to-onemodelsIsystem-contentionscope,SCS......PthreadSchedulingAPIIIPOSIXPthreadAPIallowsspecifyingeitherPCSorSCSduringthreadcreationIPTHREADSCOPEPROCESS,many-to-manyIPTHREADSCOPESYSTEM,one-to-oneIcreateandbindanLWPforeac

8、huser-levelthreadIexample#include#include#defineNUMTHREADS5intmain(intargc,char*argv[])finti;pthreadttid[NUMTHREADS];pthreadattrtattr;pthreadattrinit(&attr);/*getthedefaultatt