第十二章UNIX操作系统清华大学12.1历史回顾12.1历史回顾第1版（1971）12.2系统结构内核部分内核部分外壳部分12.3进程管理12.3.1进程组成(映像)12.3.2进程控制块structproc{charp_stat;charp_flag;charp_pri;charp_sig;//signalreceivedcharp_uid;//useridcharp_time;//residenttimeforschedulingcharp_cpu;//cpuusagecharp_nice;//niceforschedulingcharp_ttyp;//controllingttyintp_pid;//uniqueprocessidintp_ppid;//parentprocessidintp_addr;//addressofswappableimageintp_size;//sizeofswappableimage(*64bytes)intp_wchan//eventprocessiswaitingint*p_textp;//pointertotextstructure}structuser{intu_rsav[2]intu_fsav[25]……charu_uid;//effectiveuseridcharu_gid;//effectivegroupidcharu_ruid;//realuseridcharu_rgid;//realgroupidintu_procp;//pointertoprocstructureint*u_base;//baseaddressforIOint*u_count;//bytesremainingforIOint*u_offset[2];//offsetinfileforIOint*u_cdir;//pointertoinodeofcurrentdirint*u_pdir;//inodeofparentdirectoryintu_uisa[16];//prototypesegmentationaddressintu_uisd[16];//prototypesegmentationdescriptintu_ofile[NOFILE];//pointerstofilestructintu_arg[5];//argumentstosystemcallintu_tsize;//textsize(*64)intu_dsize;//datasize(*64)intu_sszie;//stacksize(*64)intu_utime;//thisprocessusertimeintu_stime;//thisprocesssystemtimeintu_cutime[2];//childprocessusertimeintu_cstime[2];//childprocesssystemtime……}structtext{intx_daddr;//diskaddressofsegmentintx_caddr;//coreaddressifloadedintx_size;//*64int*x_iptr;//inodeofprototypecharx_count;//referencecountcharx_ccount;//numberofloadedreferences}12.3.3进程状态及其转换进程状态及其转换12.3.4进程调度进程调度实现12.3.5进程互斥12.3.6进程同步信号(signal)信号(signal)信号(signal)信号(signal)管道(Pipes)套接字(socket)12.4存储管理12.4.1存储管理方式12.4.2存储分配算法12.4.3进程空间扩充12.4.4交换技术(swapping)12.4.5虚拟页式(Paging)页面置换页面置换页面置换12.5UNIX文件系统12.5.1文件类型12.5.2文件体系12.5.3文件结构12.5.4文件目录与连接连接实现read(4,…)相关表目3.Inode表(系统一个)structinode{inti_flag;chari_count;chari_dev;chari_number;chari_mode;chari_nlink;chari_uid;chari_gid;chari_size0;char*i_size1;inti_addr[8];inti_lastr;}inode[NINODE];12.5.6文件卷的安装超级块Structfilesys{ints_isize;//sizeinb