操作系統(tǒng)實驗報告(進(jìn)程的創(chuàng)建)

1、實驗題目進(jìn)程的創(chuàng)建小組合作否姓名班級學(xué) 號一、實驗?zāi)康牧私膺M(jìn)程的創(chuàng)建。了解進(jìn)程間的調(diào)用以及實現(xiàn)。分析進(jìn)程競爭資源的現(xiàn)象，學(xué)習(xí)解決互斥的方法。加深對進(jìn)程概念的理解，認(rèn)識并發(fā)執(zhí)行的本質(zhì)。二.實驗環(huán)境Windows系統(tǒng)的計算機(jī)一臺，安裝了 Linux虛擬機(jī)三、實驗內(nèi)容與步驟1、fork ()系統(tǒng)調(diào)用的使用例子程序代碼：#include<>#include<sys/>#include<>int glob=3;int main(void)pid_t pid;int 10c=3;printf("before fork();glod=%d,loc=%d.n&qu

2、ot;,glob,loc);if(pid=fork()<0)printf("fork() error. n");exit(0);else if(pid=0)glob+;loc-;printf("child process changes glob and loc: n");elsewait(0);printf("parent process doesn't change the glob and loc:n");printf("glob=%d,loc=%dn",glob,loc);exit(0);運(yùn)行

3、結(jié)果：文件® 編輯®肉標(biāo)。ftMG) 1WWW| coo t'laca I hus i ml drril # g 匚仁raotloca Ih-051 mldmlHt 1 kexebe fore fork()glad-3 +loc-3tcbl Id proce i i change 5 glub ;k! lac：pa reji l proce S5 doc sn ' l change 1he lob and Ine：g I ob= t Jqc=2pa rent proce is doe n I change ihe glob and loc：lob=3 J心亡

4、=3r oo I 'loca I hos i mid nil# |2、理解vofork ()調(diào)用：程序代碼：#include<>#include<sys/>#include<>int glob=3;int main(void)pid_t pid;int loc=3;if(pid=vfork()<0)printf("vfork() errorn");exit(0);else if(pid=0)glob+;loc-;printf("child process changes the glob and locn"

5、;);exit(0);elseprintf ("parent process doesn't change the glob and locn");printf("glob=%d,val=%dn",glob,loc);運(yùn)行結(jié)果：r uo tildes I hdn l ml cirri)# ,ril 史 2.電工電ch l Id prore 5 s change s the g 1-oh and l-o-cpa ren L proce as doe sn t chang史 ihe Rloh and Locf I Q b =4 Aa J=2|mIml

6、dml曲3、給進(jìn)程指定一個新的運(yùn)行程序的函數(shù)exec().程序代碼：代碼：#include<>int main(int argc,char * argv口) int n;char * * ptr;extern char * * environ;for(n=0;n<argc;n+)printf("argv%d:%sn",n,argvn);for(ptr=environ; * ptr!=0;ptr+) printf("%sn",* ptr);exit(0);代碼如下：#include<>#include<sys/>#

7、include<>#include<sys/>char * env_list尸"USER=root","PATH=/root/",NULL;int main()pid_t pid；if(pid=fork()<0)printf("fork error!n");exit(0);else if(pid=0)if(execle("/root/print1","print1","arg1","arg2",(char *)0,env_li

8、st)<0) printf("execle error!n");exit(0);if(waitpid(pid,NULL,0)<0)printf("WAIT ERROR!n");exit(0);if(pid=fork()<0)printf("fork error!n");exit(0);else if(pid=0)if(execlp("print1","print1","arg1",(char *)0)<0) printf("execle er

9、ror!n");exit(0);exit(0);運(yùn)行結(jié)果：ruu tluca & i inldraill A . / f i le4 .cxeargO：piriitarg 1 Largl arg2：arg?LSER-roulPATH=7root|rno t loca Ihos t mldH#JL4、進(jìn)程終止函數(shù)exit()。程序代碼：#include<>main()printf("this is a exit system call! n");exit(0);printf("this sentence never be display

10、en:n");#include<>main()printf("this is a _exit_test system call! n");printf("content in buffer");exit(0);運(yùn)行結(jié)果：rooIhost mldnri# gee ex i i_iest .c -o exi L_Lest_eie r uu lluca I ho Ji L ml JnJ . /ex. i t trat .cxcthis is a exit sysle m ca 11J !T r oo t ：k)ca I ho-s l ni

11、ldrri Irunt luca Ihos I mldirj p jtc ent tesL.c -o _c i i i _ tes t exe ruot11iq l unldcd# ./_七工 i l _丘 .亡 xcthis is a _ex i l_lesl pystEm ca I I !口他Me lhn&i ,nUdnjl!5、wait()函數(shù)和 sleep()函數(shù)。程序代碼：#include<>main()int pidl;if(pid1=fork()if(fork()printf("parent's context,n");printf

12、("parent's waiting the childl terminate,n");wait(0);printf("parent's waiting the child2 terminate,n");wait(0);printf("parent terminates,、)；exit(0); elseprintf("child2's context,n");sleep(5);printf("child2 terminates,n");exit(0);elseif(pid1=0)p

13、rintf("child1's context,n");sleep(10);printf("child1 terminates,n");exit(0);運(yùn)行結(jié)果：r oo tloca I host MdmJ# . Zf i l-eli .eice ck id s can lex t rchi ld2 s con text *pa reji t1 s con lex tpa reii L1 s vdi l I ing the ch i Idl Irrmina te Fch i Ld2 ir mina ie s bpa ren t' s ai

14、ling t he ch i Id2 terrrim t« r chi l-dl lorminn les ,pa re ji L ier mi ns te s Ptloca I hos t ml dmJ #6、編寫一段程序，父進(jìn)程使用fork()創(chuàng)建兩個子進(jìn)程，利用輸出函數(shù)putchar父進(jìn)程顯示字符"a"，兩個子進(jìn)程分別顯示“ b”和“ c”。程序代碼：#include<>#include<sys/>#include<>int main()int pid;if(pid=fork()if(fork()printf("p

15、arent process is n");putchar('A');printf("n");elseprintf("child2 process is n");putchar('C');printf("n");elseif(pid=0)printf("child1 process is n");putchar('B'); printf("n");運(yùn)行結(jié)果：文件(舊漏輯查看出隆瑞3 轉(zhuǎn)到 幫助QDfoq tloca IIioa L mid向

16、# y im kao&h i *roo t Inca Iho ii t mldml* v im kansh i »rootloca Ihos i mldnil# ./kooshi .xechi Id procesi iwHchild2 prncess isCparent pro« ss iwAroo t''loca Iho t mldnj . /kansh i四、實驗過程與分析1、在1例子中，調(diào)用正確完成時，給父進(jìn)程返回的是被創(chuàng)建子進(jìn)程標(biāo)識，給子進(jìn)程自己返回的是0；創(chuàng)建失敗時，返回給父進(jìn)程的是-1。2、在2例子中，vfork ()調(diào)用后需要注意兩點(diǎn)：(1)子進(jìn)程先運(yùn)行，父進(jìn)程掛起。子進(jìn)程調(diào)用exec ()或exit ()之后父進(jìn)程的執(zhí)行順序不再有限制。(2)子進(jìn)程在調(diào)用exec ()或exit ()之前。父進(jìn)程被激活，就會造成 死鎖。3、在6例子中，上述程序是父進(jìn)程先創(chuàng)建一個子進(jìn)程，若成功，再創(chuàng)建 另一個子進(jìn)程，之后三個進(jìn)程并發(fā)執(zhí)行。究竟誰先執(zhí)行，是隨機(jī)的。所以 執(zhí)行結(jié)果有多重種。五、實驗總結(jié)1、一個進(jìn)程調(diào)用exec()函數(shù)來運(yùn)行一個新程序。之后該進(jìn)程的代碼段、數(shù)據(jù)段和堆棧段就被新程序的所代替。 新程序從自己的main ()函數(shù)開始執(zhí)行。exec ()函數(shù)有6種不同的形式，任何一個都可以完成 exec()的 功能，只是調(diào)用參