#include<stdio.h>#include<stdlib.h>#include<sys/ipc.h>#include<sys/msg.h>#include<sys/types.h>#include<unistd.h>#include<errno.h>#include<sys/ipc.h>#include<sys/sem.h>#include<sys/wait.h>#define DELAY (rand() % 5 + 1)#define ERR_EXIT(m)     do {         perror(m);         exit(EXIT_FAILURE);     } while(0)union semun{    int val;    // Value for SETVAL    struct semid_ds *buf;    //Buffer for IPC_STAT, IPC_SET     unsigned short  *array;  /* Array for GETALL, SETALL */    struct seminfo  *__buf;  /* Buffer for IPC_INFO (Linux-specific) */};//semid ! this is the number of share memoryint semid;//waiting for fork here//left and right = the number of soursesvoid wait_for_1fork(int no)  {    int left = no;    //system defined struct    //"first":the current number of pro     //"second":resourses -1:wait cannot use;+1:can use    //"thired":?    struct sembuf buf[1] =    {        {left, -1, 0},    };    //semop do wait or signal (p/v)    //"first": the  number of share memory pro    //"second":the first point of struct    //"third":the number of signal to complete    semop(semid, buf, 1);}void wait_for_2fork(int no)  {    int right = (no + 1) % 5;    //system defined struct    //"first":the current number of pro     //"second":resourses -1:wait cannot use;+1:can use    //"thired":?    struct sembuf buf[1] =    {        {right, -1, 0}    };    //semop do wait or signal (p/v)    //"first": the  number of share memory pro    //"second":the first point of struct    //"third":the number of signal to complete    semop(semid, buf, 1);}void free_1fork(int no){    int left = no;    //system defined struct    //"first":the current number of pro     //"second":resourses -1:wait cannot use;+1:can use    //"thired":?    struct sembuf buf[1] =     {        {left, 1, 0},    };    semop(semid, buf, 1);}void free_2fork(int no){    int right = (no + 1) % 5;    //system defined struct    //"first":the current number of pro     //"second":resourses -1:wait cannot use;+1:can use    //"thired":?    struct sembuf buf[1] =     {        {right, 1, 0}    };    semop(semid, buf, 1);}void philosopere(int num){    srand(getpid());    for (; ;)    {        //printf("%d is thinking\n", num);        printf("\033[36m%d is thinking\n\033[0m", num);        if(num!=0)        sleep(DELAY);        //printf("%d is hungry\n", num);        wait_for_1fork(num);        //printf("%d pick up left chopsticks\n", num);        printf("\033[31m%d pick up left chopsticks\n\033[0m", num);        sleep(DELAY);        sleep(DELAY);        wait_for_2fork(num);        //printf("%d pick up right chopsticks\n", num);        printf("\033[34m%d pick up right chopsticks\n\033[0m", num);        //printf("%d is eating\n", num);        sleep(DELAY);        free_1fork(num);        //printf("%d return left chopsticks\n", num);        printf("\033[33m%d return left chopsticks\n\033[0m", num);        sleep(DELAY);        free_2fork(num);        //printf("%d return right chopsticks\n", num);        printf("\033[37m%d return right chopsticks\n\033[0m", num);    }}int main(){    //use IPC to connect between processes . A new share memory    //semget() return the number of share memory     //new signal key=0 and never change .So not use key    //"first":use IPC_PRIVATE to share memory between relation processes    //"second":(size_t)naxSize    //"third":(int flag)private:666--read and write ; IPC_CREAT creat new memory    semid = semget(IPC_PRIVATE, 5, IPC_CREAT | 0666);    if (semid == -1)        ERR_EXIT("semget");    union semun su;    su.val = 1;    for (int i = 0; i < 5; i++)    {        //creat a new object on "semid"         //use i to depart 5 processes        semctl(semid, i, SETVAL, su);    }    int no = 0;    //pid_t (Process ID _ Type) Just like  int    pid_t pid;     for (int i = 1; i < 5; i++)    {        //use fork() to make a copy of father process named with child pro        //father.pid>0 and child.pid=0        //after for loop will exist a father and five childs(0-4)        pid = fork();        if (pid == -1)            ERR_EXIT("fork");        if (pid == 0)        {            no = i;            //break the child process loop to run the philosopere            break;        }    }    philosopere(no);    return 0;}

#include<stdio.h>#include<stdlib.h>#include<sys/ipc.h>#include<sys/msg.h>#include<sys/types.h>#include<unistd.h>#include<errno.h>#include<sys/ipc.h>#include<sys/sem.h>#include<sys/wait.h>#define DELAY (rand() % 5 + 1)#define ERR_EXIT(m)     do {         perror(m);         exit(EXIT_FAILURE);     } while(0)union semun{    int val;    // Value for SETVAL    struct semid_ds *buf;    //Buffer for IPC_STAT, IPC_SET     unsigned short  *array;  /* Array for GETALL, SETALL */    struct seminfo  *__buf;  /* Buffer for IPC_INFO (Linux-specific) */};//semid ! this is the number of share memoryint semid;//waiting for fork here//left and right = the number of soursesvoid wait_for_2fork(int no)  {    int left = no;    int right = (no + 1) % 5;    //system defined struct    //"first":the current number of pro     //"second":resourses -1:wait cannot use;+1:can use    //"thired":?    struct sembuf buf[2] =    {        {left, -1, 0},        {right, -1, 0}    };    //semop do wait or signal (p/v)    //"first": the  number of share memory pro    //"second":the first point of struct    //"third":the number of signal to complete    semop(semid, buf, 2);}void free_2fork(int no){    int left = no;    int right = (no + 1) % 5;    //system defined struct    //"first":the current number of pro     //"second":resourses -1:wait cannot use;+1:can use    //"thired":?    struct sembuf buf[2] =     {        {left, 1, 0},        {right, 1, 0}    };    semop(semid, buf, 2);}void philosopere(int num){    srand(getpid());    for (; ;)    {        //printf("\033[31m Hello\n\033[0m");        //printf("\033[36m Hello\n\033[0m");        //printf("\%d is thinking\n", num);        printf("\033[31m%d is thinking\n\033[0m", num);        sleep(DELAY);        printf("%d pick up two chopsticks\n", num);        printf("\033[36m%d pick up two chopsticks\n\033[0m", num);        wait_for_2fork(num);        //printf("%d is eating\n", num);        printf("\033[34m%d is eating\n\033[0m", num);        sleep(DELAY);        free_2fork(num);    }}int main(){    //use IPC to connect between processes . A new share memory    //semget() return the number of share memory     //new signal key=0 and never change .So not use key    //"first":use IPC_PRIVATE to share memory between relation processes    //"second":(size_t)naxSize    //"third":(int flag)private:666--read and write ; IPC_CREAT creat new memory    semid = semget(IPC_PRIVATE, 5, IPC_CREAT | 0666);    if (semid == -1)        ERR_EXIT("semget");    union semun su;    su.val = 1;    for (int i = 0; i < 5; i++)    {        //creat a new object on "semid"         //use i to depart 5 processes        semctl(semid, i, SETVAL, su);    }    int no = 0;    //pid_t (Process ID _ Type) Just like  int    pid_t pid;     for (int i = 1; i < 5; i++)    {        //use fork() to make a copy of father process named with child pro        //father.pid>0 and child.pid=0        //after for loop will exist a father and five childs(0-4)        pid = fork();        if (pid == -1)            ERR_EXIT("fork");        if (pid == 0)        {            no = i;            //break the child process loop to run the philosopere            break;        }    }    philosopere(no);    return 0;}