Linux进程间通信之生产者消费者

#include <stdio.h> #include <stdlib.h> #include <sys/types.h> #include <sys/ipc.h> #include <sys/sem.h> #include <sys/shm.h> #include <unistd.h> #include <string.h> #include <errno.h> #define DATA_LENGTH 128 struct mydata { int size; char data[DATA_LENGTH]; }; void producer() { printf("producer.\n"); int ret; unsigned short sem_array[2]; union semun { int val; struct semid_ds *buf; unsigned short *array; }arg; key_t key_sem = ftok(".", 'b'); if (-1 == key_sem) { perror("key"); } int sem_id = semget(key_sem, 2, IPC_CREAT | 0660); if (-1 == sem_id) { perror("semget"); } sem_array[0] = 0; // 初始数据个数为0 sem_array[1] = 1; // 初始空间个数为1 arg.array = sem_array; ret = semctl(sem_id, 0, SETALL, arg); //设置信号量 if(ret == -1) { perror("semctl"); } key_t key_shm = ftok(".", 'd'); int shm_id=shmget(key_shm, 512, IPC_CREAT | 0666); if (-1 == shm_id) { perror("shmget"); } printf("shmid is:%d\n", shm_id); struct mydata * p_mydata; p_mydata = (struct mydata *) shmat(shm_id, NULL, 0); struct sembuf sops[2]; sops[0].sem_num = 0; // 数据 sops[0].sem_op = 1; sops[0].sem_flg = 0; sops[1].sem_num = 1; // 空间 sops[1].sem_op = -1; sops[1].sem_flg = 0; char * data = "data produced."; int i = 0; for (i=0; i<10; i++) { semop(sem_id, (struct sembuf *)&sops[1], 1); printf("produceing\n"); p_mydata->size = strlen(data); strcpy(p_mydata->data, data); semop(sem_id, (struct sembuf *)&sops[0], 1); sleep(1); } if(shmdt(p_mydata) == -1) { perror("detach error"); } semctl(sem_id, IPC_RMID , 0); } void consumer() { printf("consumer.\n"); key_t key_sem = ftok(".", 'b'); // 获取键值 int sem_id = semget(key_sem, 2, IPC_CREAT|0666); // 得到信号量标示符 if (-1 == sem_id) { perror("semget"); } struct sembuf sops[2]; sops[0].sem_num = 0; // 数据 sops[0].sem_op = -1; sops[0].sem_flg = 0; sops[1].sem_num = 1; // 空间 sops[1].sem_op = 1; sops[1].sem_flg = 0; key_t key_shm = ftok(".", 'd'); int shm_id=shmget(key_shm, 512, IPC_CREAT | 0666); if (-1 == shm_id) { perror("shmget"); } struct mydata * p_mydata; p_mydata = (struct mydata *) shmat(shm_id, NULL, 0); int i = 0; for (i=0; i<10; i++) { semop(sem_id, (struct sembuf *)&sops[0], 1); printf("customering\n"); printf("data size is %d, data is %s \n", p_mydata->size, p_mydata->data); semop(sem_id, (struct sembuf *)&sops[1], 1); sleep(1); } } int main(int argc, char * argv[]) { pid_t pid; pid = fork(); if (-1 == pid) { perror("fork error:"); } if (0 == pid) { producer(); } else { consumer(); } return 0; }