linux操作系统编程——线程的应用

来源：互联网发布：stc52单片机控制浇花编辑：程序博客网时间：2024/05/16 17:54

程序功能：

程序分成两个部分，一个写端一个读端，采用fifo进行进程间的通信，写端负责写入命令，读端负责读命令，读端采用多线程的方式进行编写程序，创建两个线程，一个唤醒线程用于唤醒发送线程，一个发送线程用于发送消息；主线程读取命令后，将命令添加到任务队列中，唤醒线程进行判断，如果任务队列为空则睡眠，否则唤醒发送线程，采用条件变量与互斥锁进行线程间的同步互斥；

程序如下：

（1）、pthread_read.c

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <pthread.h>#include <fcntl.h>struct node{    int cmd;    struct node *next;};struct node *head;char buf[100];pthread_mutex_t send_mutex, wake_mutex;pthread_cond_t send_cond, wake_cond;struct node *create_list(void);void insert_list(struct node *, int );void delete_list(struct node *, int );int is_empty_list(struct node *);int get_list_cmd(struct node *);void *wake_func(void *);void *send_func(void *);int main(int argc, const char *argv[]){    pthread_t wake_pthread, send_pthread;    int err;    int fifo_fd;    char cmd_buf[20];    if (argc < 2)    {        fprintf(stderr, "usages: %s filename\n", argv[0]);        exit(-1);    }    head = create_list();    if ((fifo_fd = open(argv[1], O_RDONLY)) < 0)    {        perror("failed to open fifo");        exit(-1);    }    err = pthread_create(&wake_pthread, NULL, wake_func, NULL);    if (err < 0)    {        perror("failed to create wake_pthread");        exit(-1);    }    err = pthread_create(&send_pthread, NULL, send_func, NULL);    if (err < 0)    {        perror("failed to create send_pthread");        exit(-1);    }    err = pthread_mutex_init(&wake_mutex, NULL);    if (err < 0)    {        perror("failed to init wake_mutex");        exit(-1);    }    err = pthread_mutex_init(&send_mutex, NULL);    if (err < 0)    {        perror("failed to init send_mutex");        exit(-1);    }    err = pthread_cond_init(&wake_cond, NULL);    if (err < 0)    {        perror("failed to init wake_cond");        exit(-1);    }    err = pthread_cond_init(&send_cond, NULL);    if (err < 0)    {        perror("failed to init send_cond");        exit(-1);    }    while(1)    {        read(fifo_fd, cmd_buf, sizeof(cmd_buf));        if(strncmp(cmd_buf, "quit", 4) == 0)            break;        insert_list(head, atoi(cmd_buf));        pthread_mutex_lock(&wake_mutex);        pthread_cond_signal(&wake_cond);        pthread_mutex_unlock(&wake_mutex);    }    return 0;}struct node *create_list(void){    struct node *head;    head = (struct node *)malloc(sizeof(struct node));    head->next = NULL;    return head;}void insert_list(struct node *head, int cmd){    struct node *new;    new = (struct node *)malloc(sizeof(struct node));    new->cmd = cmd;    new->next = head->next;    head->next = new;    return ;}void delete_list(struct node *head, int cmd){    struct node *p = head->next;    struct node *q = head;    while (p != NULL)    {        if (p->cmd == cmd)            break;                p = p->next;        q = q->next;    }    q->next = p->next;    p->next = NULL;    free(p);    return ;}int is_empty_list(struct node *head){    int value;    if (head->next == NULL)        value = 1;    else        value = 0;    return value;}int get_list_cmd(struct node *head){    struct node *p = head->next;    return p->cmd;}void *wake_func(void *arg){    int cmd;    while (1)    {        pthread_mutex_lock(&wake_mutex);        if (is_empty_list(head))            pthread_cond_wait(&wake_cond, &wake_mutex);                cmd = get_list_cmd(head);        printf("cmd : %d\n", cmd);        switch(cmd)        {            case 1:                strcpy(buf, "fire is coming");                pthread_cond_signal(&send_cond);                delete_list(head, cmd);                break;            case 2:                strcpy(buf, "thief is coming");                pthread_cond_signal(&send_cond);                delete_list(head, cmd);                break;            case 3:                strcpy(buf, "take photos");                pthread_cond_signal(&send_cond);                delete_list(head, cmd);                break;            default:                delete_list(head, cmd);                break;        }        pthread_mutex_unlock(&wake_mutex);    }    return ;}void *send_func(void *arg){    while(1)    {        pthread_mutex_lock(&send_mutex);        pthread_cond_wait(&send_cond, &send_mutex);        pthread_mutex_unlock(&send_mutex);                printf("recv: %s\n", buf);    }    return ;}

（2）write_fifo.c

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <fcntl.h>#include <errno.h>int main(int argc, const char *argv[]){    int fifo_fd;    char buf[20];    if (argc < 2)    {        fprintf(stderr, "usages: %s fifo\n", argv[0]);        exit(-1);    }    if (mkfifo(argv[1], 0666 | O_CREAT | O_EXCL) < 0)    {        if (errno == EEXIST)        {            if (mkfifo(argv[1], 0666) < 0)            {                perror("failed to create fifo");                exit(-1);            }        }    }    if ((fifo_fd = open(argv[1], O_WRONLY)) < 0)    {        perror("failed to open fifo");        exit(-1);    }    while(1)    {        printf(">");        fgets(buf, sizeof(buf), stdin);        buf[strlen(buf) - 1] = 0;        write(fifo_fd, buf, strlen(buf) + 1);        if(strncmp(buf, "quit", 4) == 0)            break;    }    return 0;}