完成了第 18 章 多线程服务器端的实现

ch18/chat_server.c

@@ -0,0 +1,100 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <arpa/inet.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <pthread.h>
+
+#define BUF_SIZE 100
+#define MAX_CLNT 256
+
+void *handle_clnt(void *arg);
+void send_msg(char *msg, int len);
+void error_handling(char *msg);
+
+int clnt_cnt = 0;
+int clnt_socks[MAX_CLNT];
+pthread_mutex_t mutx;
+
+int main(int argc, char *argv[])
+{
+    int serv_sock, clnt_sock;
+    struct sockaddr_in serv_adr, clnt_adr;
+    int clnt_adr_sz;
+    pthread_t t_id;
+    if (argc != 2)
+    {
+        printf("Usage : %s <port>\n", argv[0]);
+        exit(1);
+    }
+
+    pthread_mutex_init(&mutx, NULL); //创建互斥锁
+    serv_sock = socket(PF_INET, SOCK_STREAM, 0);
+
+    memset(&serv_adr, 0, sizeof(serv_adr));
+    serv_adr.sin_family = AF_INET;
+    serv_adr.sin_addr.s_addr = htonl(INADDR_ANY);
+    serv_adr.sin_port = htons(atoi(argv[1]));
+
+    if (bind(serv_sock, (struct sockaddr *)&serv_adr, sizeof(serv_adr)) == -1)
+        error_handling("bind() error");
+    if (listen(serv_sock, 5) == -1)
+        error_handling("listen() error");
+
+    while (1)
+    {
+        clnt_adr_sz = sizeof(clnt_adr);
+        clnt_sock = accept(serv_sock, (struct sockaddr *)&clnt_adr, &clnt_adr_sz);
+
+        pthread_mutex_lock(&mutx);          //上锁
+        clnt_socks[clnt_cnt++] = clnt_sock; //写入新连接
+        pthread_mutex_unlock(&mutx);        //解锁
+
+        pthread_create(&t_id, NULL, handle_clnt, (void *)&clnt_sock);       //创建线程为新客户端服务，并且把clnt_sock作为参数传递
+        pthread_detach(t_id);                                               //引导线程销毁，不阻塞
+        printf("Connected client IP: %s \n", inet_ntoa(clnt_adr.sin_addr)); //客户端连接的ip地址
+    }
+    close(serv_sock);
+    return 0;
+}
+
+void *handle_clnt(void *arg)
+{
+    int clnt_sock = *((int *)arg);
+    int str_len = 0, i;
+    char msg[BUF_SIZE];
+
+    while ((str_len = read(clnt_sock, msg, sizeof(msg))) != 0)
+        send_msg(msg, str_len);
+    //接收到消息为0，代表当前客户端已经断开连接
+    pthread_mutex_lock(&mutx);
+    for (i = 0; i < clnt_cnt; i++) //删除没有连接的客户端
+    {
+        if (clnt_sock == clnt_socks[i])
+        {
+            while (i++ < clnt_cnt - 1)
+                clnt_socks[i] = clnt_socks[i + 1];
+            break;
+        }
+    }
+    clnt_cnt--;
+    pthread_mutex_unlock(&mutx);
+    close(clnt_sock);
+    return NULL;
+}
+void send_msg(char *msg, int len) //向连接的所有客户端发送消息
+{
+    int i;
+    pthread_mutex_lock(&mutx);
+    for (i = 0; i < clnt_cnt; i++)
+        write(clnt_socks[i], msg, len);
+    pthread_mutex_unlock(&mutx);
+}
+void error_handling(char *msg)
+{
+    fputs(msg, stderr);
+    fputc('\n', stderr);
+    exit(1);
+}