测试Linux下socket每次发送数据和接受数据的最大值

经试验发现，客户端一次发送数据大小有个上线，本机试验数据最大是384KB，超出最大值的时候，客户端会阻塞到发送语句哪里等待服务端接受数据。服务多也是一样，有一个最大的一次性接受数据的上线，本机试验最大接受数据是64KB，但是这个服务端好像不确定具体接受多少

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <errno.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <pthread.h>#define MAXBUF 1024 * 1024void* recvsocket(void *arg){int st = *(int *)arg;char s[1024];while (1){memset(s, 0, sizeof(s));int rc = recv(st, s, sizeof(s), 0);if (rc <= 0)break;printf("%s\n", s);}return NULL;}void* sendsocket(void *arg){int st = *(int *)arg;char s[1024];char *p = malloc(MAXBUF);//1Mwhile (1){memset(s, 0, sizeof(s));read(STDIN_FILENO, s, sizeof(s));int rc = send(st, p, MAXBUF, 0);printf("rc = %d\n", rc);}return NULL;}int main(int arg, char *args[]){if (arg < 3){return -1;}int port = atoi(args[2]);int st = socket(AF_INET, SOCK_STREAM, 0);//初始化socketstruct sockaddr_in addr; // 定义一个IP地址的结构memset(&addr, 0, sizeof(addr));addr.sin_family = AF_INET;// 设置结构地址类型为TCP/IP地址addr.sin_port = htons(port); // 制定一个端口号：8080，htons：将short类型从host字节类型转到net字节类型// 将字符类型的IP地址转化为int，赋给addr结构//addr.sin_addr.s_addr = inet_addr("127.0.0.1");addr.sin_addr.s_addr = inet_addr(args[1]);//if (connect(st, (struct sockaddr *)&addr, sizeof(addr)) == -1){printf("connect failed %s\n", strerror(errno));return EXIT_FAILURE;}pthread_t thrd1, thrd2;pthread_create(&thrd1, NULL, recvsocket, &st);pthread_create(&thrd2, NULL, sendsocket, &st);pthread_join(thrd1, NULL);//pthread_join(thrd2, NULL);// 加上这一句话会导致线程如法退出，主线程会一直等待子线程，子线程一直是退步出来的close(st);return EXIT_SUCCESS;}

#define MAXBUF 1024 * 128struct ps{int st;pthread_t *thr;};pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;int status = 0;void* recvsocket(void *arg){struct ps *p = (struct ps *)arg;int st = p->st;char s[1024];char *pp = malloc(MAXBUF);while (1){char buf[100];read(STDIN_FILENO, buf, sizeof(buf));memset(s, 0, sizeof(s));int rc = recv(st, pp, MAXBUF, 0);printf("rc = %d\n", rc);if (rc <= 0)//如果recv返回小于等于0，代表socket已经关闭或者出错了break;//printf("%s\n", s);}pthread_mutex_lock(&mutex);status = 0;pthread_mutex_unlock(&mutex);pthread_cancel(*(p->thr));return NULL;}void* sendsocket(void *arg){int st = *(int *)arg;char s[1024];while (1){memset(s, 0, sizeof(s));read(STDIN_FILENO, s, sizeof(s));send(st, s, strlen(s), 0);}return NULL;}int main(int arg, char *args[]){if (arg < 2){return -1;}int port = atoi(args[1]);int st = socket(AF_INET, SOCK_STREAM, 0); //初始化socketint on = 1;if (setsockopt(st, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1){printf("setsockopt failed %s\n", strerror(errno));return EXIT_FAILURE;}struct sockaddr_in addr; // 定义一个IP地址结构memset(&addr, 0, sizeof(addr));addr.sin_family = AF_INET; // 将addr结构的属性定位为TCP/IP地址addr.sin_port = htons(port); // 将本地字节顺序转化为网络字节顺序addr.sin_addr.s_addr = htonl(INADDR_ANY); // INADDR_ANY代表这个server上所有的地址// 将ip与server程序绑定if (bind(st, (struct sockaddr *) &addr, sizeof(addr)) == -1){printf("bind failed %s\n", strerror(errno));return EXIT_FAILURE;}// server端开始listenif (listen(st, 20) == -1){printf("listen failed %s\n", strerror(errno));return EXIT_FAILURE;}//printf("listen success\n");int client_st = 0;struct sockaddr_in client_addr; // 表示client端的IP地址pthread_t thrd1, thrd2;while (1){memset(&client_addr, 0, sizeof(client_addr));socklen_t len = sizeof(client_addr);client_st = accept(st, (struct sockaddr*) &client_addr, &len);pthread_mutex_lock(&mutex);status++;pthread_mutex_unlock(&mutex);if (status > 1){close(client_st);continue;}if (client_st == -1){printf("accept failed %s\n", strerror(errno));return EXIT_FAILURE;}printf("accept by %s\n", inet_ntoa(client_addr.sin_addr));struct ps ps1;ps1.st = client_st;ps1.thr = &thrd2;pthread_create(&thrd1, NULL, recvsocket, &ps1);pthread_detach(thrd1);//设置线程为可分离//pthread_create(&thrd2, NULL, sendsocket, &client_st);//pthread_detach(thrd2);//设置线程为可分离}close(st);return EXIT_SUCCESS;}