应用程序级修改缓冲区大小
我们可以在程序中动态地修改(通过setsockopt系统调用)持有的有效Socket的读写缓冲区大小。
复制代码
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
int main(int argc, char **argv)
{
if (argc != 2)
{
printf("Usage: %s $RCFBUFSIZE
", argv[0]);
goto error;
}
int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
if (sockfd < 0)
{
printf("create socket error=%d(%s)!!!
", errno, strerror(errno));
goto error;
}
// 查看系统默认的socket接收缓冲区大小
int defRcvBufSize = -1;
socklen_t optlen = sizeof(defRcvBufSize);
if (getsockopt(sockfd, SOL_SOCKET, SO_RCVBUF, &defRcvBufSize, &optlen) < 0)
{
printf("getsockopt error=%d(%s)!!!
", errno, strerror(errno));
goto error;
}
printf("OS default udp socket recv buff size is: %d
", defRcvBufSize);
// 按照执行参数设置UDP SOCKET接收缓冲区大小
int rcvBufSize = atoi(argv[1]);
if (rcvBufSize <= 0)
{
printf("rcvBufSize(%d) <= 0, error!!!
", rcvBufSize);
goto error;
}
printf("you want to set udp socket recv buff size to %d
", rcvBufSize);
optlen = sizeof(rcvBufSize);
if (setsockopt(sockfd, SOL_SOCKET, SO_RCVBUF, &rcvBufSize, optlen) < 0)
{
printf("setsockopt error=%d(%s)!!!
", errno, strerror(errno));
goto error;
}
printf("set udp socket(%d) recv buff size to %d OK!!!
", sockfd, rcvBufSize);
// 查看当前UDP SOCKET接收缓冲区大小
int curRcvBufSize = -1;
optlen = sizeof(curRcvBufSize);
if (getsockopt(sockfd, SOL_SOCKET, SO_RCVBUF, &curRcvBufSize, &optlen) < 0)
{
printf("getsockopt error=%d(%s)!!!
", errno, strerror(errno));
goto error;
}
printf("OS current udp socket(%d) recv buff size is: %d
", curRcvBufSize);
close(sockfd);
exit(0);
error:
if (sockfd >= 0)
close(sockfd);
exit(1);
}