计算机网络中的几个性能指标
带宽:用来表示网络的通信线路传送数据的能力,通常是指单位时间内从网络中的某一点通过另一点的最高数据率,即网络设备所支持的最高速度
吞吐量:表示单位时间内通过某个网络(或信道、接口)的数据量。
代码位置及分析
ttcp代码位置:muduo-master/examples/ace/ttcp
ttcp_blocking.cc就是简单的客户端服务端通信(阻塞IO),通信的过程中加入测试的逻辑
客户端主要函数
void transmit(const Options& opt)
{
struct sockaddr_in addr = resolveOrDie(opt.host.c_str(), opt.port);
printf("connecting to %s:%d\n", inet_ntoa(addr.sin_addr), opt.port);
int sockfd = ::socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
assert(sockfd >= 0);
int ret = ::connect(sockfd, reinterpret_cast<struct sockaddr*>(&addr), sizeof(addr));
if (ret)
{
perror("connect");
printf("Unable to connect %s\n", opt.host.c_str());
::close(sockfd);
return;
}
printf("connected\n");
muduo::Timestamp start(muduo::Timestamp::now()); // 发送前记录时间
struct SessionMessage sessionMessage = { 0, 0 };
sessionMessage.number = htonl(opt.number);
sessionMessage.length = htonl(opt.length);
if (write_n(sockfd, &sessionMessage, sizeof(sessionMessage)) != sizeof(sessionMessage))
{
perror("write SessionMessage");
exit(1);
}
const int total_len = static_cast<int>(sizeof(int32_t) + opt.length);
PayloadMessage* payload = static_cast<PayloadMessage*>(::malloc(total_len));
assert(payload);
payload->length = htonl(opt.length);
for (int i = 0; i < opt.length; ++i)
{
payload->data[i] = "0123456789ABCDEF"[i % 16];
}
// 发送的数据总量
double total_mb = 1.0 * opt.length * opt.number / 1024 / 1024;
printf("%.3f MiB in total\n", total_mb);
for (int i = 0; i < opt.number; ++i)
{
int nw = write_n(sockfd, payload, total_len);
assert(nw == total_len);
int ack = 0;
int nr = read_n(sockfd, &ack, sizeof(ack));
assert(nr == sizeof(ack));
ack = ntohl(ack);
assert(ack == opt.length);
}
::free(payload);
::close(sockfd);
// 计算出时间差
double elapsed = timeDifference(muduo::Timestamp::now(), start);
// 数据总量/时间,单位 mb\s
printf("%.3f seconds\n%.3f MiB/s\n", elapsed, total_mb / elapsed);
}
服务端的主要函数
void receive(const Options& opt)
{
int sockfd = acceptOrDie(opt.port);
struct SessionMessage sessionMessage = { 0, 0 };
if (read_n(sockfd, &sessionMessage, sizeof(sessionMessage)) != sizeof(sessionMessage))
{
perror("read SessionMessage");
exit(1);
}
sessionMessage.number = ntohl(sessionMessage.number);
sessionMessage.length = ntohl(sessionMessage.length);
printf("receive number = %d\nreceive length = %d\n",
sessionMessage.number, sessionMessage.length);
const int total_len = static_cast<int>(sizeof(int32_t) + sessionMessage.length);
PayloadMessage* payload = static_cast<PayloadMessage*>(::malloc(total_len));
assert(payload);
for (int i = 0; i < sessionMessage.number; ++i)
{
payload->length = 0;
if (read_n(sockfd, &payload->length, sizeof(payload->length)) != sizeof(payload->length))
{
perror("read length");
exit(1);
}
payload->length = ntohl(payload->length);
assert(payload->length == sessionMessage.length);
if (read_n(sockfd, payload->data, payload->length) != payload->length)
{
perror("read payload data");
exit(1);
}
int32_t ack = htonl(payload->length);
if (write_n(sockfd, &ack, sizeof(ack)) != sizeof(ack))
{
perror("write ack");
exit(1);
}
}
::free(payload);
::close(sockfd);
}
还有非阻塞IO版的,也就是ttcp.cc,大部份依照回调函数的方式实现
测试
环境:两条桥联的虚拟机(Centos)
阻塞io
[wang@localhost bin]$./ttcp_blocking -t ip -l 1024000
port = 5001
buffer length = 1024000
number of buffers = 8192
8000.000 MiB in total
40.412 seconds
197.960 MiB/s
非阻塞io
[wang@localhost bin]$ ./ttcp_muduo -t ip -l 1024000
port = 5001
buffer length = 1024000
number of buffers = 8192
INFO payload bytes 8388608000 - ttcp.cc:69
8000.000 MiB transferred
198.619 MiB/s
两种方式吞吐量差不多