首先让我指出你在这种测试中做错的事情。
- 手动设置 TCP 缓冲区大小
最好留给 TCP 算法来确定最佳大小。这通常在 TCP slow-start 阶段确定，在该阶段 TCP 算法最终根据拥塞情况决定最佳可能的 window-size。由于我们使用的是本地主机，而且网络组件之间也没有任何点对点连接，因此拥塞将接近于零。
- 启用 Nagles 算法
这实际上是不需要的，因为您没有发送短长度的成帧数据包。通常，当打开 Nagles 时，latency 会给您带来一些好处（对于吞吐量，我不太确定是否会有任何改进）。
- 服务器端不需要的处理
我看到您正在迭代接收到的缓冲区并进行某种无意义的检查。 iperf 肯定不会那样做。我已经注释掉了那段代码。
- 接收应用程序缓冲区大小
我不知道，但出于某种原因，您选择每次接收只读取 2048 字节。有什么特别的原因吗？我已将其更改回客户端正在写入的实际大小。您可能只是在服务器接收部分排队更多数据。
新服务器代码：
#include <thread>
#include <chrono>
#include <vector>
#include <signal.h>
#include <asio.hpp>
#include <system_error>
namespace
{
bool keepGoing = true;
void shutdown(int)
{
keepGoing = false;
}
std::size_t bytesAccum = 0;
void justReceive(std::error_code ec, std::size_t bytesReceived,
asio::ip::tcp::socket &socket, std::vector<unsigned char> &buffer)
{
bytesAccum += bytesReceived;
/*
auto end = buffer.begin() + bytesReceived;
for (auto it = buffer.begin(); it != end; ++it)
{
if (*it == 'e')
{
std::printf("server got: %lu\n", bytesAccum);
bytesAccum = 0;
}
}
*/
socket.async_receive(
asio::buffer(buffer),
0,
[&] (auto ec, auto bytes) {
justReceive(ec, bytes, socket, buffer);
});
}
}
int main(int, char **)
{
signal(SIGINT, shutdown);
asio::io_service io;
asio::io_service::work work(io);
std::thread t1([&]() { io.run(); });
std::thread t2([&]() { io.run(); });
std::thread t3([&]() { io.run(); });
std::thread t4([&]() { io.run(); });
asio::ip::tcp::acceptor acceptor(io,
asio::ip::tcp::endpoint(
asio::ip::address::from_string("127.0.0.1"), 1234));
asio::ip::tcp::socket socket(io);
// accept 1 client
std::vector<unsigned char> buffer(131072, 0);
acceptor.async_accept(socket, [&socket, &buffer](std::error_code ec)
{
// options
//socket.set_option(asio::ip::tcp::no_delay(true));
//socket.set_option(asio::socket_base::receive_buffer_size(8192 * 2));
//socket.set_option(asio::socket_base::send_buffer_size(8192));
socket.async_receive(
asio::buffer(buffer),
0,
[&](auto ec, auto bytes) {
justReceive(ec, bytes, socket, buffer);
});
});
while (keepGoing)
{
std::this_thread::sleep_for(std::chrono::seconds(1));
}
io.stop();
t1.join();
t2.join();
t3.join();
t4.join();
std::printf("server: goodbye\n");
}
新客户端代码：
#include <thread>
#include <chrono>
#include <vector>
#include <signal.h>
#include <asio.hpp>
#include <system_error>
namespace
{
bool keepGoing = true;
void shutdown(int) { keepGoing = false; }
}
int main(int, char **)
{
signal(SIGINT, shutdown);
asio::io_service io;
asio::io_service::work work(io);
std::thread t1([&]() { io.run(); });
std::thread t2([&]() { io.run(); });
std::thread t3([&]() { io.run(); });
std::thread t4([&]() { io.run(); });
asio::ip::tcp::socket socket(io);
auto endpoint = asio::ip::tcp::resolver(io).resolve({
"127.0.0.1", "1234" });
asio::connect(socket, endpoint);
// options to test
//socket.set_option(asio::ip::tcp::no_delay(true));
//socket.set_option(asio::socket_base::receive_buffer_size(8192));
//socket.set_option(asio::socket_base::send_buffer_size(8192 * 2));
std::vector<unsigned char> buffer(131072, 0);
buffer.back() = 'e';
std::chrono::time_point<std::chrono::system_clock> last =
std::chrono::system_clock::now();
std::chrono::duration<double> delta = std::chrono::seconds(0);
std::size_t bytesSent = 0;
while (keepGoing)
{
// blocks during send
asio::write(socket, asio::buffer(buffer));
//socket.send(asio::buffer(buffer));
// accumulate bytes sent
bytesSent += buffer.size();
// accumulate time spent sending
delta += std::chrono::system_clock::now() - last;
last = std::chrono::system_clock::now();
// print information periodically
if (delta.count() >= 5.0)
{
std::printf("Mbytes/sec: %f, Gbytes/sec: %f, Mbits/sec: %f, Gbits/sec: %f\n",
bytesSent / 1.0e6 / delta.count(),
bytesSent / 1.0e9 / delta.count(),
8 * bytesSent / 1.0e6 / delta.count(),
8 * bytesSent / 1.0e9 / delta.count());
// reset accumulators
bytesSent = 0;
delta = std::chrono::seconds(0);
}
}
io.stop();
t1.join();
t2.join();
t3.join();
t4.join();
std::printf("client: goodbyte\n");
}
注意：我使用了独立版本的 asio，但 OP 报告的结果可以在我的机器上重现：
MacBook Pro Yosemite - 2.6 GHz Intel Core i5 处理器 - 8GB DDR3 RAM
.