Windows req/res very slow compared to Linux

[hconcessa]

I'm using gtest to do some performance testing. On Linux I have less than 1 ms, but the same code on Windows has ~30ms.

I think it's a significant difference, but i don't undestand why

Client

// Create client
httplib::Client cli(ADDR, PORT);
ASSERT_TRUE(cli.is_valid());

httplib::Result res;

// Measure the get req/res time
auto start_time = std::chrono::high_resolution_clock::now();
res = cli.get(ROUTE_GET_TEST_TEXT);
auto end_time = std::chrono::high_resolution_clock::now();

auto elapsed_time = std::chrono::duration_cast<std::chrono::microseconds>(end_time - start_time).count();

// Verify response
ASSERT_TRUE(res);
ASSERT_TRUE(res != nullptr);
EXPECT_EQ(httplib::StatusCode::OK_200, res->status);
EXPECT_EQ(httplib::Error::Success, res.error());
EXPECT_EQ(TXT_DEFAULT_RESPONSE, res->body);

// Verify elapsed time		
ASSERT_LE(elapsed_time, TIME_GET_US);

Server handle:

_svr.Get(ROUTE_GET_TEST_TEXT, [&](const httplib::Request& req, httplib::Response& res) {
	res.set_content(TXT_DEFAULT_RESPONSE, "text/plain");
	});

Common:

#define ADDR "127.0.0.1"
#define PORT 8181

#define TXT_DEFAULT_RESPONSE  "Default Response to txt request"

[rpmocchet]

I´ve made some unit tests based on your code and had similar results:

On Linux:

On Windows:

[yhirose]

@hconcessa @rpmocchet sorry for the late reply. I'll take a look at the behavior on my Windows machine when I have time. Thanks!

[q2a3z]

Hey Guys.
I did some time investigation on the client side in Win64 PC.
I found socket_t create_socket will took 1ms to process.

So I suspected WSASocketW took so much time, and got it.
But even I forced it to ues the std.socket to create a socket. It also cost around 1ms.
Is any possiable when Win create a socket will take more time than Linux or BSD?
I don't have Linux or BSD eniviroment right now.
Can you test this patten for me? Thank you.

for (auto rp = result; rp; rp = rp->ai_next) {
    // Create a socket
#ifdef _WIN32
    auto sock =
        WSASocketW(rp->ai_family, rp->ai_socktype, rp->ai_protocol, nullptr, 0,
                   WSA_FLAG_NO_HANDLE_INHERIT | WSA_FLAG_OVERLAPPED);
    /*...*/
    if (sock == INVALID_SOCKET) {
      sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
    }
#else
    auto sock = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
#endif
    if (sock == INVALID_SOCKET) { continue; }

[RCECoder]

There is a significant delay when connecting to localhost. It tries first to connect to 0.0.0.0 returned from getaddrinfo which always fails. This needs some kind of filtering on connect and skip connecting to INADDR_ANY.