listener.Accept() runs only after a byte is received

[vikulin]

listener.Accept() runs only after a byte is received: but expected to run it after kcp.Dial.

The test code:

package main

import (
    "log"
    "time"
    kcp "github.com/xtaci/kcp-go/v5"
)

func main() {

    // start the server

    ln, err := kcp.Listen("127.0.0.1:48000")
    log.Println("Listening KCP...")
    if err != nil {
        panic(err)
    }
    // run the client
    go client()
    /**
    Listening for a connection
    **/
    _, err = ln.Accept()
    if err != nil {
        panic(err)
    } else {
        log.Println("OK.")
    }
}

func client() {

    // wait for server to become ready
    time.Sleep(time.Second)

    // dial to the echo server
    if sess, err := kcp.Dial("127.0.0.1:48000"); err == nil {
        // wait for data write
        time.Sleep(time.Second)
        data := "."
        log.Println("sent:", data[:1])
        if _, err := sess.Write([]byte(data[:1])); err != nil {
            log.Fatal(err)              
        }
    } else {
        log.Fatal(err)
    }
}

Output:

$ go run examples/main.go
2022/06/04 12:36:33 Listening KCP...
2022/06/04 12:36:35 sent: .
2022/06/04 12:36:35 OK.

Expected "OK." to follow right after "Listening KCP..."

[vikulin]

Test code for TCP:

package main

import (
    "net"
    "log"
    "time"
    //kcp "github.com/xtaci/kcp-go/v5"
)

func main() {

    // start the server

    ln, err := net.Listen("tcp", "127.0.0.1:48000")
    log.Println("Listening KCP...")
    if err != nil {
        panic(err)
    }
    // run the client
    go client()
    /**
    Listening for a connection
    **/
    _, err = ln.Accept()
    if err != nil {
        panic(err)
    } else {
        log.Println("OK.")
    }
}

func client() {

    // wait for server to become ready
    time.Sleep(time.Second)

    // dial to the echo server
    if sess, err := net.Dial("tcp", "127.0.0.1:48000"); err == nil {
        // wait for data write
        time.Sleep(time.Second)
        data := "."
        log.Println("sent:", data[:1])
        if _, err := sess.Write([]byte(data[:1])); err != nil {
            log.Fatal(err)              
        }
    } else {
        log.Fatal(err)
    }
}

Output:

$ go run examples/main.go
2022/06/04 12:39:52 Listening KCP...
2022/06/04 12:39:53 OK.