Feat/kqueue support et

[byene0923]

1. add MaxConnReadTimesPerEventLoop support in Kqueue
2. add ET support for Kqueue

by the way, this is the wip version, I wrote the example in the bsd machine, but I have no linux machine now, i will test in linux version latter,

[byene0923]

package main

import (
    "context"
    "fmt"
    "github.com/lesismal/nbio"
    "github.com/lesismal/nbio/logging"
    "time"
)

func LTServer() {
    engine := nbio.NewEngine(nbio.Config{
        Network:                      "tcp",
        Addrs:                        []string{":8899"},
        ReadBufferSize:               2,
        MaxConnReadTimesPerEventLoop: 1,
        MaxWriteBufferSize:           2,
    })

    engine.OnData(func(c *nbio.Conn, data []byte) {
        fmt.Printf("【LT】read data len: %d, value: %s\n", len(data), string(data))
    })
    err := engine.Start()
    if err != nil {
        fmt.Printf("nbio.start failed: %v\n", err)
        return
    }
    defer engine.Stop()
    time.Sleep(3 * time.Second)
    go Client("localhost:8899", "hello")

    <-make(chan int)
}

// ETServer In ETMod
func ETServer() {
    engine := nbio.NewEngine(nbio.Config{
        Network:                      "tcp",
        Addrs:                        []string{":8888"},
        ReadBufferSize:               2,
        MaxConnReadTimesPerEventLoop: 1,
        MaxWriteBufferSize:           2,
        EpollMod:                     nbio.EPOLLET,
    })

    engine.OnData(func(c *nbio.Conn, data []byte) {
        fmt.Printf("【ET】read data len: %d, value: %s\n", len(data), string(data))
    })
    err := engine.Start()
    if err != nil {
        fmt.Printf("nbio.start failed: %v\n", err)
        return
    }
    defer engine.Stop()
    time.Sleep(3 * time.Second)
    go Client("localhost:8888", "world")

    <-make(chan int)
}

func Client(addr string, data string) {
    ctx, _ := context.WithTimeout(context.Background(), 60*time.Second)
    engine := nbio.NewEngine(nbio.Config{})
    done := make(chan int)

    err := engine.Start()
    if err != nil {
        fmt.Printf("start failed: %v\n", err)
    }
    defer engine.Stop()

    c, err := nbio.Dial("tcp", addr)
    if err != nil {
        panic(err)
    }
    engine.AddConn(c)
    time.Sleep(2 * time.Second)
    c.Write([]byte(data))

    select {
    case <-ctx.Done():
        logging.Error("timeout")
    case <-done:
        logging.Info("success")
    }
}

// The difference of ET and LT
// In LT mode, Kernel will register epitem to wq again after trigger event, but In ET mode,  Kernel will not register
// epitem to wq

// How nbio handle
// when socket data first come, io poller for per conn will only register Read Event(linux call EPOLLIN, bsd call EVFILT_READ)
// When Read event come
// In LT mode, nbio will read MaxConnReadTimesPerEventLoop * ReadBufferSize size。left data will be read in next Read Event
// In ET mode, nbio will change MaxConnReadTimesPerEventLoop to (1<<31 - 1), this indicates nbio will read all the data

// When Write event come and Kernel can't read all the data
// In LT / ET, nbio will both register the Write event(linux call EPOLLOUT, bsd call EVFILT_WRITE)。and when next Write event arrive
// nbio will call flush() to write left data and finally reset the Read Event
func main() {
    logging.SetLevel(logging.LevelDebug)
    fmt.Println("start to handle LT server")
    go LTServer()
    time.Sleep(10 * time.Second)
    fmt.Println("start to handle ET server")
    go ETServer()
    <-make(chan int)
}

this example indicates how nbio will handle ET and LT
In ET mode, output

2024/05/10 13:29:06.392 [DBG] NBIO[NB][POLLER_0] trigger event, filter: -1, mod: 1
【ET】read data len: 2, value: wo
【ET】read data len: 2, value: rl
【ET】read data len: 1, value: d

In LT mode, output

2024/05/10 13:28:56.396 [DBG] NBIO[NB][POLLER_1] trigger event, filter: -1, mod: 0
【LT】read data len: 2, value: he
2024/05/10 13:28:56.396 [DBG] NBIO[NB][POLLER_1] trigger event, filter: -1, mod: 0
【LT】read data len: 2, value: ll
2024/05/10 13:28:56.396 [DBG] NBIO[NB][POLLER_1] trigger event, filter: -1, mod: 0
【LT】read data len: 1, value: o

[byene0923]

@lesismal is there any case that i ignore?

[lesismal]

I will run some test

[lesismal]

please add ./idea to gitignore