gnet
is an Event-Loop networking framework that is fast and small. It makes direct epoll and kqueue syscalls rather than using the standard Go net package, and works in a similar manner as libuv and libevent.
The goal of this project is to create a server framework for Go that performs on par with Redis and Haproxy for packet handling.
gnet
sells itself as a high-performance, lightweight, nonblocking network library written in pure Go, it works on transport layer with TCP/UDP/Unix-Socket protocols, so it allows developers to implement their own protocols of application layer upon gnet
for building diversified network applications, for instance, you get a HTTP Server or Web Framework if you implement HTTP protocol upon gnet
while you have a Redis Server done with the implementation of Redis protocol upon gnet
and so on.
gent
derives from project evio
while having higher performance.
- High-performance Event-Loop under multi-threads model
- Built-in load balancing algorithm: Round-Robin
- Concise APIs
- Efficient memory usage: Ring-Buffer
- Supporting multiple protocols: TCP, UDP, and Unix Sockets
- Supporting two event-notification mechanisms: epoll in Linux and kqueue in FreeBSD
- Supporting asynchronous write operation
- Allowing multiple network binding on the same Event-Loop
- Flexible ticker event
- SO_REUSEPORT socket option
gnet
redesigns and implements a new built-in multiple-threads model: 『Multiple Reactors』 which is also the default multiple-threads model of netty
, Here's the schematic diagram:
and it works as the following sequence diagram:
The subsequent multiple-threads model of gnet
: 『Multiple Reactors with thread/goroutine pool』is under development and about to be delivered soon, the architecture diagram of new model is in here:
and it works as the following sequence diagram:
gnet
builds its 『Multiple Reactors』Model under Goroutines in Golang, one Reactor per Goroutine, so there is a critical requirement handling extremely large amounts of messages between Goroutines in this networking model of gnet
, which means gnet
needs a efficient communication mechanism between Goroutines. I choose a tricky solution of Disruptor(Ring-Buffer) which provides a higher performance of messages dispatching in networking, instead of the recommended pattern: CSP(Channel) under Golang-Best-Practices.
That is why I finally settle on go-disruptor: the Golang port of the LMAX Disruptor(a high performance inter-thread messaging library).
gnet
leverages Ring-Buffer to cache TCP streams and manage memory cache in networking.
$ go get -u github.com/panjf2000/gnet
// ======================== Echo Server implemented with gnet ===========================
package main
import (
"flag"
"fmt"
"log"
"strings"
"github.com/panjf2000/gnet"
"github.com/panjf2000/gnet/ringbuffer"
)
func main() {
var port int
var loops int
var udp bool
var trace bool
var reuseport bool
flag.IntVar(&port, "port", 5000, "server port")
flag.BoolVar(&udp, "udp", false, "listen on udp")
flag.BoolVar(&reuseport, "reuseport", false, "reuseport (SO_REUSEPORT)")
flag.BoolVar(&trace, "trace", false, "print packets to console")
flag.IntVar(&loops, "loops", 0, "num loops")
flag.Parse()
var events gnet.Events
events.NumLoops = loops
events.OnInitComplete = func(srv gnet.Server) (action gnet.Action) {
log.Printf("echo server started on port %d (loops: %d)", port, srv.NumLoops)
if reuseport {
log.Printf("reuseport")
}
return
}
events.React = func(c gnet.Conn, inBuf *ringbuffer.RingBuffer) (out []byte, action gnet.Action) {
top, tail := inBuf.PreReadAll()
out = append(top, tail...)
inBuf.Reset()
if trace {
log.Printf("%s", strings.TrimSpace(string(top)+string(tail)))
}
return
}
scheme := "tcp"
if udp {
scheme = "udp"
}
log.Fatal(gnet.Serve(events, fmt.Sprintf("%s://:%d", scheme, port)))
}
Current supported I/O events in gnet
:
OnInitComplete
is activated when the server is ready to accept new connections.OnOpened
is activated when a connection has opened.OnClosed
is activated when a connection has closed.OnDetached
is activated when a connection has been detached using theDetach
return action.React
is activated when the server receives new data from a connection.Tick
is activated immediately after the server starts and will fire again after a specified interval.PreWrite
is activated just before any data is written to any client socket.
Go Version : go1.12.9 linux/amd64
OS : Ubuntu 18.04/x86_64
CPU : 8 Virtual CPUs
Memory : 16.0 GiB
Go Version : go version go1.12.9 darwin/amd64
OS : macOS Mojave 10.14.6/x86_64
CPU : 4 CPUs
Memory : 8.0 GiB
Source code in gnet
is available under the MIT License.
gnet is still under active development so the code and documentation will continue to be updated, if you are interested in gnet, please feel free to make your code contributions to it, also if you like gnet, give it a star ~~