acceptor_unix.go

// Copyright (c) 2021 The Gnet Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//go:build darwin || dragonfly || freebsd || linux || netbsd || openbsd
// +build darwin dragonfly freebsd linux netbsd openbsd

package gnet

import (
	"time"

	"golang.org/x/sys/unix"

	"github.com/panjf2000/gnet/v2/internal/netpoll"
	"github.com/panjf2000/gnet/v2/internal/queue"
	"github.com/panjf2000/gnet/v2/internal/socket"
	"github.com/panjf2000/gnet/v2/pkg/errors"
)

func (el *eventloop) accept0(fd int, _ netpoll.IOEvent, _ netpoll.IOFlags) error {
	for {
		nfd, sa, err := socket.Accept(fd)
		switch err {
		case nil:
		case unix.EAGAIN: // the Accept queue has been drained out, we can return now
			return nil
		case unix.EINTR, unix.ECONNRESET, unix.ECONNABORTED:
			// ECONNRESET or ECONNABORTED could indicate that a socket
			// in the Accept queue was closed before we Accept()ed it.
			// It's a silly error, let's retry it.
			continue
		default:
			el.getLogger().Errorf("Accept() failed due to error: %v", err)
			return errors.ErrAcceptSocket
		}

		remoteAddr := socket.SockaddrToTCPOrUnixAddr(sa)
		if el.engine.opts.TCPKeepAlive > 0 && el.listeners[fd].network == "tcp" {
			err = socket.SetKeepAlivePeriod(nfd, int(el.engine.opts.TCPKeepAlive.Seconds()))
			if err != nil {
				el.getLogger().Errorf("failed to set TCP keepalive on fd=%d: %v", fd, err)
			}
		}

		el := el.engine.eventLoops.next(remoteAddr)
		c := newTCPConn(nfd, el, sa, el.listeners[fd].addr, remoteAddr)
		err = el.poller.Trigger(queue.HighPriority, el.register, c)
		if err != nil {
			el.getLogger().Errorf("failed to enqueue the accepted socket fd=%d to poller: %v", c.fd, err)
			_ = unix.Close(nfd)
			c.release()
		}
	}
}

func (el *eventloop) accept(fd int, ev netpoll.IOEvent, flags netpoll.IOFlags) error {
	if el.listeners[fd].network == "udp" {
		return el.readUDP(fd, ev, flags)
	}

	nfd, sa, err := socket.Accept(fd)
	switch err {
	case nil:
	case unix.EINTR, unix.EAGAIN, unix.ECONNRESET, unix.ECONNABORTED:
		// ECONNRESET or ECONNABORTED could indicate that a socket
		// in the Accept queue was closed before we Accept()ed it.
		// It's a silly error, let's retry it.
		return nil
	default:
		el.getLogger().Errorf("Accept() failed due to error: %v", err)
		return errors.ErrAcceptSocket
	}

	remoteAddr := socket.SockaddrToTCPOrUnixAddr(sa)
	if el.engine.opts.TCPKeepAlive > 0 && el.listeners[fd].network == "tcp" {
		err = socket.SetKeepAlivePeriod(nfd, int(el.engine.opts.TCPKeepAlive/time.Second))
		if err != nil {
			el.getLogger().Errorf("failed to set TCP keepalive on fd=%d: %v", fd, err)
		}
	}

	c := newTCPConn(nfd, el, sa, el.listeners[fd].addr, remoteAddr)
	return el.register0(c)
}