111 lines
2.7 KiB
Go
111 lines
2.7 KiB
Go
package tcp
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import (
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"fmt"
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"os"
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"syscall"
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"time"
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)
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const maxEpollEvents = 32
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// createSocket creates a socket with necessary options set.
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func createSocketZeroLinger(zeroLinger bool) (fd int, err error) {
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// Create socket
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fd, err = _createNonBlockingSocket()
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if err == nil {
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if zeroLinger {
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err = _setZeroLinger(fd)
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}
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}
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return
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}
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// createNonBlockingSocket creates a non-blocking socket with necessary options all set.
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func _createNonBlockingSocket() (int, error) {
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// Create socket
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fd, err := _createSocket()
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if err != nil {
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return 0, err
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}
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// Set necessary options
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err = _setSockOpts(fd)
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if err != nil {
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syscall.Close(fd)
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}
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return fd, err
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}
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// createSocket creates a socket with CloseOnExec set
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func _createSocket() (int, error) {
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fd, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_STREAM, 0)
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syscall.CloseOnExec(fd)
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return fd, err
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}
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// setSockOpts sets SOCK_NONBLOCK and TCP_QUICKACK for given fd
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func _setSockOpts(fd int) error {
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err := syscall.SetNonblock(fd, true)
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if err != nil {
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return err
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}
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return syscall.SetsockoptInt(fd, syscall.SOL_TCP, syscall.TCP_QUICKACK, 0)
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}
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var zeroLinger = syscall.Linger{Onoff: 1, Linger: 0}
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// setLinger sets SO_Linger with 0 timeout to given fd
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func _setZeroLinger(fd int) error {
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return syscall.SetsockoptLinger(fd, syscall.SOL_SOCKET, syscall.SO_LINGER, &zeroLinger)
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}
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func createPoller() (fd int, err error) {
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fd, err = syscall.EpollCreate1(syscall.EPOLL_CLOEXEC)
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if err != nil {
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err = os.NewSyscallError("epoll_create1", err)
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}
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return fd, err
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}
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const EPOLLET = 1 << 31
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// registerEvents registers given fd with read and write events.
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func registerEvents(pollerFd int, fd int) error {
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var event syscall.EpollEvent
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event.Events = syscall.EPOLLOUT | syscall.EPOLLIN | EPOLLET
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event.Fd = int32(fd)
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if err := syscall.EpollCtl(pollerFd, syscall.EPOLL_CTL_ADD, fd, &event); err != nil {
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return os.NewSyscallError(fmt.Sprintf("epoll_ctl(%d, ADD, %d, ...)", pollerFd, fd), err)
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}
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return nil
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}
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func pollEvents(pollerFd int, timeout time.Duration) ([]event, error) {
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var timeoutMS = int(timeout.Nanoseconds() / 1000000)
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var epollEvents [maxEpollEvents]syscall.EpollEvent
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nEvents, err := syscall.EpollWait(pollerFd, epollEvents[:], timeoutMS)
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if err != nil {
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if err == syscall.EINTR {
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return nil, nil
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}
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return nil, os.NewSyscallError("epoll_wait", err)
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}
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var events = make([]event, 0, nEvents)
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for i := 0; i < nEvents; i++ {
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var fd = int(epollEvents[i].Fd)
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var evt = event{Fd: fd, Err: nil}
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errCode, err := syscall.GetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_ERROR)
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if err != nil {
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evt.Err = os.NewSyscallError("getsockopt", err)
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}
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if errCode != 0 {
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evt.Err = newErrConnect(errCode)
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}
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events = append(events, evt)
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}
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return events, nil
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}
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