59 lines
1006 B
Go
59 lines
1006 B
Go
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// +build darwin freebsd dragonfly netbsd openbsd
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package poll
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import (
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"context"
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"golang.org/x/sys/unix"
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"time"
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)
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type Poller struct {
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kqfd int
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event unix.Kevent_t
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}
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func New(fd int) (p *Poller, err error) {
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p = &Poller{}
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p.kqfd, err = unix.Kqueue()
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if p.kqfd == -1 || err != nil {
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return nil, err
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}
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p.event = unix.Kevent_t{
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Ident: uintp(fd),
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Filter: unix.EVFILT_WRITE,
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Flags: unix.EV_ADD | unix.EV_ENABLE | unix.EV_ONESHOT,
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}
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return p, nil
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}
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func (p *Poller) Close() error {
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return unix.Close(p.kqfd)
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}
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func (p *Poller) WaitWriteCtx(ctx context.Context) error {
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deadline, _ := ctx.Deadline()
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// setup timeout
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var timeout *unix.Timespec
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if !deadline.IsZero() {
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d := deadline.Sub(time.Now())
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t := unix.NsecToTimespec(d.Nanoseconds())
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timeout = &t
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}
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// wait on kevent
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events := make([]unix.Kevent_t, 1)
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n, err := unix.Kevent(p.kqfd, []unix.Kevent_t{p.event}, events, timeout)
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if err != nil {
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return err
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}
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if n < 1 {
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return errTimeout
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}
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return nil
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}
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