58 lines
1.6 KiB
Go
58 lines
1.6 KiB
Go
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// Copyright 2017 The Periph Authors. All rights reserved.
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// Use of this source code is governed under the Apache License, Version 2.0
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// that can be found in the LICENSE file.
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package fs
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import "syscall"
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const isLinux = true
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func ioctl(f uintptr, op uint, arg uintptr) error {
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if _, _, errno := syscall.Syscall(syscall.SYS_IOCTL, f, uintptr(op), arg); errno != 0 {
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return syscall.Errno(errno)
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}
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return nil
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}
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const (
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epollET = 1 << 31
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epollPRI = 2
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epollCTLAdd = 1
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epollCTLDel = 2
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epollCTLMod = 3
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)
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type event struct {
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event [1]syscall.EpollEvent
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epollFd int
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fd int
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}
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// makeEvent creates an epoll *edge* triggered event.
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//
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// References:
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// behavior and flags: http://man7.org/linux/man-pages/man7/epoll.7.html
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// syscall.EpollCreate: http://man7.org/linux/man-pages/man2/epoll_create.2.html
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// syscall.EpollCtl: http://man7.org/linux/man-pages/man2/epoll_ctl.2.html
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func (e *event) makeEvent(fd uintptr) error {
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epollFd, err := syscall.EpollCreate(1)
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if err != nil {
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return err
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}
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e.epollFd = epollFd
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e.fd = int(fd)
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// EPOLLWAKEUP could be used to force the system to not go do sleep while
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// waiting for an edge. This is generally a bad idea, as we'd instead have
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// the system to *wake up* when an edge is triggered. Achieving this is
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// outside the scope of this interface.
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e.event[0].Events = epollPRI | epollET
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e.event[0].Fd = int32(e.fd)
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return syscall.EpollCtl(e.epollFd, epollCTLAdd, e.fd, &e.event[0])
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}
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func (e *event) wait(timeoutms int) (int, error) {
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// http://man7.org/linux/man-pages/man2/epoll_wait.2.html
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return syscall.EpollWait(e.epollFd, e.event[:], timeoutms)
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}
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