PKGBUILD/vendor/periph.io/x/periph/host/fs/fs_linux.go
2018-12-07 20:42:30 +01:00

58 lines
1.6 KiB
Go

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