--- a/vendor/github.com/fsnotify/fsnotify/inotify_poller.go Thu Sep 22 16:37:07 2022 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,187 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build linux
-// +build linux
-
-package fsnotify
-
-import (
- "errors"
-
- "golang.org/x/sys/unix"
-)
-
-type fdPoller struct {
- fd int // File descriptor (as returned by the inotify_init() syscall)
- epfd int // Epoll file descriptor
- pipe [2]int // Pipe for waking up
-}
-
-func emptyPoller(fd int) *fdPoller {
- poller := new(fdPoller)
- poller.fd = fd
- poller.epfd = -1
- poller.pipe[0] = -1
- poller.pipe[1] = -1
- return poller
-}
-
-// Create a new inotify poller.
-// This creates an inotify handler, and an epoll handler.
-func newFdPoller(fd int) (*fdPoller, error) {
- var errno error
- poller := emptyPoller(fd)
- defer func() {
- if errno != nil {
- poller.close()
- }
- }()
-
- // Create epoll fd
- poller.epfd, errno = unix.EpollCreate1(unix.EPOLL_CLOEXEC)
- if poller.epfd == -1 {
- return nil, errno
- }
- // Create pipe; pipe[0] is the read end, pipe[1] the write end.
- errno = unix.Pipe2(poller.pipe[:], unix.O_NONBLOCK|unix.O_CLOEXEC)
- if errno != nil {
- return nil, errno
- }
-
- // Register inotify fd with epoll
- event := unix.EpollEvent{
- Fd: int32(poller.fd),
- Events: unix.EPOLLIN,
- }
- errno = unix.EpollCtl(poller.epfd, unix.EPOLL_CTL_ADD, poller.fd, &event)
- if errno != nil {
- return nil, errno
- }
-
- // Register pipe fd with epoll
- event = unix.EpollEvent{
- Fd: int32(poller.pipe[0]),
- Events: unix.EPOLLIN,
- }
- errno = unix.EpollCtl(poller.epfd, unix.EPOLL_CTL_ADD, poller.pipe[0], &event)
- if errno != nil {
- return nil, errno
- }
-
- return poller, nil
-}
-
-// Wait using epoll.
-// Returns true if something is ready to be read,
-// false if there is not.
-func (poller *fdPoller) wait() (bool, error) {
- // 3 possible events per fd, and 2 fds, makes a maximum of 6 events.
- // I don't know whether epoll_wait returns the number of events returned,
- // or the total number of events ready.
- // I decided to catch both by making the buffer one larger than the maximum.
- events := make([]unix.EpollEvent, 7)
- for {
- n, errno := unix.EpollWait(poller.epfd, events, -1)
- if n == -1 {
- if errno == unix.EINTR {
- continue
- }
- return false, errno
- }
- if n == 0 {
- // If there are no events, try again.
- continue
- }
- if n > 6 {
- // This should never happen. More events were returned than should be possible.
- return false, errors.New("epoll_wait returned more events than I know what to do with")
- }
- ready := events[:n]
- epollhup := false
- epollerr := false
- epollin := false
- for _, event := range ready {
- if event.Fd == int32(poller.fd) {
- if event.Events&unix.EPOLLHUP != 0 {
- // This should not happen, but if it does, treat it as a wakeup.
- epollhup = true
- }
- if event.Events&unix.EPOLLERR != 0 {
- // If an error is waiting on the file descriptor, we should pretend
- // something is ready to read, and let unix.Read pick up the error.
- epollerr = true
- }
- if event.Events&unix.EPOLLIN != 0 {
- // There is data to read.
- epollin = true
- }
- }
- if event.Fd == int32(poller.pipe[0]) {
- if event.Events&unix.EPOLLHUP != 0 {
- // Write pipe descriptor was closed, by us. This means we're closing down the
- // watcher, and we should wake up.
- }
- if event.Events&unix.EPOLLERR != 0 {
- // If an error is waiting on the pipe file descriptor.
- // This is an absolute mystery, and should never ever happen.
- return false, errors.New("Error on the pipe descriptor.")
- }
- if event.Events&unix.EPOLLIN != 0 {
- // This is a regular wakeup, so we have to clear the buffer.
- err := poller.clearWake()
- if err != nil {
- return false, err
- }
- }
- }
- }
-
- if epollhup || epollerr || epollin {
- return true, nil
- }
- return false, nil
- }
-}
-
-// Close the write end of the poller.
-func (poller *fdPoller) wake() error {
- buf := make([]byte, 1)
- n, errno := unix.Write(poller.pipe[1], buf)
- if n == -1 {
- if errno == unix.EAGAIN {
- // Buffer is full, poller will wake.
- return nil
- }
- return errno
- }
- return nil
-}
-
-func (poller *fdPoller) clearWake() error {
- // You have to be woken up a LOT in order to get to 100!
- buf := make([]byte, 100)
- n, errno := unix.Read(poller.pipe[0], buf)
- if n == -1 {
- if errno == unix.EAGAIN {
- // Buffer is empty, someone else cleared our wake.
- return nil
- }
- return errno
- }
- return nil
-}
-
-// Close all poller file descriptors, but not the one passed to it.
-func (poller *fdPoller) close() {
- if poller.pipe[1] != -1 {
- unix.Close(poller.pipe[1])
- }
- if poller.pipe[0] != -1 {
- unix.Close(poller.pipe[0])
- }
- if poller.epfd != -1 {
- unix.Close(poller.epfd)
- }
-}