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author | Valentin Rothberg <rothberg@redhat.com> | 2019-02-05 11:51:41 +0100 |
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committer | Valentin Rothberg <rothberg@redhat.com> | 2019-02-06 11:14:06 +0100 |
commit | 9ac0ebb0791851aea81ecc847802db5a39bfb6e7 (patch) | |
tree | 30ad98bcc2c2dd1136f46a48cbc44d422adfa184 /vendor/gopkg.in/fsnotify.v1/inotify_poller.go | |
parent | 51714d5da7aaa19014fd67b48b79dfbd5f69c1f0 (diff) | |
download | podman-9ac0ebb0791851aea81ecc847802db5a39bfb6e7.tar.gz podman-9ac0ebb0791851aea81ecc847802db5a39bfb6e7.tar.bz2 podman-9ac0ebb0791851aea81ecc847802db5a39bfb6e7.zip |
Cirrus: add vendor_check_task
* Make sure that all vendored dependencies are in sync with the code and
the vendor.conf by running `make vendor` with a follow-up status check
of the git tree.
* Vendor ginkgo and gomega to include the test dependencies.
Signed-off-by: Chris Evic <cevich@redhat.com>
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>
Diffstat (limited to 'vendor/gopkg.in/fsnotify.v1/inotify_poller.go')
-rw-r--r-- | vendor/gopkg.in/fsnotify.v1/inotify_poller.go | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/vendor/gopkg.in/fsnotify.v1/inotify_poller.go b/vendor/gopkg.in/fsnotify.v1/inotify_poller.go new file mode 100644 index 000000000..cc7db4b22 --- /dev/null +++ b/vendor/gopkg.in/fsnotify.v1/inotify_poller.go @@ -0,0 +1,187 @@ +// 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. + +// +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() + } + }() + poller.fd = fd + + // Create epoll fd + poller.epfd, errno = unix.EpollCreate1(0) + 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) + 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) + } +} |