containerd/runtime/v2/runc/epoll.go
Michael Crosby d50e25360c Add context cancel for epoll
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
2018-08-29 10:44:47 -04:00

130 lines
2.7 KiB
Go

// +build linux
/*
Copyright The containerd Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package runc
import (
"context"
"sync"
"github.com/containerd/cgroups"
eventstypes "github.com/containerd/containerd/api/events"
"github.com/containerd/containerd/events"
"github.com/containerd/containerd/runtime"
"github.com/sirupsen/logrus"
"golang.org/x/sys/unix"
)
func newOOMEpoller(publisher events.Publisher) (*epoller, error) {
fd, err := unix.EpollCreate1(unix.EPOLL_CLOEXEC)
if err != nil {
return nil, err
}
return &epoller{
fd: fd,
publisher: publisher,
set: make(map[uintptr]*item),
}, nil
}
type epoller struct {
mu sync.Mutex
fd int
publisher events.Publisher
set map[uintptr]*item
}
type item struct {
id string
cg cgroups.Cgroup
}
func (e *epoller) Close() error {
return unix.Close(e.fd)
}
func (e *epoller) run(ctx context.Context) {
var events [128]unix.EpollEvent
for {
select {
case <-ctx.Done():
e.Close()
return
default:
n, err := unix.EpollWait(e.fd, events[:], -1)
if err != nil {
if err == unix.EINTR {
continue
}
logrus.WithError(err).Error("cgroups: epoll wait")
}
for i := 0; i < n; i++ {
e.process(ctx, uintptr(events[i].Fd))
}
}
}
}
func (e *epoller) add(id string, cg cgroups.Cgroup) error {
e.mu.Lock()
defer e.mu.Unlock()
fd, err := cg.OOMEventFD()
if err != nil {
return err
}
e.set[fd] = &item{
id: id,
cg: cg,
}
event := unix.EpollEvent{
Fd: int32(fd),
Events: unix.EPOLLHUP | unix.EPOLLIN | unix.EPOLLERR,
}
return unix.EpollCtl(e.fd, unix.EPOLL_CTL_ADD, int(fd), &event)
}
func (e *epoller) process(ctx context.Context, fd uintptr) {
flush(fd)
e.mu.Lock()
i, ok := e.set[fd]
if !ok {
e.mu.Unlock()
return
}
e.mu.Unlock()
if i.cg.State() == cgroups.Deleted {
e.mu.Lock()
delete(e.set, fd)
e.mu.Unlock()
unix.Close(int(fd))
return
}
if err := e.publisher.Publish(ctx, runtime.TaskOOMEventTopic, &eventstypes.TaskOOM{
ContainerID: i.id,
}); err != nil {
logrus.WithError(err).Error("publish OOM event")
}
}
func flush(fd uintptr) error {
var buf [8]byte
_, err := unix.Read(int(fd), buf[:])
return err
}