/* Create a new EventFD. */
func New() (*EventFD, error) {
fd, err := C.eventfd(0, C.EFD_CLOEXEC)
if err != nil {
return nil, err
}
e := &EventFD{
fd: int(fd),
valid: true,
}
return e, nil
}
func NewEventFD() (*EventFD, error) {
fd, err := C.eventfd(0, C.EFD_CLOEXEC)
if err != nil {
return nil, err
}
if fd == -1 {
return nil, fmt.Errorf("unknown eventfd error")
}
efd := &EventFD{fd: int(fd)}
runtime.SetFinalizer(efd, func(efd *EventFD) {
efd.Close()
})
return efd, nil
}
// NewMemCGThresholdNotifier sends notifications when a cgroup threshold
// is crossed (in either direction) for a given cgroup attribute
func NewMemCGThresholdNotifier(path, attribute, threshold, description string, handler thresholdNotifierHandlerFunc) (ThresholdNotifier, error) {
watchfd, err := syscall.Open(fmt.Sprintf("%s/%s", path, attribute), syscall.O_RDONLY, 0)
if err != nil {
return nil, err
}
defer func() {
if err != nil {
syscall.Close(watchfd)
}
}()
controlfd, err := syscall.Open(fmt.Sprintf("%s/cgroup.event_control", path), syscall.O_WRONLY, 0)
if err != nil {
return nil, err
}
defer func() {
if err != nil {
syscall.Close(controlfd)
}
}()
efd, err := C.eventfd(0, C.EFD_CLOEXEC)
if err != nil {
return nil, err
}
eventfd := int(efd)
if eventfd < 0 {
err = fmt.Errorf("eventfd call failed")
return nil, err
}
defer func() {
if err != nil {
syscall.Close(eventfd)
}
}()
glog.V(2).Infof("eviction: setting notification threshold to %s", threshold)
config := fmt.Sprintf("%d %d %s", eventfd, watchfd, threshold)
_, err = syscall.Write(controlfd, []byte(config))
if err != nil {
return nil, err
}
return &memcgThresholdNotifier{
watchfd: watchfd,
controlfd: controlfd,
eventfd: eventfd,
handler: handler,
description: description,
}, nil
}
func NewAIOScheduler(maxEvents int) (Scheduler, error) {
fd, err := C.eventfd(0, C.EFD_NONBLOCK)
if err != nil {
return nil, err
}
eventfd, err := poller.NewFD(int(fd))
if err != nil {
return nil, err
}
sch := &aioScheduler{
eventfd: eventfd,
reqs: make(map[*C.iocb_t]*event),
}
errno := C.io_queue_init(C.int(maxEvents), &sch.ctx)
if errno != 0 {
return nil, syscall.Errno(-errno)
}
go sch.wait_for_completions()
return sch, nil
}