func (gpio *GPIO) AddEdgeDetect(edge GPIOEdge) (chan bool, error) {
gpio.RemoveEdgeDetect()
err := gpio.SetDirection(GPIO_INPUT)
if err != nil {
return nil, err
}
err = gpio.SetEdge(edge)
if err != nil {
return nil, err
}
err = gpio.openValueFile()
if err != nil {
return nil, err
}
epfd, err := syscall.EpollCreate(1)
if err != nil {
return nil, err
}
event := &syscall.EpollEvent{
Events: syscall.EPOLLIN | _EPOLLET | syscall.EPOLLPRI,
Fd: int32(gpio.value.Fd()),
}
err = syscall.EpollCtl(epfd, syscall.EPOLL_CTL_ADD, int(gpio.value.Fd()), event)
if err != nil {
syscall.Close(epfd)
return nil, err
}
// / first time triggers with current state, so ignore
_, err = syscall.EpollWait(epfd, make([]syscall.EpollEvent, 1), -1)
if err != nil {
syscall.Close(epfd)
return nil, err
}
gpio.epfd.Set(epfd)
valueChan := make(chan bool)
go func() {
for gpio.epfd.Get() != 0 {
n, _ := syscall.EpollWait(epfd, make([]syscall.EpollEvent, 1), -1)
if n > 0 {
value, err := gpio.Value()
if err == nil {
valueChan <- value
}
}
}
}()
return valueChan, nil
}
// setupEpoll sets up epoll for use
func setupEpoll() {
var err error
epollFD, err = syscall.EpollCreate1(0)
if err != nil {
fmt.Println("Unable to create epoll FD: ", err.Error())
os.Exit(1)
}
go func() {
var epollEvents [GPIOCount]syscall.EpollEvent
for {
numEvents, err := syscall.EpollWait(epollFD, epollEvents[:], -1)
if err != nil {
panic(fmt.Sprintf("EpollWait error: %s", err.Error()))
}
for i := 0; i < numEvents; i++ {
if eventPin, exists := watchEventCallbacks[int(epollEvents[i].Fd)]; exists {
if eventPin.initial {
eventPin.initial = false
} else {
eventPin.callback()
}
}
}
}
}()
}
/*-----------------------------------------------------------------------------
-- FUNCTION: listen
--
-- DATE: February 6, 2016
--
-- REVISIONS: February 10, 2016 - Modified for EPoll
--
-- DESIGNER: Marc Vouve
--
-- PROGRAMMER: Marc Vouve
--
-- INTERFACE: func listen(srvInfo serverInfo)
-- srvInfo: information about the overall application, IPC and networking
--
-- RETURNS: void doesn't actually return.
--
-- NOTES: This function handles Epoll in a foreverloop. This function never
-- exits
------------------------------------------------------------------------------*/
func listen(srvInfo serverInfo) {
client := make(map[int]connectionInfo)
epollFd, _ := syscall.EpollCreate1(0)
events := make([]syscall.EpollEvent, epollQueueLen)
addConnectionToEPoll(epollFd, srvInfo.listener)
for {
n, _ := syscall.EpollWait(epollFd, events[:], -1)
for i := 0; i < n; i++ {
if events[i].Events&(syscall.EPOLLHUP|syscall.EPOLLERR) != 0 {
fmt.Println("Error on epoll")
endConnection(srvInfo, client[int(events[i].Fd)])
}
if events[i].Fd == int32(srvInfo.listener) { // new connection
newClient, err := newConnection(srvInfo.listener)
if err == nil {
srvInfo.serverConnection <- newConnectionConst
client[newClient.FileDescriptor] = newClient
addConnectionToEPoll(epollFd, newClient.FileDescriptor)
}
} else { // data to read from connection
// client[int(ev.Fd)] can not be used as an argument in handleData
conn := client[int(events[i].Fd)]
err := handleData(&conn)
client[int(events[i].Fd)] = conn
if err != nil {
endConnection(srvInfo, client[int(events[i].Fd)])
}
}
}
}
}
func initEpollListener() *epollListener {
fd, err := syscall.EpollCreate1(0)
if err != nil {
panic(fmt.Sprintf("Unable to create epoll: %v", err))
}
listener := &epollListener{fd: fd, interruptablePins: make(map[int]*interrupt)}
go func() {
var epollEvents [MaxGPIOInterrupt]syscall.EpollEvent
for {
n, err := syscall.EpollWait(listener.fd, epollEvents[:], -1)
if err != nil {
panic(fmt.Sprintf("EpollWait error: %v", err))
}
listener.mu.Lock()
for i := 0; i < n; i++ {
if irq, ok := listener.interruptablePins[int(epollEvents[i].Fd)]; ok {
irq.Signal()
}
}
listener.mu.Unlock()
}
}()
return listener
}
// loop blocks until either inotify or pipe file descriptor is ready for I/O.
// All read operations triggered by filesystem notifications are forwarded to
// one of the event's consumers. If pipe fd became ready, loop function closes
// all file descriptors opened by lazyinit method and returns afterwards.
func (i *inotify) loop(esch chan<- []*event) {
epes := make([]syscall.EpollEvent, 1)
fd := atomic.LoadInt32(&i.fd)
for {
switch _, err := syscall.EpollWait(i.epfd, epes, -1); err {
case nil:
switch epes[0].Fd {
case fd:
esch <- i.read()
epes[0].Fd = 0
case int32(i.pipefd[0]):
i.Lock()
defer i.Unlock()
if err = syscall.Close(int(fd)); err != nil && err != syscall.EINTR {
panic("notify: close(2) error " + err.Error())
}
atomic.StoreInt32(&i.fd, invalidDescriptor)
if err = i.epollclose(); err != nil && err != syscall.EINTR {
panic("notify: epollclose error " + err.Error())
}
close(esch)
return
}
case syscall.EINTR:
continue
default: // We should never reach this line.
panic("notify: epoll_wait(2) error " + err.Error())
}
}
}
func listenPort(cReq chan<- []byte, epollFd int, reader *bufio.Reader) {
events := make([]syscall.EpollEvent, 32)
var buf []byte
var err error
for {
if _, err := syscall.EpollWait(epollFd, events, -1); err != nil {
log.Fatalln("Error receiving epoll events:", err)
}
buf, err = reader.ReadBytes('\x0a')
switch err {
case nil:
case io.EOF:
time.Sleep(time.Second * 1)
continue
default:
log.Fatalln(err)
}
break
}
cReq <- buf
}
func (ep *EPoll) Poll(timeout int) (int, error) {
nfds, err := syscall.EpollWait(ep.fd, ep.events[0:], timeout)
if err != nil {
return 0, err
}
ep.nfds = nfds
return nfds, nil
}
func (gpio *GPIO) WaitForEdge(edge Edge) (value Value, err error) {
if err = gpio.setEdge(edge); err != nil {
return 0, err
}
if err = gpio.ensureValueFileIsOpen(); err != nil {
return 0, err
}
epollFd := gpio.epollFd.Get()
if epollFd == 0 {
epollFd, err = syscall.EpollCreate(1)
if err != nil {
return 0, err
}
event := &syscall.EpollEvent{
Events: syscall.EPOLLIN | syscall.EPOLLPRI | _EPOLLET,
Fd: int32(gpio.valueFile.Fd()),
}
err = syscall.EpollCtl(epollFd, syscall.EPOLL_CTL_ADD, int(gpio.valueFile.Fd()), event)
if err != nil {
syscall.Close(epollFd)
return 0, err
}
// first time triggers with current state, so ignore
_, err = syscall.EpollWait(epollFd, dummyEpollEvents, -1)
if err != nil {
syscall.Close(epollFd)
return 0, err
}
gpio.epollFd.Set(epollFd)
}
_, err = syscall.EpollWait(epollFd, dummyEpollEvents, -1)
if err != nil {
return 0, err
}
return gpio.Value()
}
func (p *pollster) WaitFD(nsec int64) (fd int, mode int, err os.Error) {
// Get an event.
var evarray [1]syscall.EpollEvent
ev := &evarray[0]
var msec int = -1
if nsec > 0 {
msec = int((nsec + 1e6 - 1) / 1e6)
}
n, e := syscall.EpollWait(p.epfd, evarray[0:], msec)
for e == syscall.EAGAIN || e == syscall.EINTR {
n, e = syscall.EpollWait(p.epfd, evarray[0:], msec)
}
if e != 0 {
return -1, 0, os.NewSyscallError("epoll_wait", e)
}
if n == 0 {
return -1, 0, nil
}
fd = int(ev.Fd)
if ev.Events&writeFlags != 0 {
p.StopWaiting(fd, writeFlags)
return fd, 'w', nil
}
if ev.Events&readFlags != 0 {
p.StopWaiting(fd, readFlags)
return fd, 'r', nil
}
// Other events are error conditions - wake whoever is waiting.
events, _ := p.events[fd]
if events&writeFlags != 0 {
p.StopWaiting(fd, writeFlags)
return fd, 'w', nil
}
p.StopWaiting(fd, readFlags)
return fd, 'r', nil
}
func (p *Poller) WaitWrite(deadline time.Time) error {
msec := -1
if !deadline.IsZero() {
d := deadline.Sub(time.Now())
msec = int(d.Nanoseconds() / 1000000) // ms!? omg...
}
n, err := syscall.EpollWait(p.epfd, p.events[:], msec)
if err != nil {
return err
}
if n < 1 {
return errTimeout
}
return nil
}
func (p *pollster) WaitFD(s *pollServer, nsec int64) (fd int, mode int, err error) {
for len(p.waitEvents) == 0 {
var msec int = -1
if nsec > 0 {
msec = int((nsec + 1e6 - 1) / 1e6)
}
s.Unlock()
n, e := syscall.EpollWait(p.epfd, p.waitEventBuf[0:], msec)
s.Lock()
if e != nil {
if e == syscall.EAGAIN || e == syscall.EINTR {
continue
}
return -1, 0, os.NewSyscallError("epoll_wait", e)
}
if n == 0 {
return -1, 0, nil
}
p.waitEvents = p.waitEventBuf[0:n]
}
ev := &p.waitEvents[0]
p.waitEvents = p.waitEvents[1:]
fd = int(ev.Fd)
if ev.Events&writeFlags != 0 {
p.StopWaiting(fd, writeFlags)
return fd, 'w', nil
}
if ev.Events&readFlags != 0 {
p.StopWaiting(fd, readFlags)
return fd, 'r', nil
}
// Other events are error conditions - wake whoever is waiting.
events, _ := p.events[fd]
if events&writeFlags != 0 {
p.StopWaiting(fd, writeFlags)
return fd, 'w', nil
}
p.StopWaiting(fd, readFlags)
return fd, 'r', nil
}
func Run(t *Tunnel) {
var err error
epollFd, err = syscall.EpollCreate(1024)
if err != nil {
logger.Log(logger.ERR, "Create epoll fd error [%s]", err)
os.Exit(-2)
}
for _, step := range initStep {
err = step.Action(t)
if err != nil {
fmt.Fprintf(os.Stderr, step.ErrFmt, err)
os.Exit(-2)
}
}
runTunnel = t
events := make([]syscall.EpollEvent, 10, 10)
for {
en, err := syscall.EpollWait(epollFd, events, 1000)
if err != nil {
logger.Log(logger.ERR, "Wail epoll fd error [%s]", err)
os.Exit(-2)
}
for i := 0; i < en; i++ {
ee := events[i]
if runTunnel.LFd == int(ee.Fd) {
runTunnel.newConn()
continue
}
tc, ok := fdTunnelConn[int(ee.Fd)]
if !ok {
continue
}
if ee.Events&syscall.EPOLLIN != 0 {
tc.handleIn(int(ee.Fd))
}
if ee.Events&syscall.EPOLLOUT != 0 {
tc.handleOut(int(ee.Fd))
}
if ee.Events&syscall.EPOLLHUP != 0 {
tc.shutdown()
}
}
}
}
func inotify_observe_collect(buf []byte) map[string]int {
epoll_buf := make([]syscall.EpollEvent, 1)
collect := make(map[string]int)
for {
nread, _ := syscall.Read(inotify_fd, buf)
for offset := 0; offset < nread; offset += event_size {
event := (*syscall.InotifyEvent)(unsafe.Pointer(&buf[offset]))
if syscall.IN_IGNORED == event.Mask {
continue
}
collect[name_by_wd[event.Wd]] = 1
}
nevents, err := syscall.EpollWait(epoll_fd, epoll_buf, 500)
if 0 >= nevents {
if -1 == nevents {
tabby_log("inotify_observe_collect: " + err.Error())
}
break
}
}
return collect
}
func poller() {
debugf("Started.")
events := make([]syscall.EpollEvent, 128)
for {
n, err := syscall.EpollWait(epfd, events, -1)
if err != nil {
if err == syscall.EINTR {
continue
}
log.Panicf("poller: EpollWait: %s", err.Error())
}
for i := 0; i < n; i++ {
ev := &events[i]
if isReadEvent(ev) {
epollEvent(ev, false)
}
if isWriteEvent(ev) {
epollEvent(ev, true)
}
}
}
}
func (w *Watcher) epollEvents(epfd int, donePipe *os.File) {
w.isRunning = true
defer func() {
syscall.Close(epfd)
w.isRunning = false
w.closed <- true
}()
events := make([]syscall.EpollEvent, EPOLL_MAX_EVENTS)
doneFd := int32(donePipe.Fd())
for {
nevents, err := syscall.EpollWait(epfd, events, -1)
if err != nil {
w.Errors <- os.NewSyscallError("epoll_wait", err)
continue
}
if nevents == 0 {
continue
}
for i := 0; i < nevents; i++ {
if events[i].Fd == doneFd {
if err = donePipe.Close(); err != nil {
w.Errors <- err
}
syscall.Close(w.fd)
close(w.Events)
close(w.Errors)
return
} else if events[i].Fd != int32(w.fd) {
continue
}
if err = w.readEvents(); err != nil {
w.Errors <- err
}
}
}
}
func (io *IO) eventLoop() {
const mask = syscall.EPOLLIN | syscall.EPOLLERR | syscall.EPOLLHUP
buf := make([]syscall.EpollEvent, epollEventBufferSize)
for {
n, err := syscall.EpollWait(io.epollFd, buf, -1)
if err != nil {
panic(err)
}
io.lock.Lock()
for _, e := range buf[:n] {
if e.Events&mask != 0 {
if w := io.workers[e.Fd]; w != nil {
w.notify()
}
}
}
io.lock.Unlock()
}
}
func (u *NetLinkProbe) start(nsPath string) {
var context *common.NetNSContext
var err error
// Enter the network namespace if necessary
if nsPath != "" {
context, err = common.NewNetNsContext(nsPath)
if err != nil {
logging.GetLogger().Errorf("Failed to switch namespace: %s", err.Error())
return
}
}
// Both NewHandle and Subscribe need to done in the network namespace.
h, err := netlink.NewHandle(syscall.NETLINK_ROUTE)
if err != nil {
logging.GetLogger().Errorf("Failed to create netlink handle: %s", err.Error())
context.Close()
return
}
defer h.Delete()
s, err := nl.Subscribe(syscall.NETLINK_ROUTE, syscall.RTNLGRP_LINK, syscall.RTNLGRP_IPV4_IFADDR, syscall.RTNLGRP_IPV6_IFADDR)
if err != nil {
logging.GetLogger().Errorf("Failed to subscribe to netlink messages: %s", err.Error())
context.Close()
return
}
defer s.Close()
u.ethtool, err = ethtool.NewEthtool()
if err != nil {
logging.GetLogger().Errorf("Failed to create ethtool object: %s", err.Error())
context.Close()
return
}
defer u.ethtool.Close()
epfd, e := syscall.EpollCreate1(0)
if e != nil {
logging.GetLogger().Errorf("Failed to create epoll: %s", err.Error())
return
}
defer syscall.Close(epfd)
// Leave the network namespace
context.Close()
u.wg.Add(1)
defer u.wg.Done()
atomic.StoreInt64(&u.state, common.RunningState)
defer atomic.StoreInt64(&u.state, common.StoppedState)
u.netlink = h
u.initialize()
fd := s.GetFd()
err = syscall.SetNonblock(fd, true)
if err != nil {
logging.GetLogger().Errorf("Failed to set the netlink fd as non-blocking: %s", err.Error())
return
}
event := syscall.EpollEvent{Events: syscall.EPOLLIN, Fd: int32(fd)}
if err = syscall.EpollCtl(epfd, syscall.EPOLL_CTL_ADD, fd, &event); err != nil {
logging.GetLogger().Errorf("Failed to control epoll: %s", err.Error())
return
}
events := make([]syscall.EpollEvent, maxEpollEvents)
for atomic.LoadInt64(&u.state) == common.RunningState {
n, err := syscall.EpollWait(epfd, events[:], 1000)
if err != nil {
errno, ok := err.(syscall.Errno)
if ok && errno != syscall.EINTR {
logging.GetLogger().Errorf("Failed to receive from events from netlink: %s", err.Error())
}
continue
}
if n == 0 {
continue
}
msgs, err := s.Receive()
if err != nil {
if errno, ok := err.(syscall.Errno); !ok || !errno.Temporary() {
logging.GetLogger().Errorf("Failed to receive from netlink messages: %s", err.Error())
return
}
time.Sleep(1 * time.Second)
continue
}
for _, msg := range msgs {
switch msg.Header.Type {
case syscall.RTM_NEWLINK:
link, err := netlink.LinkDeserialize(msg.Data)
if err != nil {
logging.GetLogger().Warningf("Failed to deserialize netlink message: %s", err.Error())
continue
}
u.onLinkAdded(link)
case syscall.RTM_DELLINK:
link, err := netlink.LinkDeserialize(msg.Data)
if err != nil {
logging.GetLogger().Warningf("Failed to deserialize netlink message: %s", err.Error())
continue
}
u.onLinkDeleted(link)
case syscall.RTM_NEWADDR:
addr, family, ifindex, err := parseAddr(msg.Data)
if err != nil {
logging.GetLogger().Warningf("Failed to parse newlink message: %s", err.Error())
continue
}
u.onAddressAdded(addr, family, ifindex)
case syscall.RTM_DELADDR:
addr, family, ifindex, err := parseAddr(msg.Data)
if err != nil {
logging.GetLogger().Warningf("Failed to parse newlink message: %s", err.Error())
continue
}
u.onAddressDeleted(addr, family, ifindex)
}
}
}
}
func (watcher *PinWatcher) pinHandler() {
exf, exf_err := os.OpenFile("/sys/class/gpio/export", syscall.O_WRONLY, 0400)
if exf_err != nil {
log.Panicln("Error opening /sys/class/gpio/export:", exf_err)
}
_, ex_err := exf.WriteString(fmt.Sprintf("%d", watcher.pin))
if ex_err != nil {
log.Panicln("Error writing to /sys/class/gpio/export:", ex_err)
}
exf.Close()
time.Sleep(time.Microsecond)
edge_file := fmt.Sprintf("/sys/class/gpio/gpio%d/edge", watcher.pin)
edgef, edgef_err := os.OpenFile(edge_file, syscall.O_WRONLY, 0400)
if edgef_err != nil {
log.Panicf("Error opening %s: %s\n", edge_file, edgef_err)
}
_, edge_err := edgef.WriteString("both")
if edge_err != nil {
log.Panicf("Error writing to %s: %s\n", edge_file, edge_err)
}
edgef.Close()
time.Sleep(time.Microsecond)
value_file := fmt.Sprintf("/sys/class/gpio/gpio%d/value", watcher.pin)
irq_fd, irq_err := syscall.Open(value_file, syscall.O_RDONLY|syscall.O_NONBLOCK, syscall.S_IREAD)
if irq_err != nil {
log.Panicln("Error opening %s: %s\n", value_file, irq_err)
}
epfd, eperr := syscall.EpollCreate1(syscall.EPOLL_CLOEXEC)
if eperr != nil {
log.Panicln("Error creating epoll:", eperr)
}
event := new(syscall.EpollEvent)
event.Fd = int32(irq_fd)
event.Events |= syscall.EPOLLPRI
if ctlerr := syscall.EpollCtl(epfd, syscall.EPOLL_CTL_ADD, irq_fd, event); ctlerr != nil {
log.Panicln("Error on epoll control operation:", ctlerr)
}
var events_buffer [10]syscall.EpollEvent
var buf [1]byte
for !watcher.shutdown {
n, werr := syscall.EpollWait(epfd, events_buffer[0:], 4000)
if werr != nil {
log.Println("Epoll error:", werr)
} else if n == 1 {
syscall.Seek(irq_fd, 0, 0)
syscall.Read(irq_fd, buf[0:])
log.Println("Interrupt!", events_buffer[0].Fd, events_buffer[0].Events, buf)
} else {
log.Println("Timeout")
}
}
syscall.Close(irq_fd)
unexf, unexf_err := os.OpenFile("/sys/class/gpio/unexport", syscall.O_WRONLY|syscall.O_SYNC, 0400)
if unexf_err != nil {
log.Panicln("Error opening /sys/class/gpio/unexport:", unexf_err)
}
_, unex_err := unexf.WriteString(fmt.Sprintf("%d", watcher.pin))
if unex_err != nil {
log.Panicln("Error writing to /sys/class/gpio/unexport:", unex_err)
}
unexf.Close()
watcher.wg.Done()
}
func (self HciDev) Request(opcode OpCode, params ...Parameter) (Parameters, error) {
req := make([]byte, 4)
req[0] = HCI_COMMAND_PKT
binary.LittleEndian.PutUint16(req[1:], uint16(opcode))
if pbuf, err := Parameters(params).MarshalBinary(); err != nil {
return nil, err
} else {
req[3] = uint8(len(pbuf))
req = append(req, pbuf...)
}
if filter, err := GetsockoptHciFilter(int(self), SOL_HCI, HCI_FILTER); err != nil {
return nil, err
} else {
defer SetsockoptHciFilter(int(self), SOL_HCI, HCI_FILTER, filter)
}
filter := &HciFilter{
Type_mask: 1 << HCI_EVENT_PKT,
Event_mask: FilterEventMask(EVT_CMD_STATUS, EVT_CMD_COMPLETE),
Opcode: opcode.Native(),
}
if opcode.Ogf() == OGF_LE_CTL {
filter.Event_mask = FilterEventMask(EVT_CMD_STATUS, EVT_CMD_COMPLETE, EVT_LE_META_EVENT)
}
if err := SetsockoptHciFilter(int(self), SOL_HCI, HCI_FILTER, filter); err != nil {
return nil, err
}
if n, err := self.Write(req); err != nil {
return nil, err
} else if n != len(req) {
return nil, fmt.Errorf("write incomplete")
}
if efd, err := syscall.EpollCreate1(syscall.EPOLL_CLOEXEC); err != nil {
return nil, err
} else {
defer syscall.Close(efd)
var events [1]syscall.EpollEvent
syscall.EpollCtl(efd, syscall.EPOLL_CTL_ADD, int(self), &syscall.EpollEvent{
Events: syscall.EPOLLIN,
Fd: int32(self),
})
capture := make([]byte, 0, 258)
buf := make([]byte, 258)
for {
if n, err := syscall.EpollWait(efd, events[:], 100); err != nil {
return nil, err
} else if n == 0 {
continue
}
// todo: operation timeout
if n, _, _, _, err := syscall.Recvmsg(int(self), buf, nil, syscall.MSG_DONTWAIT); err != nil {
if errno, ok := err.(syscall.Errno); ok && errno.Temporary() {
continue
}
return nil, err
} else if n == 0 {
continue
} else {
capture = append(capture, buf[:n]...)
}
if pkt, step := Parse(capture); step == 0 {
continue
} else if p, err := pkt.(EventPkt).Parse(); err != nil {
continue
} else {
switch ev := p.(type) {
case EvtCmdComplete:
if ev.OpCode == uint16(opcode) {
return opcode.Response(ev.Params)
}
case EvtCmdStatus:
if ev.OpCode == uint16(opcode) && ev.Status != 0 {
return nil, HciError(ev.Status)
}
case EvtLeMetaEvent:
// todo: OGF_LE_CTL opcode expects this
}
capture = capture[step:]
}
}
return nil, fmt.Errorf("should not reach")
}
}
// EpollWait directly calls syscall.EpollWait
func EpollWait(epfd int, events []syscall.EpollEvent, msec int) (int, error) {
return syscall.EpollWait(epfd, events, msec)
}
func (u *NetLinkTopoUpdater) start() {
logging.GetLogger().Debug("Start NetLink Topo Updater for container: %s", u.Container.ID)
s, err := nl.Subscribe(syscall.NETLINK_ROUTE, syscall.RTNLGRP_LINK)
if err != nil {
logging.GetLogger().Error("Failed to subscribe to netlink RTNLGRP_LINK messages: %s", err.Error())
return
}
u.nlSocket = s
fd := u.nlSocket.GetFd()
err = syscall.SetNonblock(fd, true)
if err != nil {
logging.GetLogger().Error("Failed to set the netlink fd as non-blocking: %s", err.Error())
return
}
epfd, e := syscall.EpollCreate1(0)
if e != nil {
logging.GetLogger().Error("Failed to set the netlink fd as non-blocking: %s", err.Error())
return
}
defer syscall.Close(epfd)
u.initialize()
event := syscall.EpollEvent{Events: syscall.EPOLLIN, Fd: int32(fd)}
if e = syscall.EpollCtl(epfd, syscall.EPOLL_CTL_ADD, fd, &event); e != nil {
logging.GetLogger().Error("Failed to set the netlink fd as non-blocking: %s", err.Error())
return
}
events := make([]syscall.EpollEvent, maxEpollEvents)
Loop:
for {
n, err := syscall.EpollWait(epfd, events[:], 1000)
if err != nil {
logging.GetLogger().Error("Failed to receive from netlink messages: %s", err.Error())
continue
}
if n == 0 {
select {
case <-u.doneChan:
logging.GetLogger().Debug("WHOU")
break Loop
default:
continue
}
}
msgs, err := s.Receive()
if err != nil {
logging.GetLogger().Error("Failed to receive from netlink messages: %s", err.Error())
time.Sleep(1 * time.Second)
continue
}
for _, msg := range msgs {
switch msg.Header.Type {
case syscall.RTM_NEWLINK:
ifmsg := nl.DeserializeIfInfomsg(msg.Data)
u.onLinkAdded(int(ifmsg.Index))
case syscall.RTM_DELLINK:
ifmsg := nl.DeserializeIfInfomsg(msg.Data)
u.onLinkDeleted(int(ifmsg.Index))
}
}
}
u.nlSocket.Close()
}
func NewFdset() *Fdset {
self := &Fdset{
rListener: make(map[int]fdListener),
wListener: make(map[int]fdListener),
rDeadline: make(map[int]time.Time),
wDeadline: make(map[int]time.Time),
}
efd, e1 := syscall.EpollCreate1(syscall.EPOLL_CLOEXEC)
if e1 != nil {
return nil
}
ctls, e2 := syscall.Socketpair(syscall.AF_UNIX, syscall.SOCK_STREAM|syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC, 0)
if e2 != nil {
return nil
}
self.ctl = ctls[0]
self.rListener[ctls[1]] = fdDrain(ctls[1])
go func() {
defer func() {
syscall.Close(ctls[1])
self.Close()
}()
evs := make([]syscall.EpollEvent, 8)
for {
fds := make(map[int]uint32)
for fd, _ := range self.rListener {
fds[fd] |= syscall.EPOLLIN
}
for fd, _ := range self.wListener {
fds[fd] |= syscall.EPOLLOUT
}
if len(fds) == 0 {
break
}
have_tm := false
var tm time.Time
for _, t := range self.rDeadline {
if !have_tm || t.Before(tm) {
tm = t
}
have_tm = true
}
for _, t := range self.wDeadline {
if !have_tm || t.Before(tm) {
tm = t
}
have_tm = true
}
for fd, flags := range fds {
if err := syscall.EpollCtl(efd, syscall.EPOLL_CTL_ADD, fd, &syscall.EpollEvent{
Events: flags,
Fd: int32(fd),
}); err != nil {
if fd == int(ctls[1]) {
// maybe ctrl closed
return
} else {
log.Print(err)
delete(fds, fd)
}
}
}
dur := time.Hour
if have_tm {
dur = tm.Sub(time.Now())
}
evLen := 0
if dur > 0 {
if n, err := syscall.EpollWait(efd, evs, int(dur/time.Millisecond)); err != nil {
if eno, ok := err.(syscall.Errno); !ok || !eno.Temporary() {
// notify fdset poll loop error
for _, li := range self.wListener {
li.FdListen(err)
}
for _, li := range self.rListener {
li.FdListen(err)
}
return
}
} else {
evLen = n
}
}
if len(self.wDeadline) > 0 || len(self.rDeadline) > 0 {
tm := time.Now()
for fd, t := range self.wDeadline {
if li, ok := self.wListener[fd]; ok {
if t.Before(tm) {
if !li.FdListen(Timeout(t)) {
delete(self.wListener, fd)
}
delete(self.wDeadline, fd)
}
}
}
for fd, t := range self.rDeadline {
if li, ok := self.rListener[fd]; ok {
if t.Before(tm) {
if !li.FdListen(Timeout(t)) {
delete(self.rListener, fd)
}
delete(self.rDeadline, fd)
}
}
}
}
for _, ev := range evs[:evLen] {
if ev.Events&syscall.EPOLLOUT != 0 {
if li, ok := self.wListener[int(ev.Fd)]; ok {
if !li.FdListen(nil) {
delete(self.wListener, int(ev.Fd))
}
delete(self.wDeadline, int(ev.Fd))
}
}
if ev.Events&syscall.EPOLLIN != 0 {
if li, ok := self.rListener[int(ev.Fd)]; ok {
if !li.FdListen(nil) {
delete(self.rListener, int(ev.Fd))
}
delete(self.rDeadline, int(ev.Fd))
}
}
}
for fd, _ := range fds {
if err := syscall.EpollCtl(efd, syscall.EPOLL_CTL_DEL, fd, nil); err != nil {
panic(err)
}
}
}
}()
return self
}
func doParent(mpid int, stdin_fd, stdout_fd, stderr_fd [2]int) resultPack {
syscall.Close(stdin_fd[0])
syscall.Close(stdout_fd[1])
syscall.Close(stderr_fd[1])
exit_chan := make(chan resultPack)
if err := SetupScope(uint32(mpid)); err != nil {
poePanic(err, "setup systemd scope unit failed")
}
go func() {
runtime.LockOSThread()
sig_chan := make(chan os.Signal, 1)
signal.Notify(sig_chan, syscall.SIGCHLD)
signal.Notify(sig_chan, syscall.SIGTERM)
signal.Notify(sig_chan, syscall.SIGINT)
if err := PtraceSeize(mpid, syscall.PTRACE_O_TRACECLONE|syscall.PTRACE_O_TRACEFORK|PTRACE_O_TRACESECCOMP|syscall.PTRACE_O_TRACEVFORK); err != nil {
poePanic(error(err), "PTRACE_SEIZE failed")
}
for {
sig := <-sig_chan
switch sig {
case syscall.SIGCHLD:
if res := handleSigchld(mpid); res != nil {
exit_chan <- *res
}
case syscall.SIGTERM, syscall.SIGINT:
exit_chan <- resultPack{POE_TIMEDOUT, -1, "Supervisor terminated"}
}
}
}()
// TODO: output order is not preserved
out_chan := make(chan childOutput, 1)
go func() {
epfd, err := syscall.EpollCreate1(0)
if err != nil {
poePanic(err, "epoll_create1 failed")
}
defer syscall.Close(epfd)
event1 := syscall.EpollEvent{Events: syscall.EPOLLIN, Fd: int32(stdout_fd[0]), Pad: 1} // Fd/Pad is epoll_data_t (userdata)
if err := syscall.EpollCtl(epfd, syscall.EPOLL_CTL_ADD, stdout_fd[0], &event1); err != nil {
poePanic(err, "epoll_ctl (EPOLL_CTL_ADD) failed")
}
event2 := syscall.EpollEvent{Events: syscall.EPOLLIN, Fd: int32(stderr_fd[0]), Pad: 2}
if err := syscall.EpollCtl(epfd, syscall.EPOLL_CTL_ADD, stderr_fd[0], &event2); err != nil {
poePanic(err, "epoll_ctl (EPOLL_CTL_ADD) failed")
}
var events [32]syscall.EpollEvent
for {
en, err := syscall.EpollWait(epfd, events[:], -1)
if err != nil {
poePanic(err, "epoll_wait failed")
}
var buf [65536]byte // TODO: how to get PIPE_BUF?
for ev := 0; ev < en; ev++ {
for {
n, err := syscall.Read(int(events[ev].Fd), buf[:])
if err != nil {
break
}
if n > 0 {
nbuf := make([]byte, n)
copy(nbuf, buf[:n])
out_chan <- childOutput{int(events[ev].Pad), n, nbuf}
}
}
}
}
}()
go func() {
for {
out := <-out_chan
var outbuf bytes.Buffer
binary.Write(&outbuf, binary.LittleEndian, int32(out.fd))
binary.Write(&outbuf, binary.LittleEndian, int32(out.n))
if _, err := os.Stdout.Write(outbuf.Bytes()); err != nil {
poePanic(err, "stdout write failed")
}
if _, err := os.Stdout.Write(out.buf); err != nil {
poePanic(err, "stdout write failed")
}
}
}()
go func() {
<-time.After(3 * time.Second)
exit_chan <- resultPack{POE_TIMEDOUT, -1, ""}
}()
if _, err := syscall.Write(stdin_fd[1], []byte{0}); err != nil {
poePanic(err, "write to stdin failed")
}
return <-exit_chan
}
func DialTCPTimeoutWithMD5Sig(host string, port int, localAddr, key string, msec int) (*net.TCPConn, error) {
var family int
var ra, la syscall.Sockaddr
ip, err := net.ResolveIPAddr("ip", host)
if err != nil {
return nil, fmt.Errorf("invalid ip: %s", err)
}
l, err := net.ResolveIPAddr("ip", localAddr)
if l == nil {
return nil, fmt.Errorf("invalid local ip: %s", err)
}
if (ip.IP.To4() != nil) != (l.IP.To4() != nil) {
return nil, fmt.Errorf("remote and local ip address family is not same")
}
switch {
case ip.IP.To4() != nil:
family = syscall.AF_INET
i := &syscall.SockaddrInet4{
Port: port,
}
for idx, _ := range i.Addr {
i.Addr[idx] = ip.IP.To4()[idx]
}
ra = i
j := &syscall.SockaddrInet4{}
for idx, _ := range j.Addr {
j.Addr[idx] = l.IP.To4()[idx]
}
la = j
default:
family = syscall.AF_INET6
i := &syscall.SockaddrInet6{
Port: port,
}
for idx, _ := range i.Addr {
i.Addr[idx] = ip.IP[idx]
}
ra = i
var zone uint32
if l.Zone != "" {
intf, err := net.InterfaceByName(l.Zone)
if err != nil {
return nil, err
}
zone = uint32(intf.Index)
}
j := &syscall.SockaddrInet6{
ZoneId: zone,
}
for idx, _ := range j.Addr {
j.Addr[idx] = l.IP[idx]
}
la = j
}
sotype := syscall.SOCK_STREAM | syscall.SOCK_CLOEXEC | syscall.SOCK_NONBLOCK
proto := 0
fd, err := syscall.Socket(family, sotype, proto)
if err != nil {
return nil, err
}
fi := os.NewFile(uintptr(fd), "")
defer fi.Close()
t, err := buildTcpMD5Sig(host, key)
if err != nil {
return nil, err
}
if _, _, e := syscall.Syscall6(syscall.SYS_SETSOCKOPT, uintptr(fd),
uintptr(syscall.IPPROTO_TCP), uintptr(TCP_MD5SIG),
uintptr(unsafe.Pointer(&t)), unsafe.Sizeof(t), 0); e > 0 {
return nil, os.NewSyscallError("setsockopt", e)
}
if err = syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_BROADCAST, 1); err != nil {
return nil, os.NewSyscallError("setsockopt", err)
}
if err = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_NODELAY, 1); err != nil {
return nil, os.NewSyscallError("setsockopt", err)
}
if err = syscall.Bind(fd, la); err != nil {
return nil, os.NewSyscallError("bind", err)
}
tcpconn := func(fi *os.File) (*net.TCPConn, error) {
conn, err := net.FileConn(fi)
return conn.(*net.TCPConn), err
}
err = syscall.Connect(fd, ra)
switch err {
case syscall.EINPROGRESS, syscall.EALREADY, syscall.EINTR:
// do timeout handling
case nil, syscall.EISCONN:
return tcpconn(fi)
default:
return nil, os.NewSyscallError("connect", err)
}
epfd, e := syscall.EpollCreate1(syscall.EPOLL_CLOEXEC)
if e != nil {
return nil, e
}
defer syscall.Close(epfd)
var event syscall.EpollEvent
events := make([]syscall.EpollEvent, 1)
event.Events = syscall.EPOLLIN | syscall.EPOLLOUT | syscall.EPOLLPRI
event.Fd = int32(fd)
if e = syscall.EpollCtl(epfd, syscall.EPOLL_CTL_ADD, fd, &event); e != nil {
return nil, e
}
for {
nevents, e := syscall.EpollWait(epfd, events, msec)
if e != nil {
return nil, e
}
if nevents == 0 {
return nil, fmt.Errorf("timeout")
} else if nevents == 1 && events[0].Fd == int32(fd) {
nerr, err := syscall.GetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_ERROR)
if err != nil {
return nil, os.NewSyscallError("getsockopt", err)
}
switch err := syscall.Errno(nerr); err {
case syscall.EINPROGRESS, syscall.EALREADY, syscall.EINTR:
case syscall.Errno(0), syscall.EISCONN:
return tcpconn(fi)
default:
return nil, os.NewSyscallError("getsockopt", err)
}
} else {
return nil, fmt.Errorf("unexpected epoll behavior")
}
}
}
func (u *NetLinkProbe) start() {
s, err := nl.Subscribe(syscall.NETLINK_ROUTE, syscall.RTNLGRP_LINK)
if err != nil {
logging.GetLogger().Errorf("Failed to subscribe to netlink RTNLGRP_LINK messages: %s", err.Error())
return
}
u.nlSocket = s
defer u.nlSocket.Close()
fd := u.nlSocket.GetFd()
err = syscall.SetNonblock(fd, true)
if err != nil {
logging.GetLogger().Errorf("Failed to set the netlink fd as non-blocking: %s", err.Error())
return
}
epfd, e := syscall.EpollCreate1(0)
if e != nil {
logging.GetLogger().Errorf("Failed to create epoll: %s", err.Error())
return
}
defer syscall.Close(epfd)
u.initialize()
event := syscall.EpollEvent{Events: syscall.EPOLLIN, Fd: int32(fd)}
if e = syscall.EpollCtl(epfd, syscall.EPOLL_CTL_ADD, fd, &event); e != nil {
logging.GetLogger().Errorf("Failed to control epoll: %s", err.Error())
return
}
events := make([]syscall.EpollEvent, maxEpollEvents)
for u.running.Load() == true {
n, err := syscall.EpollWait(epfd, events[:], 1000)
if err != nil {
errno, ok := err.(syscall.Errno)
if ok && errno != syscall.EINTR {
logging.GetLogger().Errorf("Failed to receive from events from netlink: %s", err.Error())
}
continue
}
if n == 0 {
continue
}
msgs, err := s.Receive()
if err != nil {
logging.GetLogger().Errorf("Failed to receive from netlink messages: %s", err.Error())
time.Sleep(1 * time.Second)
continue
}
for _, msg := range msgs {
switch msg.Header.Type {
case syscall.RTM_NEWLINK:
ifmsg := nl.DeserializeIfInfomsg(msg.Data)
u.onLinkAdded(int(ifmsg.Index))
case syscall.RTM_DELLINK:
ifmsg := nl.DeserializeIfInfomsg(msg.Data)
u.onLinkDeleted(int(ifmsg.Index))
}
}
}
}
func StartProxyServer(conf *ProxyConfig, proxy_log l4g.Logger) (err error) {
logger = proxy_log
var filter *IOFilterProtocol
var netio *NetIOManager
proxy := &ProxyServer{
max_listen_fds: 1024,
timeout: 1000,
quit: false,
epoll_fd: -1,
events: make([]syscall.EpollEvent, 100),
sighnd: make(chan os.Signal, 1),
}
if !parse_config(proxy, conf) {
logger.Error("Failed to initialize proxy server.")
goto Error
}
filter = NewIOFilterProtocol(conf)
if filter == nil {
logger.Error("Failed to initialize filter protocol.")
goto Error
} else {
if filter.FilterEnabled() {
go filter.MonitDiskUsage()
}
}
netio = NewNetIOManager()
netio.SetFilter(filter)
proxy.epoll_fd, err = syscall.EpollCreate(proxy.max_listen_fds)
if err != nil {
logger.Critical("Failed to initialize epoll listener [%s].", err)
goto Cleanup
}
netio.SetEpollFd(proxy.epoll_fd)
err = netio.ProxyNetListen(&proxy.proxy_endpoint)
if err != nil {
logger.Critical("Failed to initialize server listener [%s].", err)
goto Cleanup
}
setup_sighnd(proxy)
logger.Info("Mongodb proxy server start.")
for {
wait_signal(proxy, syscall.SIGTERM)
if proxy.quit {
break
}
nfds, err := syscall.EpollWait(proxy.epoll_fd, proxy.events,
proxy.timeout)
if err != nil {
logger.Critical("Failed to do epoll wait [%s].", err)
break
}
for i := 0; i < nfds; i++ {
fd := int(proxy.events[i].Fd)
if netio.ProxyNetIsProxyServer(fd) {
clientinfo, err := netio.ProxyNetAccept(&proxy.mongo_endpoint)
if err != nil {
logger.Critical("Failed to establish bridge between mongo client and server [%s].", err)
} else {
ipaddr, port := parse_sockaddr(clientinfo)
logger.Debug("Succeed to establish bridge for client [%s:%d].", ipaddr, port)
}
} else {
event := proxy.events[i].Events
if event&syscall.EPOLLIN != 0 {
errno := netio.ProxyNetRecv(fd)
switch errno {
case READ_ERROR:
sa := netio.ProxyNetConnInfo(fd)
if sa != nil {
ipaddr, port := parse_sockaddr(sa)
logger.Error("Failed to read data from [%s:%d].", ipaddr, port)
}
case SESSION_EOF:
sa := netio.ProxyNetConnInfo(fd)
if sa != nil {
ipaddr, port := parse_sockaddr(sa)
logger.Debug("One side [%s:%d] close the session.", ipaddr, port)
}
}
if errno != NO_ERROR {
netio.ProxyNetClosePeers(fd)
}
}
if event&syscall.EPOLLOUT != 0 {
errno := netio.ProxyNetSend(fd)
switch errno {
case WRITE_ERROR:
sa := netio.ProxyNetConnInfo(fd)
if sa != nil {
ipaddr, port := parse_sockaddr(sa)
logger.Error("Failed to write data to [%s:%d]", ipaddr, port)
}
case FILTER_BLOCK:
sa := netio.ProxyNetConnInfo(fd)
if sa != nil {
ipaddr, port := parse_sockaddr(sa)
logger.Error("Filter block request from client [%s:%d].", ipaddr, port)
}
}
if errno != NO_ERROR {
netio.ProxyNetClosePeers(fd)
}
}
if event&syscall.EPOLLRDHUP != 0 {
sa := netio.ProxyNetConnInfo(fd)
if sa != nil {
ipaddr, port := parse_sockaddr(sa)
logger.Debug("shutdown connection with [%s:%d].", ipaddr, port)
netio.ProxyNetClosePeers(fd)
}
}
if event&syscall.EPOLLHUP != 0 {
sa := netio.ProxyNetConnInfo(fd)
if sa != nil {
ipaddr, port := parse_sockaddr(sa)
logger.Debug("shutdown connection with [%s:%d].", ipaddr, port)
netio.ProxyNetClosePeers(fd)
}
}
}
}
}
Cleanup:
netio.DestroyNetIO()
Error:
logger.Info("Mongodb proxy server quit.")
logger.Close()
return err
}
func StartProxyServer(conf *ProxyConfig, proxy_log l4g.Logger) (err error) {
logger = proxy_log
var filter *IOFilterProtocol
var netio *NetIOManager
proxy := &ProxyServer{
max_listen_fds: 1024,
timeout: 1000,
quit: false,
epoll_fd: -1,
events: make([]syscall.EpollEvent, 100),
sighnd: make(chan os.Signal, 1),
}
if !parse_config(proxy, conf) {
logger.Error("Failed to initialize proxy server.")
goto Error
}
filter = NewIOFilterProtocol(conf)
if filter == nil {
logger.Error("Failed to initialize filter protocol.")
goto Error
} else {
if filter.FilterEnabled() {
go filter.MonitQuotaFiles()
go filter.MonitQuotaDataSize()
}
}
netio = NewNetIOManager()
netio.SetFilter(filter)
proxy.epoll_fd, err = syscall.EpollCreate(proxy.max_listen_fds)
if err != nil {
logger.Critical("Failed to initialize epoll listener [%s].", err)
goto Cleanup
}
netio.SetEpollFd(proxy.epoll_fd)
err = netio.ProxyNetListen(&proxy.proxy_endpoint)
if err != nil {
logger.Critical("Failed to initialize server listener [%s].", err)
goto Cleanup
}
setup_sighnd(proxy)
logger.Info("Mongodb proxy server start.")
for {
wait_signal(proxy, syscall.SIGTERM)
if proxy.quit {
break
}
nfds, err := syscall.EpollWait(proxy.epoll_fd, proxy.events,
proxy.timeout)
if err != nil {
logger.Critical("Failed to do epoll wait [%s].", err)
break
}
for i := 0; i < nfds; i++ {
fd := int(proxy.events[i].Fd)
if netio.ProxyNetIsProxyServer(fd) {
clientinfo, err := netio.ProxyNetAccept(&proxy.mongo_endpoint)
if err != nil {
logger.Critical("Failed to establish bridge between mongo client and server [%s].", err)
} else {
addr, port := parse_sockaddr(clientinfo)
logger.Debug("Succeed to establish bridge for client [%s:%d].", addr, port)
}
} else {
event := proxy.events[i].Events
if event&syscall.EPOLLIN != 0 {
errno := netio.ProxyNetRecv(fd)
if errno != NO_ERROR {
var addr string
var port int
sa := netio.ProxyNetConnInfo(fd)
if sa != nil {
addr, port = parse_sockaddr(sa)
}
switch errno {
case READ_ERROR:
if sa != nil {
logger.Error("Failed to read data from [%s:%d].", addr, port)
}
case SESSION_EOF:
/* normal close */
netio.ProxyNetFlush(fd)
if sa != nil {
logger.Debug("One side [%s:%d] close the session.", addr, port)
}
case UNKNOWN_ERROR:
if sa != nil {
logger.Debug("Unknown error during read happened at [%s:%d].", addr, port)
}
}
netio.ProxyNetClosePeers(fd)
}
}
if event&syscall.EPOLLOUT != 0 {
errno := netio.ProxyNetSend(fd)
if errno != NO_ERROR && errno != PARTIAL_SKB {
var addr string
var port int
sa := netio.ProxyNetConnInfo(fd)
if sa != nil {
addr, port = parse_sockaddr(sa)
}
switch errno {
case WRITE_ERROR:
if sa != nil {
logger.Error("Failed to write data to [%s:%d]", addr, port)
}
case FILTER_BLOCK:
/*
* 'block' handler only happens on 'proxy->server' io write, here
* we need to log the 'client->proxy' connection information, if
* we call 'ConnInfo' method we get the 'proxy->server' connection,
* so we shall call 'OtherSideConnInfo' method here.
*/
sa = netio.ProxyNetOtherSideConnInfo(fd)
if sa != nil {
addr, port = parse_sockaddr(sa)
logger.Error("Filter block request from client [%s:%d].", addr, port)
}
case UNKNOWN_ERROR:
if sa != nil {
logger.Debug("Unknown error during write happened at [%s:%d].", addr, port)
}
}
netio.ProxyNetClosePeers(fd)
}
}
if event&syscall.EPOLLRDHUP != 0 {
netio.ProxyNetFlush(fd)
sa := netio.ProxyNetConnInfo(fd)
if sa != nil {
ipaddr, port := parse_sockaddr(sa)
logger.Debug("shutdown connection with [%s:%d].", ipaddr, port)
netio.ProxyNetClosePeers(fd)
}
}
if event&syscall.EPOLLHUP != 0 {
netio.ProxyNetFlush(fd)
sa := netio.ProxyNetConnInfo(fd)
if sa != nil {
ipaddr, port := parse_sockaddr(sa)
logger.Debug("shutdown connection with [%s:%d].", ipaddr, port)
netio.ProxyNetClosePeers(fd)
}
}
}
}
}
Cleanup:
netio.DestroyNetIO()
Error:
logger.Info("Mongodb proxy server quit.")
logger.Close()
return err
}
// 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([]syscall.EpollEvent, 7)
for {
n, errno := syscall.EpollWait(poller.epfd, events, -1)
if n == -1 {
if errno == syscall.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&syscall.EPOLLHUP != 0 {
// This should not happen, but if it does, treat it as a wakeup.
epollhup = true
}
if event.Events&syscall.EPOLLERR != 0 {
// If an error is waiting on the file descriptor, we should pretend
// something is ready to read, and let syscall.Read pick up the error.
epollerr = true
}
if event.Events&syscall.EPOLLIN != 0 {
// There is data to read.
epollin = true
}
}
if event.Fd == int32(poller.pipe[0]) {
if event.Events&syscall.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&syscall.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&syscall.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
}
}