func bootNewCommand(slaveNode *processtree.SlaveNode, command string, err error) (*unixsocket.Usock, error) { if err != nil { return nil, err } request := &processtree.CommandRequest{command, make(chan *os.File)} slaveNode.RequestCommandBoot(request) commandFile := <-request.Retchan // TODO: don't really want to wait indefinitely. // defer commandFile.Close() // TODO: can't do this here anymore. return unixsocket.NewUsockFromFile(commandFile) }
func StartSlaveMonitor(tree *ProcessTree, done chan bool) chan bool { quit := make(chan bool) go func() { localMasterFile, remoteMasterFile, err := unixsocket.Socketpair(syscall.SOCK_DGRAM) if err != nil { Error("Couldn't create socketpair") } monitor := &SlaveMonitor{tree, remoteMasterFile} localMasterSocket, err := unixsocket.NewUsockFromFile(localMasterFile) if err != nil { Error("Couldn't Open UNIXSocket") } // We just want this unix socket to be a channel so we can select on it... registeringFds := make(chan int, 3) go func() { for { fd, err := localMasterSocket.ReadFD() if err != nil { slog.Error(err) } registeringFds <- fd } }() for _, slave := range monitor.tree.SlavesByName { go slave.Run(monitor) } for { select { case <-quit: monitor.cleanupChildren() done <- true return case fd := <-registeringFds: go monitor.slaveDidBeginRegistration(fd) } } }() return quit }
func (mon *SlaveMonitor) slaveDidBeginRegistration(fd int) { // Having just started the process, we expect an IO, which we convert to a UNIX domain socket fileName := strconv.Itoa(rand.Int()) slaveFile := unixsocket.FdToFile(fd, fileName) slaveUsock, err := unixsocket.NewUsockFromFile(slaveFile) if err != nil { slog.Error(err) } if err = slaveUsock.Conn.SetReadBuffer(1024); err != nil { slog.Error(err) } if err = slaveUsock.Conn.SetWriteBuffer(1024); err != nil { slog.Error(err) } // We now expect the slave to use this fd they send us to send a Pid&Identifier Message msg, err := slaveUsock.ReadMessage() if err != nil { slog.Error(err) } pid, identifier, err := messages.ParsePidMessage(msg) // And the last step before executing its action, the slave sends us a pipe it will later use to // send us all the features it's loaded. featurePipeFd, err := slaveUsock.ReadFD() if err != nil { slog.Error(err) } slaveNode := mon.tree.FindSlaveByName(identifier) if slaveNode == nil { Error("slavemonitor.go:slaveDidBeginRegistration:Unknown identifier:" + identifier) } slaveNode.SlaveWasInitialized(pid, slaveUsock, featurePipeFd) }