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//
// rhctl
//
// Copyright (C) 2009-2016 Christian Pointner <equinox@helsinki.at>
//
// This file is part of rhctl.
//
// rhctl is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// any later version.
//
// rhctl is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with rhctl. If not, see <http://www.gnu.org/licenses/>.
//
package main
import (
"fmt"
"strings"
"time"
)
type ServerHealth bool
const (
ServerDead ServerHealth = false
ServerAlive ServerHealth = true
)
func (s ServerHealth) String() string {
switch s {
case ServerDead:
return "dead"
case ServerAlive:
return "alive"
}
return "unknown"
}
type ServerState struct {
Name string
Health ServerHealth
Channel string
Changed time.Time
}
type PlayoutServer struct {
name string
control *SerialPort
heartbeat *SerialPort
hbtimeout time.Duration
hbtimer *time.Timer
hbthreshold uint
hbcnt uint
state ServerState
StateChanges chan ServerState
UpdateRequest chan bool
SwitchUpdates chan SwitchUpdate
}
func (srv *PlayoutServer) handleControl(data string) {
rhdl.Printf("Server(%s): got control message: %q", srv.name, data)
if strings.HasPrefix(data, "channel ") {
if len(data) <= 8 {
rhl.Printf("Server(%s) sent empty channel name", srv.name)
return
}
srv.state.Channel = data[8:]
srv.state.Changed = time.Now()
srv.StateChanges <- srv.state
return
}
rhl.Printf("Server(%s): ignoring unknown control message: %q", srv.name, data)
}
func (srv *PlayoutServer) handleHeartbeat(data string) {
rhdl.Printf("Server(%s): got heartbeat message: %q", srv.name, data)
srv.hbtimer.Reset(srv.hbtimeout)
if (srv.hbcnt + 1) < srv.hbthreshold {
srv.hbcnt++
return
}
old := srv.state.Health
srv.state.Health = ServerAlive
srv.state.Changed = time.Now()
if old != srv.state.Health {
srv.StateChanges <- srv.state
rhl.Printf("Server(%s): is back from the dead!", srv.name)
if srv.state.Channel == "" {
srv.control.tx <- "channel ?"
}
}
}
func (srv *PlayoutServer) handleHBTimeout() {
rhl.Printf("Server(%s): heartbeat timed-out", srv.name)
srv.hbcnt = 0
srv.state.Health = ServerDead
srv.state.Changed = time.Now()
srv.StateChanges <- srv.state
}
func (srv *PlayoutServer) Run() {
stop := make(chan bool)
srv.control.Run(stop)
srv.heartbeat.Run(stop)
srv.hbtimer = time.NewTimer(srv.hbtimeout)
srv.hbcnt = 0
rhdl.Printf("Server(%s): handler running...", srv.name)
for {
select {
case <-stop:
return
case data := <-srv.control.rx:
srv.handleControl(data)
case data := <-srv.heartbeat.rx:
srv.handleHeartbeat(data)
case <-srv.hbtimer.C:
srv.handleHBTimeout()
case <-srv.UpdateRequest:
if srv.state.Health == ServerDead {
srv.StateChanges <- srv.state
} else {
srv.control.tx <- "channel ?"
}
case update := <-srv.SwitchUpdates:
srv.control.tx <- update.Data
}
}
}
func ServerInit(name string, conf *Config) (srv *PlayoutServer, err error) {
srv = &PlayoutServer{}
srv.name = name
srv.hbtimeout = 3 * time.Second
if conf.Servers[name].HeartbeatTimeout.Duration > time.Duration(0) {
srv.hbtimeout = conf.Servers[name].HeartbeatTimeout.Duration
}
srv.hbthreshold = 10
if conf.Servers[name].HeartbeatThreshold > 0 {
srv.hbthreshold = conf.Servers[name].HeartbeatThreshold
}
srv.state.Name = srv.name
srv.state.Health = ServerDead
srv.state.Channel = ""
srv.StateChanges = make(chan ServerState, 16)
srv.UpdateRequest = make(chan bool, 8)
srv.SwitchUpdates = make(chan SwitchUpdate, 32)
if srv.control, err = SerialOpen(conf.Servers[name].ControlDevice, conf.Servers[name].ControlBaudrate, "\n"); err != nil {
err = fmt.Errorf("Server(%s): error opening control port: %s", srv.name, err)
return
}
if srv.heartbeat, err = SerialOpen(conf.Servers[name].HeartbeatDevice, conf.Servers[name].HeartbeatBaudrate, "\n"); err != nil {
err = fmt.Errorf("Server(%s): error opening heartbeat port: %s", srv.name, err)
return
}
return
}
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