{--------------------------------------------------}
{ Simple telephone connection phase - TMDL Example }
{ January 31, 1995                                 }
{--------------------------------------------------}

Map Map5 is

{--------------------------------------------------}

INTERNAL  { Hidden global activities }
   GiveTone, GotDial, AskAnswer, GotAnswer,
   EndDial, EndRing, EndConnect, Disconnected,
   AllowHangUp

{--------------------------------------------------}

INTERACTIONS
   &Grouping1, &Grouping2  on  GiveTone, GotDial, EndDial, AskAnswer, GotAnswer, EndRing;
   
   Where
      Group &Grouping1 is
         ConnectionPhase, Disconnecting  on  EndConnect, AllowHangUp;
      EndGroup
   
      Group &Grouping2 is
         Answering, Dialing on  Nothing;
      EndGroup

{--------------------------------------------------}

DESCRIPTIONS

Timethread ConnectionPhase is
   { This is the main timethread. }
   
   AbortedOn (EndConnect)  { Can be aborted (HangUp) }
   Internal 
	RegInit,       { Register the initiator in the database }
	CheckDB        { Check a abstract (and virtual!) database }
   
   Trigger (OffHook)
   Action (RegInit)
   Sync (AllowHangUp)      { Starts the Disconnecting TT }
   Sync (GiveTone)        { Starts the Dialing TT }
   
   Wait Time (GotDial)
   OrFork
       Guard (TimeGotDial eq OK)
       { Dial is finished in time }
       Continue
     OR
       Guard (TimeGotDial eq TOut)
       { TimeOut: Took too much time to dial }
       Path
          Abort (EndDial)   { Abort Dialing TT }
          Result (ErrorDial) { ... and ask user to hangup }
       EndPath
   EndOrFork
       
   Action (CheckDB)
   
   { The following choice is made by the simulation's user. }
   { Tags and guards could be used, but they are unnecessary since }
   { we do not really simulate the database. }
   OrFork
       Continue  { Not busy and valid number }
     OR
       Path
          Result (WrongNumber)
       EndPath
     OR
       Path 
          Result (BusyTone)
       EndPath
   EndOrFork
   
   Sync (AskAnswer)  { Starts the Answering TT }
   
   Wait Time (GotAnswer)
   OrFork
       Guard (TimeGotAnswer eq OK)
       { Answered in allowed time }
       Continue
     OR
       Guard (TimeGotAnswer eq TOut)
       { TimeOut: Not answered in allowed time }
       Path
          Abort (EndRing)   { Abort the answering TT }
          Result (NoAnswer) { ... and ask user to hangup }
       EndPath
   EndOrFork
   
   Result (Connected)       { Connection done. }
EndTT { ConnectionPhase }

{--------------------------------------------------}

Timethread Disconnecting is
   EndRec  { LOTOS end recursion }
   
   Trigger (AllowHangUp)
   Wait (HangUp)
   
   { Caller hangups. Abort everything and disconnect. }
   Par
       Abort(EndConnect)
     And
       Abort(EndDial)
     And
       Abort(EndRing)
   EndPar
      
   Result (Disconnected)
   
EndTT { Disconnecting }

{--------------------------------------------------}

Timethread Dialing is
   AbortedOn (EndDial)
   
   Trigger (GiveTone)
   Action (Tone)
   Wait (Dial)
   Result (GotDial)
   
EndTT { Dialing }

{--------------------------------------------------}

Timethread Answering is
   AbortedOn (EndRing)

   Trigger (AskAnswer)
   Action (Ring)
   Wait (Answer)
   Result (GotAnswer)
   
EndTT { Answering }

EndMap { Map5 }