DEFINITION MODULE Handler;
(* Exception and Event Handling. *)

FROM SYSTEM IMPORT ADDRESS, WORD;

EXPORT QUALIFIED (* CONSTs *)
		 BufferEmpty, BufferFull, KeyboardInt, ADCComplete, VSync,
		 TimerInt, Escape, Other,
		 NoUserSuppliedHandler,

		 (* TYPEs *)
		 Register, RegisterSet,
		 PSRBit, PSRContents,
		 LinkTableEntry,
		 ModuleRecord,
		 PointerToModuleRecord,
		 UsersEnvironment,
		 UsersEnvironmentPTR,
		 ConditionHandlerType,
		 UserEventHandler,
		 ExceptionType,
		 TypeCode,

		 (* PROCEDUREs *)
		 Signal, CallHandler,
		 DeclareEventHandler, RemoveEventHandler,
		 EventStatus, SetEventStatus,
		 DeclareConditionHandler,
		 XSignal, XCallHandler,
		 XDeclareEventHandler, XRemoveEventHandler,
		 XEventStatus, XSetEventStatus,
		 XDeclareConditionHandler;


CONST  BufferEmpty =   0;
       BufferFull  =   1;
       KeyboardInt =   2;
       ADCComplete =   3;
       VSync	   =   4;
       TimerInt    =   5;
       Escape	   =   6;
       Other	   = 255;


TYPE
   Register	= (pc,sp1,fp,upsr,mod,
		   r0,r1,r2,r3,r4,r5,r6,r7,
		   f0,f1,f2,f3,f4,f5,f6,f7);
   RegisterSet	= SET OF Register;
   PSRBit	= (c,t,l,b3,b4,f,z,n,u,s,p,i);
   PSRContents	= SET OF PSRBit;
   TypeCode	= (Init,Stop,Except,ExceptPassedOn,
		   Diagnose,DiagnosePassedOn,DescribeFrame,
		   DescribeModuleData,Unwind);

   Huge = [-1000000..+1000000];

   LinkTableEntry = WORD;

   ExceptionType = (NVI,NMI,ABT,FPU,ILL,SVC,DVZ,FLG,BPT,TRC,UND);

   PointerToModuleRecord = POINTER TO ModuleRecord;
   ModuleRecord =
      RECORD
	 StaticBase    : ADDRESS;
	 LinkTableBase : POINTER TO ARRAY Huge OF LinkTableEntry;
	 ProgramBase   : ADDRESS;
	 Reserved      : WORD;
      END;

   UsersEnvironment =
      RECORD
	 Validity   : RegisterSet;
	 PC	    : ADDRESS;
	 SP1	    : ADDRESS;
	 FP	    : ADDRESS;
	 UserPSR    : PSRContents;
	 Mod	    : PointerToModuleRecord;
	 Register   : ARRAY [0..7] OF WORD;
	 FPRegister : ARRAY [0..7] OF WORD;
      END;
   UsersEnvironmentPTR = POINTER TO UsersEnvironment;

TYPE  ConditionHandlerType = PROCEDURE(TypeCode,
				   INTEGER,
				   VAR UsersEnvironment,
				   VAR UsersEnvironment):INTEGER;



TYPE UserEventHandler = PROCEDURE( INTEGER,INTEGER,INTEGER,
			       INTEGER,VAR UsersEnvironment);


CONST  NoUserSuppliedHandler = 0;


PROCEDURE Signal(Cause:INTEGER;Buffer:ADDRESS);

PROCEDURE CallHandler(		Type:TypeCode;
			   Parameter:INTEGER;
		      VAR CurrentEnv:UsersEnvironment;
		      VAR  ExceptEnv:UsersEnvironment):INTEGER;

PROCEDURE DeclareEventHandler (NewHandler : UserEventHandler;
				Event:CARDINAL;
				Action:CARDINAL;
				Handle:CARDINAL):INTEGER;

PROCEDURE RemoveEventHandler (Handler : UserEventHandler;
				Event:CARDINAL;
				Handle:CARDINAL):INTEGER;

PROCEDURE EventStatus(Event:CARDINAL):INTEGER;

PROCEDURE SetEventStatus( Event:CARDINAL;
			 Enable:BOOLEAN):INTEGER;

PROCEDURE DeclareConditionHandler(ConditionHandler : ConditionHandlerType)
				 :INTEGER;

PROCEDURE XSignal(Cause:INTEGER;Buffer:ADDRESS);

PROCEDURE XCallHandler(		Type:TypeCode;
			   Parameter:INTEGER;
		      VAR CurrentEnv:UsersEnvironment;
		      VAR  ExceptEnv:UsersEnvironment):INTEGER;

PROCEDURE XDeclareEventHandler (NewHandler : UserEventHandler;
				Event:CARDINAL;
				Action:CARDINAL;
				Handle:CARDINAL):INTEGER;

PROCEDURE XRemoveEventHandler (Handler : UserEventHandler;
				Event:CARDINAL;
				Handle:CARDINAL):INTEGER;

PROCEDURE XEventStatus(Event:CARDINAL):INTEGER;

PROCEDURE XSetEventStatus( Event:CARDINAL;
			 Enable:BOOLEAN):INTEGER;

PROCEDURE XDeclareConditionHandler(ConditionHandler : ConditionHandlerType)
				 :INTEGER;

END Handler.