#ifndef EXEC_TASKS_H
#define EXEC_TASKS_H

/*
    (C) 1995-96 AROS - The Amiga Replacement OS
    $Id: tasks.h,v 1.3 1997/04/18 14:50:58 aros Exp $

    Desc: Task structure and constants
    Lang: english
*/
#ifndef EXEC_NODES_H
#   include <exec/nodes.h>
#endif
#ifndef EXEC_LISTS_H
#   include <exec/lists.h>
#endif
#ifndef EXEC_PORTS_H
#   include <exec/ports.h>
#endif


/* You must use Exec functions to modify task structure fields. */
struct Task
{
    struct Node tc_Node;
    UBYTE	tc_Flags;
    UBYTE	tc_State;
    BYTE	tc_IDNestCnt;	/* Interrupt disabled nesting */
    BYTE	tc_TDNestCnt;	/* Task disabled nesting */
    ULONG	tc_SigAlloc;	/* Allocated signals */
    ULONG	tc_SigWait;	/* Signals we are waiting for */
    ULONG	tc_SigRecvd;	/* Received signals */
    ULONG	tc_SigExcept;	/* Signals we will take exceptions for */
    union
    {
	struct
	{
	    UWORD tc_ETrapAlloc;   /* Allocated traps */
	    UWORD tc_ETrapAble;    /* Enabled traps */
	} tc_ETrap;
	APTR	  tc_ETask;	   /* Valid if TF_ETASK is set */
    }		tc_UnionETask;
    APTR	tc_ExceptData;	/* Exception data */
    APTR	tc_ExceptCode;	/* Exception code */
    APTR	tc_TrapData;	/* Trap data */
    APTR	tc_TrapCode;	/* Trap code */
    APTR	tc_SPReg;	/* Stack pointer */
    APTR	tc_SPLower;	/* Stack lower bound */
    APTR	tc_SPUpper;	/* Stack upper bound */
    VOID     (* tc_Switch)();   /* Task loses CPU */
    VOID     (* tc_Launch)();   /* Task gets CPU */
    struct List tc_MemEntry;	/* Allocated memory. Freed by RemTask(). */
    APTR	tc_UserData;	/* For use by the task; no restrictions! */
};

#define tc_TrapAlloc	    tc_UnionETask.tc_ETrap.tc_ETrapAlloc
#define tc_TrapAble	    tc_UnionETask.tc_ETrap.tc_ETrapAble

/* Macros */
#define GetTrapAlloc(t) \
	((((struct Task *)t)->tc_Flags & TF_ETASK) ? \
	    ((struct ETask *)(((struct Task *)t)->tc_UnionETask.tc_ETask))-> \
		et_TrapAlloc : \
	    ((struct Task *)t)->tc_UnionETask.tc_ETrap.tc_ETrapAlloc)
#define GetTrapAble(t) \
	((((struct Task *)t)->tc_Flags & TF_ETASK) ? \
	    ((struct ETask *)(((struct Task *)t)->tc_UnionETask.tc_ETask))-> \
		et_TrapAble : \
	    ((struct Task *)t)->tc_UnionETask.tc_ETrap.tc_ETrapAble)
#define GetETask(t) \
	((((struct Task *)t)->tc_Flags & TF_ETASK) ? \
	    ((struct ETask *)(((struct Task *)t)->tc_UnionETask.tc_ETask)) \
	    : NULL \
	)


/* Stack swap structure as passed to StackSwap() */
struct StackSwapStruct
{
    APTR  stk_Lower;   /* Lowest byte of stack */
    ULONG stk_Upper;   /* Upper end of stack (size + Lowest) */
    APTR  stk_Pointer; /* Stack pointer at switch point */
};

/* tc_Flags Bits */
#define TB_PROCTIME	0
#define TB_ETASK	3
#define TB_STACKCHK	4
#define TB_EXCEPT	5
#define TB_SWITCH	6
#define TB_LAUNCH	7

#define TF_PROCTIME	(1L<<0)
#define TF_ETASK	(1L<<3)
#define TF_STACKCHK	(1L<<4)
#define TF_EXCEPT	(1L<<5)
#define TF_SWITCH	(1L<<6)
#define TF_LAUNCH	(1L<<7)

/* Task States (tc_State) */
#define TS_INVALID	0
#define TS_ADDED	1
#define TS_RUN		2
#define TS_READY	3
#define TS_WAIT 4
#define TS_EXCEPT	5
#define TS_REMOVED	6

/* Predefined Signals */
#define SIGB_ABORT	0
#define SIGB_CHILD	1
#define SIGB_BLIT	4	/* Note: same as SIGB_SINGLE */
#define SIGB_SINGLE	4	/* Note: same as SIGB_BLIT */
#define SIGB_INTUITION	5
#define SIGB_NET	7
#define SIGB_DOS	8

#define SIGF_ABORT	(1L<<0)
#define SIGF_CHILD	(1L<<1)
#define SIGF_BLIT	(1L<<4)
#define SIGF_SINGLE	(1L<<4)
#define SIGF_INTUITION	(1L<<5)
#define SIGF_NET	(1L<<7)
#define SIGF_DOS	(1L<<8)

/* Extended Task structure */
struct ETask
{
    APTR	   et_Parent;	    /* Pointer to task */
    ULONG	   et_UniqueID;
    struct MinList et_Children;     /* List of children */
    UWORD	   et_TrapAlloc;
    UWORD	   et_TrapAble;
    ULONG	   et_Result1;	    /* First result */
    APTR	   et_Result2;	    /* Result data pointer (AllocVec) */
    struct MsgPort et_TaskMsgPort;

    /* Internal fields follow */
};

/* Return codes from new child functions */
#define CHILD_NOTNEW   1 /* Function not called from a new style task */
#define CHILD_NOTFOUND 2 /* Child not found */
#define CHILD_EXITED   3 /* Child has exited */
#define CHILD_ACTIVE   4 /* ??? */

#endif /* EXEC_TASKS_H */