/* Copyright (c) 1993 Stephen F. White */

#ifndef EXECUTE_H
#define EXECUTE_H

typedef struct timeval Timeval;

typedef struct Event Event;

struct Event {
  int msgid;                    /* current message id */
  int age;                      /* current message's age */
  int ticks;                    /* current task's ticks */
  Objid player;                 /* current player */
  Objid this;                   /* object to which message was sent */
  Object *on;                   /* object on which method is located */
  Objid caller;                 /* object which sent the message */
  List *args;                   /* arguments to message */
  Method *m;                    /* method which was being executed */

  /* the following fields are used when the method gets blocked */
  enum { BL_MESSAGE, BL_LOCK, BL_TIMER, BL_SYS_MESSAGE, BL_DEAD } blocked_on;
  /* what the method is blocked on */
  Timeval timeout_at;           /* time at which message should time out */
  int blocked_msgid;            /* message for which MESSAGE event is waiting */
  Objid blocked_objid;          /* object to which MESSAGE event was sent */
  String *msg;                  /* if sent to remote, text of message */
  Timeval retry_at;             /* absolute time to retry at */
  int retry_interval;           /* relative msec on next retry */

  String *lock;                 /* name of lock which LOCK is blocked on */

  int sp;                       /* stack pointer */
  int pc;                       /* program counter */
  Var stack[STACK_SIZE];        /* the stack */
  int nvars;                    /* and how many of them */
  int last_opcode;              /* useful for error recovery */
  Event *prev;                  /* previous event in queue */
  Event *next;                  /* next event in queue */
};

/*
 * Execution globals
 */

extern Event frame;             /* the currently executing frame */
extern enum state ex_state;     /* execution state */
extern Var ex_retval;           /* return value (set by op_return()) */
extern Object *this;            /* this object, may be 0 */

/*
 * from execute.c
 */

extern void push (Var v);
extern Var pop (void);
extern Var pop_args (int num);  /* pop an argument list */
extern void pushn (long i);     /* push an integer onto the stack */
extern void pushpc (int i);     /* push the PC onto the stack */
extern void raise (Error e);    /* raise an error */
extern void send_raise (List * raise_args);     /* send the raise msg */
extern Error call_verb (int msgid, int age, int ticks, Objid player,
  Objid from, Objid to, List * args);
extern Method *find_method (Object * o, const char *name);
extern void send_message_and_block (Objid from, Objid to,
  String * msg, List * args, Objid on);
extern void resume_method_return (Event * e, Var retval);
extern void resume_method_raise (Event * e, List * raise_args);
extern void resume_method_halt (Event * e);
extern void resume_method (Event * e);
extern String *add_traceback_header (String * str, Error e);
extern List *make_raise_args (Error e);
extern Timeval timer_sub (Timeval t1, Timeval t2);
extern Timeval timer_addmsec (Timeval t, int msec);

/*
 * from message.c
 */
extern Error send_message (int msgid, int age, int ticks, Objid player,
  Objid from, Objid to, String * message, List * args, Event * e, Objid on);
extern void event_add (Event * e);
extern void event_rm (Event * e);

/*
 * Prototypes for all the opcodes
 */

extern void op_numpush (void), op_strpush (void), op_objpush (void),
op_errpush (void), op_listpush (void), op_mappush (void),
op_pushpc (void), op_if (void), op_elseif (void), op_null (void),
op_for (void), op_forrng (void), op_while (void), op_do (void),
op_dowhile (void), op_break (void), op_continue (void),
op_add (void), op_sub (void), op_mul (void), op_div (void),
op_mod (void), op_negate (void), op_message (void),
op_message_expr (void), op_and (void), op_or (void),
op_not (void), op_index (void), op_subset (void),
op_lsubset (void), op_rsubset (void), op_gt (void), op_lt (void),
op_ge (void), op_le (void), op_eq (void), op_ne (void),
op_echo (void), op_echo_file (void), op_clone (void),
op_destroy (void), op_chparents (void), op_time (void),
op_ctime (void), op_in (void), op_explode (void),
op_strsub (void), op_psub (void), op_random (void), op_pop (void),
op_pad (void), op_setadd (void), op_setremove (void),
op_listinsert (void), op_listappend (void), op_listdelete (void),
op_listassign (void), op_asgnlvar (void), op_asgngvar (void),
op_asgngvarindex (void), op_asgnlvarindex (void),
op_asgngvarexpr (void), op_getlvar (void), op_getgvar (void),
op_getgvarexpr (void), op_parents (void), op_this (void),
op_player (void), op_caller (void), op_args (void),
op_setplayer (void), op_return (void), op_stop (void),
op_abort (void), op_crypt (void), op_checkmem (void),
op_cache_stats (void), op_lock (void), op_unlock (void),
op_at (void), op_tostr (void), op_tonum (void), op_toobj (void),
op_toerr (void), op_typeof (void), op_lengthof (void),
op_serverof (void), op_servername (void), op_servers (void),
op_verbs (void), op_vars (void), op_methods (void),
op_verb (void), op_rmverb (void), op_rmmethod (void),
op_rmvar (void), op_program (void), op_compile (void),
op_find_method (void), op_spew_method (void),
op_list_method (void), op_decompile (void), op_hasparent (void),
op_objsize (void), op_match (void), op_match_full (void),
op_shutdown (void), op_dump (void), op_boot (void),
op_writelog (void), op_raise (void), op_pass (void),
op_sleep (void), op_ps (void), op_kill (void);

#endif /* !EXECUTE_H */