/* $Header: lwp.h,v 1.2 88/09/20 18:33:53 kazar Exp $ */
/* $Source: /afs/andrew.cmu.edu/usr7/kazar/afs/lwp/RCS/lwp.h,v $ */

#ifndef __LWP_INCLUDE_
#define	__LWP_INCLUDE_	1
#if !defined(lint) && !defined(LOCORE) && defined(RCS_HDRS)
static char *rcsidlwp = "$Header: lwp.h,v 1.2 88/09/20 18:33:53 kazar Exp $";
#endif

/*
 * P_R_P_Q_# (C) COPYRIGHT IBM CORPORATION 1987
 * LICENSED MATERIALS - PROPERTY OF IBM
 * REFER TO COPYRIGHT INSTRUCTIONS FORM NUMBER G120-2083
 */

/*******************************************************************\
* 								    *
* 	Information Technology Center				    *
* 	Carnegie-Mellon University				    *
* 								    *
* 								    *
\*******************************************************************/

#define LWP_SUCCESS	0
#define LWP_EBADPID	-1
#define LWP_EBLOCKED	-2
#define LWP_EINIT	-3
#define LWP_EMAXPROC	-4
#define LWP_ENOBLOCK	-5
#define LWP_ENOMEM	-6
#define LWP_ENOPROCESS	-7
#define LWP_ENOWAIT	-8
#define LWP_EBADCOUNT	-9
#define LWP_EBADEVENT	-10
#define LWP_EBADPRI	-11
#define LWP_NO_STACK	-12
/* These two are for the signal mechanism. */
#define LWP_EBADSIG	-13		/* bad signal number */
#define LWP_ESYSTEM	-14		/* system call failed */
/* These are for the rock mechanism */
#define LWP_ENOROCKS	-15	/* all rocks are in use */
#define LWP_EBADROCK	-16	/* the specified rock does not exist */


/* Maximum priority permissible (minimum is always 0) */
#define LWP_MAX_PRIORITY 4	/* changed from 1 by Satya, 22 Nov. 85 */

/* Usual priority used by user LWPs */
#define LWP_NORMAL_PRIORITY (LWP_MAX_PRIORITY-1)

/* Initial size of eventlist in a PCB; grows dynamically  */ 
#define EVINITSIZE  5

typedef struct lwp_pcb *PROCESS;

struct lwp_context {	/* saved context for dispatcher */
    char *topstack;	/* ptr to top of process stack */
};

struct rock
    {/* to hide things associated with this LWP under */
    int  tag;		/* unique identifier for this rock */
    char *value;	/* pointer to some arbitrary data structure */
    };

#define MAXROCKS	4	/* max no. of rocks per LWP */

struct lwp_pcb {			/* process control block */
  char		name[32];		/* ASCII name */
  int		rc;			/* most recent return code */
  char		status;			/* status flags */
  char		**eventlist;		/* ptr to array of eventids */
  char		eventlistsize;		/* size of eventlist array */
  int		eventcnt;		/* no. of events currently in eventlist array*/
  int		wakevent;		/* index of eventid causing wakeup */
  int		waitcnt;		/* min number of events awaited */
  char		blockflag;		/* if (blockflag), process blocked */
  int		priority;		/* dispatching priority */
  PROCESS	misc;			/* for LWP internal use only */
  char		*stack;			/* ptr to process stack */
  int		stacksize;		/* size of stack */
  long		stackcheck;		/* first word of stack for overflow checking */
  int		(*ep)();		/* initial entry point */
  char		*parm;			/* initial parm for process */
  struct lwp_context
		context;		/* saved context for next dispatch */
  int		rused;			/* no of rocks presently in use */
  struct rock	rlist[MAXROCKS];		/* set of rocks to hide things under */
  PROCESS	next, prev;		/* ptrs to next and previous pcb */
  int		level;			/* nesting level of critical sections */
  struct IoRequest	*iomgrRequest;	/* request we're waiting for */
  int           index;                  /* LWP index: should be small index; actually is
                                           incremented on each lwp_create_process */ 
  };

int lwp_nextindex;                      /* Next lwp index to assign */

#ifndef LWP_KERNEL
#define LWP_ActiveProcess	(lwp_cpptr+0)
#define LWP_Index() (LWP_ActiveProcess->index)
#define LWP_HighestIndex() (lwp_nextindex - 1)
#define LWP_SignalProcess(event)	LWP_INTERNALSIGNAL(event, 1)
#define LWP_NoYieldSignal(event)	LWP_INTERNALSIGNAL(event, 0)

extern
#endif
  PROCESS	lwp_cpptr;	/* pointer to current process pcb */

struct	 lwp_ctl {			/* LWP control structure */
    int		processcnt;		/* number of lightweight processes */
    char	*outersp;		/* outermost stack pointer */
    PROCESS	outerpid;		/* process carved by Initialize */
    PROCESS	first, last;		/* ptrs to first and last pcbs */
    char	dsptchstack[800];	/* stack for dispatcher use only */
};

#ifndef LWP_KERNEL
extern
#endif
       char lwp_debug;		/* ON = show LWP debugging trace */

/* Action to take on stack overflow. */
#define LWP_SOQUIET	1		/* do nothing */
#define LWP_SOABORT	2		/* abort the program */
#define LWP_SOMESSAGE	3		/* print a message and be quiet */
extern int lwp_overflowAction;

/* Tells if stack size counting is enabled. */
extern int lwp_stackUseEnabled;
#endif __LWP_INCLUDE_