/* Implement tasking-related runtime actions for CHILL.
   Copyright (C) 1992,1993 Free Software Foundation, Inc.
   Author: Wilfried Moser

This file is part of GNU CC.

GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "rtltypes.h"
#include "rts.h"

extern void __cause_ex1 (char *ex, char *file, int lineno);

EXCEPTION (delayfail);
#define CAUSE_DELAYFAIL     __cause_ex1 ("delayfail", filename, lineno)

EXCEPTION (notyetimplemented);
#define CAUSE_NOTIMPLEMENTED   __cause_ex1 ("notyetimplemeyed", filename, lineno)

/*
 * function __delay_event
 *
 * parameters:
 *     ev_got      pointer to location where to write the event got.
 *     nevents     number of events in list
 *     evptrs      array of event descriptors
 *     priority    specified priority
 *     insloc      pointer to resulting instance location
 *     to          timeout value
 *     filename    filename of caller
 *     lineno      linenumber of caller
 *
 * returns:
 *     int         0 .. success
 *                 1 .. timed out
 *
 * exceptions:
 *     delayfail
 *
 * abstract:
 *     implement the CHILL DELAY and DELAY CASE actions.
 *
 */

int
__delay_event (ev_got, nevents, evptrs, priority, to, insloc, filename, lineno)
     void         **ev_got;
     int            nevents;
     Event_Descr   *evptrs;
     int            priority;
     void          *to;
     INSTANCE      *insloc;
     char          *filename;
     int            lineno;
{
  int             i, already_done = 0;
  Event_Queue    *start_list = 0;
  Event_Queue   **retval = 0;
  Event_Queue    *wrk;
  int		  timed_out = 0;
  
  /* check if all specified event queues have enough space left
     to perform the delay */
  for (i = 0; i < nevents; i++)
    {
      Event_Queue  *e;
      unsigned long cnt = 0;
      int j, have_done = 0;

      if (evptrs[i].maxqueuelength == 0)
	CAUSE_DELAYFAIL;
      else if (evptrs[i].maxqueuelength == (unsigned long)-1L)
	/* infinite length */
	continue;

      /* check if we already have processed this one, that means, this
         event is mentioned more then once */
      for (j = 0; j < i; j++)
        {
          if (evptrs[i].ev == evptrs[j].ev)
	    {
              have_done = 1;
              break;
	    }
        }
      if (have_done)
	continue;
      
      memcpy (&e, evptrs[i].ev, sizeof (Event_Queue *));
      while (e)
	{
	  cnt++;
	  e = e->forward;
	}
      if (cnt >= evptrs[i].maxqueuelength)
	CAUSE_DELAYFAIL;
    }

  for (i = 0; i < nevents; i++)
    {
      /* queue that stuff on each event */
      Event_Queue      *wrk;
      Event_Queue      *ev;
      Event_Queue      *prev_queue_entry = 0;
      Event_Queue      *prev_list_entry;
      int               j, have_done = 0;
      
      /* check for this event already processed */
      for (j = 0; j < i; j++)
	{
          if (evptrs[i].ev == evptrs[j].ev)
	    {
              have_done = 1;
              break;
	    }
	}
      if (have_done)
	continue;

      memcpy (&ev, &evptrs[i].ev, sizeof (Event_Queue *));
      MALLOC (wrk, sizeof (Event_Queue));
      memset (wrk, 0, sizeof (Event_Queue));

      wrk->priority = priority;
      wrk->this = THIS;
      wrk->listhead = evptrs[i].ev;

      /* search for the place to queue this entry in */
      while (ev->forward != 0 && ev->priority >= priority)
	{
	  prev_queue_entry = ev;
	  ev = ev->forward;
	}

      /* ready to put entry into queue */
      if (ev->forward == 0 || prev_queue_entry == 0)
	{
	  /* beginning or end of the list */
	  wrk->forward = ev->forward;
	  ev->forward = wrk;
	}
      else
	{
	  /* this is somewhere in the middle */
	  wrk->forward = prev_queue_entry->forward;
	  prev_queue_entry->forward = wrk;
	}

      /* queue it into list */
      wrk->startlist = start_list;
      if (! start_list)
	{
	  /* we are the first in the list */
	  start_list = wrk;
	  prev_list_entry = wrk;
	  wrk->startlist = start_list;
	}
      else
	{
	  prev_list_entry->chain = wrk;
	  prev_list_entry = wrk;
	}
    }

  /* tell runtime system to delay that process */
  timed_out = __delay_this (wait_event_delay, to, filename, lineno);
  if (timed_out)
    {
      /* we have to remove the entries from the queue's */
      wrk = start_list;
      while (wrk)
        {
	  Event_Queue *tmp = (Event_Queue *)wrk->listhead;
	  
	  while (tmp->forward != wrk)
	    tmp = tmp->forward;
	  tmp->forward = wrk->forward;
	  wrk = wrk->chain;
        }
    }
  
  wrk = start_list;
  while (wrk)
    {
      Event_Queue  *tmp;

      if (wrk->is_continued && ! already_done)
	{
	  already_done = 1;
	  retval = wrk->listhead;
	  if (insloc && !timed_out)
	    {
	      insloc->ptype = wrk->who_continued.ptype;
	      insloc->pcopy = wrk->who_continued.pcopy;
	    }
	}
      tmp = wrk->chain;
      FREE (wrk);
      wrk = tmp;
    }
  if (!timed_out && ev_got)
    *ev_got = (void *)retval;
  return timed_out;
}

/* force function print_event to be linked */
extern void __print_event ();
static EntryPoint pev = __print_event;