"I am a person who works hard and plays hard."

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Yuan Wei
Second Year Graduate Student Department of Computer Science
University of Virginia Charlottesville, VA 22903
Email: yw3f@cs.virginia.edu

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Source Code Analysis
         

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eventq.c

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/*
 * eventq.c - event queue manager routines
 *
 * This file is a part of the SimpleScalar tool suite written by
 * Todd M. Austin as a part of the Multiscalar Research Project.
 *  
 * The tool suite is currently maintained by Doug Burger and Todd M. Austin.
 * 
 * Copyright (C) 1994, 1995, 1996, 1997, 1998 by Todd M. Austin
 *
 * This source file is distributed "as is" in the hope that it will be
 * useful.  The tool set comes with no warranty, and no author or
 * distributor accepts any responsibility for the consequences of its
 * use. 
 * 
 * Everyone is granted permission to copy, modify and redistribute
 * this tool set under the following conditions:
 * 
 *    This source code is distributed for non-commercial use only. 
 *    Please contact the maintainer for restrictions applying to 
 *    commercial use.
 *
 *    Permission is granted to anyone to make or distribute copies
 *    of this source code, either as received or modified, in any
 *    medium, provided that all copyright notices, permission and
 *    nonwarranty notices are preserved, and that the distributor
 *    grants the recipient permission for further redistribution as
 *    permitted by this document.
 *
 *    Permission is granted to distribute this file in compiled
 *    or executable form under the same conditions that apply for
 *    source code, provided that either:
 *
 *    A. it is accompanied by the corresponding machine-readable
 *       source code,
 *    B. it is accompanied by a written offer, with no time limit,
 *       to give anyone a machine-readable copy of the corresponding
 *       source code in return for reimbursement of the cost of
 *       distribution.  This written offer must permit verbatim
 *       duplication by anyone, or
 *    C. it is distributed by someone who received only the
 *       executable form, and is accompanied by a copy of the
 *       written offer of source code that they received concurrently.
 *
 * In other words, you are welcome to use, share and improve this
 * source file.  You are forbidden to forbid anyone else to use, share
 * and improve what you give them.
 *
 * INTERNET: dburger@cs.wisc.edu
 * US Mail:  1210 W. Dayton Street, Madison, WI 53706
 *
 * $Id: eventq.c,v 1.1.1.1 2000/05/26 15:18:57 taustin Exp $
 *
 * $Log: eventq.c,v $
 * Revision 1.1.1.1  2000/05/26 15:18:57  taustin
 * SimpleScalar Tool Set
 *
 *
 * Revision 1.4  1998/08/27 08:28:03  taustin
 * implemented host interface description in host.h
 * added target interface support
 *
 * Revision 1.3  1997/03/11  01:12:18  taustin
 * updated copyright
 *
 * Revision 1.1  1996/12/05  18:52:32  taustin
 * Initial revision
 *
 *
 */

#include <stdio.h>
#include <stdlib.h>

#include "host.h"
#include "misc.h"
#include "machine.h"
#include "eventq.h"

int eventq_max_events;
int eventq_event_count;
struct eventq_desc *eventq_pending;
struct eventq_desc *eventq_free;

static EVENTQ_ID_TYPE next_ID = 1;

void
eventq_init(int max_events)
{
  eventq_max_events = max_events;
  eventq_event_count = 0;
  eventq_pending = NULL;
  eventq_free = NULL;
}

#define __QUEUE_EVENT(WHEN, ID, ACTION)                                 \
  struct eventq_desc *prev, *ev, *new;                                  \
  /* get a free event descriptor */                                     \
  if (!eventq_free)                                                     \
    {                                                                   \
      if (eventq_max_events && eventq_event_count >= eventq_max_events) \
        panic("too many events");                                       \
      eventq_free = calloc(1, sizeof(struct eventq_desc));              \
    }                                                                   \
  new = eventq_free;                                                    \
  eventq_free = eventq_free->next;                                      \
  /* plug in event data */                                              \
  new->when = (WHEN); (ID) = new->id = next_ID++; ACTION;               \
  /* locate insertion point */                                          \
  for (prev=NULL,ev=eventq_pending;                                     \
       ev && ev->when < when;                                           \
       prev=ev, ev=ev->next);                                           \
  /* insert new record */                                               \
  if (prev)                                                             \
    {                                                                   \
      /* insert middle or end */                                        \
      new->next = prev->next;                                           \
      prev->next = new;                                                 \
    }                                                                   \
  else                                                                  \
    {                                                                   \
      /* insert beginning */                                            \
      new->next = eventq_pending;                                       \
      eventq_pending = new;                                             \
    }

EVENTQ_ID_TYPE
eventq_queue_setbit(SS_TIME_TYPE when,
                    BITMAP_ENT_TYPE *bmap, int sz, int bitnum)
{
  EVENTQ_ID_TYPE id;
  __QUEUE_EVENT(when, id,                                               \
                new->action = EventSetBit; new->data.bit.bmap = bmap;   \
                new->data.bit.sz = sz; new->data.bit.bitnum = bitnum);
  return id;
}

EVENTQ_ID_TYPE
eventq_queue_clearbit(SS_TIME_TYPE when,
                      BITMAP_ENT_TYPE *bmap, int sz, int bitnum)
{
  EVENTQ_ID_TYPE id;
  __QUEUE_EVENT(when, id,                                               \
                new->action = EventClearBit; new->data.bit.bmap = bmap; \
                new->data.bit.sz = sz; new->data.bit.bitnum = bitnum);
  return id;
}

EVENTQ_ID_TYPE
eventq_queue_setflag(SS_TIME_TYPE when, int *pflag, int value)
{
  EVENTQ_ID_TYPE id;
  __QUEUE_EVENT(when, id,                                               \
                new->action = EventSetFlag;                             \
                new->data.flag.pflag = pflag; new->data.flag.value = value);
  return id;
}

EVENTQ_ID_TYPE
eventq_queue_addop(SS_TIME_TYPE when, int *summand, int addend)
{
  EVENTQ_ID_TYPE id;
  __QUEUE_EVENT(when, id,                                               \
                new->action = EventAddOp;                               \
                new->data.addop.summand = summand;                      \
                new->data.addop.addend = addend);
  return id;
}

EVENTQ_ID_TYPE
eventq_queue_callback(SS_TIME_TYPE when,
                      void (*fn)(SS_TIME_TYPE time, int arg), int arg)
{
  EVENTQ_ID_TYPE id;
  __QUEUE_EVENT(when, id,                                               \
                new->action = EventCallback; new->data.callback.fn = fn;\
                new->data.callback.arg = arg);
  return id;
}

#define EXECUTE_ACTION(ev, now)                                         \
  /* execute action */                                                  \
  switch (ev->action) {                                                 \
  case EventSetBit:                                                     \
    BITMAP_SET(ev->data.bit.bmap, ev->data.bit.sz, ev->data.bit.bitnum);\
    break;                                                              \
  case EventClearBit:                                                   \
    BITMAP_CLEAR(ev->data.bit.bmap, ev->data.bit.sz, ev->data.bit.bitnum);\
    break;                                                              \
  case EventSetFlag:                                                    \
    *ev->data.flag.pflag = ev->data.flag.value;                         \
    break;                                                              \
  case EventAddOp:                                                      \
    *ev->data.addop.summand += ev->data.addop.addend;                   \
    break;                                                              \
  case EventCallback:                                                   \
    (*ev->data.callback.fn)(now, ev->data.callback.arg);                \
    break;                                                              \
  default:                                                              \
    panic("bogus event action");                                        \
  }

/* execute an event immediately, returns non-zero if the event was
   located an deleted */
int
eventq_execute(EVENTQ_ID_TYPE id)
{
  struct eventq_desc *prev, *ev;

  for (prev=NULL,ev=eventq_pending; ev; prev=ev,ev=ev->next)
    {
      if (ev->id == id)
        {
          if (prev)
            {
              /* middle of end of list */
              prev->next = ev->next;
            }
          else /* !prev */
            {
              /* beginning of list */
              eventq_pending = ev->next;
            }

          /* handle action, now is munged */
          EXECUTE_ACTION(ev, 0);

          /* put event on free list */
          ev->next = eventq_free;
          eventq_free = ev;

          /* return success */
          return TRUE;
        }
    }
  /* not found */
  return FALSE;
}

/* remove an event from the eventq, action is never performed, returns
   non-zero if the event was located an deleted */
int
eventq_remove(EVENTQ_ID_TYPE id)
{
  struct eventq_desc *prev, *ev;

  for (prev=NULL,ev=eventq_pending; ev; prev=ev,ev=ev->next)
    {
      if (ev->id == id)
        {
          if (prev)
            {
              /* middle of end of list */
              prev->next = ev->next;
            }
          else /* !prev */
            {
              /* beginning of list */
              eventq_pending = ev->next;
            }

          /* put event on free list */
          ev->next = eventq_free;
          eventq_free = ev;

          /* return success */
          return TRUE;
        }
    }
  /* not found */
  return FALSE;
}

void
eventq_service_events(SS_TIME_TYPE now)
{
  while (eventq_pending && eventq_pending->when <= now)
    {
      struct eventq_desc *ev = eventq_pending;

      /* handle action */
      EXECUTE_ACTION(ev, now);

      /* return the event record to the free list */
      eventq_pending = ev->next;
      ev->next = eventq_free;
      eventq_free = ev;
  }
}

void
eventq_dump(FILE *stream)
{
  struct eventq_desc *ev;

  if (!stream)
    stream = stderr;

  fprintf(stream, "Pending Events: ");
  for (ev=eventq_pending; ev; ev=ev->next)
    {
      fprintf(stream, "@ %.0f:%s:",
              (double)ev->when,
              ev->action == EventSetBit ? "set bit"
              : ev->action == EventClearBit ? "clear bit"
              : ev->action == EventSetFlag ? "set flag"
              : ev->action == EventAddOp ? "add operation"
              : ev->action == EventCallback ? "call back"
              : (abort(), ""));
      switch (ev->action) {
      case EventSetBit:
      case EventClearBit:
        fprintf(stream, "0x%p, %d, %d",
                ev->data.bit.bmap, ev->data.bit.sz, ev->data.bit.bitnum);
        break;
      case EventSetFlag:
        fprintf(stream, "0x%p, %d", ev->data.flag.pflag, ev->data.flag.value);
        break;
      case EventAddOp:
        fprintf(stream, "0x%p, %d",
                ev->data.addop.summand, ev->data.addop.addend);
        break;
      case EventCallback:
        fprintf(stream, "0x%p, %d",
                ev->data.callback.fn, ev->data.callback.arg);
        break;
      default:
        panic("bogus event action");
      }
      fprintf(stream, " ");
    }
}

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