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Forward the simulation time for every event.

This commit is contained in:
steve 2001-05-05 23:51:49 +00:00
parent d45c7c58df
commit e09a14aa44
1 changed files with 41 additions and 7 deletions
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48
vvp/schedule.cc
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@ -17,7 +17,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#if !defined(WINNT)
#ident "$Id: schedule.cc,v 1.7 2001/05/01 01:09:39 steve Exp $"
#ident "$Id: schedule.cc,v 1.8 2001/05/05 23:51:49 steve Exp $"
#endif
# include "schedule.h"
@ -27,6 +27,20 @@
# include <malloc.h>
# include <assert.h>
/*
* The event queue is arranged as a skip list, with the simulation
* time the key to the list. The simulation time is stored in each
* event as the delta time from the previous event so that there is no
* limit to the time values that are supported.
*
* The list is started by the ``list'' variable below. This points to
* the very next event to be executed. Each event, in turn, points to
* the next item in the event queue with the ->next member.
*
* The ->last member points to the last event in the current
* time. That is, all the events to and including the ->last event are
* zero delay from the current event.
*/
struct event_s {
unsigned delay;
@ -96,10 +110,18 @@ bool schedule_finished(void)
return !schedule_runnable;
}
/*
* This function does all the hard work of putting an event into the
* event queue. The event delay is taken from the event structure
* itself, and the structure is placed in the right place in the
* queue.
*/
static void schedule_event_(struct event_s*cur)
{
cur->last = cur;
/* If the list is completely empty, then start the list with
this the only event. */
if (list == 0) {
list = cur;
cur->next = 0;
@ -108,13 +130,21 @@ static void schedule_event_(struct event_s*cur)
struct event_s*idx = list;
if (cur->delay < idx->delay) {
/* If this new event is earlier then even the first
event, then insert it in front. Adjust the delay of
the next event, and set the start to me. */
idx->delay -= cur->delay;
cur->next = idx;
list = cur;
} else {
struct event_s*prev = idx;
/* Look for the first event after the cur
event. Decrease the cur->delay as I go, and use the
skip member to accellerate the search. When I'm done,
prev will point to the even immediately before where
this event goes. */
struct event_s*prev = idx;
while (cur->delay > idx->delay) {
cur->delay -= idx->delay;
prev = idx->last;
@ -128,14 +158,14 @@ static void schedule_event_(struct event_s*cur)
if (cur->delay < idx->delay) {
idx->delay -= cur->delay;
cur->last = cur;
//cur->last = cur;
cur->next = idx;
prev->next = cur;
} else {
assert(cur->delay == idx->delay);
cur->delay = 0;
cur->last = cur;
//cur->last = cur;
cur->next = idx->last->next;
idx->last->next = cur;
idx->last = cur;
@ -205,14 +235,15 @@ void schedule_simulate(void)
struct event_s*cur = list;
list = cur->next;
if (cur->last != cur) {
assert(list);
assert(list->delay == 0);
list->last = cur->last;
} else {
schedule_time += cur->delay;
//printf("TIME: %u\n", schedule_time);
}
schedule_time += cur->delay;
//printf("TIME: %u\n", schedule_time);
switch (cur->type) {
case TYPE_THREAD:
vthread_run(cur->thr);
@ -240,6 +271,9 @@ void schedule_simulate(void)
/*
* $Log: schedule.cc,v $
* Revision 1.8 2001/05/05 23:51:49 steve
* Forward the simulation time for every event.
*
* Revision 1.7 2001/05/01 01:09:39 steve
* Add support for memory objects. (Stephan Boettcher)
*