1 files changed, 387 insertions, 0 deletions

diff --git a/sim/ppc/events.c b/sim/ppc/events.c
new file mode 100644
index 0000000..8384622
--- /dev/null
+++ b/sim/ppc/events.c
@@ -0,0 +1,387 @@
+/*  This file is part of the program psim.
+
+    Copyright (C) 1994-1998, Andrew Cagney <cagney@highland.com.au>
+
+    This program 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 of the License, or
+    (at your option) any later version.
+
+    This program 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 this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ 
+    */
+
+
+#ifndef _EVENTS_C_
+#define _EVENTS_C_
+
+#include "basics.h"
+#include "events.h"
+
+#include <signal.h>
+
+#if !defined (SIM_EVENTS_POLL_RATE)
+#define SIM_EVENTS_POLL_RATE 0x1000
+#endif
+
+
+
+/* The event queue maintains a single absolute time using two
+   variables.
+   
+   TIME_OF_EVENT: this holds the time at which the next event is ment
+   to occure.  If no next event it will hold the time of the last
+   event.
+
+   TIME_FROM_EVENT: The current distance from TIME_OF_EVENT.  If an
+   event is pending, this will be positive.  If no future event is
+   pending this will be negative.  This variable is decremented once
+   for each iteration of a clock cycle.
+
+   Initially, the clock is started at time one (1) with TIME_OF_EVENT
+   == 0 and TIME_FROM_EVENT == -1.
+
+   Clearly there is a bug in that this code assumes that the absolute
+   time counter will never become greater than 2^62. */
+
+typedef struct _event_entry event_entry;
+struct _event_entry {
+  void *data;
+  event_handler *handler;
+  signed64 time_of_event;  
+  event_entry *next;
+};
+
+struct _event_queue {
+  int processing;
+  event_entry *queue;
+  event_entry *volatile held;
+  event_entry *volatile *volatile held_end;
+  signed64 time_of_event;
+  signed64 time_from_event;
+};
+
+
+STATIC_INLINE_EVENTS\
+(void)
+sim_events_poll (void *data)
+{
+  event_queue *queue = data;
+  /* just re-schedule in 1000 million ticks time */
+  event_queue_schedule (queue, SIM_EVENTS_POLL_RATE, sim_events_poll, queue);
+  sim_io_poll_quit ();
+}
+
+
+INLINE_EVENTS\
+(event_queue *)
+event_queue_create(void)
+{
+  event_queue *new_event_queue = ZALLOC(event_queue);
+
+  new_event_queue->processing = 0;
+  new_event_queue->queue = NULL;
+  new_event_queue->held = NULL;
+  new_event_queue->held_end = &new_event_queue->held;
+
+  /* both times are already zero */
+  return new_event_queue;
+}
+
+
+INLINE_EVENTS\
+(void)
+event_queue_init(event_queue *queue)
+{
+  event_entry *event;
+
+  /* drain the interrupt queue */
+  {
+#if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK)
+    sigset_t old_mask;
+    sigset_t new_mask;
+    sigfillset(&new_mask);
+    /*-LOCK-*/ sigprocmask(SIG_SETMASK, &new_mask, &old_mask);
+#endif
+    event = queue->held;
+    while (event != NULL) {
+      event_entry *dead = event;
+      event = event->next;
+      zfree(dead);
+    }
+    queue->held = NULL;
+    queue->held_end = &queue->held;
+#if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK)
+    /*-UNLOCK-*/ sigprocmask(SIG_SETMASK, &old_mask, NULL);
+#endif
+  }
+
+  /* drain the normal queue */
+  event = queue->queue;
+  while (event != NULL) {
+    event_entry *dead = event;
+    event = event->next;
+    zfree(dead);
+  }
+  queue->queue = NULL;
+    
+  /* wind time back to one */
+  queue->processing = 0;
+  queue->time_of_event = 0;
+  queue->time_from_event = -1;
+
+  /* schedule our initial counter event */
+  event_queue_schedule (queue, 0, sim_events_poll, queue);
+}
+
+INLINE_EVENTS\
+(signed64)
+event_queue_time(event_queue *queue)
+{
+  return queue->time_of_event - queue->time_from_event;
+}
+
+STATIC_INLINE_EVENTS\
+(void)
+update_time_from_event(event_queue *events)
+{
+  signed64 current_time = event_queue_time(events);
+  if (events->queue != NULL) {
+    events->time_from_event = (events->queue->time_of_event - current_time);
+    events->time_of_event = events->queue->time_of_event;
+  }
+  else {
+    events->time_of_event = current_time - 1;
+    events->time_from_event = -1;
+  }
+  ASSERT(current_time == event_queue_time(events));
+  ASSERT((events->time_from_event >= 0) == (events->queue != NULL));
+}
+
+STATIC_INLINE_EVENTS\
+(void)
+insert_event_entry(event_queue *events,
+		   event_entry *new_event,
+		   signed64 delta)
+{
+  event_entry *curr;
+  event_entry **prev;
+  signed64 time_of_event;
+
+  if (delta < 0)
+    error("what is past is past!\n");
+
+  /* compute when the event should occure */
+  time_of_event = event_queue_time(events) + delta;
+
+  /* find the queue insertion point - things are time ordered */
+  prev = &events->queue;
+  curr = events->queue;
+  while (curr != NULL && time_of_event >= curr->time_of_event) {
+    ASSERT(curr->next == NULL
+	   || curr->time_of_event <= curr->next->time_of_event);
+    prev = &curr->next;
+    curr = curr->next;
+  }
+  ASSERT(curr == NULL || time_of_event < curr->time_of_event);
+
+  /* insert it */
+  new_event->next = curr;
+  *prev = new_event;
+  new_event->time_of_event = time_of_event;
+
+  /* adjust the time until the first event */
+  update_time_from_event(events);
+}
+
+INLINE_EVENTS\
+(event_entry_tag)
+event_queue_schedule(event_queue *events,
+		     signed64 delta_time,
+		     event_handler *handler,
+		     void *data)
+{
+  event_entry *new_event = ZALLOC(event_entry);
+  new_event->data = data;
+  new_event->handler = handler;
+  insert_event_entry(events, new_event, delta_time);
+  TRACE(trace_events, ("event scheduled at %ld - tag 0x%lx - time %ld, handler 0x%lx, data 0x%lx\n",
+		       (long)event_queue_time(events),
+		       (long)new_event,
+		       (long)new_event->time_of_event,
+		       (long)new_event->handler,
+		       (long)new_event->data));
+  return (event_entry_tag)new_event;
+}
+
+
+INLINE_EVENTS\
+(event_entry_tag)
+event_queue_schedule_after_signal(event_queue *events,
+				  signed64 delta_time,
+				  event_handler *handler,
+				  void *data)
+{
+  event_entry *new_event = ZALLOC(event_entry);
+
+  new_event->data = data;
+  new_event->handler = handler;
+  new_event->time_of_event = delta_time; /* work it out later */
+  new_event->next = NULL;
+
+  {
+#if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK)
+    sigset_t old_mask;
+    sigset_t new_mask;
+    sigfillset(&new_mask);
+    /*-LOCK-*/ sigprocmask(SIG_SETMASK, &new_mask, &old_mask);
+#endif
+    if (events->held == NULL) {
+      events->held = new_event;
+    }
+    else {
+      *events->held_end = new_event;
+    }
+    events->held_end = &new_event->next;
+#if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK)
+    /*-UNLOCK-*/ sigprocmask(SIG_SETMASK, &old_mask, NULL);
+#endif
+  }
+
+  TRACE(trace_events, ("event scheduled at %ld - tag 0x%lx - time %ld, handler 0x%lx, data 0x%lx\n",
+		       (long)event_queue_time(events),
+		       (long)new_event,
+		       (long)new_event->time_of_event,
+		       (long)new_event->handler,
+		       (long)new_event->data));
+
+  return (event_entry_tag)new_event;
+}
+
+
+INLINE_EVENTS\
+(void)
+event_queue_deschedule(event_queue *events,
+		       event_entry_tag event_to_remove)
+{
+  event_entry *to_remove = (event_entry*)event_to_remove;
+  ASSERT((events->time_from_event >= 0) == (events->queue != NULL));
+  if (event_to_remove != NULL) {
+    event_entry *current;
+    event_entry **ptr_to_current;
+    for (ptr_to_current = &events->queue, current = *ptr_to_current;
+	 current != NULL && current != to_remove;
+	 ptr_to_current = &current->next, current = *ptr_to_current);
+    if (current == to_remove) {
+      *ptr_to_current = current->next;
+      TRACE(trace_events, ("event descheduled at %ld - tag 0x%lx - time %ld, handler 0x%lx, data 0x%lx\n",
+			   (long)event_queue_time(events),
+			   (long)event_to_remove,
+			   (long)current->time_of_event,
+			   (long)current->handler,
+			   (long)current->data));
+      zfree(current);
+      update_time_from_event(events);
+    }
+    else {
+      TRACE(trace_events, ("event descheduled at %ld - tag 0x%lx - not found\n",
+			   (long)event_queue_time(events),
+			   (long)event_to_remove));
+    }
+  }
+  ASSERT((events->time_from_event >= 0) == (events->queue != NULL));
+}
+
+
+
+
+INLINE_EVENTS\
+(int)
+event_queue_tick(event_queue *events)
+{
+  signed64 time_from_event;
+
+  /* we should only be here when the previous tick has been fully processed */
+  ASSERT(!events->processing);
+
+  /* move any events that were queued by any signal handlers onto the
+     real event queue.  BTW: When inlining, having this code here,
+     instead of in event_queue_process() causes GCC to put greater
+     weight on keeping the pointer EVENTS in a register.  This, in
+     turn results in better code being output. */
+  if (events->held != NULL) {
+    event_entry *held_events;
+    event_entry *curr_event;
+
+    {
+#if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK)
+      sigset_t old_mask;
+      sigset_t new_mask;
+      sigfillset(&new_mask);
+      /*-LOCK-*/ sigprocmask(SIG_SETMASK, &new_mask, &old_mask);
+#endif
+      held_events = events->held;
+      events->held = NULL;
+      events->held_end = &events->held;
+#if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK)
+      /*-UNLOCK-*/ sigprocmask(SIG_SETMASK, &old_mask, NULL);
+#endif
+    }
+
+    do {
+      curr_event = held_events;
+      held_events = curr_event->next;
+      insert_event_entry(events, curr_event, curr_event->time_of_event);
+    } while (held_events != NULL);
+  }
+
+  /* advance time, checking to see if we've reached time zero which
+     would indicate the time for the next event has arrived */
+  time_from_event = events->time_from_event;
+  events->time_from_event = time_from_event - 1;
+  return time_from_event == 0;
+}
+
+
+
+INLINE_EVENTS\
+(void)
+event_queue_process(event_queue *events)
+{
+  signed64 event_time = event_queue_time(events);
+
+  ASSERT((events->time_from_event == -1 && events->queue != NULL)
+	 || events->processing); /* something to do */
+
+  /* consume all events for this or earlier times.  Be careful to
+     allow a new event to appear under our feet */
+  events->processing = 1;
+  while (events->queue != NULL
+	 && events->queue->time_of_event <= event_time) {
+    event_entry *to_do = events->queue;
+    event_handler *handler = to_do->handler;
+    void *data = to_do->data;
+    events->queue = to_do->next;
+    TRACE(trace_events, ("event issued at %ld - tag 0x%lx - handler 0x%lx, data 0x%lx\n",
+			 (long)event_time,
+			 (long)to_do,
+			 (long)handler,
+			 (long)data));
+    zfree(to_do);
+    handler(data);
+  }
+  events->processing = 0;
+
+  /* re-caculate time for new events */
+  update_time_from_event(events);
+}
+
+
+#endif /* _EVENTS_C_ */