[haiku-commits] r41776 - haiku/branches/developer/bonefish/signals/src/system/kernel

From: ingo_weinhold@xxxxxx
To: haiku-commits@xxxxxxxxxxxxx
Date: Fri, 27 May 2011 18:52:27 +0200 (CEST)
Author: bonefish
Date: 2011-05-27 18:52:27 +0200 (Fri, 27 May 2011)
New Revision: 41776
Changeset: https://dev.haiku-os.org/changeset/41776

Modified:
   haiku/branches/developer/bonefish/signals/src/system/kernel/timer.cpp
Log:
* A timer::schedule_time value 0 is no longer treated specially. In fact it
  wasn't checked for 0 anywhere anywhere. Now we don't reset it to 0 in
  timer_interrupt() anymore and don't try to avoid 0 for regular schedule times.
* timer_interrupt(): Made periodic timers more precise. The next schedule time
  is no longer computed based on the current time, but on the last schedule
  time. We skip complete ticks, if we lag too much behind.


Modified: haiku/branches/developer/bonefish/signals/src/system/kernel/timer.cpp
===================================================================
--- haiku/branches/developer/bonefish/signals/src/system/kernel/timer.cpp       
2011-05-27 16:09:02 UTC (rev 41775)
+++ haiku/branches/developer/bonefish/signals/src/system/kernel/timer.cpp       
2011-05-27 16:52:27 UTC (rev 41776)
@@ -95,7 +95,6 @@
                cpuData.events = (timer*)event->next;
                cpuData.current_event = event;
                cpuData.current_event_in_progress = 1;
-               event->schedule_time = 0;
 
                release_spinlock(spinlock);
 
@@ -132,13 +131,17 @@
                if ((mode & ~B_TIMER_FLAGS) == B_PERIODIC_TIMER
                        && cpuData.current_event != NULL) {
                        // we need to adjust it and add it back to the list
-                       bigtime_t scheduleTime = system_time() + event->period;
-                       if (scheduleTime == 0) {
-                               // if we wrapped around and happen to hit zero, 
set
-                               // it to one, since zero represents not 
scheduled
-                               scheduleTime = 1;
+                       event->schedule_time += event->period;
+
+                       // If the new schedule time is a full interval or more 
in the past,
+                       // skip ticks.
+                       bigtime_t now =  system_time();
+                       if (now >= event->schedule_time + event->period) {
+                               // pick the closest tick in the past
+                               event->schedule_time = now
+                                       - (now - event->schedule_time) % 
event->period;
                        }
-                       event->schedule_time = (int64)scheduleTime;
+
                        add_event_to_list(event, &cpuData.events);
                }
 
@@ -177,8 +180,6 @@
        scheduleTime = period;
        if ((flags & ~B_TIMER_FLAGS) != B_ONE_SHOT_ABSOLUTE_TIMER)
                scheduleTime += currentTime;
-       if (scheduleTime == 0)
-               scheduleTime = 1;
 
        event->schedule_time = (int64)scheduleTime;
        event->period = period;
[haiku-commits] r41776 - haiku/branches/developer/bonefish/signals/src/system/kernel

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