[haiku-commits] r41785 - in haiku/branches/developer/bonefish/signals: headers/private/kernel src/system/kernel

From: ingo_weinhold@xxxxxx
To: haiku-commits@xxxxxxxxxxxxx
Date: Sat, 28 May 2011 01:34:37 +0200 (CEST)
Author: bonefish
Date: 2011-05-28 01:34:37 +0200 (Sat, 28 May 2011)
New Revision: 41785
Changeset: https://dev.haiku-os.org/changeset/41785

Modified:
   haiku/branches/developer/bonefish/signals/headers/private/kernel/timer.h
   haiku/branches/developer/bonefish/signals/src/system/kernel/timer.cpp
Log:
Introduced flag B_TIMER_USE_TIMER_STRUCT_TIMES for add_timer(). When specified
the function ignores the period parameter and instead uses the timer::period and
timer::schedule_time fields. This allows to add a periodic timer with a start
time independent from the interval.


Modified: 
haiku/branches/developer/bonefish/signals/headers/private/kernel/timer.h
===================================================================
--- haiku/branches/developer/bonefish/signals/headers/private/kernel/timer.h    
2011-05-27 22:45:43 UTC (rev 41784)
+++ haiku/branches/developer/bonefish/signals/headers/private/kernel/timer.h    
2011-05-27 23:34:37 UTC (rev 41785)
@@ -15,8 +15,15 @@
 
 struct kernel_args;
 
+#define B_TIMER_USE_TIMER_STRUCT_TIMES 0x4000
+       // For add_timer(): Use the timer::schedule_time (absolute time) and
+       // timer::period values instead of the period parameter.
 #define B_TIMER_ACQUIRE_SCHEDULER_LOCK 0x8000
-#define B_TIMER_FLAGS                                  
B_TIMER_ACQUIRE_SCHEDULER_LOCK
+       // The timer hook is invoked with the scheduler lock held. When invoking
+       // cancel_timer() with the scheduler lock held, too, this helps to avoid
+       // race conditions.
+#define B_TIMER_FLAGS  \
+       (B_TIMER_USE_TIMER_STRUCT_TIMES | B_TIMER_ACQUIRE_SCHEDULER_LOCK)
 
 /* Timer info structure */
 struct timer_info {

Modified: haiku/branches/developer/bonefish/signals/src/system/kernel/timer.cpp
===================================================================
--- haiku/branches/developer/bonefish/signals/src/system/kernel/timer.cpp       
2011-05-27 22:45:43 UTC (rev 41784)
+++ haiku/branches/developer/bonefish/signals/src/system/kernel/timer.cpp       
2011-05-27 23:34:37 UTC (rev 41785)
@@ -168,7 +168,6 @@
 status_t
 add_timer(timer* event, timer_hook hook, bigtime_t period, int32 flags)
 {
-       bigtime_t scheduleTime;
        bigtime_t currentTime = system_time();
        cpu_status state;
 
@@ -177,12 +176,19 @@
 
        TRACE(("add_timer: event %p\n", event));
 
-       scheduleTime = period;
-       if ((flags & ~B_TIMER_FLAGS) != B_ONE_SHOT_ABSOLUTE_TIMER)
-               scheduleTime += currentTime;
+       // compute the schedule time
+       bigtime_t scheduleTime;
+       if ((flags & B_TIMER_USE_TIMER_STRUCT_TIMES) != 0) {
+               scheduleTime = event->schedule_time;
+               period = event->period;
+       } else {
+               scheduleTime = period;
+               if ((flags & ~B_TIMER_FLAGS) != B_ONE_SHOT_ABSOLUTE_TIMER)
+                       scheduleTime += currentTime;
+               event->schedule_time = (int64)scheduleTime;
+               event->period = period;
+       }
 
-       event->schedule_time = (int64)scheduleTime;
-       event->period = period;
        event->hook = hook;
        event->flags = flags;
[haiku-commits] r41785 - in haiku/branches/developer/bonefish/signals: headers/private/kernel src/system/kernel

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