score: Replace watchdog handler implementation

Use a red-black tree instead of delta chains.

Close #2344.
Update #2554.
Update #2555.
Close #2606.

14 files changed, 157 insertions, 441 deletions

diff --git a/cpukit/score/src/condition.c b/cpukit/score/src/condition.c
index 22c2a9b97c..420681955a 100644
--- a/cpukit/score/src/condition.c
+++ b/cpukit/score/src/condition.c
@@ -282,7 +282,7 @@ static int _Condition_Wake( struct _Condition_Control *_condition, int count )
 
       next = _Chain_Next( node );
       thread = THREAD_CHAIN_NODE_TO_THREAD( node );
-      _Watchdog_Remove_ticks( &thread->Timer );
+      _Thread_Timer_remove( thread );
       _Thread_Unblock( thread );
 
       node = next;
diff --git a/cpukit/score/src/coretodset.c b/cpukit/score/src/coretodset.c
index 3230179414..b2efc07115 100644
--- a/cpukit/score/src/coretodset.c
+++ b/cpukit/score/src/coretodset.c
@@ -26,30 +26,26 @@ void _TOD_Set_with_timestamp(
   const Timestamp_Control *tod_as_timestamp
 )
 {
-  struct timespec ts;
-  uint32_t nanoseconds;
-  Watchdog_Interval seconds_next;
-  Watchdog_Interval seconds_now;
-  Watchdog_Header *header;
+  struct timespec tod_as_timespec;
+  uint64_t        tod_as_ticks;
+  uint32_t        cpu_count;
+  uint32_t        cpu_index;
 
-  _Timestamp_To_timespec( tod_as_timestamp, &ts );
-  nanoseconds = ts.tv_nsec;
-  seconds_next = ts.tv_sec;
+  _Timestamp_To_timespec( tod_as_timestamp, &tod_as_timespec );
 
   _Thread_Disable_dispatch();
 
-  seconds_now = _TOD_Seconds_since_epoch();
+  _Timecounter_Set_clock( &tod_as_timespec );
 
-  _Timecounter_Set_clock( &ts );
+  tod_as_ticks = _Watchdog_Ticks_from_timespec( &tod_as_timespec );
+  cpu_count = _SMP_Get_processor_count();
 
-  header = &_Watchdog_Seconds_header;
+  for ( cpu_index = 0 ; cpu_index < cpu_count ; ++cpu_index ) {
+    Per_CPU_Control *cpu = _Per_CPU_Get_by_index( cpu_index );
 
-  if ( seconds_next < seconds_now )
-    _Watchdog_Adjust_backward( header, seconds_now - seconds_next );
-  else
-    _Watchdog_Adjust_forward( header, seconds_next - seconds_now );
+    _Watchdog_Per_CPU_tickle_absolute( cpu, tod_as_ticks );
+  }
 
-  _TOD.seconds_trigger = nanoseconds;
   _TOD.is_set = true;
 
   _Thread_Enable_dispatch();
diff --git a/cpukit/score/src/coretodtickle.c b/cpukit/score/src/coretodtickle.c
deleted file mode 100644
index 3d7c71e1c1..0000000000
--- a/cpukit/score/src/coretodtickle.c
+++ /dev/null
@@ -1,36 +0,0 @@
-/**
- * @file
- *
- * @brief Increments time of day at each clock tick
- *
- * @ingroup ScoreTOD
- */
-
-/*  COPYRIGHT (c) 1989-2014.
- *  On-Line Applications Research Corporation (OAR).
- *
- *  The license and distribution terms for this file may be
- *  found in the file LICENSE in this distribution or at
- *  http://www.rtems.org/license/LICENSE.
- */
-
-#if HAVE_CONFIG_H
-#include "config.h"
-#endif
-
-#include <rtems/score/todimpl.h>
-#include <rtems/score/watchdogimpl.h>
-#include <rtems/config.h>
-
-void _TOD_Tickle_ticks( void )
-{
-  /* Update the counter of ticks since boot */
-  _Watchdog_Ticks_since_boot += 1;
-
-  _TOD.seconds_trigger += rtems_configuration_get_nanoseconds_per_tick();
-  if ( _TOD.seconds_trigger >= 1000000000UL ) {
-    _TOD.seconds_trigger -= 1000000000UL;
-    _Watchdog_Tickle_seconds();
-  }
-}
-
diff --git a/cpukit/score/src/kern_tc.c b/cpukit/score/src/kern_tc.c
index e56c292ea3..316a16f05b 100644
--- a/cpukit/score/src/kern_tc.c
+++ b/cpukit/score/src/kern_tc.c
@@ -1971,6 +1971,7 @@ tc_ticktock(int cnt)
 		return;
 	count = 0;
 #else /* __rtems__ */
+#include <rtems/score/smp.h>
 void
 _Timecounter_Tick(void)
 {
@@ -2021,7 +2022,7 @@ _Timecounter_Tick_simple(uint32_t delta, uint32_t offset,
 
 	_Timecounter_Release(lock_context);
 
-	_Watchdog_Tick(_Per_CPU_Get());
+	_Watchdog_Tick(_Per_CPU_Get_snapshot());
 }
 #endif /* __rtems__ */
 
diff --git a/cpukit/score/src/smp.c b/cpukit/score/src/smp.c
index 9d9507d1b9..85256b044c 100644
--- a/cpukit/score/src/smp.c
+++ b/cpukit/score/src/smp.c
@@ -87,6 +87,7 @@ void _SMP_Handler_initialize( void )
   for ( cpu_index = 0 ; cpu_index < cpu_max; ++cpu_index ) {
     Per_CPU_Control *cpu = _Per_CPU_Get_by_index( cpu_index );
 
+    _ISR_lock_Initialize( &cpu->Watchdog.Lock, "Watchdog" );
     _SMP_ticket_lock_Initialize( &cpu->Lock );
     _SMP_lock_Stats_initialize( &cpu->Lock_stats, "Per-CPU" );
   }
diff --git a/cpukit/score/src/threadinitialize.c b/cpukit/score/src/threadinitialize.c
index a49406f160..0b5fd3a125 100644
--- a/cpukit/score/src/threadinitialize.c
+++ b/cpukit/score/src/threadinitialize.c
@@ -160,6 +160,10 @@ bool _Thread_Initialize(
   the_thread->Start.budget_algorithm = budget_algorithm;
   the_thread->Start.budget_callout   = budget_callout;
 
+  _ISR_lock_Initialize( &the_thread->Timer.Lock, "Thread Timer" );
+  the_thread->Timer.header = &cpu->Watchdog.Header[ PER_CPU_WATCHDOG_RELATIVE ];
+  _Watchdog_Preinitialize( &the_thread->Timer.Watchdog, cpu );
+
   switch ( budget_algorithm ) {
     case THREAD_CPU_BUDGET_ALGORITHM_NONE:
     case THREAD_CPU_BUDGET_ALGORITHM_RESET_TIMESLICE:
diff --git a/cpukit/score/src/threadqenqueue.c b/cpukit/score/src/threadqenqueue.c
index 960783c74c..07618fc800 100644
--- a/cpukit/score/src/threadqenqueue.c
+++ b/cpukit/score/src/threadqenqueue.c
@@ -35,7 +35,7 @@
 
 static void _Thread_queue_Unblock( Thread_Control *the_thread )
 {
-  _Watchdog_Remove_ticks( &the_thread->Timer );
+  _Thread_Timer_remove( the_thread );
   _Thread_Unblock( the_thread );
 
 #if defined(RTEMS_MULTIPROCESSING)
@@ -84,8 +84,12 @@ void _Thread_queue_Enqueue_critical(
    */
   if ( timeout != WATCHDOG_NO_TIMEOUT ) {
     _Thread_Wait_set_timeout_code( the_thread, timeout_code );
-    _Watchdog_Initialize( &the_thread->Timer, _Thread_Timeout, 0, the_thread );
-    _Watchdog_Insert_ticks( &the_thread->Timer, timeout );
+    _Thread_Timer_insert_relative(
+      the_thread,
+      cpu_self,
+      _Thread_Timeout,
+      timeout
+    );
   }
 
   success = _Thread_Wait_flags_try_change(
diff --git a/cpukit/score/src/threadrestart.c b/cpukit/score/src/threadrestart.c
index 03b1fba8ff..d366f97a0f 100644
--- a/cpukit/score/src/threadrestart.c
+++ b/cpukit/score/src/threadrestart.c
@@ -84,7 +84,7 @@ static void _Thread_Make_zombie( Thread_Control *the_thread )
 
   _Thread_Set_state( the_thread, STATES_ZOMBIE );
   _Thread_queue_Extract_with_proxy( the_thread );
-  _Watchdog_Remove_ticks( &the_thread->Timer );
+  _Thread_Timer_remove( the_thread );
 
   _ISR_lock_ISR_disable_and_acquire( &zombies->Lock, &lock_context );
   _Chain_Append_unprotected( &zombies->Chain, &the_thread->Object.Node );
@@ -191,7 +191,9 @@ static void _Thread_Start_life_change_for_executing(
   Thread_Control *executing
 )
 {
-  _Assert( executing->Timer.state == WATCHDOG_INACTIVE );
+  _Assert(
+    _Watchdog_Get_state( &executing->Timer.Watchdog ) == WATCHDOG_INACTIVE
+  );
   _Assert(
     executing->current_state == STATES_READY
       || executing->current_state == STATES_SUSPENDED
@@ -246,7 +248,9 @@ void _Thread_Life_action_handler(
       /* Someone deleted us in the mean-time */
       _Thread_Start_life_change_for_executing( executing );
     } else {
-      _Assert( executing->Timer.state == WATCHDOG_INACTIVE );
+      _Assert(
+        _Watchdog_Get_state( &executing->Timer.Watchdog ) == WATCHDOG_INACTIVE
+      );
       _Assert(
         executing->current_state == STATES_READY
           || executing->current_state == STATES_SUSPENDED
@@ -274,7 +278,7 @@ static void _Thread_Start_life_change(
 
   _Thread_Set_state( the_thread, STATES_RESTARTING );
   _Thread_queue_Extract_with_proxy( the_thread );
-  _Watchdog_Remove_ticks( &the_thread->Timer );
+  _Thread_Timer_remove( the_thread );
   _Thread_Change_priority(
     the_thread,
     priority,
diff --git a/cpukit/score/src/threadtimeout.c b/cpukit/score/src/threadtimeout.c
index 8ecaebde06..59f6bd97f0 100644
--- a/cpukit/score/src/threadtimeout.c
+++ b/cpukit/score/src/threadtimeout.c
@@ -33,7 +33,7 @@ static void _Thread_Do_timeout( Thread_Control *the_thread )
   _Thread_Lock_restore_default( the_thread );
 }
 
-void _Thread_Timeout( Objects_Id id, void *arg )
+void _Thread_Timeout( Watchdog_Control *watchdog )
 {
   Thread_Control    *the_thread;
   void              *thread_lock;
@@ -41,7 +41,7 @@ void _Thread_Timeout( Objects_Id id, void *arg )
   Thread_Wait_flags  wait_flags;
   bool               unblock;
 
-  the_thread = arg;
+  the_thread = RTEMS_CONTAINER_OF( watchdog, Thread_Control, Timer.Watchdog );
   thread_lock = _Thread_Lock_acquire( the_thread, &lock_context );
 
   wait_flags = _Thread_Wait_flags_get( the_thread );
diff --git a/cpukit/score/src/watchdog.c b/cpukit/score/src/watchdog.c
deleted file mode 100644
index 8d172fb8f9..0000000000
--- a/cpukit/score/src/watchdog.c
+++ /dev/null
@@ -1,36 +0,0 @@
-/**
- *  @file
- *
- *  @brief Watchdog Handler Initialization
- *  @ingroup ScoreWatchdog
- */
-
-/*
- *  Watchdog Handler
- *
- *
- *  COPYRIGHT (c) 1989-1999.
- *  On-Line Applications Research Corporation (OAR).
- *
- *  The license and distribution terms for this file may be
- *  found in the file LICENSE in this distribution or at
- *  http://www.rtems.org/license/LICENSE.
- */
-
-#if HAVE_CONFIG_H
-#include "config.h"
-#endif
-
-#include <rtems/score/watchdogimpl.h>
-
-Watchdog_Header _Watchdog_Ticks_header;
-
-Watchdog_Header _Watchdog_Seconds_header;
-
-void _Watchdog_Handler_initialization( void )
-{
-  _Watchdog_Ticks_since_boot = 0;
-
-  _Watchdog_Header_initialize( &_Watchdog_Ticks_header );
-  _Watchdog_Header_initialize( &_Watchdog_Seconds_header );
-}
diff --git a/cpukit/score/src/watchdogadjust.c b/cpukit/score/src/watchdogadjust.c
deleted file mode 100644
index 32b5f7990e..0000000000
--- a/cpukit/score/src/watchdogadjust.c
+++ /dev/null
@@ -1,80 +0,0 @@
-/**
- *  @file
- *
- *  @brief Watchdog Adjust
- *  @ingroup ScoreWatchdog
- */
-
-/*
- *  COPYRIGHT (c) 1989-1999.
- *  On-Line Applications Research Corporation (OAR).
- *
- *  The license and distribution terms for this file may be
- *  found in the file LICENSE in this distribution or at
- *  http://www.rtems.org/license/LICENSE.
- */
-
-#if HAVE_CONFIG_H
-#include "config.h"
-#endif
-
-#include <rtems/score/watchdogimpl.h>
-
-void _Watchdog_Adjust_backward_locked(
-  Watchdog_Header   *header,
-  Watchdog_Interval  units
-)
-{
-  if ( !_Watchdog_Is_empty( header ) ) {
-     _Watchdog_First( header )->delta_interval += units;
-  }
-}
-
-void _Watchdog_Adjust_backward(
-  Watchdog_Header   *header,
-  Watchdog_Interval  units
-)
-{
-  ISR_lock_Context lock_context;
-
-  _Watchdog_Acquire( header, &lock_context );
-  _Watchdog_Adjust_backward_locked( header, units );
-  _Watchdog_Release( header, &lock_context );
-}
-
-void _Watchdog_Adjust_forward_locked(
-  Watchdog_Header   *header,
-  Watchdog_Interval  units,
-  ISR_lock_Context  *lock_context
-)
-{
-  while ( !_Watchdog_Is_empty( header ) && units > 0 ) {
-    Watchdog_Control *first = _Watchdog_First( header );
-
-    if ( units < first->delta_interval ) {
-      first->delta_interval -= units;
-      break;
-    } else {
-      units -= first->delta_interval;
-      first->delta_interval = 1;
-
-      _Watchdog_Release( header, lock_context );
-
-      _Watchdog_Tickle( header );
-
-      _Watchdog_Acquire( header, lock_context );
-    }
-  }
-}
-
-void _Watchdog_Adjust_forward(
-  Watchdog_Header   *header,
-  Watchdog_Interval  units
-)
-{
-  ISR_lock_Context lock_context;
-
-  _Watchdog_Acquire( header, &lock_context );
-  _Watchdog_Adjust_forward_locked( header, units, &lock_context );
-  _Watchdog_Release( header, &lock_context );
-}
diff --git a/cpukit/score/src/watchdoginsert.c b/cpukit/score/src/watchdoginsert.c
index db15f55b0d..22fc7a5f76 100644
--- a/cpukit/score/src/watchdoginsert.c
+++ b/cpukit/score/src/watchdoginsert.c
@@ -1,17 +1,22 @@
 /**
- * @file 
+ * @file
  *
  * @brief Watchdog Insert
  * @ingroup ScoreWatchdog
  */
- 
+
 /*
- *  COPYRIGHT (c) 1989-1999.
- *  On-Line Applications Research Corporation (OAR).
+ * Copyright (c) 2016 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
  *
- *  The license and distribution terms for this file may be
- *  found in the file LICENSE in this distribution or at
- *  http://www.rtems.org/license/LICENSE.
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
  */
 
 #if HAVE_CONFIG_H
@@ -20,106 +25,41 @@
 
 #include <rtems/score/watchdogimpl.h>
 
-static void _Watchdog_Insert_fixup(
-  Watchdog_Header   *header,
-  Watchdog_Control  *the_watchdog,
-  Watchdog_Interval  delta,
-  Watchdog_Control  *next_watchdog,
-  Watchdog_Interval  delta_next
-)
-{
-  const Chain_Node *iterator_tail;
-  Chain_Node       *iterator_node;
-
-  next_watchdog->delta_interval = delta_next - delta;
-
-  iterator_node = _Chain_First( &header->Iterators );
-  iterator_tail = _Chain_Immutable_tail( &header->Iterators );
-
-  while ( iterator_node != iterator_tail ) {
-    Watchdog_Iterator *iterator;
-
-    iterator = (Watchdog_Iterator *) iterator_node;
-
-    if ( iterator->current == &next_watchdog->Node ) {
-      iterator->current = &the_watchdog->Node;
-    }
-
-    iterator_node = _Chain_Next( iterator_node );
-  }
-}
-
-void _Watchdog_Insert_locked(
+void _Watchdog_Insert(
   Watchdog_Header  *header,
   Watchdog_Control *the_watchdog,
-  ISR_lock_Context *lock_context
+  uint64_t          expire
 )
 {
-  if ( the_watchdog->state == WATCHDOG_INACTIVE ) {
-    Watchdog_Iterator  iterator;
-    Chain_Node        *current;
-    Chain_Node        *next;
-    Watchdog_Interval  delta;
-
-    the_watchdog->state = WATCHDOG_BEING_INSERTED;
-
-    _Chain_Append_unprotected( &header->Iterators, &iterator.Node );
-
-    delta = the_watchdog->initial;
-    current = _Chain_Head( &header->Watchdogs );
+  RBTree_Node **link;
+  RBTree_Node  *parent;
+  RBTree_Node  *old_first;
+  RBTree_Node  *new_first;
 
-    while (
-      ( next = _Chain_Next( current ) ) != _Chain_Tail( &header->Watchdogs )
-    ) {
-      Watchdog_Control  *next_watchdog;
-      Watchdog_Interval  delta_next;
+  _Assert( _Watchdog_Get_state( the_watchdog ) == WATCHDOG_INACTIVE );
 
-      next_watchdog = (Watchdog_Control *) next;
-      delta_next = next_watchdog->delta_interval;
+  link = _RBTree_Root_reference( &header->Watchdogs );
+  parent = NULL;
+  old_first = header->first;
+  new_first = &the_watchdog->Node.RBTree;
 
-      if ( delta < delta_next ) {
-        _Watchdog_Insert_fixup(
-          header,
-          the_watchdog,
-          delta,
-          next_watchdog,
-          delta_next
-        );
-        break;
-      }
+  the_watchdog->expire = expire;
 
-      iterator.delta_interval = delta - delta_next;
-      iterator.current = next;
+  while ( *link != NULL ) {
+    Watchdog_Control *parent_watchdog;
 
-      _Watchdog_Flash( header, lock_context );
+    parent = *link;
+    parent_watchdog = (Watchdog_Control *) parent;
 
-      if ( the_watchdog->state != WATCHDOG_BEING_INSERTED ) {
-        goto abort_insert;
-      }
-
-      delta = iterator.delta_interval;
-      current = iterator.current;
+    if ( expire < parent_watchdog->expire ) {
+      link = _RBTree_Left_reference( parent );
+    } else {
+      link = _RBTree_Right_reference( parent );
+      new_first = old_first;
     }
-
-    the_watchdog->delta_interval = delta;
-    the_watchdog->start_time = _Watchdog_Ticks_since_boot;
-    _Watchdog_Activate( the_watchdog );
-    _Chain_Insert_unprotected( current, &the_watchdog->Node );
-
-abort_insert:
-
-    _Chain_Extract_unprotected( &iterator.Node );
   }
-}
-
-void _Watchdog_Insert(
-  Watchdog_Header  *header,
-  Watchdog_Control *the_watchdog
-)
-{
-  ISR_lock_Context lock_context;
 
-  _Watchdog_Acquire( header, &lock_context );
-  _Watchdog_Insert_locked( header, the_watchdog, &lock_context );
-  _Watchdog_Release( header, &lock_context );
+  header->first = new_first;
+  _RBTree_Add_child( &the_watchdog->Node.RBTree, parent, link );
+  _RBTree_Insert_color( &header->Watchdogs, &the_watchdog->Node.RBTree );
 }
diff --git a/cpukit/score/src/watchdogremove.c b/cpukit/score/src/watchdogremove.c
index 2aa72a4e75..2605a67fa4 100644
--- a/cpukit/score/src/watchdogremove.c
+++ b/cpukit/score/src/watchdogremove.c
@@ -1,17 +1,22 @@
 /**
  * @file
  *
- * @brief Remove Watchdog from List
+ * @brief Remove Watchdog
  * @ingroup ScoreWatchdog
  */
 
 /*
- *  COPYRIGHT (c) 1989-1999.
- *  On-Line Applications Research Corporation (OAR).
+ * Copyright (c) 2016 embedded brains GmbH.  All rights reserved.
  *
- *  The license and distribution terms for this file may be
- *  found in the file LICENSE in this distribution or at
- *  http://www.rtems.org/license/LICENSE.
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
  */
 
 #if HAVE_CONFIG_H
@@ -19,161 +24,18 @@
 #endif
 
 #include <rtems/score/watchdogimpl.h>
-#include <rtems/score/assert.h>
-
-static void _Watchdog_Remove_it(
-  Watchdog_Header   *header,
-  Watchdog_Control  *the_watchdog
-)
-{
-  Chain_Node        *next;
-  Watchdog_Interval  delta;
-  const Chain_Node  *iterator_tail;
-  Chain_Node        *iterator_node;
-
-  _Assert( the_watchdog->state == WATCHDOG_ACTIVE );
-
-  the_watchdog->state = WATCHDOG_INACTIVE;
-  the_watchdog->stop_time = _Watchdog_Ticks_since_boot;
-
-  next = _Chain_Next( &the_watchdog->Node );
-  delta = the_watchdog->delta_interval;
-
-  if ( next != _Chain_Tail( &header->Watchdogs ) ) {
-    Watchdog_Control *next_watchdog;
-
-    next_watchdog = (Watchdog_Control *) next;
-    next_watchdog->delta_interval += delta;
-  }
-
-  _Chain_Extract_unprotected( &the_watchdog->Node );
-
-  iterator_node = _Chain_First( &header->Iterators );
-  iterator_tail = _Chain_Immutable_tail( &header->Iterators );
-
-  while ( iterator_node != iterator_tail ) {
-    Watchdog_Iterator *iterator;
-
-    iterator = (Watchdog_Iterator *) iterator_node;
-
-    if ( iterator->current == next ) {
-      iterator->delta_interval += delta;
-    }
-
-    if ( iterator->current == &the_watchdog->Node ) {
-      Chain_Node *previous = _Chain_Previous( &the_watchdog->Node );
-
-      iterator->current = previous;
-
-      if ( previous != _Chain_Head( &header->Watchdogs ) ) {
-        Watchdog_Control *previous_watchdog;
-
-        previous_watchdog = (Watchdog_Control *) previous;
-        iterator->delta_interval += previous_watchdog->delta_interval;
-      }
-    }
-
-    iterator_node = _Chain_Next( iterator_node );
-  }
-}
 
-Watchdog_States _Watchdog_Remove(
+void _Watchdog_Remove(
   Watchdog_Header  *header,
   Watchdog_Control *the_watchdog
 )
 {
-  ISR_lock_Context  lock_context;
-  Watchdog_States   previous_state;
-  Watchdog_Interval now;
-
-  _Watchdog_Acquire( header, &lock_context );
-  previous_state = the_watchdog->state;
-  switch ( previous_state ) {
-    case WATCHDOG_INACTIVE:
-      break;
-
-    case WATCHDOG_BEING_INSERTED:
-
-      /*
-       *  It is not actually on the chain so just change the state and
-       *  the Insert operation we interrupted will be aborted.
-       */
-      the_watchdog->state = WATCHDOG_INACTIVE;
-      now = _Watchdog_Ticks_since_boot;
-      the_watchdog->start_time = now;
-      the_watchdog->stop_time = now;
-      break;
-
-    case WATCHDOG_ACTIVE:
-      _Watchdog_Remove_it( header, the_watchdog );
-      break;
-  }
-
-  _Watchdog_Release( header, &lock_context );
-  return( previous_state );
-}
-
-void _Watchdog_Tickle(
-  Watchdog_Header *header
-)
-{
-  ISR_lock_Context lock_context;
-
-  _Watchdog_Acquire( header, &lock_context );
-
-  if ( !_Watchdog_Is_empty( header ) ) {
-    Watchdog_Control  *first;
-    Watchdog_Interval  delta;
-
-    first = _Watchdog_First( header );
-    delta = first->delta_interval;
-
-    /*
-     * Although it is forbidden to insert watchdogs with a delta interval of
-     * zero it is possible to observe watchdogs with a delta interval of zero
-     * at this point.  For example lets have a watchdog chain of one watchdog
-     * with a delta interval of one and insert a new one with an initial value
-     * of one.  At the start of the insert procedure it will advance one step
-     * and reduce its delta interval by one yielding zero.  Now a tick happens.
-     * This will remove the watchdog on the chain and update the insert
-     * iterator.  Now the insert operation continues and will insert the new
-     * watchdog with a delta interval of zero.
-     */
-    if ( delta > 0 ) {
-      --delta;
-      first->delta_interval = delta;
+  if ( _Watchdog_Is_scheduled( the_watchdog ) ) {
+    if ( header->first == &the_watchdog->Node.RBTree ) {
+      _Watchdog_Next_first( header, the_watchdog );
     }
 
-    while ( delta == 0 ) {
-      bool                            run;
-      Watchdog_Service_routine_entry  routine;
-      Objects_Id                      id;
-      void                           *user_data;
-
-      run = ( first->state == WATCHDOG_ACTIVE );
-
-      _Watchdog_Remove_it( header, first );
-
-      routine = first->routine;
-      id = first->id;
-      user_data = first->user_data;
-
-      _Watchdog_Release( header, &lock_context );
-
-      if ( run ) {
-        (*routine)( id, user_data );
-      }
-
-      _Watchdog_Acquire( header, &lock_context );
-
-      if ( _Watchdog_Is_empty( header ) ) {
-        break;
-      }
-
-      first = _Watchdog_First( header );
-      delta = first->delta_interval;
-    }
+    _RBTree_Extract( &header->Watchdogs, &the_watchdog->Node.RBTree );
+    _Watchdog_Set_state( the_watchdog, WATCHDOG_INACTIVE );
   }
-
-  _Watchdog_Release( header, &lock_context );
 }
diff --git a/cpukit/score/src/watchdogtick.c b/cpukit/score/src/watchdogtick.c
index e89c088350..ab7eadcf1d 100644
--- a/cpukit/score/src/watchdogtick.c
+++ b/cpukit/score/src/watchdogtick.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015 embedded brains GmbH.  All rights reserved.
+ * Copyright (c) 2015, 2016 embedded brains GmbH.  All rights reserved.
  *
  *  embedded brains GmbH
  *  Dornierstr. 4
@@ -12,25 +12,81 @@
  * http://www.rtems.org/license/LICENSE.
  */
 
-#include <rtems/score/assert.h>
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/score/watchdogimpl.h>
 #include <rtems/score/schedulerimpl.h>
 #include <rtems/score/threaddispatch.h>
-#include <rtems/score/todimpl.h>
-#include <rtems/score/watchdogimpl.h>
+#include <rtems/score/timecounter.h>
 
-#if HAVE_CONFIG_H
-#include "config.h"
+void _Watchdog_Do_tickle(
+  Watchdog_Header  *header,
+  uint64_t          now,
+#ifdef RTEMS_SMP
+  ISR_lock_Control *lock,
 #endif
+  ISR_lock_Context *lock_context
+)
+{
+  while ( true ) {
+    Watchdog_Control *the_watchdog;
+
+    the_watchdog = (Watchdog_Control *) header->first;
+
+    if ( the_watchdog == NULL ) {
+      break;
+    }
+
+    if ( the_watchdog->expire <= now ) {
+      Watchdog_Service_routine_entry routine;
+
+      _Watchdog_Next_first( header, the_watchdog );
+      _RBTree_Extract( &header->Watchdogs, &the_watchdog->Node.RBTree );
+      _Watchdog_Set_state( the_watchdog, WATCHDOG_INACTIVE );
+      routine = the_watchdog->routine;
+
+      _ISR_lock_Release_and_ISR_enable( lock, lock_context );
+      ( *routine )( the_watchdog );
+      _ISR_lock_ISR_disable_and_acquire( lock, lock_context );
+    } else {
+      break;
+    }
+  }
+
+  _ISR_lock_Release_and_ISR_enable( lock, lock_context );
+}
 
 void _Watchdog_Tick( Per_CPU_Control *cpu )
 {
-  _Assert( !_Thread_Dispatch_is_enabled() );
+  ISR_lock_Context lock_context;
+  uint64_t         ticks;
+  struct timespec  now;
 
   if ( _Per_CPU_Is_boot_processor( cpu ) ) {
-    _TOD_Tickle_ticks();
+    ++_Watchdog_Ticks_since_boot;
+  }
 
-    _Watchdog_Tickle_ticks();
+  _ISR_lock_ISR_disable_and_acquire( &cpu->Watchdog.Lock, &lock_context );
 
-    _Scheduler_Tick();
-  }
+  ticks = cpu->Watchdog.ticks;
+  _Assert( ticks < UINT64_MAX );
+  ++ticks;
+  cpu->Watchdog.ticks = ticks;
+
+  _Watchdog_Tickle(
+    &cpu->Watchdog.Header[ PER_CPU_WATCHDOG_RELATIVE ],
+    ticks,
+    &cpu->Watchdog.Lock,
+    &lock_context
+  );
+
+  _Timecounter_Getnanotime( &now );
+  _Watchdog_Per_CPU_tickle_absolute(
+    cpu,
+    _Watchdog_Ticks_from_timespec( &now )
+  );
+
+  _Scheduler_Tick( cpu );
 }