score: Replace watchdog handler implementation

Use a red-black tree instead of delta chains.

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

9 files changed, 462 insertions, 427 deletions

diff --git a/cpukit/score/include/rtems/score/mrsp.h b/cpukit/score/include/rtems/score/mrsp.h
index 08f96ac4ac..cb3de67e26 100644
--- a/cpukit/score/include/rtems/score/mrsp.h
+++ b/cpukit/score/include/rtems/score/mrsp.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014 embedded brains GmbH.  All rights reserved.
+ * Copyright (c) 2014, 2016 embedded brains GmbH.  All rights reserved.
  *
  *  embedded brains GmbH
  *  Dornierstr. 4
@@ -128,6 +128,11 @@ typedef struct {
    * MRSP_TIMEOUT.  State changes are protected by the MrsP control lock.
    */
   volatile MRSP_Status status;
+
+  /**
+   * @brief Watchdog for timeouts.
+   */
+  Watchdog_Control Watchdog;
 } MRSP_Rival;
 
 /**
diff --git a/cpukit/score/include/rtems/score/mrspimpl.h b/cpukit/score/include/rtems/score/mrspimpl.h
index bc9ed4b511..7638fb5975 100644
--- a/cpukit/score/include/rtems/score/mrspimpl.h
+++ b/cpukit/score/include/rtems/score/mrspimpl.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2015 embedded brains GmbH.  All rights reserved.
+ * Copyright (c) 2014, 2016 embedded brains GmbH.  All rights reserved.
  *
  *  embedded brains GmbH
  *  Dornierstr. 4
@@ -159,18 +159,13 @@ RTEMS_INLINE_ROUTINE void _MRSP_Set_ceiling_priority(
   mrsp->ceiling_priorities[ scheduler_index ] = ceiling_priority;
 }
 
-RTEMS_INLINE_ROUTINE void _MRSP_Timeout(
-  Objects_Id  id,
-  void       *arg
-)
+RTEMS_INLINE_ROUTINE void _MRSP_Timeout( Watchdog_Control *watchdog )
 {
-  MRSP_Rival *rival = arg;
+  MRSP_Rival *rival = RTEMS_CONTAINER_OF( watchdog, MRSP_Rival, Watchdog );
   MRSP_Control *mrsp = rival->resource;
   Thread_Control *thread = rival->thread;
   ISR_lock_Context lock_context;
 
-  (void) id;
-
   _ISR_lock_ISR_disable_and_acquire( &mrsp->Lock, &lock_context );
 
   if ( rival->status == MRSP_WAIT_FOR_OWNERSHIP ) {
@@ -209,6 +204,7 @@ RTEMS_INLINE_ROUTINE MRSP_Status _MRSP_Wait_for_ownership(
   bool initial_life_protection;
   Per_CPU_Control *cpu_self;
   ISR_lock_Context giant_lock_context;
+  ISR_Level level;
 
   rival.thread = executing;
   rival.resource = mrsp;
@@ -236,13 +232,11 @@ RTEMS_INLINE_ROUTINE MRSP_Status _MRSP_Wait_for_ownership(
   _Thread_Raise_priority( executing, ceiling_priority );
 
   if ( timeout > 0 ) {
-    _Watchdog_Initialize(
-      &executing->Timer,
-      _MRSP_Timeout,
-      0,
-      &rival
-    );
-    _Watchdog_Insert_ticks( &executing->Timer, timeout );
+    _Watchdog_Preinitialize( &rival.Watchdog, cpu_self );
+    _Watchdog_Initialize( &rival.Watchdog, _MRSP_Timeout );
+    _ISR_Disable_without_giant( level );
+    _Watchdog_Per_CPU_insert_relative( &rival.Watchdog, cpu_self, timeout );
+    _ISR_Enable_without_giant( level );
   }
 
   initial_life_protection = _Thread_Set_life_protection( true );
@@ -258,7 +252,13 @@ RTEMS_INLINE_ROUTINE MRSP_Status _MRSP_Wait_for_ownership(
   _Thread_Set_life_protection( initial_life_protection );
 
   if ( timeout > 0 ) {
-    _Watchdog_Remove_ticks( &executing->Timer );
+    _ISR_Disable_without_giant( level );
+    _Watchdog_Per_CPU_remove(
+      &rival.Watchdog,
+      cpu_self,
+      &cpu_self->Watchdog.Header[ PER_CPU_WATCHDOG_RELATIVE ]
+    );
+    _ISR_Enable_without_giant( level );
 
     if ( status == MRSP_TIMEOUT ) {
       _MRSP_Restore_priority( executing, initial_priority );
diff --git a/cpukit/score/include/rtems/score/percpu.h b/cpukit/score/include/rtems/score/percpu.h
index 39be1e3367..22017889b3 100644
--- a/cpukit/score/include/rtems/score/percpu.h
+++ b/cpukit/score/include/rtems/score/percpu.h
@@ -23,10 +23,11 @@
   #include <rtems/asm.h>
 #else
   #include <rtems/score/assert.h>
-  #include <rtems/score/isrlevel.h>
+  #include <rtems/score/isrlock.h>
   #include <rtems/score/smp.h>
   #include <rtems/score/smplock.h>
   #include <rtems/score/timestamp.h>
+  #include <rtems/score/watchdog.h>
 #endif
 
 #ifdef __cplusplus
@@ -41,7 +42,7 @@ extern "C" {
    * processor.
    */
   #if defined( RTEMS_PROFILING )
-    #define PER_CPU_CONTROL_SIZE_LOG2 8
+    #define PER_CPU_CONTROL_SIZE_LOG2 9
   #else
     #define PER_CPU_CONTROL_SIZE_LOG2 7
   #endif
@@ -226,6 +227,32 @@ typedef struct {
 } Per_CPU_Stats;
 
 /**
+ * @brief Per-CPU watchdog header index.
+ */
+typedef enum {
+  /**
+   * @brief Index for relative per-CPU watchdog header.
+   *
+   * The reference time point for this header is current ticks value
+   * during insert.  Time is measured in clock ticks.
+   */
+  PER_CPU_WATCHDOG_RELATIVE,
+
+  /**
+   * @brief Index for absolute per-CPU watchdog header.
+   *
+   * The reference time point for this header is the POSIX Epoch.  Time is
+   * measured in nanoseconds since POSIX Epoch.
+   */
+  PER_CPU_WATCHDOG_ABSOLUTE,
+
+  /**
+   * @brief Count of per-CPU watchdog headers.
+   */
+  PER_CPU_WATCHDOG_COUNT
+} Per_CPU_Watchdog_index;
+
+/**
  *  @brief Per CPU Core Structure
  *
  *  This structure is used to hold per core state information.
@@ -309,6 +336,28 @@ typedef struct Per_CPU_Control {
   /** This is the time of the last context switch on this CPU. */
   Timestamp_Control time_of_last_context_switch;
 
+  /**
+   * @brief Watchdog state for this processor.
+   */
+  struct {
+    /**
+     * @brief Protects all watchdog operations on this processor.
+     */
+    ISR_LOCK_MEMBER( Lock )
+
+    /**
+     * @brief Watchdog ticks on this processor used for relative watchdogs.
+     */
+    uint64_t ticks;
+
+    /**
+     * @brief Header for watchdogs.
+     *
+     * @see Per_CPU_Watchdog_index.
+     */
+    Watchdog_Header Header[ PER_CPU_WATCHDOG_COUNT ];
+  } Watchdog;
+
   #if defined( RTEMS_SMP )
     /**
      * @brief This lock protects some parts of the low-level thread dispatching.
diff --git a/cpukit/score/include/rtems/score/schedulerimpl.h b/cpukit/score/include/rtems/score/schedulerimpl.h
index cadebfd02f..d50c36a7b9 100644
--- a/cpukit/score/include/rtems/score/schedulerimpl.h
+++ b/cpukit/score/include/rtems/score/schedulerimpl.h
@@ -452,19 +452,13 @@ RTEMS_INLINE_ROUTINE void _Scheduler_Release_job(
  * scheduler which support standard RTEMS features, this includes
  * time-slicing management.
  */
-RTEMS_INLINE_ROUTINE void _Scheduler_Tick( void )
+RTEMS_INLINE_ROUTINE void _Scheduler_Tick( const Per_CPU_Control *cpu )
 {
-  uint32_t cpu_count = _SMP_Get_processor_count();
-  uint32_t cpu_index;
+  const Scheduler_Control *scheduler = _Scheduler_Get_by_CPU( cpu );
+  Thread_Control *executing = cpu->executing;
 
-  for ( cpu_index = 0 ; cpu_index < cpu_count ; ++cpu_index ) {
-    const Per_CPU_Control *cpu = _Per_CPU_Get_by_index( cpu_index );
-    const Scheduler_Control *scheduler = _Scheduler_Get_by_CPU( cpu );
-    Thread_Control *executing = cpu->executing;
-
-    if ( scheduler != NULL && executing != NULL ) {
-      ( *scheduler->Operations.tick )( scheduler, executing );
-    }
+  if ( scheduler != NULL && executing != NULL ) {
+    ( *scheduler->Operations.tick )( scheduler, executing );
   }
 }
 
diff --git a/cpukit/score/include/rtems/score/thread.h b/cpukit/score/include/rtems/score/thread.h
index 73776b3ec1..44b706d7ff 100644
--- a/cpukit/score/include/rtems/score/thread.h
+++ b/cpukit/score/include/rtems/score/thread.h
@@ -347,6 +347,15 @@ typedef struct {
 }   Thread_Wait_information;
 
 /**
+ * @brief Information required to manage a thread timer.
+ */
+typedef struct {
+  ISR_LOCK_MEMBER( Lock )
+  Watchdog_Header *header;
+  Watchdog_Control Watchdog;
+} Thread_Timer_information;
+
+/**
  *  The following defines the control block used to manage
  *  each thread proxy.
  *
@@ -400,7 +409,7 @@ typedef struct {
   /** This field is the blocking information for this proxy. */
   Thread_Wait_information  Wait;
   /** This field is the Watchdog used to manage proxy delays and timeouts. */
-  Watchdog_Control         Timer;
+  Thread_Timer_information Timer;
 #if defined(RTEMS_MULTIPROCESSING)
   /** This field is the received response packet in an MP system. */
   MP_packet_Prefix        *receive_packet;
@@ -728,7 +737,7 @@ struct _Thread_Control {
   /** This field is the blocking information for this thread. */
   Thread_Wait_information  Wait;
   /** This field is the Watchdog used to manage thread delays and timeouts. */
-  Watchdog_Control         Timer;
+  Thread_Timer_information Timer;
 #if defined(RTEMS_MULTIPROCESSING)
   /** This field is the received response packet in an MP system. */
   MP_packet_Prefix        *receive_packet;
diff --git a/cpukit/score/include/rtems/score/threadimpl.h b/cpukit/score/include/rtems/score/threadimpl.h
index 1377543118..ec9851dba0 100644
--- a/cpukit/score/include/rtems/score/threadimpl.h
+++ b/cpukit/score/include/rtems/score/threadimpl.h
@@ -33,6 +33,7 @@
 #include <rtems/score/threadqimpl.h>
 #include <rtems/score/todimpl.h>
 #include <rtems/score/freechain.h>
+#include <rtems/score/watchdogimpl.h>
 #include <rtems/config.h>
 
 #ifdef __cplusplus
@@ -1472,10 +1473,64 @@ RTEMS_INLINE_ROUTINE void _Thread_Wait_set_timeout_code(
 /**
  * @brief General purpose thread wait timeout.
  *
- * @param[in] id Unused.
- * @param[in] arg The thread.
+ * @param[in] watchdog The thread timer watchdog.
  */
-void _Thread_Timeout( Objects_Id id, void *arg );
+void _Thread_Timeout( Watchdog_Control *watchdog );
+
+RTEMS_INLINE_ROUTINE void _Thread_Timer_insert_relative(
+  Thread_Control                 *the_thread,
+  Per_CPU_Control                *cpu,
+  Watchdog_Service_routine_entry  routine,
+  Watchdog_Interval               ticks
+)
+{
+  ISR_lock_Context lock_context;
+
+  _ISR_lock_ISR_disable_and_acquire( &the_thread->Timer.Lock, &lock_context );
+
+  the_thread->Timer.header = &cpu->Watchdog.Header[ PER_CPU_WATCHDOG_RELATIVE ];
+  the_thread->Timer.Watchdog.routine = routine;
+  _Watchdog_Per_CPU_insert_relative( &the_thread->Timer.Watchdog, cpu, ticks );
+
+  _ISR_lock_Release_and_ISR_enable( &the_thread->Timer.Lock, &lock_context );
+}
+
+RTEMS_INLINE_ROUTINE void _Thread_Timer_insert_absolute(
+  Thread_Control                 *the_thread,
+  Per_CPU_Control                *cpu,
+  Watchdog_Service_routine_entry  routine,
+  uint64_t                        expire
+)
+{
+  ISR_lock_Context lock_context;
+
+  _ISR_lock_ISR_disable_and_acquire( &the_thread->Timer.Lock, &lock_context );
+
+  the_thread->Timer.header = &cpu->Watchdog.Header[ PER_CPU_WATCHDOG_ABSOLUTE ];
+  the_thread->Timer.Watchdog.routine = routine;
+  _Watchdog_Per_CPU_insert_absolute( &the_thread->Timer.Watchdog, cpu, expire );
+
+  _ISR_lock_Release_and_ISR_enable( &the_thread->Timer.Lock, &lock_context );
+}
+
+RTEMS_INLINE_ROUTINE void _Thread_Timer_remove( Thread_Control *the_thread )
+{
+  ISR_lock_Context lock_context;
+
+  _ISR_lock_ISR_disable_and_acquire( &the_thread->Timer.Lock, &lock_context );
+
+  _Watchdog_Per_CPU_remove(
+    &the_thread->Timer.Watchdog,
+#if defined(RTEMS_SMP)
+    the_thread->Timer.Watchdog.cpu,
+#else
+    _Per_CPU_Get(),
+#endif
+    the_thread->Timer.header
+  );
+
+  _ISR_lock_Release_and_ISR_enable( &the_thread->Timer.Lock, &lock_context );
+}
 
 RTEMS_INLINE_ROUTINE void _Thread_Debug_set_real_processor(
   Thread_Control  *the_thread,
diff --git a/cpukit/score/include/rtems/score/todimpl.h b/cpukit/score/include/rtems/score/todimpl.h
index b61651cdba..b1f8a6d6b6 100644
--- a/cpukit/score/include/rtems/score/todimpl.h
+++ b/cpukit/score/include/rtems/score/todimpl.h
@@ -132,15 +132,6 @@ extern "C" {
  */
 typedef struct {
   /**
-   * @brief Time of day seconds trigger.
-   *
-   * This value specifies the nanoseconds since the last time of day second.
-   * It is updated and evaluated in _TOD_Tickle_ticks().  It is set in
-   * _TOD_Set_with_timestamp().
-   */
-  uint32_t seconds_trigger;
-
-  /**
    *  @brief Indicates if the time of day is set.
    *
    *  This is true if the application has set the current
@@ -273,14 +264,6 @@ static inline uint32_t _TOD_Seconds_since_epoch( void )
 }
 
 /**
- *  @brief Increments time of day at each clock tick.
- *
- *  This routine increments the ticks field of the current time of
- *  day at each clock tick.
- */
-void _TOD_Tickle_ticks( void );
-
-/**
  *  @brief Gets number of ticks in a second.
  *
  *  This method returns the number of ticks in a second.
diff --git a/cpukit/score/include/rtems/score/watchdog.h b/cpukit/score/include/rtems/score/watchdog.h
index bad7269051..c582dbd1ae 100644
--- a/cpukit/score/include/rtems/score/watchdog.h
+++ b/cpukit/score/include/rtems/score/watchdog.h
@@ -20,7 +20,11 @@
 #ifndef _RTEMS_SCORE_WATCHDOG_H
 #define _RTEMS_SCORE_WATCHDOG_H
 
-#include <rtems/score/object.h>
+#include <rtems/score/basedefs.h>
+#include <rtems/score/chain.h>
+#include <rtems/score/rbtree.h>
+
+struct Per_CPU_Control;
 
 #ifdef __cplusplus
 extern "C" {
@@ -39,6 +43,8 @@ extern "C" {
  */
 /**@{*/
 
+typedef struct Watchdog_Control Watchdog_Control;
+
 /**
  *  @brief Type is used to specify the length of intervals.
  *
@@ -58,10 +64,8 @@ typedef void Watchdog_Service_routine;
  *
  *  This type define a pointer to a watchdog service routine.
  */
-typedef Watchdog_Service_routine ( *Watchdog_Service_routine_entry )(
-                 Objects_Id,
-                 void *
-             );
+typedef Watchdog_Service_routine
+  ( *Watchdog_Service_routine_entry )( Watchdog_Control * );
 
 /**
  *  @brief The constant for indefinite wait.
@@ -72,22 +76,20 @@ typedef Watchdog_Service_routine ( *Watchdog_Service_routine_entry )(
 #define WATCHDOG_NO_TIMEOUT  0
 
 /**
- *  @brief Set of the states which a watchdog timer may be at any given time.
- *
- *  This enumerated type is the set of the states in which a
- *  watchdog timer may be at any given time.
+ * @brief The watchdog header to manage scheduled watchdogs.
  */
+typedef struct {
+  /**
+   * @brief Red-black tree of scheduled watchdogs sorted by expiration time.
+   */
+  RBTree_Control Watchdogs;
 
-typedef enum {
-  /** This is the state when the watchdog is off all chains */
-  WATCHDOG_INACTIVE,
-  /** This is the state when the watchdog is off all chains, but we are
-   *  currently searching for the insertion point.
+  /**
+   * @brief The scheduled watchdog with the earliest expiration time or NULL in
+   * case no watchdog is scheduled.
    */
-  WATCHDOG_BEING_INSERTED,
-  /** This is the state when the watchdog is on a chain, and allowed to fire. */
-  WATCHDOG_ACTIVE
-} Watchdog_States;
+  RBTree_Node *first;
+} Watchdog_Header;
 
 /**
  *  @brief The control block used to manage each watchdog timer.
@@ -95,30 +97,35 @@ typedef enum {
  *  The following record defines the control block used
  *  to manage each watchdog timer.
  */
-typedef struct {
-  /** This field is a Chain Node structure and allows this to be placed on
-   *  chains for set management.
-   */
-  Chain_Node                      Node;
-  /** This field is the state of the watchdog. */
-  Watchdog_States                 state;
-  /** This field is the initially requested interval. */
-  Watchdog_Interval               initial;
-  /** This field is the remaining portion of the interval. */
-  Watchdog_Interval               delta_interval;
-  /** This field is the number of system clock ticks when this was scheduled. */
-  Watchdog_Interval               start_time;
-  /** This field is the number of system clock ticks when this was suspended. */
-  Watchdog_Interval               stop_time;
-  /** This field is the function to invoke. */
-  Watchdog_Service_routine_entry  routine;
-  /** This field is the Id to pass as an argument to the routine. */
-  Objects_Id                      id;
-  /** This field is an untyped pointer to user data that is passed to the
-   *  watchdog handler routine.
+struct Watchdog_Control {
+  /**
+   * @brief Nodes for the watchdog.
    */
-  void                           *user_data;
-}   Watchdog_Control;
+  union {
+    /**
+     * @brief this field is a red-black tree node structure and allows this to
+     * be placed on a red-black tree used to manage the scheduled watchdogs.
+     */
+    RBTree_Node RBTree;
+
+    /**
+     * @brief this field is a chain node structure and allows this to be placed
+     * on a chain used to manage pending watchdogs by the timer server.
+     */
+    Chain_Node Chain;
+  } Node;
+
+#if defined(RTEMS_SMP)
+  /** @brief This field references the processor of this watchdog control. */
+  struct Per_CPU_Control *cpu;
+#endif
+
+  /** @brief This field is the function to invoke. */
+  Watchdog_Service_routine_entry routine;
+
+  /** @brief This field is the expiration time point. */
+  uint64_t expire;
+};
 
 /**
  * @brief The watchdog ticks counter.
diff --git a/cpukit/score/include/rtems/score/watchdogimpl.h b/cpukit/score/include/rtems/score/watchdogimpl.h
index 49ac2a12b1..2b24cc68e5 100644
--- a/cpukit/score/include/rtems/score/watchdogimpl.h
+++ b/cpukit/score/include/rtems/score/watchdogimpl.h
@@ -21,9 +21,11 @@
 
 #include <rtems/score/watchdog.h>
 #include <rtems/score/assert.h>
-#include <rtems/score/chainimpl.h>
 #include <rtems/score/isrlock.h>
 #include <rtems/score/percpu.h>
+#include <rtems/score/rbtreeimpl.h>
+
+#include <sys/timespec.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -35,241 +37,116 @@ extern "C" {
  */
 
 /**
- * @brief Watchdog initializer for static initialization.
- *
- * @see _Watchdog_Initialize().
- */
-#define WATCHDOG_INITIALIZER( routine, id, user_data ) \
-  { \
-    { NULL, NULL }, \
-    WATCHDOG_INACTIVE, \
-    0, 0, 0, 0, \
-    ( routine ), ( id ), ( user_data ) \
-  }
-
-/**
- * @brief Iterator item to synchronize concurrent insert, remove and tickle
- * operations.
+ * @brief Watchdog states.
  */
-typedef struct {
+typedef enum {
   /**
-   * @brief A node for a Watchdog_Header::Iterators chain.
+   * @brief The watchdog is scheduled and a black node in the red-black tree.
    */
-  Chain_Node Node;
+  WATCHDOG_SCHEDULED_BLACK,
 
   /**
-   * @brief The current delta interval of the new watchdog to insert.
+   * @brief The watchdog is scheduled and a red node in the red-black tree.
    */
-  Watchdog_Interval delta_interval;
+  WATCHDOG_SCHEDULED_RED,
 
   /**
-   * @brief The current watchdog of the chain on the way to insert the new
-   * watchdog.
+   * @brief The watchdog is inactive.
    */
-  Chain_Node *current;
-} Watchdog_Iterator;
-
-/**
- * @brief Watchdog header.
- */
-typedef struct {
-  /**
-   * @brief ISR lock to protect this watchdog chain.
-   */
-  ISR_LOCK_MEMBER( Lock )
+  WATCHDOG_INACTIVE,
 
   /**
-   * @brief The chain of active or transient watchdogs.
-   */
-  Chain_Control Watchdogs;
-
-  /**
-   * @brief Currently active iterators.
+   * @brief The watchdog is on a chain of pending watchdogs.
    *
-   * The iterators are registered in _Watchdog_Insert() and updated in case the
-   * watchdog chain changes.
+   * This state is used by the timer server for example.
    */
-  Chain_Control Iterators;
-} Watchdog_Header;
+  WATCHDOG_PENDING
+} Watchdog_State;
 
 /**
- *  @brief Watchdog chain which is managed at ticks.
+ * @brief Watchdog initializer for static initialization.
  *
- *  This is the watchdog chain which is managed at ticks.
- */
-extern Watchdog_Header _Watchdog_Ticks_header;
-
-/**
- *  @brief Watchdog chain which is managed at second boundaries.
+ * The processor of this watchdog is set to processor with index zero.
  *
- *  This is the watchdog chain which is managed at second boundaries.
+ * @see _Watchdog_Preinitialize().
  */
-extern Watchdog_Header _Watchdog_Seconds_header;
-
-RTEMS_INLINE_ROUTINE void _Watchdog_Acquire(
-  Watchdog_Header  *header,
-  ISR_lock_Context *lock_context
-)
-{
-  _ISR_lock_ISR_disable_and_acquire( &header->Lock, lock_context );
-}
+#if defined(RTEMS_SMP)
+  #define WATCHDOG_INITIALIZER( routine ) \
+    { \
+      { { { NULL, NULL, NULL, WATCHDOG_INACTIVE } } }, \
+      &_Per_CPU_Information[ 0 ].per_cpu, \
+      ( routine ), \
+      0 \
+    }
+#else
+  #define WATCHDOG_INITIALIZER( routine ) \
+    { \
+      { { { NULL, NULL, NULL, WATCHDOG_INACTIVE } } }, \
+      ( routine ), \
+      0 \
+    }
+#endif
 
-RTEMS_INLINE_ROUTINE void _Watchdog_Release(
-  Watchdog_Header  *header,
-  ISR_lock_Context *lock_context
+RTEMS_INLINE_ROUTINE void _Watchdog_Header_initialize(
+  Watchdog_Header *header
 )
 {
-  _ISR_lock_Release_and_ISR_enable( &header->Lock, lock_context );
+  _RBTree_Initialize_empty( &header->Watchdogs );
+  header->first = NULL;
 }
 
-RTEMS_INLINE_ROUTINE void _Watchdog_Flash(
-  Watchdog_Header  *header,
-  ISR_lock_Context *lock_context
+RTEMS_INLINE_ROUTINE void _Watchdog_Header_destroy(
+  Watchdog_Header *header
 )
 {
-  _ISR_lock_Flash( &header->Lock, lock_context );
+  /* Do nothing */
+  (void) header;
 }
 
 /**
- *  @brief Initialize the watchdog handler.
- *
- *  This routine initializes the watchdog handler.  The watchdog
- *  synchronization flag is initialized and the watchdog chains are
- *  initialized and emptied.
- */
-void _Watchdog_Handler_initialization( void );
-
-/**
  *  @brief Performs a watchdog tick.
  *
  *  @param cpu The processor for this watchdog tick.
  */
-void _Watchdog_Tick( Per_CPU_Control *cpu );
-
-/**
- *  @brief Removes @a the_watchdog from the watchdog chain.
- *
- *  This routine removes @a the_watchdog from the watchdog chain on which
- *  it resides and returns the state @a the_watchdog timer was in.
- *
- *  @param[in] header The watchdog chain.
- *  @param[in] the_watchdog will be removed
- *  @retval the state in which @a the_watchdog was in when removed
- */
-Watchdog_States _Watchdog_Remove (
-  Watchdog_Header  *header,
-  Watchdog_Control *the_watchdog
-);
-
-/**
- *  @brief Adjusts the header watchdog chain in the backward direction for
- *  units ticks.
- *
- *  @param[in] header The watchdog chain.
- *  @param[in] units The units of ticks to adjust.
- */
-void _Watchdog_Adjust_backward(
-  Watchdog_Header   *header,
-  Watchdog_Interval  units
-);
-
-/**
- * @brief Adjusts the watchdogs in backward direction in a locked context.
- *
- * The caller must be the owner of the watchdog lock and will be the owner
- * after the call.
- *
- * @param[in] header The watchdog header.
- * @param[in] units The units of ticks to adjust.
- *
- * @see _Watchdog_Adjust_forward().
- */
-void _Watchdog_Adjust_backward_locked(
-  Watchdog_Header   *header,
-  Watchdog_Interval  units
-);
+void _Watchdog_Tick( struct Per_CPU_Control *cpu );
 
-/**
- *  @brief Adjusts the header watchdog chain in the forward direction for units
- *  ticks.
- *
- *  This may lead to several _Watchdog_Tickle() invocations.
- *
- *  @param[in] header The watchdog chain.
- *  @param[in] units The units of ticks to adjust.
- */
-void _Watchdog_Adjust_forward(
-  Watchdog_Header   *header,
-  Watchdog_Interval  units
-);
+RTEMS_INLINE_ROUTINE Watchdog_State _Watchdog_Get_state(
+  const Watchdog_Control *the_watchdog
+)
+{
+  return RB_COLOR( &the_watchdog->Node.RBTree, Node );
+}
 
-/**
- * @brief Adjusts the watchdogs in forward direction in a locked context.
- *
- * The caller must be the owner of the watchdog lock and will be the owner
- * after the call.  This function may release and acquire the watchdog lock
- * internally.
- *
- * @param[in] header The watchdog header.
- * @param[in] units The units of ticks to adjust.
- * @param[in] lock_context The lock context.
- *
- * @see _Watchdog_Adjust_forward().
- */
-void _Watchdog_Adjust_forward_locked(
-  Watchdog_Header   *header,
-  Watchdog_Interval  units,
-  ISR_lock_Context  *lock_context
-);
+RTEMS_INLINE_ROUTINE void _Watchdog_Set_state(
+  Watchdog_Control *the_watchdog,
+  Watchdog_State    state
+)
+{
+  RB_COLOR( &the_watchdog->Node.RBTree, Node ) = state;
+}
 
-/**
- *  @brief Inserts @a the_watchdog into the @a header watchdog chain
- *  for a time of @a units.
- *
- *  This routine inserts @a the_watchdog into the @a header watchdog chain
- *  for a time of @a units.
- *  Update the delta interval counters.
- *
- *  @param[in] header is @a the_watchdog list to insert @a the_watchdog on
- *  @param[in] the_watchdog is the watchdog to insert
- */
-void _Watchdog_Insert (
-  Watchdog_Header  *header,
-  Watchdog_Control *the_watchdog
-);
+RTEMS_INLINE_ROUTINE Per_CPU_Control *_Watchdog_Get_CPU(
+  const Watchdog_Control *the_watchdog
+)
+{
+#if defined(RTEMS_SMP)
+  return the_watchdog->cpu;
+#else
+  return _Per_CPU_Get_by_index( 0 );
+#endif
+}
 
-/**
- * @brief Inserts the watchdog in a locked context.
- *
- * The caller must be the owner of the watchdog lock and will be the owner
- * after the call.  This function may release and acquire the watchdog lock
- * internally.
- *
- * @param[in] header The watchdog header.
- * @param[in] the_watchdog The watchdog.
- * @param[in] lock_context The lock context.
- *
- * @see _Watchdog_Insert().
- */
-void _Watchdog_Insert_locked(
-  Watchdog_Header  *header,
+RTEMS_INLINE_ROUTINE void _Watchdog_Set_CPU(
   Watchdog_Control *the_watchdog,
-  ISR_lock_Context *lock_context
-);
-
-/**
- *  @brief This routine is invoked at appropriate intervals to update
- *  the @a header watchdog chain.
- *
- *  This routine is invoked at appropriate intervals to update
- *  the @a header watchdog chain.
- *  This routine decrements the delta counter in response to a tick.
- *
- *  @param[in] header is the watchdog chain to tickle
- */
-void _Watchdog_Tickle (
-  Watchdog_Header *header
-);
+  Per_CPU_Control  *cpu
+)
+{
+#if defined(RTEMS_SMP)
+  the_watchdog->cpu = cpu;
+#else
+  (void) cpu;
+#endif
+}
 
 /**
  * @brief Pre-initializes a watchdog.
@@ -280,228 +157,284 @@ void _Watchdog_Tickle (
  * @param[in] the_watchdog The uninitialized watchdog.
  */
 RTEMS_INLINE_ROUTINE void _Watchdog_Preinitialize(
-  Watchdog_Control *the_watchdog
+  Watchdog_Control *the_watchdog,
+  Per_CPU_Control  *cpu
 )
 {
-  the_watchdog->state = WATCHDOG_INACTIVE;
+  _Watchdog_Set_CPU( the_watchdog, cpu );
+  _Watchdog_Set_state( the_watchdog, WATCHDOG_INACTIVE );
+
 #if defined(RTEMS_DEBUG)
   the_watchdog->routine = NULL;
-  the_watchdog->id = 0;
-  the_watchdog->user_data = NULL;
+  the_watchdog->expire = 0;
 #endif
 }
 
 /**
- * This routine initializes the specified watchdog.  The watchdog is
- * made inactive, the watchdog id and handler routine are set to the
- * specified values.
+ * @brief Initializes a watchdog with a new service routine.
+ *
+ * The watchdog must be inactive.
  */
-
 RTEMS_INLINE_ROUTINE void _Watchdog_Initialize(
   Watchdog_Control               *the_watchdog,
-  Watchdog_Service_routine_entry  routine,
-  Objects_Id                      id,
-  void                           *user_data
+  Watchdog_Service_routine_entry  routine
 )
 {
-  _Assert( the_watchdog->state == WATCHDOG_INACTIVE );
-  the_watchdog->routine   = routine;
-  the_watchdog->id        = id;
-  the_watchdog->user_data = user_data;
+  _Assert( _Watchdog_Get_state( the_watchdog ) == WATCHDOG_INACTIVE );
+  the_watchdog->routine = routine;
 }
 
+void _Watchdog_Do_tickle(
+  Watchdog_Header  *header,
+  uint64_t          now,
+#if defined(RTEMS_SMP)
+  ISR_lock_Control *lock,
+#endif
+  ISR_lock_Context *lock_context
+);
+
+#if defined(RTEMS_SMP)
+  #define _Watchdog_Tickle( header, now, lock, lock_context ) \
+    _Watchdog_Do_tickle( header, now, lock, lock_context )
+#else
+  #define _Watchdog_Tickle( header, now, lock, lock_context ) \
+    _Watchdog_Do_tickle( header, now, lock_context )
+#endif
+
 /**
- * This routine returns true if the watchdog timer is in the ACTIVE
- * state, and false otherwise.
+ * @brief Inserts a watchdog into the set of scheduled watchdogs according to
+ * the specified expiration time.
+ *
+ * The watchdog must be inactive.
  */
+void _Watchdog_Insert(
+  Watchdog_Header  *header,
+  Watchdog_Control *the_watchdog,
+  uint64_t          expire
+);
 
-RTEMS_INLINE_ROUTINE bool _Watchdog_Is_active(
+/**
+ * @brief In case the watchdog is scheduled, then it is removed from the set of
+ * scheduled watchdogs.
+ *
+ * The watchdog must be initialized before this call.
+ */
+void _Watchdog_Remove(
+  Watchdog_Header  *header,
   Watchdog_Control *the_watchdog
-)
-{
-
-  return ( the_watchdog->state == WATCHDOG_ACTIVE );
-
-}
+);
 
 /**
- * This routine activates THE_WATCHDOG timer which is already
- * on a watchdog chain.
+ * @brief In case the watchdog is scheduled, then it is removed from the set of
+ * scheduled watchdogs.
+ *
+ * The watchdog must be initialized before this call.
+ *
+ * @retval 0 The now time is greater than or equal to the expiration time of
+ * the watchdog.
+ * @retval other The difference of the now and expiration time.
  */
-
-RTEMS_INLINE_ROUTINE void _Watchdog_Activate(
-  Watchdog_Control *the_watchdog
+RTEMS_INLINE_ROUTINE uint64_t _Watchdog_Cancel(
+  Watchdog_Header  *header,
+  Watchdog_Control *the_watchdog,
+  uint64_t          now
 )
 {
+  uint64_t expire;
+  uint64_t remaining;
 
-  the_watchdog->state = WATCHDOG_ACTIVE;
+  expire = the_watchdog->expire;
 
-}
-
-/**
- * This routine is invoked at each clock tick to update the ticks
- * watchdog chain.
- */
-
-RTEMS_INLINE_ROUTINE void _Watchdog_Tickle_ticks( void )
-{
+  if ( now < expire ) {
+    remaining = expire - now;
+  } else {
+    remaining = 0;
+  }
 
-  _Watchdog_Tickle( &_Watchdog_Ticks_header );
+  _Watchdog_Remove( header, the_watchdog );
 
+  return remaining;
 }
 
-/**
- * This routine is invoked at each clock tick to update the seconds
- * watchdog chain.
- */
-
-RTEMS_INLINE_ROUTINE void _Watchdog_Tickle_seconds( void )
+RTEMS_INLINE_ROUTINE bool _Watchdog_Is_scheduled(
+  const Watchdog_Control *the_watchdog
+)
 {
-
-  _Watchdog_Tickle( &_Watchdog_Seconds_header );
-
+  return _Watchdog_Get_state( the_watchdog ) < WATCHDOG_INACTIVE;
 }
 
-/**
- * This routine inserts THE_WATCHDOG into the ticks watchdog chain
- * for a time of UNITS ticks.  The INSERT_MODE indicates whether
- * THE_WATCHDOG is to be activated automatically or later, explicitly
- * by the caller.
- */
-
-RTEMS_INLINE_ROUTINE void _Watchdog_Insert_ticks(
-  Watchdog_Control      *the_watchdog,
-  Watchdog_Interval      units
+RTEMS_INLINE_ROUTINE void _Watchdog_Next_first(
+  Watchdog_Header  *header,
+  Watchdog_Control *the_watchdog
 )
 {
+  RBTree_Node *node = _RBTree_Right( &the_watchdog->Node.RBTree );
 
-  the_watchdog->initial = units;
+  if ( node != NULL ) {
+    RBTree_Node *left;
 
-  _Watchdog_Insert( &_Watchdog_Ticks_header, the_watchdog );
+    while ( ( left = _RBTree_Left( node ) ) != NULL ) {
+      node = left;
+    }
 
+    header->first = node;
+  } else {
+    header->first = _RBTree_Parent( &the_watchdog->Node.RBTree );
+  }
 }
 
 /**
- * This routine inserts THE_WATCHDOG into the seconds watchdog chain
- * for a time of UNITS seconds.  The INSERT_MODE indicates whether
- * THE_WATCHDOG is to be activated automatically or later, explicitly
- * by the caller.
+ * @brief The bits necessary to store 1000000000 nanoseconds.
+ *
+ * The expiration time is an unsigned 64-bit integer.  To store absolute
+ * timeouts we use 30 bits (2**30 == 1073741824) for the nanoseconds and 34
+ * bits for the seconds since UNIX Epoch.  This leads to a year 2514 problem.
  */
+#define WATCHDOG_BITS_FOR_1E9_NANOSECONDS 30
 
-RTEMS_INLINE_ROUTINE void _Watchdog_Insert_seconds(
-  Watchdog_Control      *the_watchdog,
-  Watchdog_Interval      units
+RTEMS_INLINE_ROUTINE uint64_t _Watchdog_Ticks_from_seconds(
+  uint32_t seconds
 )
 {
+  uint64_t ticks = seconds;
 
-  the_watchdog->initial = units;
-
-  _Watchdog_Insert( &_Watchdog_Seconds_header, the_watchdog );
+  ticks <<= WATCHDOG_BITS_FOR_1E9_NANOSECONDS;
 
+  return ticks;
 }
 
-RTEMS_INLINE_ROUTINE Watchdog_States _Watchdog_Remove_ticks(
-  Watchdog_Control *the_watchdog
+RTEMS_INLINE_ROUTINE uint64_t _Watchdog_Ticks_from_timespec(
+  const struct timespec *ts
 )
 {
-  return _Watchdog_Remove( &_Watchdog_Ticks_header, the_watchdog );
+  /*
+   * The seconds are in time_t which is a signed integer.  Thus this cast is
+   * subject to the year 2038 problem in case time_t is a 32-bit integer.
+   */
+  uint64_t ticks = (uint64_t) ts->tv_sec;
+
+  _Assert( ticks < 0x400000000 );
+  _Assert( ts->tv_nsec >= 0 );
+  _Assert( ts->tv_nsec < 1000000000 );
+
+  ticks <<= WATCHDOG_BITS_FOR_1E9_NANOSECONDS;
+  ticks |= ts->tv_nsec;
+
+  return ticks;
 }
 
-RTEMS_INLINE_ROUTINE Watchdog_States _Watchdog_Remove_seconds(
-  Watchdog_Control *the_watchdog
+RTEMS_INLINE_ROUTINE void _Watchdog_Per_CPU_acquire_critical(
+  Per_CPU_Control  *cpu,
+  ISR_lock_Context *lock_context
 )
 {
-  return _Watchdog_Remove( &_Watchdog_Seconds_header, the_watchdog );
+  _ISR_lock_Acquire( &cpu->Watchdog.Lock, lock_context );
 }
 
-/**
- * This routine resets THE_WATCHDOG timer to its state at INSERT
- * time.  This routine is valid only on interval watchdog timers
- * and is used to make an interval watchdog timer fire "every" so
- * many ticks.
- */
-
-RTEMS_INLINE_ROUTINE void _Watchdog_Reset_ticks(
-  Watchdog_Control *the_watchdog
+RTEMS_INLINE_ROUTINE void _Watchdog_Per_CPU_release_critical(
+  Per_CPU_Control  *cpu,
+  ISR_lock_Context *lock_context
 )
 {
-
-  _Watchdog_Remove_ticks( the_watchdog );
-
-  _Watchdog_Insert( &_Watchdog_Ticks_header, the_watchdog );
-
+  _ISR_lock_Release( &cpu->Watchdog.Lock, lock_context );
 }
 
-/**
- * This routine returns a pointer to the watchdog timer following
- * THE_WATCHDOG on the watchdog chain.
- */
-
-RTEMS_INLINE_ROUTINE Watchdog_Control *_Watchdog_Next(
-  Watchdog_Control *the_watchdog
+RTEMS_INLINE_ROUTINE void _Watchdog_Per_CPU_insert_relative(
+  Watchdog_Control *the_watchdog,
+  Per_CPU_Control  *cpu,
+  uint32_t          ticks
 )
 {
+  ISR_lock_Context lock_context;
 
-  return ( (Watchdog_Control *) the_watchdog->Node.next );
+  _Watchdog_Set_CPU( the_watchdog, cpu );
 
+  _Watchdog_Per_CPU_acquire_critical( cpu, &lock_context );
+  _Watchdog_Insert(
+    &cpu->Watchdog.Header[ PER_CPU_WATCHDOG_RELATIVE ],
+    the_watchdog,
+    cpu->Watchdog.ticks + ticks
+  );
+  _Watchdog_Per_CPU_release_critical( cpu, &lock_context );
 }
 
-/**
- * This routine returns a pointer to the watchdog timer preceding
- * THE_WATCHDOG on the watchdog chain.
- */
-
-RTEMS_INLINE_ROUTINE Watchdog_Control *_Watchdog_Previous(
-  Watchdog_Control *the_watchdog
+RTEMS_INLINE_ROUTINE void _Watchdog_Per_CPU_insert_absolute(
+  Watchdog_Control *the_watchdog,
+  Per_CPU_Control  *cpu,
+  uint64_t          expire
 )
 {
+  ISR_lock_Context lock_context;
 
-  return ( (Watchdog_Control *) the_watchdog->Node.previous );
+  _Watchdog_Set_CPU( the_watchdog, cpu );
 
+  _Watchdog_Per_CPU_acquire_critical( cpu, &lock_context );
+  _Watchdog_Insert(
+    &cpu->Watchdog.Header[ PER_CPU_WATCHDOG_ABSOLUTE ],
+    the_watchdog,
+    expire
+  );
+  _Watchdog_Per_CPU_release_critical( cpu, &lock_context );
 }
 
-/**
- * This routine returns a pointer to the first watchdog timer
- * on the watchdog chain HEADER.
- */
-
-RTEMS_INLINE_ROUTINE Watchdog_Control *_Watchdog_First(
-  Watchdog_Header *header
+RTEMS_INLINE_ROUTINE void _Watchdog_Per_CPU_remove(
+  Watchdog_Control *the_watchdog,
+  Per_CPU_Control  *cpu,
+  Watchdog_Header  *header
 )
 {
-
-  return ( (Watchdog_Control *) _Chain_First( &header->Watchdogs ) );
-
+  ISR_lock_Context lock_context;
+
+  _Watchdog_Per_CPU_acquire_critical( cpu, &lock_context );
+  _Watchdog_Remove(
+    header,
+    the_watchdog
+  );
+  _Watchdog_Per_CPU_release_critical( cpu, &lock_context );
 }
 
-/**
- * This routine returns a pointer to the last watchdog timer
- * on the watchdog chain HEADER.
- */
-
-RTEMS_INLINE_ROUTINE Watchdog_Control *_Watchdog_Last(
-  Watchdog_Header *header
+RTEMS_INLINE_ROUTINE void _Watchdog_Per_CPU_remove_relative(
+  Watchdog_Control *the_watchdog
 )
 {
-
-  return ( (Watchdog_Control *) _Chain_Last( &header->Watchdogs ) );
-
+  Per_CPU_Control *cpu;
+
+  cpu = _Watchdog_Get_CPU( the_watchdog );
+  _Watchdog_Per_CPU_remove(
+    the_watchdog,
+    cpu,
+    &cpu->Watchdog.Header[ PER_CPU_WATCHDOG_RELATIVE ]
+  );
 }
 
-RTEMS_INLINE_ROUTINE bool _Watchdog_Is_empty(
-  const Watchdog_Header *header
+RTEMS_INLINE_ROUTINE void _Watchdog_Per_CPU_remove_absolute(
+  Watchdog_Control *the_watchdog
 )
 {
-  return _Chain_Is_empty( &header->Watchdogs );
+  Per_CPU_Control *cpu;
+
+  cpu = _Watchdog_Get_CPU( the_watchdog );
+  _Watchdog_Per_CPU_remove(
+    the_watchdog,
+    cpu,
+    &cpu->Watchdog.Header[ PER_CPU_WATCHDOG_ABSOLUTE ]
+  );
 }
 
-RTEMS_INLINE_ROUTINE void _Watchdog_Header_initialize(
-  Watchdog_Header *header
+RTEMS_INLINE_ROUTINE void _Watchdog_Per_CPU_tickle_absolute(
+  Per_CPU_Control *cpu,
+  uint64_t         now
 )
 {
-  _ISR_lock_Initialize( &header->Lock, "Watchdog" );
-  _Chain_Initialize_empty( &header->Watchdogs );
-  _Chain_Initialize_empty( &header->Iterators );
+  ISR_lock_Context lock_context;
+
+  _ISR_lock_ISR_disable_and_acquire( &cpu->Watchdog.Lock, &lock_context );
+  _Watchdog_Tickle(
+    &cpu->Watchdog.Header[ PER_CPU_WATCHDOG_ABSOLUTE ],
+    now,
+    &cpu->Watchdog.Lock,
+    &lock_context
+  );
 }
 
 /** @} */