score: Introduce CPU budget operations

This patch set replaces the CPU budget algorithm enumeration with a set of CPU
budget operations which implement a particular CPU budget algorithm.  This
helps to hide the CPU budget algorithm implementation details from the general
thread handling.  The CPU budget callouts are turned into CPU budget
operations.  This slightly reduces the size of the thread control block.

All schedulers used the default scheduler tick implementation.  The tick
scheduler operation is removed and the CPU budget operations are directly used
in _Watchdog_Tick() if the executing thread uses a CPU budget algorithm.  This
is performance improvement for all threads which do not use a CPU budget
algorithm (default behaviour).

3 files changed, 18 insertions, 18 deletions

diff --git a/cpukit/rtems/src/signalsend.c b/cpukit/rtems/src/signalsend.c
index 72407e2b01..6ce59f2e74 100644
--- a/cpukit/rtems/src/signalsend.c
+++ b/cpukit/rtems/src/signalsend.c
@@ -35,16 +35,15 @@ static void _Signal_Action_handler(
   ISR_lock_Context *lock_context
 )
 {
-  RTEMS_API_Control           *api;
-  ASR_Information             *asr;
-  rtems_signal_set             signal_set;
-  bool                         normal_is_preemptible;
-  uint32_t                     normal_cpu_time_budget;
-  Thread_CPU_budget_algorithms normal_budget_algorithm;
-  uint32_t                     normal_isr_level;
-  uint32_t                     before_call_isr_level;
-  bool                         after_call_is_preemptible;
-  bool                         after_call_asr_is_enabled;
+  RTEMS_API_Control        *api;
+  ASR_Information          *asr;
+  rtems_signal_set          signal_set;
+  bool                      normal_is_preemptible;
+  Thread_CPU_budget_control normal_cpu_budget;
+  uint32_t                  normal_isr_level;
+  uint32_t                  before_call_isr_level;
+  bool                      after_call_is_preemptible;
+  bool                      after_call_asr_is_enabled;
 
   (void) action;
 
@@ -69,8 +68,7 @@ static void _Signal_Action_handler(
 
   _Assert( asr->is_enabled );
   normal_is_preemptible = executing->is_preemptible;
-  normal_cpu_time_budget = executing->cpu_time_budget;
-  normal_budget_algorithm = executing->budget_algorithm;
+  normal_cpu_budget = executing->CPU_budget;
 
   /* Set mode for ASR processing */
 
@@ -102,8 +100,7 @@ static void _Signal_Action_handler(
 
   _Thread_State_acquire( executing, lock_context );
 
-  executing->cpu_time_budget = normal_cpu_time_budget ;
-  executing->budget_algorithm = normal_budget_algorithm ;
+  executing->CPU_budget = normal_cpu_budget;
   after_call_is_preemptible = executing->is_preemptible;
   executing->is_preemptible = normal_is_preemptible;
 
diff --git a/cpukit/rtems/src/taskconstruct.c b/cpukit/rtems/src/taskconstruct.c
index 6e03440aed..05fbf32ff5 100644
--- a/cpukit/rtems/src/taskconstruct.c
+++ b/cpukit/rtems/src/taskconstruct.c
@@ -154,14 +154,17 @@ rtems_status_code _RTEMS_tasks_Create(
   attributes = _Attributes_Clear( attributes, ATTRIBUTES_NOT_SUPPORTED );
 
   memset( &thread_config, 0, sizeof( thread_config ) );
-  thread_config.budget_algorithm = _Modes_Is_timeslice( config->initial_modes ) ?
-    THREAD_CPU_BUDGET_ALGORITHM_RESET_TIMESLICE
-      : THREAD_CPU_BUDGET_ALGORITHM_NONE,
   thread_config.isr_level =  _Modes_Get_interrupt_level( config->initial_modes );
   thread_config.name = config->name;
   thread_config.is_fp = _Attributes_Is_floating_point( attributes );
   thread_config.is_preemptible = _Modes_Is_preempt( config->initial_modes );
 
+  if ( _Modes_Is_timeslice( config->initial_modes ) ) {
+    thread_config.cpu_budget_operations = &_Thread_CPU_budget_reset_timeslice;
+  } else {
+    thread_config.cpu_budget_operations = NULL;
+  }
+
   /*
    *  Validate the RTEMS API priority and convert it to the core priority range.
    */
diff --git a/cpukit/rtems/src/taskmode.c b/cpukit/rtems/src/taskmode.c
index 96bed470f4..3300eafa28 100644
--- a/cpukit/rtems/src/taskmode.c
+++ b/cpukit/rtems/src/taskmode.c
@@ -73,7 +73,7 @@ rtems_status_code rtems_task_mode(
 
   old_mode  = (executing->is_preemptible) ? RTEMS_PREEMPT : RTEMS_NO_PREEMPT;
 
-  if ( executing->budget_algorithm == THREAD_CPU_BUDGET_ALGORITHM_NONE )
+  if ( executing->CPU_budget.operations == NULL )
     old_mode |= RTEMS_NO_TIMESLICE;
   else
     old_mode |= RTEMS_TIMESLICE;