2009-12-08 Glenn Humphrey <glenn.humphrey@OARcorp.com>

	* rtems/include/rtems/rtems/ratemon.h, rtems/src/ratemongetstatus.c,
	rtems/src/ratemonperiod.c: Factored out common code to ensure
	consistent behavior between rtems_rate_monotonic_get_status and
	rtems_rate_monotonic_report_statistics.

3 files changed, 150 insertions, 95 deletions

diff --git a/cpukit/rtems/include/rtems/rtems/ratemon.h b/cpukit/rtems/include/rtems/rtems/ratemon.h
index 04f45d29a6..74b4022ceb 100644
--- a/cpukit/rtems/include/rtems/rtems/ratemon.h
+++ b/cpukit/rtems/include/rtems/rtems/ratemon.h
@@ -47,6 +47,11 @@
  *
  *  This encapsulates functionality related to the
  *  Classic API Rate Monotonic Manager.
+ *
+ *  Statistics are kept for each period and can be obtained or printed via
+ *  API calls.  The statistics kept include minimum, maximum and average times
+ *  for both cpu usage and wall time.  The statistics indicate the execution time
+ *  used by the owning thread between successive calls to rtems_rate_monotonic_period.
  */
 /**@{*/
 
@@ -224,18 +229,6 @@ typedef struct {
   rtems_rate_monotonic_period_states      state;
 
   /**
-   * This field contains the total CPU usage used while executing
-   * the body of the loop that is executed each period.
-   */
-  Thread_CPU_usage_t                      owner_executed_at_period;
-
-  /**
-   * This field contains the total wall timer that passed while
-   * executing the body of the loop that is executed each period.
-   */
-  Rate_monotonic_Period_time_t            time_at_period;
-
-  /**
    * This field contains the length of the next period to be
    * executed.
    */
@@ -248,8 +241,20 @@ typedef struct {
   Thread_Control                         *owner;
 
   /**
-   * This field contains the statistics which are maintained
-   * on each period.
+   * This field contains the cpu usage value of the owning thread when
+   * the period was initiated.  It is used to compute the period's
+   * statistics.
+   */
+  Thread_CPU_usage_t                      cpu_usage_period_initiated;
+
+  /**
+   * This field contains the wall time value when the period
+   * was initiated.  It is used to compute the period's statistics.
+   */
+  Rate_monotonic_Period_time_t            time_period_initiated;
+
+  /**
+   * This field contains the statistics maintained for the period.
    */
   Rate_monotonic_Statistics               Statistics;
 }   Rate_monotonic_Control;
@@ -285,9 +290,8 @@ rtems_status_code rtems_rate_monotonic_create(
  *  @brief rtems_rate_monotonic_ident
  *
  *  This routine implements the rtems_rate_monotonic_ident directive.
- *  This directive returns the period ID associated with name.
- *  If more than one period is named name, then the period
- *  to which the ID belongs is arbitrary.
+ *  It returns the period ID associated with name.  If more than one period
+ *  is named name, then the period to which the ID belongs is arbitrary.
  */
 rtems_status_code rtems_rate_monotonic_ident(
   rtems_name    name,
@@ -341,7 +345,7 @@ rtems_status_code rtems_rate_monotonic_get_statistics(
 /**
  *  @brief rtems_rate_monotonic_reset_statistics
  *
- *  This directive allows a thread to reset the statistics information
+ *  This routine allows a thread to reset the statistics information
  *  on a specific period instance.
  */
 rtems_status_code rtems_rate_monotonic_reset_statistics(
@@ -351,7 +355,7 @@ rtems_status_code rtems_rate_monotonic_reset_statistics(
 /**
  *  @brief rtems_rate_monotonic_reset_all_statistics
  *
- *  This directive allows a thread to reset the statistics information
+ *  This routine allows a thread to reset the statistics information
  *  on ALL period instances.
  */
 void rtems_rate_monotonic_reset_all_statistics( void );
@@ -359,7 +363,7 @@ void rtems_rate_monotonic_reset_all_statistics( void );
 /**
  *  @brief rtems_rate_monotonic_report_statistics
  *
- *  This directive allows a thread to print the statistics information
+ *  This routine allows a thread to print the statistics information
  *  on ALL period instances which have non-zero counts using printk.
  */
 void rtems_rate_monotonic_report_statistics_with_plugin(
@@ -370,7 +374,7 @@ void rtems_rate_monotonic_report_statistics_with_plugin(
 /**
  *  @brief rtems_rate_monotonic_report_statistics
  *
- *  This directive allows a thread to print the statistics information
+ *  This routine allows a thread to print the statistics information
  *  on ALL period instances which have non-zero counts using printk.
  */
 void rtems_rate_monotonic_report_statistics( void );
@@ -404,6 +408,27 @@ void _Rate_monotonic_Timeout(
 );
 
 /**
+ *  @brief _Rate_monotonic_Get_status(
+ *
+ *  This routine is invoked to compute the elapsed wall time and cpu
+ *  time for a period.
+ *
+ *  @param[in] the_period points to the period being operated upon.
+ *  @param[out] wall_since_last_period is set to the wall time elapsed
+ *              since the period was initiated.
+ *  @param[out] cpu_since_last_period is set to the cpu time used by the
+ *              owning thread since the period was initiated.
+ *
+ *  @return This routine returns true if the status can be determined
+ *          and false otherwise.
+ */
+bool _Rate_monotonic_Get_status(
+  Rate_monotonic_Control        *the_period,
+  Rate_monotonic_Period_time_t  *wall_since_last_period,
+  Thread_CPU_usage_t            *cpu_since_last_period
+);
+
+/**
  *  @brief _Rate_monotonic_Initiate_statistics(
  *
  *  This routine is invoked when a period is initiated via an explicit
diff --git a/cpukit/rtems/src/ratemongetstatus.c b/cpukit/rtems/src/ratemongetstatus.c
index bb22254563..5cc6b56a5e 100644
--- a/cpukit/rtems/src/ratemongetstatus.c
+++ b/cpukit/rtems/src/ratemongetstatus.c
@@ -49,12 +49,11 @@ rtems_status_code rtems_rate_monotonic_get_status(
   rtems_rate_monotonic_period_status  *status
 )
 {
+  Thread_CPU_usage_t             executed;
   Objects_Locations              location;
+  Rate_monotonic_Period_time_t   since_last_period;
   Rate_monotonic_Control        *the_period;
-  #ifndef __RTEMS_USE_TICKS_FOR_STATISTICS__
-    Timestamp_Control            uptime;
-    Timestamp_Control            temp;
-  #endif
+  bool                           valid_status;
 
   if ( !status )
     return RTEMS_INVALID_ADDRESS;
@@ -79,22 +78,29 @@ rtems_status_code rtems_rate_monotonic_get_status(
         #endif
 
       } else {
+
+        /*
+         *  Grab the current status.
+         */
+        valid_status =
+          _Rate_monotonic_Get_status(
+            the_period, &since_last_period, &executed
+          );
+        if (!valid_status) {
+          _Thread_Enable_dispatch();
+          return RTEMS_NOT_DEFINED;
+        }
+
         #ifndef __RTEMS_USE_TICKS_FOR_STATISTICS__
-          _TOD_Get_uptime( &uptime );
-          _Timestamp_Subtract( &the_period->time_at_period, &uptime, &temp );
-          _Timestamp_To_timespec( &temp, &status->since_last_period );
-          _Timestamp_Subtract(
-            &_Thread_Time_of_last_context_switch,
-            &uptime,
-            &temp
+          _Timestamp_To_timespec(
+            &since_last_period, &status->since_last_period
+          );
+          _Timestamp_To_timespec(
+            &executed, &status->executed_since_last_period
           );
-          _Timestamp_To_timespec( &temp, &status->executed_since_last_period );
         #else
-          status->since_last_period =
-            _Watchdog_Ticks_since_boot - the_period->time_at_period;
-          status->executed_since_last_period =
-            the_period->owner->cpu_time_used -
-            the_period->owner_executed_at_period;
+          status->since_last_period = since_last_period;
+          status->executed_since_last_period = executed;
         #endif
       }
 
diff --git a/cpukit/rtems/src/ratemonperiod.c b/cpukit/rtems/src/ratemonperiod.c
index a09de1d3e2..0a0d526950 100644
--- a/cpukit/rtems/src/ratemonperiod.c
+++ b/cpukit/rtems/src/ratemonperiod.c
@@ -23,6 +23,76 @@
 #include <rtems/rtems/ratemon.h>
 #include <rtems/score/thread.h>
 
+bool _Rate_monotonic_Get_status(
+  Rate_monotonic_Control        *the_period,
+  Rate_monotonic_Period_time_t  *wall_since_last_period,
+  Thread_CPU_usage_t            *cpu_since_last_period
+)
+{
+  #ifndef __RTEMS_USE_TICKS_FOR_STATISTICS__
+    Timestamp_Control        uptime;
+  #endif
+    Thread_Control          *owning_thread = the_period->owner;
+    Thread_CPU_usage_t       used;
+
+  /*
+   *  Determine elapsed wall time since period initiated.
+   */
+  #ifndef __RTEMS_USE_TICKS_FOR_STATISTICS__
+    _TOD_Get_uptime( &uptime );
+    _Timestamp_Subtract(
+      &the_period->time_period_initiated, &uptime, wall_since_last_period
+    );
+  #else
+    *wall_since_last_period =
+      _Watchdog_Ticks_since_boot - the_period->time_period_initiated;
+  #endif
+
+  /*
+   *  Determine cpu usage since period initiated.
+   */
+  used = owning_thread->cpu_time_used;
+
+  #ifndef __RTEMS_USE_TICKS_FOR_STATISTICS__
+    if (owning_thread == _Thread_Executing) {
+
+      Thread_CPU_usage_t ran;
+
+      /* How much time time since last context switch */
+      _Timestamp_Subtract(
+        &_Thread_Time_of_last_context_switch, &uptime, &ran
+      );
+
+      /* cpu usage += ran */
+      _Timestamp_Add_to( &used, &ran );
+
+      /*
+       *  The cpu usage info was reset while executing.  Can't
+       *  determine a status.
+       */
+      if (_Timestamp_Less_than(&used, &the_period->cpu_usage_period_initiated))
+        return false;
+
+       /* used = current cpu usage - cpu usage at start of period */
+      _Timestamp_Subtract(
+         &the_period->cpu_usage_period_initiated,
+         &used,
+         cpu_since_last_period
+      );
+    }
+  #else
+      /*
+       *  The cpu usage info was reset while executing.  Can't
+       *  determine a status.
+       */
+      if (used < the_period->cpu_usage_period_initiated)
+        return false;
+
+      *cpu_since_last_period = used - the_period->cpu_usage_period_initiated;
+  #endif
+  return true;
+}
+
 void _Rate_monotonic_Initiate_statistics(
   Rate_monotonic_Control *the_period
 )
@@ -42,12 +112,12 @@ void _Rate_monotonic_Initiate_statistics(
    *  Set the starting point and the CPU time used for the statistics.
    */
   #ifndef __RTEMS_USE_TICKS_FOR_STATISTICS__
-    the_period->time_at_period = uptime;
+    the_period->time_period_initiated = uptime;
   #else
-    the_period->time_at_period = _Watchdog_Ticks_since_boot;
+    the_period->time_period_initiated = _Watchdog_Ticks_since_boot;
   #endif
 
-  the_period->owner_executed_at_period = owning_thread->cpu_time_used;
+  the_period->cpu_usage_period_initiated = owning_thread->cpu_time_used;
 
   /*
    *  If using nanosecond statistics and the period's thread is currently
@@ -70,7 +140,7 @@ void _Rate_monotonic_Initiate_statistics(
 	&_Thread_Time_of_last_context_switch, &uptime, &ran
       );
 
-      _Timespec_Add_to( &the_period->owner_executed_at_period, &ran );
+      _Timespec_Add_to( &the_period->cpu_usage_period_initiated, &ran );
     }
   #endif
 }
@@ -79,18 +149,10 @@ void _Rate_monotonic_Update_statistics(
   Rate_monotonic_Control    *the_period
 )
 {
-  Rate_monotonic_Statistics      *stats;
   Thread_CPU_usage_t              executed;
   Rate_monotonic_Period_time_t    since_last_period;
-
-  /*
-   *  If using nanosecond statistics, we need to obtain the uptime.
-   */
-  #ifndef __RTEMS_USE_TICKS_FOR_STATISTICS__
-    Timestamp_Control  uptime;
-
-    _TOD_Get_uptime( &uptime );
-  #endif
+  Rate_monotonic_Statistics      *stats;
+  bool                            valid_status;
 
   /*
    *  Assume we are only called in states where it is appropriate
@@ -108,50 +170,12 @@ void _Rate_monotonic_Update_statistics(
     stats->missed_count++;
 
   /*
-   *  Grab basic information for time statistics.
+   *  Grab status for time statistics.
    */
-  #ifndef __RTEMS_USE_TICKS_FOR_STATISTICS__
-    _Timespec_Subtract(
-      &the_period->time_at_period,
-      &uptime,
-      &since_last_period
-    );
-  #else
-    since_last_period = _Watchdog_Ticks_since_boot - the_period->time_at_period;
-  #endif
-
-  #ifndef __RTEMS_USE_TICKS_FOR_STATISTICS__
-    {
-      Thread_CPU_usage_t ran, used;
-
-      /* Grab CPU usage when the thread got switched in */
-      used = _Thread_Executing->cpu_time_used;
-
-      /* partial period, cpu usage info reset while executing.  Throw away */
-      if (_Timestamp_Less_than( &used, &the_period->owner_executed_at_period))
-        return;
-
-      /* How much time time since last context switch */
-      _Timestamp_Subtract(&_Thread_Time_of_last_context_switch, &uptime, &ran);
-
-      /* executed += ran */
-      _Timestamp_Add_to( &used, &ran );
-
-       /* executed = current cpu usage - value at start of period */
-      _Timestamp_Subtract(
-         &the_period->owner_executed_at_period,
-         &used,
-         &executed
-      );
-    }
-  #else
-      /* partial period, cpu usage info reset while executing.  Throw away */
-      if (the_period->owner->cpu_time_used <
-          the_period->owner_executed_at_period)
-        return;
-      executed = the_period->owner->cpu_time_used -
-        the_period->owner_executed_at_period;
-  #endif
+  valid_status =
+    _Rate_monotonic_Get_status( the_period, &since_last_period, &executed );
+  if (!valid_status)
+    return;
 
   /*
    *  Update CPU time