rtems: Rework rate-monotonic scheduler

Use the default thread lock to protect rate-monotonic state changes.
This avoids use of the Giant lock.  Split rtems_rate_monotonic_period()
body into several static functions.  Introduce a new thread wait class
THREAD_WAIT_CLASS_PERIOD for period objects to synchronize the blocking
operation.

Close #2631.

1 files changed, 49 insertions, 52 deletions

diff --git a/cpukit/rtems/src/ratemongetstatus.c b/cpukit/rtems/src/ratemongetstatus.c
index 29296ebca3..82a950ec6a 100644
--- a/cpukit/rtems/src/ratemongetstatus.c
+++ b/cpukit/rtems/src/ratemongetstatus.c
@@ -8,6 +8,7 @@
 /*
  *  COPYRIGHT (c) 1989-2009.
  *  On-Line Applications Research Corporation (OAR).
+ *  Copyright (c) 2016 embedded brains GmbH.
  *
  *  The license and distribution terms for this file may be
  *  found in the file LICENSE in this distribution or at
@@ -18,72 +19,68 @@
 #include "config.h"
 #endif
 
-#include <rtems/system.h>
-#include <rtems/rtems/status.h>
-#include <rtems/rtems/support.h>
-#include <rtems/score/isr.h>
 #include <rtems/rtems/ratemonimpl.h>
-#include <rtems/score/thread.h>
-#include <rtems/score/timespec.h>
 
 rtems_status_code rtems_rate_monotonic_get_status(
   rtems_id                            id,
-  rtems_rate_monotonic_period_status *status
+  rtems_rate_monotonic_period_status *period_status
 )
 {
-  Timestamp_Control       executed;
-  Objects_Locations       location;
-  Timestamp_Control       since_last_period;
   Rate_monotonic_Control *the_period;
-  bool                    valid_status;
+  ISR_lock_Context        lock_context;
+  Thread_Control         *owner;
+  rtems_status_code       status;
 
-  if ( !status )
+  if ( period_status == NULL ) {
     return RTEMS_INVALID_ADDRESS;
+  }
 
-  the_period = _Rate_monotonic_Get( id, &location );
-  switch ( location ) {
-
-    case OBJECTS_LOCAL:
-      status->owner = the_period->owner->Object.id;
-      status->state = the_period->state;
-
-      /*
-       *  If the period is inactive, there is no information.
-       */
-      if ( status->state == RATE_MONOTONIC_INACTIVE ) {
-	_Timespec_Set_to_zero( &status->since_last_period );
-	_Timespec_Set_to_zero( &status->executed_since_last_period );
-      } else {
+  the_period = _Rate_monotonic_Get( id, &lock_context );
+  if ( the_period == NULL ) {
+    return RTEMS_INVALID_ID;
+  }
 
-        /*
-         *  Grab the current status.
-         */
-        valid_status =
-          _Rate_monotonic_Get_status(
-            the_period, &since_last_period, &executed
-          );
-        if (!valid_status) {
-          _Objects_Put( &the_period->Object );
-          return RTEMS_NOT_DEFINED;
-        }
+  owner = the_period->owner;
+  _Rate_monotonic_Acquire_critical( owner, &lock_context );
 
-	_Timestamp_To_timespec(
-	  &since_last_period, &status->since_last_period
-	);
-	_Timestamp_To_timespec(
-	  &executed, &status->executed_since_last_period
-	);
-      }
+  period_status->owner = owner->Object.id;
+  period_status->state = the_period->state;
 
-      _Objects_Put( &the_period->Object );
-      return RTEMS_SUCCESSFUL;
+  if ( the_period->state == RATE_MONOTONIC_INACTIVE ) {
+    /*
+     *  If the period is inactive, there is no information.
+     */
+    _Timespec_Set_to_zero( &period_status->since_last_period );
+    _Timespec_Set_to_zero( &period_status->executed_since_last_period );
+    status = RTEMS_SUCCESSFUL;
+  } else {
+    Timestamp_Control wall_since_last_period;
+    Timestamp_Control cpu_since_last_period;
+    bool              valid_status;
 
-#if defined(RTEMS_MULTIPROCESSING)
-    case OBJECTS_REMOTE:            /* should never return this */
-#endif
-    case OBJECTS_ERROR:
-      break;
+    /*
+     *  Grab the current status.
+     */
+    valid_status = _Rate_monotonic_Get_status(
+      the_period,
+      &wall_since_last_period,
+      &cpu_since_last_period
+    );
+    if ( valid_status ) {
+      _Timestamp_To_timespec(
+        &wall_since_last_period,
+        &period_status->since_last_period
+      );
+      _Timestamp_To_timespec(
+        &cpu_since_last_period,
+        &period_status->executed_since_last_period
+      );
+      status = RTEMS_SUCCESSFUL;
+    } else {
+      status = RTEMS_NOT_DEFINED;
+    }
   }
 
-  return RTEMS_INVALID_ID;
+  _Rate_monotonic_Release( owner, &lock_context );
+  return status;
 }