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.

2 files changed, 41 insertions, 92 deletions

diff --git a/cpukit/rtems/include/rtems/rtems/ratemon.h b/cpukit/rtems/include/rtems/rtems/ratemon.h
index 0159e5c1e6..87bd064c98 100644
--- a/cpukit/rtems/include/rtems/rtems/ratemon.h
+++ b/cpukit/rtems/include/rtems/rtems/ratemon.h
@@ -84,24 +84,12 @@ typedef enum {
 
   /**
    * This value indicates the period is on the watchdog chain, and
-   * the owner is blocked waiting on it.
-   */
-  RATE_MONOTONIC_OWNER_IS_BLOCKING,
-
-  /**
-   * This value indicates the period is on the watchdog chain, and
    * running.  The owner should be executed or blocked waiting on
    * another object.
    */
   RATE_MONOTONIC_ACTIVE,
 
   /**
-   * This value indicates the period is on the watchdog chain, and
-   * has expired.  The owner should be blocked waiting for the next period.
-   */
-  RATE_MONOTONIC_EXPIRED_WHILE_BLOCKING,
-
-  /**
    * This value indicates the period is off the watchdog chain, and
    * has expired.  The owner is still executing and has taken too much
    * all time to complete this iteration of the period.
@@ -194,8 +182,12 @@ typedef struct {
 }  rtems_rate_monotonic_period_status;
 
 /**
- *  The following structure defines the control block used to manage
- *  each period.
+ * @brief The following structure defines the control block used to manage each
+ * period.
+ *
+ * State changes are protected by the default thread lock of the owner thread.
+ * The owner thread is the thread that created the period object.  The owner
+ * thread field is immutable after object creation.
  */
 typedef struct {
   /** This field is the object management portion of a Period instance. */
diff --git a/cpukit/rtems/include/rtems/rtems/ratemonimpl.h b/cpukit/rtems/include/rtems/rtems/ratemonimpl.h
index 3141bfa9ae..28837a2c16 100644
--- a/cpukit/rtems/include/rtems/rtems/ratemonimpl.h
+++ b/cpukit/rtems/include/rtems/rtems/ratemonimpl.h
@@ -8,6 +8,7 @@
 
 /*  COPYRIGHT (c) 1989-2008.
  *  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
@@ -19,6 +20,9 @@
 
 #include <rtems/rtems/ratemon.h>
 #include <rtems/score/objectimpl.h>
+#include <rtems/score/schedulerimpl.h>
+#include <rtems/score/threadimpl.h>
+#include <rtems/score/watchdogimpl.h>
 
 #include <string.h>
 
@@ -34,6 +38,15 @@ extern "C" {
  * @{
  */
 
+#define RATE_MONOTONIC_INTEND_TO_BLOCK \
+  ( THREAD_WAIT_CLASS_PERIOD | THREAD_WAIT_STATE_INTEND_TO_BLOCK )
+
+#define RATE_MONOTONIC_BLOCKED \
+  ( THREAD_WAIT_CLASS_PERIOD | THREAD_WAIT_STATE_BLOCKED )
+
+#define RATE_MONOTONIC_READY_AGAIN \
+  ( THREAD_WAIT_CLASS_PERIOD | THREAD_WAIT_STATE_READY_AGAIN )
+
 /**
  *  @brief Rate Monotonic Period Class Management Structure
  *
@@ -55,86 +68,31 @@ RTEMS_INLINE_ROUTINE Rate_monotonic_Control *_Rate_monotonic_Allocate( void )
     _Objects_Allocate( &_Rate_monotonic_Information );
 }
 
-/**
- *  @brief Allocates a period control block from
- *  the inactive chain of free period control blocks.
- *
- *  This routine allocates a period control block from
- *  the inactive chain of free period control blocks.
- */
-RTEMS_INLINE_ROUTINE void _Rate_monotonic_Free (
-  Rate_monotonic_Control *the_period
+RTEMS_INLINE_ROUTINE void _Rate_monotonic_Acquire_critical(
+  Thread_Control   *the_thread,
+  ISR_lock_Context *lock_context
 )
 {
-  _Objects_Free( &_Rate_monotonic_Information, &the_period->Object );
+  _Thread_Lock_acquire_default_critical( the_thread, lock_context );
 }
 
-/**
- *  @brief Maps period IDs to period control blocks.
- *
- *  This function maps period IDs to period control blocks.
- *  If ID corresponds to a local period, then it returns
- *  the_period control pointer which maps to ID and location
- *  is set to OBJECTS_LOCAL.  Otherwise, location is set
- *  to OBJECTS_ERROR and the_period is undefined.
- */
-RTEMS_INLINE_ROUTINE Rate_monotonic_Control *_Rate_monotonic_Get (
-  Objects_Id         id,
-  Objects_Locations *location
+RTEMS_INLINE_ROUTINE void _Rate_monotonic_Release(
+  Thread_Control   *the_thread,
+  ISR_lock_Context *lock_context
 )
 {
-  return (Rate_monotonic_Control *)
-    _Objects_Get( &_Rate_monotonic_Information, id, location );
+  _Thread_Lock_release_default( the_thread, lock_context );
 }
 
-/**
- *  @brief Checks if the_period is in the ACTIVE state.
- *
- *  This function returns TRUE if the_period is in the ACTIVE state,
- *  and FALSE otherwise.
- */
-RTEMS_INLINE_ROUTINE bool _Rate_monotonic_Is_active (
-  Rate_monotonic_Control *the_period
+RTEMS_INLINE_ROUTINE Rate_monotonic_Control *_Rate_monotonic_Get(
+  Objects_Id        id,
+  ISR_lock_Context *lock_context
 )
 {
-  return (the_period->state == RATE_MONOTONIC_ACTIVE);
-}
-
-/**
- *  @brief Checks if the_period is in the ACTIVE state.
- *
- *  This function returns TRUE if the_period is in the ACTIVE state,
- *  and FALSE otherwise.
- */
-RTEMS_INLINE_ROUTINE bool _Rate_monotonic_Is_inactive (
-  Rate_monotonic_Control *the_period
-)
-{
-  return (the_period->state == RATE_MONOTONIC_INACTIVE);
-}
-
-/**
- *  @brief Checks if the_period is in the EXPIRED state.
- *
- *  This function returns TRUE if the_period is in the EXPIRED state,
- *  and FALSE otherwise.
- */
-RTEMS_INLINE_ROUTINE bool _Rate_monotonic_Is_expired (
-  Rate_monotonic_Control *the_period
-)
-{
-  return (the_period->state == RATE_MONOTONIC_EXPIRED);
+  return (Rate_monotonic_Control *)
+    _Objects_Get_local( &_Rate_monotonic_Information, id, lock_context );
 }
 
-/**
- * @brief Rate Monotonic Timeout
- *
- * This routine is invoked when the period represented by the watchdog expires.
- * If the thread which owns this period is blocked waiting for the period to
- * expire, then it is readied and the period is restarted. If the owning thread
- * is not waiting for the period to expire, then the period is placed in the
- * EXPIRED state and not restarted.
- */
 void _Rate_monotonic_Timeout( Watchdog_Control *watchdog );
 
 /**
@@ -158,17 +116,16 @@ bool _Rate_monotonic_Get_status(
   Timestamp_Control            *cpu_since_last_period
 );
 
-/**
- *  @brief Restart Rate Monotonic Period
- *
- *  This routine is invoked when a period is initiated via an explicit
- *  call to rtems_rate_monotonic_period for the period's first iteration
- *  or from _Rate_monotonic_Timeout for period iterations 2-n.
- *
- *  @param[in] the_period points to the period being operated upon.
- */
 void _Rate_monotonic_Restart(
-  Rate_monotonic_Control *the_period
+  Rate_monotonic_Control *the_period,
+  Thread_Control         *owner,
+  ISR_lock_Context       *lock_context
+);
+
+void _Rate_monotonic_Cancel(
+  Rate_monotonic_Control *the_period,
+  Thread_Control         *owner,
+  ISR_lock_Context       *lock_context
 );
 
 RTEMS_INLINE_ROUTINE void _Rate_monotonic_Reset_min_time(