new isr synchronization algorithm using a single enumerated set of states.

12 files changed, 110 insertions, 66 deletions

diff --git a/c/src/exec/rtems/inline/event.inl b/c/src/exec/rtems/inline/event.inl
index 5377144f98..0e2a1691ed 100644
--- a/c/src/exec/rtems/inline/event.inl
+++ b/c/src/exec/rtems/inline/event.inl
@@ -23,7 +23,7 @@
 
 STATIC INLINE void _Event_Manager_initialization( void )
 {
-  _Event_Sync = FALSE;
+  _Event_Sync_state = EVENT_SYNC_SYNCHRONIZED;
 
   /*
    *  Register the MP Process Packet routine.
diff --git a/c/src/exec/rtems/inline/rtems/rtems/event.inl b/c/src/exec/rtems/inline/rtems/rtems/event.inl
index 5377144f98..0e2a1691ed 100644
--- a/c/src/exec/rtems/inline/rtems/rtems/event.inl
+++ b/c/src/exec/rtems/inline/rtems/rtems/event.inl
@@ -23,7 +23,7 @@
 
 STATIC INLINE void _Event_Manager_initialization( void )
 {
-  _Event_Sync = FALSE;
+  _Event_Sync_state = EVENT_SYNC_SYNCHRONIZED;
 
   /*
    *  Register the MP Process Packet routine.
diff --git a/c/src/exec/rtems/macros/event.inl b/c/src/exec/rtems/macros/event.inl
index 0d2f2e47c7..eb956e7639 100644
--- a/c/src/exec/rtems/macros/event.inl
+++ b/c/src/exec/rtems/macros/event.inl
@@ -24,7 +24,7 @@
 #define _Event_Manager_initialization() \
   do { \
     \
-    _Event_Sync = FALSE; \
+    _Event_Sync_state = EVENT_SYNC_SYNCHRONIZED; \
     \
     /* \
      *  Register the MP Process Packet routine. \
diff --git a/c/src/exec/rtems/macros/rtems/rtems/event.inl b/c/src/exec/rtems/macros/rtems/rtems/event.inl
index 0d2f2e47c7..eb956e7639 100644
--- a/c/src/exec/rtems/macros/rtems/rtems/event.inl
+++ b/c/src/exec/rtems/macros/rtems/rtems/event.inl
@@ -24,7 +24,7 @@
 #define _Event_Manager_initialization() \
   do { \
     \
-    _Event_Sync = FALSE; \
+    _Event_Sync_state = EVENT_SYNC_SYNCHRONIZED; \
     \
     /* \
      *  Register the MP Process Packet routine. \
diff --git a/c/src/exec/rtems/src/event.c b/c/src/exec/rtems/src/event.c
index 9bea949647..3042de2676 100644
--- a/c/src/exec/rtems/src/event.c
+++ b/c/src/exec/rtems/src/event.c
@@ -144,6 +144,7 @@ void _Event_Seize(
   rtems_event_set    pending_events;
   ISR_Level          level;
   RTEMS_API_Control  *api;
+  Event_Sync_states   sync_state;
 
   executing = _Thread_Executing;
   executing->Wait.return_code = RTEMS_SUCCESSFUL;
@@ -170,7 +171,6 @@ void _Event_Seize(
     return;
   }
 
-  _Event_Sync       = TRUE;
   _Event_Sync_state = EVENT_SYNC_NOTHING_HAPPENED;
 
   executing->Wait.option            = (unsigned32) option_set;
@@ -192,9 +192,13 @@ void _Event_Seize(
   _Thread_Set_state( executing, STATES_WAITING_FOR_EVENT );
 
   _ISR_Disable( level );
-  switch ( _Event_Sync_state ) {
+
+  sync_state = _Event_Sync_state;
+  _Event_Sync_state = EVENT_SYNC_SYNCHRONIZED;
+
+  switch ( sync_state ) {
+    case EVENT_SYNC_SYNCHRONIZED:
     case EVENT_SYNC_NOTHING_HAPPENED:
-      _Event_Sync = FALSE;
       _ISR_Enable( level );
       return;
     case EVENT_SYNC_TIMEOUT:
@@ -274,12 +278,24 @@ void _Event_Surrender(
         return;
       }
     }
-    else if ( _Event_Sync == TRUE && _Thread_Is_executing( the_thread ) ) {
-      if ( seized_events == event_condition || _Options_Is_any( option_set ) ) {
-        api->pending_events = _Event_sets_Clear( pending_events,seized_events );
-        *(rtems_event_set *)the_thread->Wait.return_argument = seized_events;
-        _Event_Sync_state = EVENT_SYNC_SATISFIED;
-      }
+
+    switch ( _Event_Sync_state ) {
+      case EVENT_SYNC_SYNCHRONIZED:
+      case EVENT_SYNC_SATISFIED:
+        break;
+ 
+      case EVENT_SYNC_NOTHING_HAPPENED:
+      case EVENT_SYNC_TIMEOUT:
+        if ( !_Thread_Is_executing( the_thread ) )
+          break;
+
+        if ( seized_events == event_condition || _Options_Is_any(option_set) ) {
+          api->pending_events = 
+               _Event_sets_Clear( pending_events,seized_events );
+          *(rtems_event_set *)the_thread->Wait.return_argument = seized_events;
+          _Event_Sync_state = EVENT_SYNC_SATISFIED;
+        }
+        break;
     }
   }
   _ISR_Enable( level );
@@ -312,7 +328,8 @@ void _Event_Timeout(
     case OBJECTS_REMOTE:  /* impossible */
       break;
     case OBJECTS_LOCAL:
-      if ( _Event_Sync == TRUE && _Thread_Is_executing( the_thread ) ) {
+      if ( _Event_Sync_state != EVENT_SYNC_SYNCHRONIZED && 
+           _Thread_Is_executing( the_thread ) ) {
         if ( _Event_Sync_state != EVENT_SYNC_SATISFIED )
           _Event_Sync_state = EVENT_SYNC_TIMEOUT;
       } else {
diff --git a/c/src/exec/score/headers/tqdata.h b/c/src/exec/score/headers/tqdata.h
index 872a29beb0..a4a5551dfd 100644
--- a/c/src/exec/score/headers/tqdata.h
+++ b/c/src/exec/score/headers/tqdata.h
@@ -41,10 +41,11 @@ typedef enum {
  */
  
 typedef enum {
+  THREAD_QUEUE_SYNCHRONIZED,
   THREAD_QUEUE_NOTHING_HAPPENED,
   THREAD_QUEUE_TIMEOUT,
   THREAD_QUEUE_SATISFIED
-}  Thread_queue_states;
+}  Thread_queue_States;
 
 /*
  *  The following record defines the control block used
@@ -59,8 +60,7 @@ typedef struct {
     Chain_Control Priority[TASK_QUEUE_DATA_NUMBER_OF_PRIORITY_HEADERS];
                                        /* priority discipline list       */
   } Queues;
-  boolean                  sync;       /* alloc/dealloc critical section */
-  Thread_queue_states      sync_state; /* what happened while in sync    */
+  Thread_queue_States      sync_state; /* alloc/dealloc critical section */
   Thread_queue_Disciplines discipline; /* queue discipline               */
   States_Control           state;      /* state of threads on Thread_q   */
   unsigned32               timeout_status;
diff --git a/c/src/exec/score/include/rtems/score/tqdata.h b/c/src/exec/score/include/rtems/score/tqdata.h
index 872a29beb0..a4a5551dfd 100644
--- a/c/src/exec/score/include/rtems/score/tqdata.h
+++ b/c/src/exec/score/include/rtems/score/tqdata.h
@@ -41,10 +41,11 @@ typedef enum {
  */
  
 typedef enum {
+  THREAD_QUEUE_SYNCHRONIZED,
   THREAD_QUEUE_NOTHING_HAPPENED,
   THREAD_QUEUE_TIMEOUT,
   THREAD_QUEUE_SATISFIED
-}  Thread_queue_states;
+}  Thread_queue_States;
 
 /*
  *  The following record defines the control block used
@@ -59,8 +60,7 @@ typedef struct {
     Chain_Control Priority[TASK_QUEUE_DATA_NUMBER_OF_PRIORITY_HEADERS];
                                        /* priority discipline list       */
   } Queues;
-  boolean                  sync;       /* alloc/dealloc critical section */
-  Thread_queue_states      sync_state; /* what happened while in sync    */
+  Thread_queue_States      sync_state; /* alloc/dealloc critical section */
   Thread_queue_Disciplines discipline; /* queue discipline               */
   States_Control           state;      /* state of threads on Thread_q   */
   unsigned32               timeout_status;
diff --git a/c/src/exec/score/inline/rtems/score/tqdata.inl b/c/src/exec/score/inline/rtems/score/tqdata.inl
index 3cf9c51ef6..b16b3a1ca1 100644
--- a/c/src/exec/score/inline/rtems/score/tqdata.inl
+++ b/c/src/exec/score/inline/rtems/score/tqdata.inl
@@ -66,7 +66,6 @@ STATIC INLINE void _Thread_queue_Enter_critical_section (
   Thread_queue_Control *the_thread_queue
 )
 {
-  the_thread_queue->sync = TRUE;
   the_thread_queue->sync_state = THREAD_QUEUE_NOTHING_HAPPENED;
 }
 
diff --git a/c/src/exec/score/inline/tqdata.inl b/c/src/exec/score/inline/tqdata.inl
index 3cf9c51ef6..b16b3a1ca1 100644
--- a/c/src/exec/score/inline/tqdata.inl
+++ b/c/src/exec/score/inline/tqdata.inl
@@ -66,7 +66,6 @@ STATIC INLINE void _Thread_queue_Enter_critical_section (
   Thread_queue_Control *the_thread_queue
 )
 {
-  the_thread_queue->sync = TRUE;
   the_thread_queue->sync_state = THREAD_QUEUE_NOTHING_HAPPENED;
 }
 
diff --git a/c/src/exec/score/macros/rtems/score/tqdata.inl b/c/src/exec/score/macros/rtems/score/tqdata.inl
index 1df3cd5270..df1508104c 100644
--- a/c/src/exec/score/macros/rtems/score/tqdata.inl
+++ b/c/src/exec/score/macros/rtems/score/tqdata.inl
@@ -52,7 +52,6 @@
  
 #define _Thread_queue_Enter_critical_section( _the_thread_queue ) \
   do { \
-    (_the_thread_queue)->sync = TRUE; \
     (_the_thread_queue)->sync_state = THREAD_QUEUE_NOTHING_HAPPENED; \
   } while ( 0 )
 
diff --git a/c/src/exec/score/macros/tqdata.inl b/c/src/exec/score/macros/tqdata.inl
index 1df3cd5270..df1508104c 100644
--- a/c/src/exec/score/macros/tqdata.inl
+++ b/c/src/exec/score/macros/tqdata.inl
@@ -52,7 +52,6 @@
  
 #define _Thread_queue_Enter_critical_section( _the_thread_queue ) \
   do { \
-    (_the_thread_queue)->sync = TRUE; \
     (_the_thread_queue)->sync_state = THREAD_QUEUE_NOTHING_HAPPENED; \
   } while ( 0 )
 
diff --git a/c/src/exec/score/src/threadq.c b/c/src/exec/score/src/threadq.c
index dc52efa954..682a0362bc 100644
--- a/c/src/exec/score/src/threadq.c
+++ b/c/src/exec/score/src/threadq.c
@@ -55,6 +55,7 @@ void _Thread_queue_Initialize(
   the_thread_queue->state          = state;
   the_thread_queue->discipline     = the_discipline;
   the_thread_queue->timeout_status = timeout_status;
+  the_thread_queue->sync_state     = THREAD_QUEUE_SYNCHRONIZED;
 
   switch ( the_discipline ) {
     case THREAD_QUEUE_DISCIPLINE_FIFO:
@@ -326,7 +327,8 @@ void _Thread_queue_Timeout(
     case OBJECTS_LOCAL:
       the_thread_queue = the_thread->Wait.queue;
 
-      if ( the_thread_queue->sync == TRUE && _Thread_Is_executing(the_thread)) {
+      if ( the_thread_queue->sync_state != THREAD_QUEUE_SYNCHRONIZED &&
+           _Thread_Is_executing( the_thread ) ) {
         if ( the_thread_queue->sync_state != THREAD_QUEUE_SATISFIED )
           the_thread_queue->sync_state = THREAD_QUEUE_TIMEOUT;
       } else {
@@ -362,13 +364,22 @@ void _Thread_queue_Enqueue_fifo (
   Watchdog_Interval    timeout
 )
 {
-  ISR_Level level;
+  ISR_Level            level;
+  Thread_queue_States  sync_state;
 
   _ISR_Disable( level );
 
-  the_thread_queue->sync = FALSE;
+  sync_state = the_thread_queue->sync_state;
+  the_thread_queue->sync_state = THREAD_QUEUE_SYNCHRONIZED;
+
+  switch ( sync_state ) {
+    case THREAD_QUEUE_SYNCHRONIZED: 
+      /*
+       *  This should never happen.  It indicates that someone did not
+       *  enter a thread queue critical section.
+       */
+      break;
 
-  switch ( the_thread_queue->sync_state ) {
     case THREAD_QUEUE_NOTHING_HAPPENED: 
       _Chain_Append_unprotected(
         &the_thread_queue->Queues.Fifo,
@@ -449,15 +460,21 @@ Thread_Control *_Thread_queue_Dequeue_fifo(
       _Thread_MP_Free_proxy( the_thread );
 
     return the_thread;
-  } else if ( the_thread_queue->sync && 
-              the_thread_queue->sync_state != THREAD_QUEUE_SATISFIED ) {
-    the_thread_queue->sync_state = THREAD_QUEUE_SATISFIED;
-    _ISR_Enable( level );
-    return _Thread_Executing;
-  } else {
-    _ISR_Enable( level );
-    return NULL;
+  } 
+
+  switch ( the_thread_queue->sync_state ) {
+    case THREAD_QUEUE_SYNCHRONIZED:
+    case THREAD_QUEUE_SATISFIED:
+      _ISR_Enable( level );
+      return NULL;
+
+    case THREAD_QUEUE_NOTHING_HAPPENED:
+    case THREAD_QUEUE_TIMEOUT:
+      the_thread_queue->sync_state = THREAD_QUEUE_SATISFIED;
+      _ISR_Enable( level );
+      return _Thread_Executing;
   }
+  return NULL;                /* this is only to prevent warnings */
 }
 
 /*PAGE
@@ -557,17 +574,18 @@ void _Thread_queue_Enqueue_priority(
   Watchdog_Interval     timeout
 )
 {
-  Priority_Control  search_priority;
-  Thread_Control   *search_thread;
-  ISR_Level         level;
-  Chain_Control    *header;
-  unsigned32        header_index;
-  Chain_Node       *the_node;
-  Chain_Node       *next_node;
-  Chain_Node       *previous_node;
-  Chain_Node       *search_node;
-  Priority_Control  priority;
-  States_Control    block_state;
+  Priority_Control     search_priority;
+  Thread_Control      *search_thread;
+  ISR_Level            level;
+  Chain_Control       *header;
+  unsigned32           header_index;
+  Chain_Node          *the_node;
+  Chain_Node          *next_node;
+  Chain_Node          *previous_node;
+  Chain_Node          *search_node;
+  Priority_Control     priority;
+  States_Control       block_state;
+  Thread_queue_States  sync_state;
 
   _Chain_Initialize_empty( &the_thread->Wait.Block2n );
 
@@ -605,10 +623,10 @@ restart_forward_search:
        (Thread_Control *)search_thread->Object.Node.next;
   }
 
-  the_thread_queue->sync = FALSE;
-
   if ( the_thread_queue->sync_state != THREAD_QUEUE_NOTHING_HAPPENED )
-    goto syncronize;
+    goto synchronize;
+
+  the_thread_queue->sync_state = THREAD_QUEUE_SYNCHRONIZED;
 
   if ( priority == search_priority )
     goto equal_priority;
@@ -650,10 +668,10 @@ restart_reverse_search:
                          search_thread->Object.Node.previous;
   }
 
-  the_thread_queue->sync = FALSE;
-
   if ( the_thread_queue->sync_state != THREAD_QUEUE_NOTHING_HAPPENED )
-    goto syncronize;
+    goto synchronize;
+
+  the_thread_queue->sync_state = THREAD_QUEUE_SYNCHRONIZED;
 
   if ( priority == search_priority )
     goto equal_priority;
@@ -681,9 +699,19 @@ equal_priority:               /* add at end of priority group */
   _ISR_Enable( level );
   return;
 
-syncronize:
+synchronize:
 
-  switch ( the_thread_queue->sync_state ) {
+  sync_state = the_thread_queue->sync_state;
+  the_thread_queue->sync_state = THREAD_QUEUE_SYNCHRONIZED;
+
+  switch ( sync_state ) {
+    case THREAD_QUEUE_SYNCHRONIZED:
+      /*
+       *  This should never happen.  It indicates that someone did not
+       *  enter a thread queue critical section.
+       */
+      break;
+ 
     case THREAD_QUEUE_NOTHING_HAPPENED:
       /*
        *  All of this was dealt with above.  This should never happen.
@@ -738,9 +766,9 @@ Thread_Control *_Thread_queue_Dequeue_priority(
   Thread_queue_Control *the_thread_queue
 )
 {
-  unsigned32             index;
-  ISR_Level              level;
-  Thread_Control *the_thread;
+  unsigned32      index;
+  ISR_Level       level;
+  Thread_Control *the_thread = NULL;  /* just to remove warnings */
   Thread_Control *new_first_thread;
   Chain_Node     *new_first_node;
   Chain_Node     *new_second_node;
@@ -759,15 +787,18 @@ Thread_Control *_Thread_queue_Dequeue_priority(
     }
   }
 
-  if ( the_thread_queue->sync && 
-       the_thread_queue->sync_state != THREAD_QUEUE_SATISFIED ) {
-    the_thread_queue->sync_state = THREAD_QUEUE_SATISFIED;
-    _ISR_Enable( level );
-    return _Thread_Executing;
-  } 
+  switch ( the_thread_queue->sync_state ) {
+    case THREAD_QUEUE_SYNCHRONIZED:
+    case THREAD_QUEUE_SATISFIED:
+      _ISR_Enable( level );
+      return NULL;
 
-  _ISR_Enable( level );
-  return NULL;
+    case THREAD_QUEUE_NOTHING_HAPPENED:
+    case THREAD_QUEUE_TIMEOUT:
+      the_thread_queue->sync_state = THREAD_QUEUE_SATISFIED;
+      _ISR_Enable( level );
+      return _Thread_Executing;
+  }
 
 dequeue:
   new_first_node   = the_thread->Wait.Block2n.first;