score: Add thread queue enqueue callout

Replace the expected thread dispatch disable level with a thread queue
enqueue callout.  This enables the use of _Thread_Dispatch_direct() in
the thread queue enqueue procedure.  This avoids impossible exection
paths, e.g. Per_CPU_Control::dispatch_necessary is always true.

3 files changed, 44 insertions, 31 deletions

diff --git a/cpukit/rtems/include/rtems/rtems/regionimpl.h b/cpukit/rtems/include/rtems/rtems/regionimpl.h
index 1f31ad4adb..178b7ea32b 100644
--- a/cpukit/rtems/include/rtems/rtems/regionimpl.h
+++ b/cpukit/rtems/include/rtems/rtems/regionimpl.h
@@ -35,6 +35,9 @@ extern "C" {
  * @{
  */
 
+#define REGION_OF_THREAD_QUEUE_QUEUE( queue ) \
+  RTEMS_CONTAINER_OF( queue, Region_Control, Wait_queue.Queue )
+
 /**
  *  The following defines the information control block used to
  *  manage this class of objects.
diff --git a/cpukit/rtems/src/regiongetsegment.c b/cpukit/rtems/src/regiongetsegment.c
index ec0c52519b..dc17b21956 100644
--- a/cpukit/rtems/src/regiongetsegment.c
+++ b/cpukit/rtems/src/regiongetsegment.c
@@ -24,6 +24,18 @@
 #include <rtems/score/threadqimpl.h>
 #include <rtems/score/statesimpl.h>
 
+static void _Region_Enqueue_callout(
+  Thread_queue_Queue   *queue,
+  Thread_Control       *the_thread,
+  Thread_queue_Context *queue_context
+)
+{
+  Region_Control *the_region;
+
+  the_region = REGION_OF_THREAD_QUEUE_QUEUE( queue );
+  _Region_Unlock( the_region );
+}
+
 rtems_status_code rtems_region_get_segment(
   rtems_id           id,
   uintptr_t          size,
@@ -64,35 +76,29 @@ rtems_status_code rtems_region_get_segment(
     } else if ( _Options_Is_no_wait( option_set ) ) {
       status = RTEMS_UNSATISFIED;
     } else {
-      Per_CPU_Control *cpu_self;
-      Thread_Control  *executing;
-
-      /*
-       *  Switch from using the memory allocation mutex to using a
-       *  dispatching disabled critical section.  We have to do this
-       *  because this thread is going to block.
-       */
-      /* FIXME: This is a home grown condition variable */
-      cpu_self = _Thread_Dispatch_disable();
-      _Region_Unlock( the_region );
+      Thread_queue_Context  queue_context;
+      Thread_Control       *executing;
 
-      executing  = _Per_CPU_Get_executing( cpu_self );
+      _Thread_queue_Context_initialize( &queue_context );
+      _Thread_queue_Acquire( &the_region->Wait_queue, &queue_context );
 
+      executing  = _Thread_Executing;
       executing->Wait.count           = size;
       executing->Wait.return_argument = segment;
 
-      _Thread_queue_Enqueue(
-        &the_region->Wait_queue,
+      /* FIXME: This is a home grown condition variable */
+      _Thread_queue_Context_set_enqueue_callout(
+        &queue_context,
+        _Region_Enqueue_callout
+      );
+      _Thread_queue_Context_set_relative_timeout( &queue_context, timeout );
+      _Thread_queue_Enqueue_critical(
+        &the_region->Wait_queue.Queue,
         the_region->wait_operations,
         executing,
         STATES_WAITING_FOR_SEGMENT,
-        timeout,
-        WATCHDOG_RELATIVE,
-        2
+        &queue_context
       );
-
-      _Thread_Dispatch_enable( cpu_self );
-
       return _Status_Get_after_wait( executing );
     }
   }
diff --git a/cpukit/rtems/src/taskdelete.c b/cpukit/rtems/src/taskdelete.c
index c3ddc77d0a..de57fb3ec0 100644
--- a/cpukit/rtems/src/taskdelete.c
+++ b/cpukit/rtems/src/taskdelete.c
@@ -25,12 +25,12 @@ rtems_status_code rtems_task_delete(
   rtems_id id
 )
 {
-  Thread_Control   *the_thread;
-  ISR_lock_Context  lock_context;
-  Thread_Control   *executing;
-  Per_CPU_Control  *cpu_self;
+  Thread_Control       *the_thread;
+  Thread_Close_context  context;
+  Thread_Control       *executing;
 
-  the_thread = _Thread_Get( id, &lock_context );
+  _Thread_queue_Context_initialize( &context.Base );
+  the_thread = _Thread_Get( id, &context.Base.Lock_context.Lock_context );
 
   if ( the_thread == NULL ) {
 #if defined(RTEMS_MULTIPROCESSING)
@@ -42,12 +42,16 @@ rtems_status_code rtems_task_delete(
     return RTEMS_INVALID_ID;
   }
 
-  cpu_self = _Thread_Dispatch_disable_critical( &lock_context );
-  _ISR_lock_ISR_enable( &lock_context );
-
-  executing = _Per_CPU_Get_executing( cpu_self );
+  executing = _Thread_Executing;
 
   if ( the_thread == executing ) {
+    Per_CPU_Control *cpu_self;
+
+    cpu_self = _Thread_Dispatch_disable_critical(
+      &context.Base.Lock_context.Lock_context
+    );
+    _ISR_lock_ISR_enable( &context.Base.Lock_context.Lock_context );
+
     /*
      * The Classic tasks are neither detached nor joinable.  In case of
      * self deletion, they are detached, otherwise joinable by default.
@@ -57,10 +61,10 @@ rtems_status_code rtems_task_delete(
       THREAD_LIFE_TERMINATING | THREAD_LIFE_DETACHED,
       NULL
     );
+    _Thread_Dispatch_enable( cpu_self );
   } else {
-    _Thread_Close( the_thread, executing );
+    _Thread_Close( the_thread, executing, &context );
   }
 
-  _Thread_Dispatch_enable( cpu_self );
   return RTEMS_SUCCESSFUL;
 }