score: Add ISR lock to Objects_Control

This enables per-object SMP locks on SMP configurations and is the first
step to support fine-grained locking.  On uni-processor configuration
there will be no overhead.  The _Objects_Acquire() is intended to
replace _Objects_Get_isr_disable().

Update #2273.

2 files changed, 82 insertions, 0 deletions

diff --git a/cpukit/score/src/objectacquire.c b/cpukit/score/src/objectacquire.c
new file mode 100644
index 0000000000..57d38f47bd
--- /dev/null
+++ b/cpukit/score/src/objectacquire.c
@@ -0,0 +1,80 @@
+/**
+ * @file
+ *
+ * @brief Object Acquire
+ *
+ * @ingroup ScoreObject
+ */
+
+/*
+ * Copyright (c) 2015 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#if HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <rtems/score/objectimpl.h>
+
+Objects_Control *_Objects_Acquire(
+  const Objects_Information *information,
+  Objects_Id                 id,
+  Objects_Locations         *location,
+  ISR_lock_Context          *lock_context
+)
+{
+  Objects_Control *the_object;
+  uint32_t         index;
+
+  index = id - information->minimum_id + 1;
+
+  if ( information->maximum >= index ) {
+    /*
+     * On uni-processor configurations we disable interrupts before we use the
+     * local table.  This prevents use of freed memory in case the object
+     * information is extended in between.  On SMP configurations bad things
+     * can happen, see https://devel.rtems.org/ticket/2280.
+     */
+#if !defined(RTEMS_SMP)
+    ISR_Level level;
+
+    _ISR_Disable( level );
+#endif
+    if ( ( the_object = information->local_table[ index ] ) != NULL ) {
+      *location = OBJECTS_LOCAL;
+#if defined(RTEMS_SMP)
+      _ISR_lock_ISR_disable_and_acquire( &the_object->Lock, lock_context );
+#else
+      lock_context->isr_level = level;
+#endif
+
+      return the_object;
+    }
+#if !defined(RTEMS_SMP)
+    _ISR_Enable( level );
+#endif
+    *location = OBJECTS_ERROR;
+
+    return NULL;
+  }
+
+  *location = OBJECTS_ERROR;
+
+#if defined(RTEMS_MULTIPROCESSING)
+  _Objects_MP_Is_remote( information, id, location, &the_object );
+
+  return the_object;
+#else
+  return NULL;
+#endif
+}
diff --git a/cpukit/score/src/objectclose.c b/cpukit/score/src/objectclose.c
index 52eb10c60b..25c7aa1a36 100644
--- a/cpukit/score/src/objectclose.c
+++ b/cpukit/score/src/objectclose.c
@@ -28,4 +28,6 @@ void _Objects_Close(
   _Objects_Invalidate_Id( information, the_object );
 
   _Objects_Namespace_remove( information, the_object );
+
+  _ISR_lock_Destroy( &the_object->Lock );
 }