From 1fcac5adc5ed38fb88ce4c6d24b2ca2e27e3cd10 Mon Sep 17 00:00:00 2001
From: Sebastian Huber <sebastian.huber@embedded-brains.de>
Date: Mon, 25 Jul 2016 16:35:37 +0200
Subject: score: Turn thread lock into thread wait lock

The _Thread_Lock_acquire() function had a potentially infinite run-time
due to the lack of fairness at atomic operations level.

Update #2412.
Update #2556.
Update #2765.
---
 cpukit/score/include/rtems/score/threadqimpl.h | 148 ++++++++++++++++++++++++-
 1 file changed, 145 insertions(+), 3 deletions(-)

(limited to 'cpukit/score/include/rtems/score/threadqimpl.h')

diff --git a/cpukit/score/include/rtems/score/threadqimpl.h b/cpukit/score/include/rtems/score/threadqimpl.h
index 1f17f1a4f1..3d4f6136f6 100644
--- a/cpukit/score/include/rtems/score/threadqimpl.h
+++ b/cpukit/score/include/rtems/score/threadqimpl.h
@@ -26,6 +26,10 @@
 #include <rtems/score/smp.h>
 #include <rtems/score/thread.h>
 
+#if defined(RTEMS_DEBUG)
+#include <string.h>
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -46,6 +50,13 @@ extern "C" {
  * relationships.
  */
 struct Thread_queue_Path {
+#if defined(RTEMS_SMP)
+  /**
+   * @brief The start of a thread queue path.
+   */
+  Thread_queue_Link Start;
+#endif
+
   /**
    * @brief A potential thread to update the priority via
    * _Thread_Update_priority().
@@ -84,10 +95,8 @@ RTEMS_INLINE_ROUTINE void _Thread_queue_Context_initialize(
 )
 {
 #if defined(RTEMS_DEBUG)
+  memset( queue_context, 0, sizeof( *queue_context ) );
   queue_context->expected_thread_dispatch_disable_level = 0xdeadbeef;
-#if defined(RTEMS_MULTIPROCESSING)
-  queue_context->mp_callout = NULL;
-#endif
 #else
   (void) queue_context;
 #endif
@@ -187,6 +196,135 @@ RTEMS_INLINE_ROUTINE void _Thread_queue_Context_set_MP_callout(
   } while ( 0 )
 #endif
 
+/**
+ * @brief Gets the thread wait queue of the thread queue context.
+ *
+ * On SMP configurations, the value is stored in the thread queue context,
+ * otherwise in the thread itself.
+ *
+ * @param queue_context The thread queue context.
+ * @param the_thread The thread.
+ */
+#if defined(RTEMS_SMP)
+#define _Thread_queue_Context_get_queue( queue_context, the_thread ) \
+  ( queue_context )->Wait.queue
+#else
+#define _Thread_queue_Context_get_queue( queue_context, the_thread ) \
+  ( the_thread )->Wait.queue
+#endif
+
+/**
+ * @brief Gets the thread wait operations of the thread queue context.
+ *
+ * On SMP configurations, the value is stored in the thread queue context,
+ * otherwise in the thread itself.
+ *
+ * @param queue_context The thread queue context.
+ * @param the_thread The thread.
+ */
+#if defined(RTEMS_SMP)
+#define _Thread_queue_Context_get_operations( queue_context, the_thread ) \
+  ( queue_context )->Wait.operations
+#else
+#define _Thread_queue_Context_get_operations( queue_context, the_thread ) \
+  ( the_thread )->Wait.operations
+#endif
+
+/**
+ * @brief Thread priority change by means of the thread queue context.
+ *
+ * On SMP configurations, the used data is stored in the thread queue context,
+ * otherwise in the thread itself.
+ *
+ * @param queue_context The thread queue context.
+ * @param the_thread The thread.
+ * @param new_priority The new thread priority.
+ * @param prepend_it Prepend it to its priority group or not.
+ */
+#if defined(RTEMS_SMP)
+#define _Thread_queue_Context_priority_change( \
+    queue_context, \
+    the_thread, \
+    new_priority, \
+    prepend_it \
+  ) \
+    ( *( queue_context )->Wait.operations->priority_change )( \
+      the_thread, \
+      new_priority, \
+      prepend_it, \
+      ( queue_context )->Wait.queue \
+    )
+#else
+#define _Thread_queue_Context_priority_change( \
+    queue_context, \
+    the_thread, \
+    new_priority, \
+    prepend_it \
+  ) \
+    ( *( the_thread )->Wait.operations->priority_change )( \
+      the_thread, \
+      new_priority, \
+      prepend_it, \
+      ( the_thread )->Wait.queue \
+    )
+#endif
+
+/**
+ * @brief Thread queue extract by means of the thread queue context.
+ *
+ * On SMP configurations, the used data is stored in the thread queue context,
+ * otherwise in the thread itself.
+ *
+ * @param queue_context The thread queue context.
+ * @param the_thread The thread.
+ */
+#if defined(RTEMS_SMP)
+#define _Thread_queue_Context_extract( \
+    queue_context, \
+    the_thread \
+  ) \
+    ( *( queue_context )->Wait.operations->extract )( \
+      ( queue_context )->Wait.queue, \
+      the_thread \
+    )
+#else
+#define _Thread_queue_Context_extract( \
+    queue_context, \
+    the_thread \
+  ) \
+    ( *( the_thread )->Wait.operations->extract )( \
+      ( the_thread )->Wait.queue, \
+      the_thread \
+    )
+#endif
+
+#if defined(RTEMS_SMP)
+RTEMS_INLINE_ROUTINE void _Thread_queue_Gate_add(
+  Chain_Control     *chain,
+  Thread_queue_Gate *gate
+)
+{
+  _Atomic_Store_uint( &gate->go_ahead, 0, ATOMIC_ORDER_RELAXED );
+  _Chain_Append_unprotected( chain, &gate->Node );
+}
+
+RTEMS_INLINE_ROUTINE void _Thread_queue_Gate_open(
+  Thread_queue_Gate *gate
+)
+{
+  _Atomic_Store_uint( &gate->go_ahead, 1, ATOMIC_ORDER_RELAXED );
+}
+
+RTEMS_INLINE_ROUTINE void _Thread_queue_Gate_wait(
+  Thread_queue_Gate *gate
+)
+{
+  while ( _Atomic_Load_uint( &gate->go_ahead, ATOMIC_ORDER_RELAXED ) == 0 ) {
+    /* Wait */
+  }
+}
+#endif
+
 RTEMS_INLINE_ROUTINE void _Thread_queue_Heads_initialize(
   Thread_queue_Heads *heads
 )
@@ -911,6 +1049,10 @@ extern const Thread_queue_Operations _Thread_queue_Operations_priority;
 
 extern const Thread_queue_Operations _Thread_queue_Operations_priority_inherit;
 
+#if defined(RTEMS_SMP)
+extern const Thread_queue_Operations _Thread_queue_Operations_stale_queue;
+#endif
+
 /**@}*/
 
 #ifdef __cplusplus
-- 
cgit v1.2.3