[PATCH v2] score: Use defines for Thread_Life_state

[Sebastian Huber]

Do not use an enum as a bit field.  Document the state flags.

This fix relates to a Coverity issue (PW.MIXED_ENUM_TYPE).
---
 cpukit/include/rtems/score/thread.h | 57 ++++++++++++++++++++++++-----
 1 file changed, 47 insertions(+), 10 deletions(-)

diff --git a/cpukit/include/rtems/score/thread.h b/cpukit/include/rtems/score/thread.h
index 8785879184..ab59ab13e9 100644
--- a/cpukit/include/rtems/score/thread.h
+++ b/cpukit/include/rtems/score/thread.h
@@ -659,22 +659,59 @@ typedef struct {
 } Thread_Action_control;
 
 /**
- * @brief Thread life states.
+ * @brief This type represents the thread life state.
  *
- * The thread life states are orthogonal to the thread states used for
+ * The thread life state is orthogonal to the thread state used for
  * synchronization primitives and blocking operations.  They reflect the state
  * changes triggered with thread restart and delete requests.
  *
- * The individual state values must be a power of two to allow use of bit
+ * The individual state flags must be a power of two to allow use of bit
  * operations to manipulate and evaluate the thread life state.
  */
-typedef enum {
-  THREAD_LIFE_PROTECTED = 0x1,
-  THREAD_LIFE_RESTARTING = 0x2,
-  THREAD_LIFE_TERMINATING = 0x4,
-  THREAD_LIFE_CHANGE_DEFERRED = 0x8,
-  THREAD_LIFE_DETACHED = 0x10
-} Thread_Life_state;
+typedef unsigned int Thread_Life_state;
+
+/**
+ * @brief Indicates that the thread life is protected.
+ *
+ * If this flag is set, then the thread restart or delete requests are deferred
+ * until the protection and deferred change flags are cleared.  It is used by
+ * _Thread_Set_life_protection().
+ */
+#define THREAD_LIFE_PROTECTED 0x1U
+
+/**
+ * @brief Indicates that thread is restarting.
+ *
+ * If this flag is set, then a thread restart request is in pending. See
+ * _Thread_Restart_self() and _Thread_Restart_other().
+ */
+#define THREAD_LIFE_RESTARTING 0x2U
+
+/**
+ * @brief Indicates that thread is terminating.
+ *
+ * If this flag is set, then a thread termination request is in pending.  See
+ * _Thread_Exit() and _Thread_Cancel().
+ */
+#define THREAD_LIFE_TERMINATING 0x4U
+
+/**
+ * @brief Indicates that thread life changes are deferred.
+ *
+ * If this flag is set, then the thread restart or delete requests are deferred
+ * until the protection and deferred change flags are cleared.  It is used by
+ * pthread_setcanceltype().
+ */
+#define THREAD_LIFE_CHANGE_DEFERRED 0x8U
+
+/**
+ * @brief Indicates that thread is detached.
+ *
+ * If this flag is set, then the thread is detached.  Detached threads do not
+ * wait during termination for other threads to join.  See rtems_task_delete(),
+ * rtems_task_exit(), and pthread_detach().
+ */
+#define THREAD_LIFE_DETACHED 0x10U
 
 /**
  * @brief Thread life control.
-- 
2.26.2