posix: Use per-thread lookup tree for POSIX Keys

Yields higher performance on SMP systems.

Close #2625.

3 files changed, 21 insertions, 10 deletions

diff --git a/cpukit/score/include/rtems/score/thread.h b/cpukit/score/include/rtems/score/thread.h
index 44b706d7ff..4e0d8cf6f9 100644
--- a/cpukit/score/include/rtems/score/thread.h
+++ b/cpukit/score/include/rtems/score/thread.h
@@ -487,6 +487,21 @@ struct Thread_Action {
 };
 
 /**
+ * @brief Per-thread information for POSIX Keys.
+ */
+typedef struct {
+  /**
+   * @brief Key value pairs registered for this thread.
+   */
+  RBTree_Control Key_value_pairs;
+
+  /**
+   * @brief Lock to protect the tree operations.
+   */
+  ISR_LOCK_MEMBER( Lock )
+} Thread_Keys_information;
+
+/**
  * @brief Control block to manage thread actions.
  *
  * Use _Thread_Action_control_initialize() to initialize this structure.
@@ -837,13 +852,9 @@ struct _Thread_Control {
 #endif
 
   /**
-   * This is the thread key value chain's control, which is used
-   * to track all key value for specific thread, and when thread
-   * exits, we can remove all key value for specific thread by
-   * iterating this chain, or we have to search a whole rbtree,
-   * which is inefficient.
+   * @brief The POSIX Keys information.
    */
-  Chain_Control           Key_Chain;
+  Thread_Keys_information               Keys;
 
   /**
    * @brief Thread life-cycle control.
diff --git a/cpukit/score/src/threadinitialize.c b/cpukit/score/src/threadinitialize.c
index 0b5fd3a125..bcf03bf833 100644
--- a/cpukit/score/src/threadinitialize.c
+++ b/cpukit/score/src/threadinitialize.c
@@ -210,10 +210,9 @@ bool _Thread_Initialize(
 
   _Scheduler_Update_priority( the_thread, priority );
 
-  /*
-   * initialize thread's key vaule node chain
-   */
-  _Chain_Initialize_empty( &the_thread->Key_Chain );
+  /* POSIX Keys */
+  _RBTree_Initialize_empty( &the_thread->Keys.Key_value_pairs );
+  _ISR_lock_Initialize( &the_thread->Keys.Lock, "POSIX Key Value Pairs" );
 
   _Thread_Action_control_initialize( &the_thread->Post_switch_actions );
 
diff --git a/cpukit/score/src/threadrestart.c b/cpukit/score/src/threadrestart.c
index f5419741bf..155acaa8d1 100644
--- a/cpukit/score/src/threadrestart.c
+++ b/cpukit/score/src/threadrestart.c
@@ -97,6 +97,7 @@ static void _Thread_Free( Thread_Control *the_thread )
     _Objects_Get_information_id( the_thread->Object.id );
 
   _User_extensions_Thread_delete( the_thread );
+  _ISR_lock_Destroy( &the_thread->Keys.Lock );
   _Scheduler_Node_destroy( _Scheduler_Get( the_thread ), the_thread );
   _ISR_lock_Destroy( &the_thread->Timer.Lock );