Generalize Thread Local Storage (TLS) support

.github/lexicon.txt

@@ -3090,6 +3090,7 @@ xtimerstartfromisr
 xtimerstop
 xtimerstopfromisr
 xtimertaskhandle
+xtlsblock
 xtos
 xtriggerlevel
 xtriggerlevelbytes

include/FreeRTOS.h

@@ -71,9 +71,60 @@
 
 /* Required if struct _reent is used. */
 #if ( configUSE_NEWLIB_REENTRANT == 1 )
+
+/* Note Newlib support has been included by popular demand, but is not
+ * used by the FreeRTOS maintainers themselves.  FreeRTOS is not
+ * responsible for resulting newlib operation.  User must be familiar with
+ * newlib and must provide system-wide implementations of the necessary
+ * stubs. Be warned that (at the time of writing) the current newlib design
+ * implements a system-wide malloc() that must be provided with locks.
+ *
+ * See the third party link http://www.nadler.com/embedded/newlibAndFreeRTOS.html
+ * for additional information. */
     #include <reent.h>
+
+    #define configUSE_C_RUNTIME_TLS_SUPPORT    1
+
+    #ifndef configTLS_BLOCK_TYPE
+        #define configTLS_BLOCK_TYPE           struct _reent
+    #endif
+
+    #ifndef configINIT_TLS_BLOCK
+        #define configINIT_TLS_BLOCK( xTLSBlock )    _REENT_INIT_PTR( &( xTLSBlock ) )
+    #endif
+
+    #ifndef configSET_TLS_BLOCK
+        #define configSET_TLS_BLOCK( xTLSBlock )    _impure_ptr = &( xTLSBlock )
+    #endif
+
+    #ifndef configDEINIT_TLS_BLOCK
+        #define configDEINIT_TLS_BLOCK( xTLSBlock )    _reclaim_reent( &( xTLSBlock ) )
+    #endif
+#endif /* if ( configUSE_NEWLIB_REENTRANT == 1 ) */
+
+#ifndef configUSE_C_RUNTIME_TLS_SUPPORT
+    #define configUSE_C_RUNTIME_TLS_SUPPORT    0
 #endif
 
+#if ( ( configUSE_NEWLIB_REENTRANT == 0 ) && ( configUSE_C_RUNTIME_TLS_SUPPORT == 1 ) )
+
+    #ifndef configTLS_BLOCK_TYPE
+        #error Missing definition:  configTLS_BLOCK_TYPE must be defined in FreeRTOSConfig.h when configUSE_C_RUNTIME_TLS_SUPPORT is set to 1.
+    #endif
+
+    #ifndef configINIT_TLS_BLOCK
+        #error Missing definition:  configINIT_TLS_BLOCK must be defined in FreeRTOSConfig.h when configUSE_C_RUNTIME_TLS_SUPPORT is set to 1.
+    #endif
+
+    #ifndef configSET_TLS_BLOCK
+        #error Missing definition:  configSET_TLS_BLOCK must be defined in FreeRTOSConfig.h when configUSE_C_RUNTIME_TLS_SUPPORT is set to 1.
+    #endif
+
+    #ifndef configDEINIT_TLS_BLOCK
+        #error Missing definition:  configDEINIT_TLS_BLOCK must be defined in FreeRTOSConfig.h when configUSE_C_RUNTIME_TLS_SUPPORT is set to 1.
+    #endif
+#endif /* if ( ( configUSE_NEWLIB_REENTRANT == 0 ) && ( configUSE_C_RUNTIME_TLS_SUPPORT == 1 ) ) */
+
 /*
  * Check all the required application specific macros have been defined.
  * These macros are application specific and (as downloaded) are defined
@@ -1223,8 +1274,8 @@ typedef struct xSTATIC_TCB
     #if ( configGENERATE_RUN_TIME_STATS == 1 )
         configRUN_TIME_COUNTER_TYPE ulDummy16;
     #endif
-    #if ( configUSE_NEWLIB_REENTRANT == 1 )
-        struct  _reent xDummy17;
+    #if ( ( configUSE_NEWLIB_REENTRANT == 1 ) || ( configUSE_C_RUNTIME_TLS_SUPPORT == 1 ) )
+        configTLS_BLOCK_TYPE xDummy17;
     #endif
     #if ( configUSE_TASK_NOTIFICATIONS == 1 )
         uint32_t ulDummy18[ configTASK_NOTIFICATION_ARRAY_ENTRIES ];

tasks.c

@@ -296,19 +296,8 @@ typedef struct tskTaskControlBlock       /* The old naming convention is used to
         configRUN_TIME_COUNTER_TYPE ulRunTimeCounter; /*< Stores the amount of time the task has spent in the Running state. */
     #endif
 
-    #if ( configUSE_NEWLIB_REENTRANT == 1 )
-
-        /* Allocate a Newlib reent structure that is specific to this task.
-         * Note Newlib support has been included by popular demand, but is not
-         * used by the FreeRTOS maintainers themselves.  FreeRTOS is not
-         * responsible for resulting newlib operation.  User must be familiar with
-         * newlib and must provide system-wide implementations of the necessary
-         * stubs. Be warned that (at the time of writing) the current newlib design
-         * implements a system-wide malloc() that must be provided with locks.
-         *
-         * See the third party link http://www.nadler.com/embedded/newlibAndFreeRTOS.html
-         * for additional information. */
-        struct  _reent xNewLib_reent;
+    #if ( ( configUSE_NEWLIB_REENTRANT == 1 ) || ( configUSE_C_RUNTIME_TLS_SUPPORT == 1 ) )
+        configTLS_BLOCK_TYPE xTLSBlock; /*< Memory block used as Thread Local Storage (TLS) Block for the task. */
     #endif
 
     #if ( configUSE_TASK_NOTIFICATIONS == 1 )
@@ -964,12 +953,10 @@ static void prvInitialiseNewTask( TaskFunction_t pxTaskCode,
     }
     #endif
 
-    #if ( configUSE_NEWLIB_REENTRANT == 1 )
+    #if ( ( configUSE_NEWLIB_REENTRANT == 1 ) || ( configUSE_C_RUNTIME_TLS_SUPPORT == 1 ) )
     {
-        /* Initialise this task's Newlib reent structure.
-         * See the third party link http://www.nadler.com/embedded/newlibAndFreeRTOS.html
-         * for additional information. */
-        _REENT_INIT_PTR( ( &( pxNewTCB->xNewLib_reent ) ) );
+        /* Allocate and initialize memory for the task's TLS Block. */
+        configINIT_TLS_BLOCK( pxNewTCB->xTLSBlock );
     }
     #endif
 
@@ -2038,15 +2025,13 @@ void vTaskStartScheduler( void )
          * starts to run. */
         portDISABLE_INTERRUPTS();
 
-        #if ( configUSE_NEWLIB_REENTRANT == 1 )
+        #if ( ( configUSE_NEWLIB_REENTRANT == 1 ) || ( configUSE_C_RUNTIME_TLS_SUPPORT == 1 ) )
         {
-            /* Switch Newlib's _impure_ptr variable to point to the _reent
-             * structure specific to the task that will run first.
-             * See the third party link http://www.nadler.com/embedded/newlibAndFreeRTOS.html
-             * for additional information. */
-            _impure_ptr = &( pxCurrentTCB->xNewLib_reent );
+            /* Switch C-Runtime's TLS Block to point to the TLS
+             * block specific to the task that will run first. */
+            configSET_TLS_BLOCK( pxCurrentTCB->xTLSBlock );
         }
-        #endif /* configUSE_NEWLIB_REENTRANT */
+        #endif
 
         xNextTaskUnblockTime = portMAX_DELAY;
         xSchedulerRunning = pdTRUE;
@@ -3078,15 +3063,13 @@ void vTaskSwitchContext( void )
         }
         #endif
 
-        #if ( configUSE_NEWLIB_REENTRANT == 1 )
+        #if ( ( configUSE_NEWLIB_REENTRANT == 1 ) || ( configUSE_C_RUNTIME_TLS_SUPPORT == 1 ) )
         {
-            /* Switch Newlib's _impure_ptr variable to point to the _reent
-             * structure specific to this task.
-             * See the third party link http://www.nadler.com/embedded/newlibAndFreeRTOS.html
-             * for additional information. */
-            _impure_ptr = &( pxCurrentTCB->xNewLib_reent );
+            /* Switch C-Runtime's TLS Block to point to the TLS
+             * Block specific to this task. */
+            configSET_TLS_BLOCK( pxCurrentTCB->xTLSBlock );
         }
-        #endif /* configUSE_NEWLIB_REENTRANT */
+        #endif
     }
 }
 /*-----------------------------------------------------------*/
@@ -3958,15 +3941,12 @@ static void prvCheckTasksWaitingTermination( void )
          * want to allocate and clean RAM statically. */
         portCLEAN_UP_TCB( pxTCB );
 
-        /* Free up the memory allocated by the scheduler for the task.  It is up
-         * to the task to free any memory allocated at the application level.
-         * See the third party link http://www.nadler.com/embedded/newlibAndFreeRTOS.html
-         * for additional information. */
-        #if ( configUSE_NEWLIB_REENTRANT == 1 )
+        #if ( ( configUSE_NEWLIB_REENTRANT == 1 ) || ( configUSE_C_RUNTIME_TLS_SUPPORT == 1 ) )
         {
-            _reclaim_reent( &( pxTCB->xNewLib_reent ) );
+            /* Free up the memory allocated for the task's TLS Block. */
+            configDEINIT_TLS_BLOCK( pxCurrentTCB->xTLSBlock );
         }
-        #endif /* configUSE_NEWLIB_REENTRANT */
+        #endif
 
         #if ( ( configSUPPORT_DYNAMIC_ALLOCATION == 1 ) && ( configSUPPORT_STATIC_ALLOCATION == 0 ) && ( portUSING_MPU_WRAPPERS == 0 ) )
         {