Generalize Thread Local Storage (TLS) support (#540)
* Generalize Thread Local Storage (TLS) support
FreeRTOS's Thread Local Storage (TLS) support used variables and
functions from newlib, thereby making the TLS support specific to
newlib. This commit generalizes the TLS support so that it can be used
with other c-runtime libraries also. The default behavior for newlib
support is still kept same for backward compatibility.
The application writer would need to set configUSE_C_RUNTIME_TLS_SUPPORT
to 1 in their FreeRTOSConfig.h and define the following macros to
support TLS for a c-runtime library:
1. configTLS_BLOCK_TYPE - Type used to define the TLS block in TCB.
2. configINIT_TLS_BLOCK( xTLSBlock ) - Allocate and initialize memory
block for the task's TLS Block.
3. configSET_TLS_BLOCK( xTLSBlock ) - Switch C-Runtime's TLS Block to
point to xTLSBlock.
4. configDEINIT_TLS_BLOCK( xTLSBlock ) - Free up the memory allocated
for the task's TLS Block.
The following is an example to support TLS for picolibc:
#define configUSE_C_RUNTIME_TLS_SUPPORT 1
#define configTLS_BLOCK_TYPE void*
#define configINIT_TLS_BLOCK( xTLSBlock ) _init_tls( xTLSBlock )
#define configSET_TLS_BLOCK( xTLSBlock ) _set_tls( xTLSBlock )
#define configDEINIT_TLS_BLOCK( xTLSBlock )
Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
diff --git a/.github/lexicon.txt b/.github/lexicon.txt
index 7510135..68a28eb 100644
--- a/.github/lexicon.txt
+++ b/.github/lexicon.txt
@@ -3090,6 +3090,7 @@
xtimerstop
xtimerstopfromisr
xtimertaskhandle
+xtlsblock
xtos
xtriggerlevel
xtriggerlevelbytes
diff --git a/include/FreeRTOS.h b/include/FreeRTOS.h
index 5ce4e28..35bef0b 100644
--- a/include/FreeRTOS.h
+++ b/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 @@
#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 ];
diff --git a/tasks.c b/tasks.c
index e5f397a..3aae3a9 100644
--- a/tasks.c
+++ b/tasks.c
@@ -296,19 +296,8 @@
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 @@
}
#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 @@
* 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 @@
}
#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 @@
* 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 ) )
{
