Refine the implementation of TLS

fs/procfs/fs_procfsproc.c

@@ -44,7 +44,7 @@
 #endif
 
 #include <nuttx/irq.h>
-#include <nuttx/arch.h>
+#include <nuttx/tls.h>
 #include <nuttx/sched.h>
 #include <nuttx/kmalloc.h>
 #include <nuttx/environ.h>

include/nuttx/arch.h

@@ -85,7 +85,6 @@
 #include <nuttx/compiler.h>
 #include <nuttx/cache.h>
 #include <nuttx/sched.h>
-#include <nuttx/tls.h>
 
 /****************************************************************************
  * Pre-processor definitions
@@ -1826,14 +1825,6 @@ int up_timer_start(FAR const struct timespec *ts);
  * implementation provided here assume the arch has a "push down" stack.
  */
 
-#ifndef up_tls_info
-#  if defined(CONFIG_TLS_ALIGNED) && !defined(__KERNEL__)
-#    define up_tls_info() TLS_INFO((uintptr_t)up_getsp())
-#  else
-#    define up_tls_info() tls_get_info()
-#  endif
-#endif
-
 /****************************************************************************
  * Name: up_tls_size
  *

include/nuttx/pthread.h

@@ -184,6 +184,7 @@ void nx_pthread_exit(FAR void *exit_value) noreturn_function;
  ****************************************************************************/
 
 #ifdef CONFIG_PTHREAD_CLEANUP
+struct tls_info_s;
 void pthread_cleanup_popall(FAR struct tls_info_s *tls);
 #endif
 

include/nuttx/sched.h

@@ -33,18 +33,16 @@
 #include <sched.h>
 #include <signal.h>
 #include <semaphore.h>
+#include <pthread.h>
 #include <time.h>
 
 #include <nuttx/clock.h>
 #include <nuttx/irq.h>
-#include <nuttx/tls.h>
 #include <nuttx/wdog.h>
 #include <nuttx/mm/shm.h>
 #include <nuttx/fs/fs.h>
 #include <nuttx/net/net.h>
 
-#include <arch/arch.h>
-
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
@@ -393,6 +391,8 @@ struct stackinfo_s
  * the struct task_group_s is free.
  */
 
+struct task_info_s;
+
 #ifndef CONFIG_DISABLE_PTHREAD
 struct join_s;                      /* Forward reference                        */
                                     /* Defined in sched/pthread/pthread.h       */

include/nuttx/tls.h

@@ -27,6 +27,7 @@
 
 #include <nuttx/config.h>
 
+#include <nuttx/arch.h>
 #include <nuttx/atexit.h>
 
 #include <sys/types.h>
@@ -209,88 +210,6 @@ struct tls_info_s
  * Public Function Prototypes
  ****************************************************************************/
 
-/****************************************************************************
- * Name: tls_alloc
- *
- * Description:
- *   Allocate a group-unique TLS data index
- *
- * Input Parameters:
- *   dtor     - The destructor of TLS data element
- *
- * Returned Value:
- *   A TLS index that is unique for use within this task group.
- *
- ****************************************************************************/
-
-#if CONFIG_TLS_NELEM > 0
-int tls_alloc(CODE void (*dtor)(FAR void *));
-#endif
-
-/****************************************************************************
- * Name: tls_free
- *
- * Description:
- *   Release a group-unique TLS data index previous obtained by tls_alloc()
- *
- * Input Parameters:
- *   tlsindex - The previously allocated TLS index to be freed
- *
- * Returned Value:
- *   OK is returned on success; a negated errno value will be returned on
- *   failure:
- *
- *     -EINVAL - the index to be freed is out of range.
- *
- ****************************************************************************/
-
-#if CONFIG_TLS_NELEM > 0
-int tls_free(int tlsindex);
-#endif
-
-/****************************************************************************
- * Name: tls_get_value
- *
- * Description:
- *   Return an the TLS data value associated with the 'tlsindx'
- *
- * Input Parameters:
- *   tlsindex - Index of TLS data element to return
- *
- * Returned Value:
- *   The value of TLS element associated with 'tlsindex'. Errors are not
- *   reported.  Zero is returned in the event of an error, but zero may also
- *   be valid value and returned when there is no error.  The only possible
- *   error would be if tlsindex < 0 or tlsindex >=CONFIG_TLS_NELEM.
- *
- ****************************************************************************/
-
-#if CONFIG_TLS_NELEM > 0
-uintptr_t tls_get_value(int tlsindex);
-#endif
-
-/****************************************************************************
- * Name: tls_set_value
- *
- * Description:
- *   Set the TLS element associated with the 'tlsindex' to 'tlsvalue'
- *
- * Input Parameters:
- *   tlsindex - Index of TLS data element to set
- *   tlsvalue - The new value of the TLS data element
- *
- * Returned Value:
- *   Zero is returned on success, a negated errno value is return on
- *   failure:
- *
- *     EINVAL - tlsindex is not in range.
- *
- ****************************************************************************/
-
-#if CONFIG_TLS_NELEM > 0
-int tls_set_value(int tlsindex, uintptr_t tlsvalue);
-#endif
-
 #if CONFIG_TLS_TASK_NELEM > 0
 
 /****************************************************************************
@@ -383,7 +302,11 @@ uintptr_t task_tls_get_value(int tlsindex);
  *
  ****************************************************************************/
 
-#if !defined(CONFIG_TLS_ALIGNED) || defined(__KERNEL__)
+#if defined(up_tls_info)
+#  define tls_get_info() up_tls_info()
+#elif defined(CONFIG_TLS_ALIGNED)
+#  define tls_get_info() TLS_INFO(up_getsp())
+#else
 FAR struct tls_info_s *tls_get_info(void);
 #endif
 

libs/libc/errno/lib_errno.c

@@ -24,7 +24,6 @@
 
 #include <nuttx/config.h>
 
-#include <nuttx/arch.h>
 #include <nuttx/tls.h>
 
 /****************************************************************************
@@ -57,7 +56,7 @@ FAR int *__errno(void)
 {
   /* Get the TLS tls_info_s structure instance for this thread */
 
-  FAR struct tls_info_s *tlsinfo = up_tls_info();
+  FAR struct tls_info_s *tlsinfo = tls_get_info();
 
   /* And return the return refernce to the error number */
 

libs/libc/pthread/pthread_cleanup.c

@@ -28,7 +28,6 @@
 #include <sched.h>
 #include <assert.h>
 
-#include <nuttx/arch.h>
 #include <nuttx/sched.h>
 #include <nuttx/tls.h>
 #include <nuttx/pthread.h>
@@ -119,7 +118,7 @@ static void pthread_cleanup_pop_tls(FAR struct tls_info_s *tls, int execute)
 
 void pthread_cleanup_pop(int execute)
 {
-  FAR struct tls_info_s *tls = up_tls_info();
+  FAR struct tls_info_s *tls = tls_get_info();
 
   DEBUGASSERT(tls != NULL);
 
@@ -135,7 +134,7 @@ void pthread_cleanup_pop(int execute)
 
 void pthread_cleanup_push(pthread_cleanup_t routine, FAR void *arg)
 {
-  FAR struct tls_info_s *tls = up_tls_info();
+  FAR struct tls_info_s *tls = tls_get_info();
 
   DEBUGASSERT(tls != NULL);
   DEBUGASSERT(tls->tos < CONFIG_PTHREAD_CLEANUP_STACKSIZE);

libs/libc/pthread/pthread_exit.c

@@ -28,7 +28,6 @@
 #include <debug.h>
 #include <sched.h>
 
-#include <nuttx/arch.h>
 #include <nuttx/pthread.h>
 #include <nuttx/tls.h>
 
@@ -64,7 +63,7 @@ void pthread_exit(FAR void *exit_value)
 #endif
 
 #ifdef CONFIG_PTHREAD_CLEANUP
-  pthread_cleanup_popall(up_tls_info());
+  pthread_cleanup_popall(tls_get_info());
 #endif
 
 #if CONFIG_TLS_NELEM > 0

libs/libc/pthread/pthread_getspecific.c

@@ -25,9 +25,12 @@
 #include <nuttx/config.h>
 
 #include <pthread.h>
+#include <assert.h>
 
 #include <nuttx/tls.h>
 
+#if CONFIG_TLS_NELEM > 0
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -59,5 +62,23 @@
 
 FAR void *pthread_getspecific(pthread_key_t key)
 {
-  return (FAR void *)tls_get_value((int)key);
+  FAR struct tls_info_s *info;
+  FAR void *ret = NULL;
+
+  DEBUGASSERT(key >= 0 && key < CONFIG_TLS_NELEM);
+  if (key >= 0 && key < CONFIG_TLS_NELEM)
+    {
+      /* Get the TLS info structure from the current threads stack */
+
+      info = tls_get_info();
+      DEBUGASSERT(info != NULL);
+
+      /* Get the element value from the TLS info. */
+
+      ret = (FAR void *)info->tl_elem[key];
+    }
+
+  return ret;
 }
+
+#endif /* CONFIG_TLS_NELEM */

libs/libc/pthread/pthread_keycreate.c

@@ -26,7 +26,9 @@
 
 #include <pthread.h>
 #include <assert.h>
+#include <errno.h>
 
+#include <nuttx/semaphore.h>
 #include <nuttx/tls.h>
 
 #if CONFIG_TLS_NELEM > 0
@@ -70,23 +72,46 @@
 int pthread_key_create(FAR pthread_key_t *key,
                        CODE void (*destructor)(FAR void *))
 {
-  int tlsindex;
+  FAR struct task_info_s *info = task_get_info();
+  int candidate;
+  int ret;
 
   DEBUGASSERT(key != NULL);
+  DEBUGASSERT(info != NULL);
 
-  /* Allocate a TLS index */
+  /* Search for an unused index.  This is done in a critical section here to
+   * avoid concurrent modification of the group TLS index set.
+   */
 
-  tlsindex = tls_alloc(destructor);
+  ret = _SEM_WAIT(&info->ta_sem);
 
-  /* Check if found a TLS index. */
+  if (ret < 0)
+    {
+      ret = _SEM_ERRNO(ret);
+      return ret;
+    }
+
+  ret = EAGAIN;
 
-  if (tlsindex >= 0)
+  for (candidate = 0; candidate < CONFIG_TLS_NELEM; candidate++)
     {
-      *key = tlsindex;
-      return OK;
+      /* Is this candidate index available? */
+
+      tls_ndxset_t mask = (tls_ndxset_t)1 << candidate;
+      if ((info->ta_tlsset & mask) == 0)
+        {
+          /* Yes.. allocate the index and break out of the loop */
+
+          info->ta_tlsset |= mask;
+          info->ta_tlsdtor[candidate] = destructor;
+          *key = candidate;
+          ret = OK;
+          break;
+        }
     }
 
-  return -tlsindex;
+  _SEM_POST(&info->ta_sem);
+  return ret;
 }
 
 #endif /* CONFIG_TLS_NELEM */

libs/libc/pthread/pthread_keydelete.c

@@ -25,9 +25,14 @@
 #include <nuttx/config.h>
 
 #include <pthread.h>
+#include <assert.h>
+#include <errno.h>
 
+#include <nuttx/semaphore.h>
 #include <nuttx/tls.h>
 
+#if CONFIG_TLS_NELEM > 0
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -52,8 +57,33 @@
 
 int pthread_key_delete(pthread_key_t key)
 {
-  /* Free the TLS index */
+  FAR struct task_info_s *info = task_get_info();
+  tls_ndxset_t mask;
+  int ret = EINVAL;
+
+  DEBUGASSERT(info != NULL);
+  DEBUGASSERT(key >= 0 && key < CONFIG_TLS_NELEM);
+  if (key >= 0 && key < CONFIG_TLS_NELEM)
+    {
+      /* This is done while holding a semaphore here to avoid concurrent
+       * modification of the group TLS index set.
+       */
 
-  int ret = tls_free((int)key);
-  return ret < 0 ? -ret : 0;
+      mask = (tls_ndxset_t)1 << key;
+      ret = _SEM_WAIT(&info->ta_sem);
+      if (ret == OK)
+        {
+          DEBUGASSERT((info->ta_tlsset & mask) != 0);
+          info->ta_tlsset &= ~mask;
+          _SEM_POST(&info->ta_sem);
+        }
+      else
+        {
+          ret = _SEM_ERRNO(ret);
+        }
+    }
+
+  return ret;
 }
+
+#endif /* CONFIG_TLS_NELEM */