sched/pthread: Implement pthread_key_delete(). This involves some minor changes to the group data structure.

include/nuttx/sched.h

@@ -375,6 +375,21 @@ struct pthread_cleanup_s
 };
 #endif
 
+/* type pthread_keyset_t *********************************************************/
+/* Smallest addressable type that can hold the entire configured number of keys */
+
+#if defined(CONFIG_NPTHREAD_KEYS) && CONFIG_NPTHREAD_KEYS > 0
+#  if CONFIG_NPTHREAD_KEYS > 32
+#    error Too many pthread keys
+#  elif CONFIG_NPTHREAD_KEYS > 16
+     typedef uint32_t pthread_keyset_t;
+#  elif CONFIG_NPTHREAD_KEYS > 8
+     typedef uint16_t pthread_keyset_t;
+#  else
+     typedef uint8_t pthread_keyset_t;
+#  endif
+#endif
+
 /* struct dspace_s ***************************************************************/
 /* This structure describes a reference counted D-Space region.  This must be a
  * separately allocated "break-away" structure that can be owned by a task and
@@ -520,7 +535,7 @@ struct task_group_s
   FAR struct join_s *tg_jointail;   /*   Tail of a list of join data            */
 #endif
 #if CONFIG_NPTHREAD_KEYS > 0
-  uint8_t tg_nkeys;                 /* Number pthread keys allocated            */
+  pthread_keyset_t tg_keyset;       /* Set of pthread keys allocated            */
 #endif
 
 #ifndef CONFIG_DISABLE_SIGNALS

sched/Kconfig

@@ -616,8 +616,10 @@ config NPTHREAD_KEYS
 	int "Maximum number of pthread keys"
 	default 4 if !DISABLE_PTHREAD
 	default 0 if DISABLE_PTHREAD
+	range 0 32
 	---help---
-		The number of items of thread-specific data that can be retained
+		The number of items of thread-specific data that can be retained.
+		The value zero disables support for pthread-specific data.
 
 if !DISABLE_PTHREAD
 

sched/pthread/pthread_getspecific.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * sched/pthread/pthread_getspecific.c
  *
- *   Copyright (C) 2007, 2009, 2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2009, 2013, 2018 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -88,11 +88,11 @@ FAR void *pthread_getspecific(pthread_key_t key)
   FAR struct task_group_s *group = rtcb->group;
   FAR void *ret = NULL;
 
-  DEBUGASSERT(group);
+  DEBUGASSERT(group != NULL && (unsigned)key < CONFIG_NPTHREAD_KEYS);
 
   /* Check if the key is valid. */
 
-  if (key < group->tg_nkeys)
+  if (key < CONFIG_NPTHREAD_KEYS && (group->tg_keyset & (1 << key)) != 0)
     {
       /* Return the stored value. */
 

sched/pthread/pthread_keycreate.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * sched/pthread/pthread_keycreate.c
  *
- *   Copyright (C) 2007-2009, 2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2013, 2018 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -44,6 +44,8 @@
 #include <assert.h>
 #include <debug.h>
 
+#include <nuttx/irq.h>
+
 #include "sched/sched.h"
 #include "pthread/pthread.h"
 
@@ -66,23 +68,23 @@
  *   associated with all defined keys in the new thread.
  *
  * Input Parameters:
- *   key = A pointer to the key to create.
+ *   key        - A pointer to the key to create.
- *   destructor = An optional destructor() function that may be associated
+ *   destructor - An optional destructor() function that may be associated
- *      with each key that is invoked when a thread exits.  However, this
+ *                with each key that is invoked when a thread exits.
- *      argument is ignored in the current implementation.
+ *                However, this argument is ignored in the current
+ *                implementation.
  *
  * Returned Value:
  *   If successful, the pthread_key_create() function will store the newly
  *   created key value at *key and return zero (OK).  Otherwise, an error
- *   number will bereturned to indicate the error:
+ *   number will be returned to indicate the error:
  *
- *      EAGAIN - The system lacked sufficient resources to create another
+ *      EAGAIN  - The system lacked sufficient resources to create another
- *         thread-specific data key, or the system-imposed limit on the total
+ *                thread-specific data key, or the system-imposed limit on
- *         number of keys pers process {PTHREAD_KEYS_MAX} has been exceeded
+ *                the total number of keys pers process {PTHREAD_KEYS_MAX}
+ *                has been exceeded
  *      ENONMEM - Insufficient memory exists to create the key.
  *
- * Assumptions:
- *
  * POSIX Compatibility:
  *   - The present implementation ignores the destructor argument.
  *
@@ -94,25 +96,41 @@ int pthread_key_create(FAR pthread_key_t *key,
 #if CONFIG_NPTHREAD_KEYS > 0
   FAR struct tcb_s *rtcb = this_task();
   FAR struct task_group_s *group = rtcb->group;
+  irqstate_t flags;
+  int candidate;
   int ret = EAGAIN;
 
-  DEBUGASSERT(group);
+  DEBUGASSERT(key != NULL && group != NULL);
 
-  /* Check if we have exceeded the system-defined number of keys. */
+  /* Search for an unused key.  This is done in a critical section here to
+   * avoid concurrent modification of the group keyset.
+   */
 
-  if (group->tg_nkeys < PTHREAD_KEYS_MAX)
+  flags = spin_lock_irqsave();
+  for (candidate = 0; candidate < PTHREAD_KEYS_MAX; candidate++)
     {
-      /* Return the key value */
+      /* Is this candidate key available? */
 
-      *key = group->tg_nkeys;
+      pthread_keyset_t mask = (1 << candidate);
+      if ((group->tg_keyset & mask) == 0)
+        {
+          /* Yes.. allocate the key and break out of the loop */
 
-      /* Increment the count of global keys. */
+          group->tg_keyset |= mask;
+          break;
+        }
+    }
 
-      group->tg_nkeys++;
+  spin_unlock_irqrestore(flags);
 
-      /* Return success. */
+  /* Check if found a valid key. */
 
-      ret = OK;
+  if (candidate < PTHREAD_KEYS_MAX)
+    {
+      /* Yes.. Return the key value and success */
+
+      *key = candidate;
+      ret  = OK;
     }
 
   return ret;

sched/pthread/pthread_keydelete.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * sched/pthread/pthread_keydelete.c
  *
- *   Copyright (C) 2007, 2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2009, 2018 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -43,6 +43,9 @@
 #include <errno.h>
 #include <debug.h>
 
+#include <nuttx/irq.h>
+
+#include "sched/sched.h"
 #include "pthread/pthread.h"
 
 /****************************************************************************
@@ -58,7 +61,7 @@
  *   does nothing in the present implementation.
  *
  * Input Parameters:
- *   key = the key to delete
+ *   key - the key to delete
  *
  * Returned Value:
  *   Always returns ENOSYS.
@@ -71,6 +74,33 @@
 
 int pthread_key_delete(pthread_key_t key)
 {
+#if CONFIG_NPTHREAD_KEYS > 0
+  FAR struct tcb_s *rtcb = this_task();
+  FAR struct task_group_s *group = rtcb->group;
+  pthread_keyset_t mask;
+  irqstate_t flags;
+  int ret = EINVAL;
+
+  DEBUGASSERT((unsigned)key < PTHREAD_KEYS_MAX && group != NULL);
+  if ((unsigned)key < PTHREAD_KEYS_MAX)
+    {
+      /* This is done in a critical section here to avoid concurrent
+       * modification of the group keyset.
+       */
+
+      mask  = (1 << key);
+      flags = spin_lock_irqsave();
+
+      DEBUGASSERT((group->tg_keyset & mask) != 0);
+      group->tg_keyset &= ~mask;
+      spin_unlock_irqrestore(flags);
+
+      ret = OK;
+    }
+
+  return ret;
+#else
   return ENOSYS;
+#endif
 }
 

sched/pthread/pthread_setspecific.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * sched/pthread/pthread_setspecific.c
  *
- *   Copyright (C) 2007-2009, 2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2013, 2018 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -99,11 +99,11 @@ int pthread_setspecific(pthread_key_t key, FAR const void *value)
   FAR struct task_group_s *group = rtcb->group;
   int ret = EINVAL;
 
-  DEBUGASSERT(group);
+  DEBUGASSERT(group != NULL && (unsigned)key < CONFIG_NPTHREAD_KEYS);
 
   /* Check if the key is valid. */
 
-  if (key < group->tg_nkeys)
+  if (key < CONFIG_NPTHREAD_KEYS && (group->tg_keyset & (1 << key)) != 0)
     {
       /* Store the data in the TCB. */