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glibc  2.9
Functions
pthread_getspecific.c File Reference
#include <stdlib.h>
#include "pthreadP.h"

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Functions

void * __pthread_getspecific (pthread_key_t key)

Function Documentation

Definition at line 25 of file pthread_getspecific.c.

{
  struct pthread_key_data *data;

  /* Special case access to the first 2nd-level block.  This is the
     usual case.  */
  if (__builtin_expect (key < PTHREAD_KEY_2NDLEVEL_SIZE, 1))
    data = &THREAD_SELF->specific_1stblock[key];
  else
    {
      /* Verify the key is sane.  */
      if (key >= PTHREAD_KEYS_MAX)
       /* Not valid.  */
       return NULL;

      unsigned int idx1st = key / PTHREAD_KEY_2NDLEVEL_SIZE;
      unsigned int idx2nd = key % PTHREAD_KEY_2NDLEVEL_SIZE;

      /* If the sequence number doesn't match or the key cannot be defined
        for this thread since the second level array is not allocated
        return NULL, too.  */
      struct pthread_key_data *level2 = THREAD_GETMEM_NC (THREAD_SELF,
                                                   specific, idx1st);
      if (level2 == NULL)
       /* Not allocated, therefore no data.  */
       return NULL;

      /* There is data.  */
      data = &level2[idx2nd];
    }

  void *result = data->data;
  if (result != NULL)
    {
      uintptr_t seq = data->seq;

      if (__builtin_expect (seq != __pthread_keys[key].seq, 0))
       result = data->data = NULL;
    }

  return result;
}