1  /* Get a thread-specific data pointer for a thread.
       2     Copyright (C) 1999-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <stdint.h>
      20  #include "thread_dbP.h"
      21  
      22  
      23  td_err_e
      24  td_thr_tsd (const td_thrhandle_t *th, const thread_key_t tk, void **data)
      25  {
      26    td_err_e err;
      27    psaddr_t tk_seq, level1, level2, seq, value;
      28    void *copy;
      29    uint32_t pthread_key_2ndlevel_size, idx1st, idx2nd;
      30  
      31    LOG ("td_thr_tsd");
      32  
      33    /* Get the key entry.  */
      34    err = DB_GET_VALUE (tk_seq, th->th_ta_p, __pthread_keys, tk);
      35    if (err == TD_NOAPLIC)
      36      return TD_BADKEY;
      37    if (err != TD_OK)
      38      return err;
      39  
      40    /* Fail if this key is not at all used.  */
      41    if (((uintptr_t) tk_seq & 1) == 0)
      42      return TD_BADKEY;
      43  
      44    /* This makes sure we have the size information on hand.  */
      45    err = DB_GET_FIELD_ADDRESS (level2, th->th_ta_p, 0, pthread_key_data_level2,
      46  			      data, 1);
      47    if (err != TD_OK)
      48      return err;
      49  
      50    /* Compute the indices.  */
      51    pthread_key_2ndlevel_size
      52      = DB_DESC_NELEM (th->th_ta_p->ta_field_pthread_key_data_level2_data);
      53    idx1st = tk / pthread_key_2ndlevel_size;
      54    idx2nd = tk % pthread_key_2ndlevel_size;
      55  
      56    /* Now fetch the first level pointer.  */
      57    err = DB_GET_FIELD (level1, th->th_ta_p, th->th_unique, pthread,
      58  		      specific, idx1st);
      59    if (err == TD_NOAPLIC)
      60      return TD_DBERR;
      61    if (err != TD_OK)
      62      return err;
      63  
      64    /* Check the pointer to the second level array.  */
      65    if (level1 == 0)
      66      return TD_NOTSD;
      67  
      68    /* Locate the element within the second level array.  */
      69    err = DB_GET_FIELD_ADDRESS (level2, th->th_ta_p,
      70  			      level1, pthread_key_data_level2, data, idx2nd);
      71    if (err == TD_NOAPLIC)
      72      return TD_DBERR;
      73    if (err != TD_OK)
      74      return err;
      75  
      76    /* Now copy in that whole structure.  */
      77    err = DB_GET_STRUCT (copy, th->th_ta_p, level2, pthread_key_data);
      78    if (err != TD_OK)
      79      return err;
      80  
      81    /* Check whether the data is valid.  */
      82    err = DB_GET_FIELD_LOCAL (seq, th->th_ta_p, copy, pthread_key_data, seq, 0);
      83    if (err != TD_OK)
      84      return err;
      85    if (seq != tk_seq)
      86      return TD_NOTSD;
      87  
      88    /* Finally, fetch the value.  */
      89    err = DB_GET_FIELD_LOCAL (value, th->th_ta_p, copy, pthread_key_data,
      90  			    data, 0);
      91    if (err == TD_OK)
      92      *data = value;
      93  
      94    return err;
      95  }