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
23td_err_e
24td_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}
96