1/* Copyright (C) 2002-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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 <stdlib.h>
20#include "pthreadP.h"
21
22
23void *
24__pthread_getspecific (pthread_key_t key)
25{
26 struct pthread_key_data *data;
27
28 /* Special case access to the first 2nd-level block. This is the
29 usual case. */
30 if (__glibc_likely (key < PTHREAD_KEY_2NDLEVEL_SIZE))
31 data = &THREAD_SELF->specific_1stblock[key];
32 else
33 {
34 /* Verify the key is sane. */
35 if (key >= PTHREAD_KEYS_MAX)
36 /* Not valid. */
37 return NULL;
38
39 unsigned int idx1st = key / PTHREAD_KEY_2NDLEVEL_SIZE;
40 unsigned int idx2nd = key % PTHREAD_KEY_2NDLEVEL_SIZE;
41
42 /* If the sequence number doesn't match or the key cannot be defined
43 for this thread since the second level array is not allocated
44 return NULL, too. */
45 struct pthread_key_data *level2 = THREAD_GETMEM_NC (THREAD_SELF,
46 specific, idx1st);
47 if (level2 == NULL)
48 /* Not allocated, therefore no data. */
49 return NULL;
50
51 /* There is data. */
52 data = &level2[idx2nd];
53 }
54
55 void *result = data->data;
56 if (result != NULL)
57 {
58 uintptr_t seq = data->seq;
59
60 if (__glibc_unlikely (seq != __pthread_keys[key].seq))
61 result = data->data = NULL;
62 }
63
64 return result;
65}
66weak_alias (__pthread_getspecific, pthread_getspecific)
67hidden_def (__pthread_getspecific)
68