glibc/nptl/pthread_getspecific.c

78 lines
2.4 KiB
C

/* Copyright (C) 2002-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <stdlib.h>
#include "pthreadP.h"
#include <shlib-compat.h>
void *
___pthread_getspecific (pthread_key_t key)
{
struct pthread_key_data *data;
/* Special case access to the first 2nd-level block. This is the
usual case. */
if (__glibc_likely (key < PTHREAD_KEY_2NDLEVEL_SIZE))
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 (__glibc_unlikely (seq != __pthread_keys[key].seq))
result = data->data = NULL;
}
return result;
}
versioned_symbol (libc, ___pthread_getspecific, pthread_getspecific,
GLIBC_2_34);
libc_hidden_ver (___pthread_getspecific, __pthread_getspecific)
#ifndef SHARED
strong_alias (___pthread_getspecific, __pthread_getspecific)
#endif
#if OTHER_SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_34)
compat_symbol (libpthread, ___pthread_getspecific, __pthread_getspecific,
GLIBC_2_0);
compat_symbol (libpthread, ___pthread_getspecific, pthread_getspecific,
GLIBC_2_0);
#endif