glibc/sysdeps/htl/pt-key-create.c

111 lines
2.9 KiB
C

/* pthread_key_create. Hurd version.
Copyright (C) 2002-2020 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 <pthread.h>
#include <stdlib.h>
#include <assert.h>
#include <pt-internal.h>
#include <pthreadP.h>
pthread_mutex_t __pthread_key_lock;
void (**__pthread_key_destructors) (void *arg);
int __pthread_key_size;
int __pthread_key_count;
int __pthread_key_invalid_count;
int
__pthread_key_create (pthread_key_t *key, void (*destructor) (void *))
{
/* Where to look for the next key slot. */
static int index;
__pthread_key_lock_ready ();
__pthread_mutex_lock (&__pthread_key_lock);
do_search:
/* Use the search hint and try to find a free slot. */
for (; index < __pthread_key_count
&& __pthread_key_destructors[index] != PTHREAD_KEY_INVALID; index++)
;
/* See if we actually found a free element. */
if (index < __pthread_key_count)
{
assert (__pthread_key_destructors[index] == PTHREAD_KEY_INVALID);
assert (__pthread_key_invalid_count > 0);
__pthread_key_invalid_count--;
__pthread_key_destructors[index] = destructor;
*key = index++;
__pthread_mutex_unlock (&__pthread_key_lock);
return 0;
}
assert (index == __pthread_key_count);
/* No space at the end. */
if (__pthread_key_size == __pthread_key_count)
{
/* See if it is worth looking for a free element. */
if (__pthread_key_invalid_count > 4
&& __pthread_key_invalid_count > __pthread_key_size / 8)
{
index = 0;
goto do_search;
}
/* Resize the array. */
{
void *t;
int newsize;
if (__pthread_key_size == 0)
newsize = 8;
else
newsize = __pthread_key_size * 2;
t = realloc (__pthread_key_destructors,
newsize * sizeof (*__pthread_key_destructors));
if (t == NULL)
{
__pthread_mutex_unlock (&__pthread_key_lock);
return ENOMEM;
}
__pthread_key_size = newsize;
__pthread_key_destructors = t;
}
}
__pthread_key_destructors[index] = destructor;
*key = index;
index++;
__pthread_key_count++;
__pthread_mutex_unlock (&__pthread_key_lock);
return 0;
}
strong_alias (__pthread_key_create, pthread_key_create)
hidden_def (__pthread_key_create)