glibc/linuxthreads_db/td_thr_tsd.c

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/* Get a thread-specific data pointer for a thread.
Copyright (C) 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1999.
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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include "thread_dbP.h"
td_err_e
td_thr_tsd (const td_thrhandle_t *th, const thread_key_t tk, void **data)
{
struct _pthread_descr_struct pds;
struct pthread_key_struct *keys = th->th_ta_p->keys;
struct pthread_key_struct key;
int pthread_keys_max = th->th_ta_p->pthread_keys_max;
int pthread_key_2ndlevel_size = th->th_ta_p->pthread_key_2ndlevel_size;
unsigned int idx1st;
unsigned int idx2nd;
void *p;
LOG (__FUNCTION__);
/* Get the thread descriptor. */
if (ps_pdread (th->th_ta_p->ph, th->th_unique, &pds,
sizeof (struct _pthread_descr_struct)) != PS_OK)
return TD_ERR; /* XXX Other error value? */
/* Check correct value of key. */
if (tk >= pthread_keys_max)
return TD_BADKEY;
/* Get the key entry. */
if (ps_pdread (th->th_ta_p->ph, keys, &key,
sizeof (struct pthread_key_struct)) != PS_OK)
return TD_ERR; /* XXX Other error value? */
/* Fail if this key is not at all used. */
if (! key.in_use)
return TD_BADKEY;
/* Compute the indeces. */
idx1st = tk / pthread_key_2ndlevel_size;
idx2nd = tk % pthread_key_2ndlevel_size;
/* Check the pointer to the second level array. */
if (pds.p_specific[idx1st] == NULL)
return TD_NOTSD;
/* Now get the real key.
XXX I don't know whether it's correct but there is currently no
easy way to determine whether a key was never set or the value
is NULL. We return an error whenever the value is NULL. */
if (ps_pdread (th->th_ta_p->ph, &pds.p_specific[idx1st][idx2nd], &p,
sizeof (void *)) != PS_OK)
return TD_ERR;
if (p != NULL)
*data = p;
return p != NULL ? TD_OK : TD_NOTSD;
}