libpthread/linuxthreads_db/td_ta_map_id2thr.c

   1 /* Map thread ID to thread handle.
   2    Copyright (C) 1999, 2001, 2002 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1999.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include "thread_dbP.h"
  21
  22
  23 td_err_e
  24 td_ta_map_id2thr (const td_thragent_t *ta, pthread_t pt, td_thrhandle_t *th)
  25 {
  26   struct pthread_handle_struct phc;
  27   struct _pthread_descr_struct pds;
  28   int pthread_threads_max;
  29
  30   LOG ("td_ta_map_id2thr");
  31
  32   /* Test whether the TA parameter is ok.  */
  33   if (! ta_ok (ta))
  34     return TD_BADTA;
  35
  36   /* Make the following expression a bit smaller.  */
  37   pthread_threads_max = ta->pthread_threads_max;
  38
  39   /* We can compute the entry in the handle array we want.  */
  40   if (ps_pdread (ta->ph, ta->handles + pt % pthread_threads_max, &phc,
  41                  sizeof (struct pthread_handle_struct)) != PS_OK)
  42     return TD_ERR;      /* XXX Other error value?  */
  43
  44   /* Test whether this entry is in use.  */
  45   if (phc.h_descr == NULL)
  46     {
  47       if (pt % pthread_threads_max == 0)
  48         {
  49           /* The initial thread always exists but the thread library
  50              might not yet be initialized.  */
  51           th->th_ta_p = (td_thragent_t *) ta;
  52           th->th_unique = NULL;
  53
  54           return TD_OK;
  55         }
  56
  57       return TD_BADTH;
  58     }
  59
  60   /* Next test: get the descriptor to see whether this is not an old
  61      thread handle.  */
  62   if (ps_pdread (ta->ph, phc.h_descr, &pds,
  63                  sizeof (struct _pthread_descr_struct)) != PS_OK)
  64     return TD_ERR;      /* XXX Other error value?  */
  65
  66   if (pds.p_tid != pt)
  67     return TD_BADTH;
  68
  69   if (pds.p_terminated != 0)
  70     return TD_NOTHR;
  71
  72   /* Create the `td_thrhandle_t' object.  */
  73   th->th_ta_p = (td_thragent_t *) ta;
  74   th->th_unique = phc.h_descr;
  75
  76   return TD_OK;
  77 }