libpthread/linuxthreads_db/td_ta_map_lwp2thr.c

   1 /* Which thread is running on an lwp?
   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_lwp2thr (const td_thragent_t *ta, lwpid_t lwpid, td_thrhandle_t *th)
  25 {
  26   int pthread_threads_max = ta->pthread_threads_max;
  27   size_t sizeof_descr = ta->sizeof_descr;
  28   struct pthread_handle_struct phc[pthread_threads_max];
  29   size_t cnt;
  30 #ifdef ALL_THREADS_STOPPED
  31   int num;
  32 #else
  33 # define num 1
  34 #endif
  35
  36   LOG ("td_ta_map_lwp2thr");
  37
  38   /* Test whether the TA parameter is ok.  */
  39   if (! ta_ok (ta))
  40     return TD_BADTA;
  41
  42   /* Read all the descriptors.  */
  43   if (ps_pdread (ta->ph, ta->handles, phc,
  44                  sizeof (struct pthread_handle_struct) * pthread_threads_max)
  45       != PS_OK)
  46     return TD_ERR;      /* XXX Other error value?  */
  47
  48 #ifdef ALL_THREADS_STOPPED
  49   /* Read the number of currently active threads.  */
  50   if (ps_pdread (ta->ph, ta->pthread_handles_num, &num, sizeof (int)) != PS_OK)
  51     return TD_ERR;      /* XXX Other error value?  */
  52 #endif
  53
  54   /* Get the entries one after the other and find out whether the ID
  55      matches.  */
  56   for (cnt = 0; cnt < pthread_threads_max && num > 0; ++cnt)
  57     if (phc[cnt].h_descr != NULL)
  58       {
  59         struct _pthread_descr_struct pds;
  60
  61 #ifdef ALL_THREADS_STOPPED
  62         /* First count this active thread.  */
  63         --num;
  64 #endif
  65
  66         if (ps_pdread (ta->ph, phc[cnt].h_descr, &pds, sizeof_descr) != PS_OK)
  67           return TD_ERR;        /* XXX Other error value?  */
  68
  69         if ((pds.p_pid ?: ps_getpid (ta->ph)) == lwpid)
  70           {
  71             /* Found it.  Now fill in the `td_thrhandle_t' object.  */
  72             th->th_ta_p = (td_thragent_t *) ta;
  73             th->th_unique = phc[cnt].h_descr;
  74
  75             return TD_OK;
  76           }
  77       }
  78     else if (cnt == 0)
  79       {
  80         /* The initial thread always exists.  But it might not yet be
  81            initialized.  Construct a value.  */
  82         th->th_ta_p = (td_thragent_t *) ta;
  83         th->th_unique = NULL;
  84
  85         return TD_OK;
  86       }
  87
  88   return TD_NOLWP;
  89 }