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, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include "thread_dbP.h"
  22 #include <linuxthreads/internals.h>
  23
  24
  25 td_err_e
  26 td_ta_map_lwp2thr (const td_thragent_t *ta, lwpid_t lwpid, td_thrhandle_t *th)
  27 {
  28   int pthread_threads_max = ta->pthread_threads_max;
  29   size_t sizeof_descr = ta->sizeof_descr;
  30   struct pthread_handle_struct phc[pthread_threads_max];
  31   size_t cnt;
  32 #ifdef ALL_THREADS_STOPPED
  33   int num;
  34 #else
  35 # define num 1
  36 #endif
  37
  38   LOG ("td_ta_map_lwp2thr");
  39
  40   /* Test whether the TA parameter is ok.  */
  41   if (! ta_ok (ta))
  42     return TD_BADTA;
  43
  44   /* Read all the descriptors.  */
  45   if (ps_pdread (ta->ph, ta->handles, phc,
  46                  sizeof (struct pthread_handle_struct) * pthread_threads_max)
  47       != PS_OK)
  48     return TD_ERR;      /* XXX Other error value?  */
  49
  50 #ifdef ALL_THREADS_STOPPED
  51   /* Read the number of currently active threads.  */
  52   if (ps_pdread (ta->ph, ta->pthread_handles_num, &num, sizeof (int)) != PS_OK)
  53     return TD_ERR;      /* XXX Other error value?  */
  54 #endif
  55
  56   /* Get the entries one after the other and find out whether the ID
  57      matches.  */
  58   for (cnt = 0; cnt < pthread_threads_max && num > 0; ++cnt)
  59     if (phc[cnt].h_descr != NULL)
  60       {
  61         struct _pthread_descr_struct pds;
  62
  63 #ifdef ALL_THREADS_STOPPED
  64         /* First count this active thread.  */
  65         --num;
  66 #endif
  67
  68         if (ps_pdread (ta->ph, phc[cnt].h_descr, &pds, sizeof_descr) != PS_OK)
  69           return TD_ERR;        /* XXX Other error value?  */
  70
  71         if ((pds.p_pid ?: ps_getpid (ta->ph)) == lwpid)
  72           {
  73             /* Found it.  Now fill in the `td_thrhandle_t' object.  */
  74             th->th_ta_p = (td_thragent_t *) ta;
  75             th->th_unique = phc[cnt].h_descr;
  76
  77             return TD_OK;
  78           }
  79       }
  80     else if (cnt == 0)
  81       {
  82         /* The initial thread always exists.  But it might not yet be
  83            initialized.  Construct a value.  */
  84         th->th_ta_p = (td_thragent_t *) ta;
  85         th->th_unique = NULL;
  86
  87         return TD_OK;
  88       }
  89
  90   return TD_NOLWP;
  91 }