libpthread/linuxthreads_db/td_ta_thr_iter.c

   1 /* Iterate over a process's threads.
   2    Copyright (C) 1999,2000,2001,2002,2003 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 #include <linuxthreads/internals.h>
  22 #include <alloca.h>
  23
  24 static int
  25 handle_descr (const td_thragent_t *ta, td_thr_iter_f *callback,
  26               void *cbdata_p, td_thr_state_e state, int ti_pri,
  27               size_t cnt, pthread_descr descr)
  28 {
  29   struct _pthread_descr_struct pds;
  30   size_t sizeof_descr = ta->sizeof_descr;
  31   td_thrhandle_t th;
  32
  33   if (descr == NULL)
  34     {
  35       /* No descriptor (yet).  */
  36       if (cnt == 0)
  37         {
  38           /* This is the main thread.  Create a fake descriptor.  */
  39           memset (&pds, '\0', sizeof (pds));
  40
  41           /* Empty thread descriptor the thread library would create.  */
  42 #if !defined __UCLIBC_HAS_TLS__ || !TLS_DTV_AT_TP
  43           pds.p_header.data.self = &pds;
  44 #endif
  45           pds.p_nextlive = pds.p_prevlive = &pds;
  46           pds.p_tid = PTHREAD_THREADS_MAX;
  47           /* The init code also sets up p_lock, p_errnop, p_herrnop, and
  48              p_userstack but this should not be necessary here.  */
  49
  50           th.th_ta_p = (td_thragent_t *) ta;
  51           th.th_unique = NULL;
  52           if (callback (&th, cbdata_p) != 0)
  53             return TD_DBERR;
  54
  55           /* All done successfully.  */
  56           return TD_OK;
  57         }
  58       else if (cnt == 1)
  59         /* The manager is not yet started.  No big deal.  */
  60         return TD_OK;
  61       else
  62         /* For every other thread this should not happen.  */
  63         return TD_ERR;
  64     }
  65
  66   if (ps_pdread (ta->ph, descr, &pds, sizeof_descr) != PS_OK)
  67     return TD_ERR;      /* XXX Other error value?  */
  68
  69   /* The manager thread must be handled special.  The descriptor
  70      exists but the thread only gets created when the first
  71      `pthread_create' call is issued.  A clear indication that this
  72      happened is when the p_pid field is non-zero.  */
  73   if (cnt == 1 && pds.p_pid == 0)
  74     return TD_OK;
  75
  76   /* Now test whether this thread matches the specified
  77      conditions.  */
  78
  79   /* Only if the priority level is as high or higher.  */
  80   if (pds.p_priority < ti_pri)
  81     return TD_OK;
  82
  83   /* Test the state.
  84      XXX This is incomplete.  */
  85   if (state != TD_THR_ANY_STATE)
  86     return TD_OK;
  87
  88   /* XXX For now we ignore threads which are not running anymore.
  89      The reason is that gdb tries to get the registers and fails.
  90      In future we should have a special mode of the thread library
  91      in which we keep the process around until the actual join
  92      operation happened.  */
  93   if (pds.p_exited != 0)
  94     return TD_OK;
  95
  96   /* Yep, it matches.  Call the callback function.  */
  97   th.th_ta_p = (td_thragent_t *) ta;
  98   th.th_unique = descr;
  99   if (callback (&th, cbdata_p) != 0)
 100     return TD_DBERR;
 101
 102   /* All done successfully.  */
 103   return TD_OK;
 104 }
 105
 106
 107 td_err_e
 108 td_ta_thr_iter (const td_thragent_t *ta, td_thr_iter_f *callback,
 109                 void *cbdata_p, td_thr_state_e state, int ti_pri,
 110                 sigset_t *ti_sigmask_p, unsigned int ti_user_flags)
 111 {
 112   int pthread_threads_max;
 113   struct pthread_handle_struct *phc;
 114   td_err_e result = TD_OK;
 115   int cnt;
 116 #ifdef ALL_THREADS_STOPPED
 117   int num;
 118 #else
 119 # define num 1
 120 #endif
 121
 122   LOG ("td_ta_thr_iter");
 123
 124   /* Test whether the TA parameter is ok.  */
 125   if (! ta_ok (ta))
 126     return TD_BADTA;
 127
 128   pthread_threads_max = ta->pthread_threads_max;
 129   phc = (struct pthread_handle_struct *) alloca (sizeof (phc[0])
 130                                                  * pthread_threads_max);
 131
 132   /* First read only the main thread and manager thread information.  */
 133   if (ps_pdread (ta->ph, ta->handles, phc,
 134                  sizeof (struct pthread_handle_struct) * 2) != PS_OK)
 135     return TD_ERR;      /* XXX Other error value?  */
 136
 137   /* Now handle these descriptors.  */
 138   result = handle_descr (ta, callback, cbdata_p, state, ti_pri, 0,
 139                          phc[0].h_descr);
 140   if (result != TD_OK)
 141     return result;
 142   result = handle_descr (ta, callback, cbdata_p, state, ti_pri, 1,
 143                          phc[1].h_descr);
 144   if (result != TD_OK)
 145     return result;
 146
 147   /* Read all the descriptors.  */
 148   if (ps_pdread (ta->ph, ta->handles + 2, &phc[2],
 149                  (sizeof (struct pthread_handle_struct)
 150                   * (pthread_threads_max - 2))) != PS_OK)
 151     return TD_ERR;      /* XXX Other error value?  */
 152
 153 #ifdef ALL_THREADS_STOPPED
 154   /* Read the number of currently active threads.  */
 155   if (ps_pdread (ta->ph, ta->pthread_handles_num, &num, sizeof (int)) != PS_OK)
 156     return TD_ERR;      /* XXX Other error value?  */
 157 #endif
 158
 159   /* Now get all descriptors, one after the other.  */
 160   for (cnt = 2; cnt < pthread_threads_max && num > 0; ++cnt)
 161     if (phc[cnt].h_descr != NULL)
 162       {
 163 #ifdef ALL_THREADS_STOPPED
 164         /* First count this active thread.  */
 165         --num;
 166 #endif
 167
 168         result = handle_descr (ta, callback, cbdata_p, state, ti_pri, cnt,
 169                                phc[cnt].h_descr);
 170         if (result != TD_OK)
 171           break;
 172       }
 173
 174   return result;
 175 }