nptl_db/td_ta_thr_iter.c

   1 /* Iterate over a process's threads.
   2    Copyright (C) 1999,2000,2001,2002,2003,2004 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@redhat.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
  23
  24 static td_err_e
  25 iterate_thread_list (td_thragent_t *ta, td_thr_iter_f *callback,
  26                      void *cbdata_p, td_thr_state_e state, int ti_pri,
  27                      psaddr_t head, int fake_empty)
  28 {
  29   td_err_e err;
  30   psaddr_t next, ofs;
  31   void *copy;
  32
  33   /* Test the state.
  34      XXX This is incomplete.  Normally this test should be in the loop.  */
  35   if (state != TD_THR_ANY_STATE)
  36     return TD_OK;
  37
  38   err = DB_GET_FIELD (next, ta, head, list_t, next, 0);
  39   if (err != TD_OK)
  40     return err;
  41
  42   if (next == 0 && fake_empty)
  43     {
  44       /* __pthread_initialize_minimal has not run.
  45          There is just the main thread to return.  */
  46       td_thrhandle_t th;
  47       err = td_ta_map_lwp2thr (ta, ps_getpid (ta->ph), &th);
  48       if (err == TD_OK)
  49         err = callback (&th, cbdata_p) != 0 ? TD_DBERR : TD_OK;
  50       return err;
  51     }
  52
  53   /* Cache the offset from struct pthread to its list_t member.  */
  54   err = DB_GET_FIELD_ADDRESS (ofs, ta, 0, pthread, list, 0);
  55   if (err != TD_OK)
  56     return err;
  57
  58   if (ta->ta_sizeof_pthread == 0)
  59     {
  60       err = _td_check_sizeof (ta, &ta->ta_sizeof_pthread, SYM_SIZEOF_pthread);
  61       if (err != TD_OK)
  62         return err;
  63     }
  64   copy = __alloca (ta->ta_sizeof_pthread);
  65
  66   while (next != head)
  67     {
  68       psaddr_t addr, schedpolicy, schedprio;
  69
  70       addr = next - (ofs - (psaddr_t) 0);
  71       if (next == 0 || addr == 0) /* Sanity check.  */
  72         return TD_DBERR;
  73
  74       /* Copy the whole descriptor in once so we can access the several
  75          fields locally.  Excess copying in one go is much better than
  76          multiple ps_pdread calls.  */
  77       if (ps_pdread (ta->ph, addr, copy, ta->ta_sizeof_pthread) != PS_OK)
  78         return TD_ERR;
  79
  80       err = DB_GET_FIELD_LOCAL (schedpolicy, ta, copy, pthread,
  81                                 schedpolicy, 0);
  82       if (err != TD_OK)
  83         break;
  84       err = DB_GET_FIELD_LOCAL (schedprio, ta, copy, pthread,
  85                                 schedparam_sched_priority, 0);
  86       if (err != TD_OK)
  87         break;
  88
  89       /* Now test whether this thread matches the specified conditions.  */
  90
  91       /* Only if the priority level is as high or higher.  */
  92       int descr_pri = ((uintptr_t) schedpolicy == SCHED_OTHER
  93                        ? 0 : (uintptr_t) schedprio);
  94       if (descr_pri >= ti_pri)
  95         {
  96           /* Yep, it matches.  Call the callback function.  */
  97           td_thrhandle_t th;
  98           th.th_ta_p = (td_thragent_t *) ta;
  99           th.th_unique = addr;
 100           if (callback (&th, cbdata_p) != 0)
 101             return TD_DBERR;
 102         }
 103
 104       /* Get the pointer to the next element.  */
 105       err = DB_GET_FIELD_LOCAL (next, ta, copy + (ofs - (psaddr_t) 0), list_t,
 106                                 next, 0);
 107       if (err != TD_OK)
 108         break;
 109     }
 110
 111   return err;
 112 }
 113
 114
 115 td_err_e
 116 td_ta_thr_iter (const td_thragent_t *ta_arg, td_thr_iter_f *callback,
 117                 void *cbdata_p, td_thr_state_e state, int ti_pri,
 118                 sigset_t *ti_sigmask_p, unsigned int ti_user_flags)
 119 {
 120   td_thragent_t *const ta = (td_thragent_t *) ta_arg;
 121   td_err_e err;
 122   psaddr_t list = 0;
 123
 124   LOG ("td_ta_thr_iter");
 125
 126   /* Test whether the TA parameter is ok.  */
 127   if (! ta_ok (ta))
 128     return TD_BADTA;
 129
 130   /* The thread library keeps two lists for the running threads.  One
 131      list contains the thread which are using user-provided stacks
 132      (this includes the main thread) and the other includes the
 133      threads for which the thread library allocated the stacks.  We
 134      have to iterate over both lists separately.  We start with the
 135      list of threads with user-defined stacks.  */
 136
 137   err = DB_GET_SYMBOL (list, ta, __stack_user);
 138   if (err == TD_OK)
 139     err = iterate_thread_list (ta, callback, cbdata_p, state, ti_pri, list, 1);
 140
 141   /* And the threads with stacks allocated by the implementation.  */
 142   if (err == TD_OK)
 143     err = DB_GET_SYMBOL (list, ta, stack_used);
 144   if (err == TD_OK)
 145     err = iterate_thread_list (ta, callback, cbdata_p, state, ti_pri, list, 0);
 146
 147   return err;
 148 }