nptl_db/td_ta_event_getmsg.c

   1 /* Retrieve event.
   2    Copyright (C) 1999, 2001, 2002, 2003 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 <stddef.h>
  22 #include <string.h>
  23
  24 #include "thread_dbP.h"
  25
  26
  27 td_err_e
  28 td_ta_event_getmsg (const td_thragent_t *ta_arg, td_event_msg_t *msg)
  29 {
  30   td_thragent_t *const ta = (td_thragent_t *) ta_arg;
  31   td_err_e err;
  32   psaddr_t eventbuf, eventnum, eventdata;
  33   psaddr_t thp, next;
  34   void *copy;
  35
  36   /* XXX I cannot think of another way but using a static variable.  */
  37   /* XXX Use at least __thread once it is possible.  */
  38   static td_thrhandle_t th;
  39
  40   LOG ("td_thr_event_getmsg");
  41
  42   /* Test whether the TA parameter is ok.  */
  43   if (! ta_ok (ta))
  44     return TD_BADTA;
  45
  46   /* Get the pointer to the thread descriptor with the last event.  */
  47   err = DB_GET_VALUE (thp, ta, __nptl_last_event, 0);
  48   if (err != TD_OK)
  49     return err;
  50
  51   if (thp == 0)
  52     /* Nothing waiting.  */
  53     return TD_NOMSG;
  54
  55   /* Copy the event message buffer in from the inferior.  */
  56   err = DB_GET_FIELD_ADDRESS (eventbuf, ta, thp, pthread, eventbuf, 0);
  57   if (err == TD_OK)
  58     err = DB_GET_STRUCT (copy, ta, eventbuf, td_eventbuf_t);
  59   if (err != TD_OK)
  60     return err;
  61
  62   /* Read the event details from the target thread.  */
  63   err = DB_GET_FIELD_LOCAL (eventnum, ta, copy, td_eventbuf_t, eventnum, 0);
  64   if (err != TD_OK)
  65     return err;
  66   /* If the structure is on the list there better be an event recorded.  */
  67   if ((int) (uintptr_t) eventnum == TD_EVENT_NONE)
  68     return TD_DBERR;
  69
  70   /* Fill the user's data structure.  */
  71   err = DB_GET_FIELD_LOCAL (eventdata, ta, copy, td_eventbuf_t, eventdata, 0);
  72   if (err != TD_OK)
  73     return err;
  74
  75   /* Generate the thread descriptor.  */
  76   th.th_ta_p = (td_thragent_t *) ta;
  77   th.th_unique = thp;
  78
  79   /* Fill the user's data structure.  */
  80   msg->msg.data = (uintptr_t) eventdata;
  81   msg->event = (uintptr_t) eventnum;
  82   msg->th_p = &th;
  83
  84   /* And clear the event message in the target.  */
  85   memset (copy, 0, ta->ta_sizeof_td_eventbuf_t);
  86   err = DB_PUT_STRUCT (ta, eventbuf, td_eventbuf_t, copy);
  87   if (err != TD_OK)
  88     return err;
  89
  90   /* Get the pointer to the next descriptor with an event.  */
  91   err = DB_GET_FIELD (next, ta, thp, pthread, nextevent, 0);
  92   if (err != TD_OK)
  93     return err;
  94
  95   /* Store the pointer in the list head variable.  */
  96   err = DB_PUT_VALUE (ta, __nptl_last_event, 0, next);
  97   if (err != TD_OK)
  98     return err;
  99
 100   if (next != 0)
 101     /* Clear the next pointer in the current descriptor.  */
 102     err = DB_PUT_FIELD (ta, thp, pthread, nextevent, 0, 0);
 103
 104   return err;
 105 }