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 <assert.h>
  22 #include <stddef.h>
  23 #include <string.h>
  24
  25 #include "thread_dbP.h"
  26
  27
  28 td_err_e
  29 td_ta_event_getmsg (const td_thragent_t *ta, td_event_msg_t *msg)
  30 {
  31   /* XXX I cannot think of another way but using a static variable.  */
  32   /* XXX Use at least __thread once it is possible.  */
  33   static td_thrhandle_t th;
  34
  35   LOG ("td_ta_event_getmsg");
  36
  37   /* Test whether the TA parameter is ok.  */
  38   if (! ta_ok (ta))
  39     return TD_BADTA;
  40
  41   /* Get the pointer to the thread descriptor with the last event.  */
  42   psaddr_t addr;
  43   if (ps_pdread (ta->ph, ta->pthread_last_event,
  44                  &addr, sizeof (struct pthread *)) != PS_OK)
  45     return TD_ERR;      /* XXX Other error value?  */
  46
  47   if (addr == 0)
  48     /* Nothing waiting.  */
  49     return TD_NOMSG;
  50
  51   /* Read the event structure from the target.  */
  52   td_eventbuf_t event;
  53   if (ps_pdread (ta->ph, (char *) addr + offsetof (struct pthread, eventbuf),
  54                  &event, sizeof (td_eventbuf_t)) != PS_OK)
  55     return TD_ERR;      /* XXX Other error value?  */
  56
  57   /* If the structure is on the list there better be an event recorded.  */
  58   assert (event.eventnum != TD_EVENT_NONE);
  59
  60   /* Generate the thread descriptor.  */
  61   th.th_ta_p = (td_thragent_t *) ta;
  62   th.th_unique = addr;
  63
  64   /* Fill the user's data structure.  */
  65   msg->event = event.eventnum;
  66   msg->th_p = &th;
  67   msg->msg.data = (uintptr_t) event.eventdata;
  68
  69   /* Get the pointer to the next descriptor with an event.  */
  70   psaddr_t next;
  71   if (ps_pdread (ta->ph, (char *) addr + offsetof (struct pthread, nextevent),
  72                  &next, sizeof (struct pthread *)) != PS_OK)
  73     return TD_ERR;      /* XXX Other error value?  */
  74
  75   /* Store the pointer in the list head variable.  */
  76   if (ps_pdwrite (ta->ph, ta->pthread_last_event,
  77                   &next, sizeof (struct pthread *)) != PS_OK)
  78     return TD_ERR;      /* XXX Other error value?  */
  79
  80   /* Clear the next pointer in the current descriptor.  */
  81   next = NULL;
  82   if (ps_pdwrite (ta->ph, (char *) addr + offsetof (struct pthread, nextevent),
  83                   &next, sizeof (struct pthread *)) != PS_OK)
  84     return TD_ERR;      /* XXX Other error value?  */
  85
  86   return TD_OK;
  87 }