linuxthreads_db/td_ta_event_getmsg.c

   1 /* Retrieve event.
   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 <stddef.h>
  22 #include <string.h>
  23
  24 #include "thread_dbP.h"
  25 #include <linuxthreads/internals.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   static td_thrhandle_t th;
  33   td_eventbuf_t event;
  34   psaddr_t addr;
  35
  36   LOG ("td_ta_event_getmsg");
  37
  38   /* Test whether the TA parameter is ok.  */
  39   if (! ta_ok (ta))
  40     return TD_BADTA;
  41
  42   /* Get the pointer to the thread descriptor with the last event.  */
  43   if (ps_pdread (ta->ph, ta->pthread_last_event,
  44                  &addr, sizeof (void *)) != PS_OK)
  45     return TD_ERR;      /* XXX Other error value?  */
  46
  47   /* If the pointer is NULL no event occurred.  */
  48   if (addr == 0)
  49     return TD_NOMSG;
  50
  51   /* Read the even structure from the target.  */
  52   if (ps_pdread (ta->ph,
  53                  ((char *) addr
  54                   + offsetof (struct _pthread_descr_struct, p_eventbuf)),
  55                  &event, sizeof (td_eventbuf_t)) != PS_OK)
  56     return TD_ERR;      /* XXX Other error value?  */
  57
  58   /* Check whether an event occurred.  */
  59   if (event.eventnum == TD_EVENT_NONE)
  60     {
  61       /* Oh well, this means the last event was already read.  So
  62          we have to look for any other event.  */
  63       struct pthread_handle_struct handles[ta->pthread_threads_max];
  64       int num;
  65       int i;
  66
  67       /* Read the number of currently active threads.  */
  68       if (ps_pdread (ta->ph, ta->pthread_handles_num, &num, sizeof (int))
  69           != PS_OK)
  70         return TD_ERR;  /* XXX Other error value?  */
  71
  72       /* Now read the handles.  */
  73       if (ps_pdread (ta->ph, ta->handles, handles,
  74                      ta->pthread_threads_max * sizeof (handles[0])) != PS_OK)
  75         return TD_ERR;  /* XXX Other error value?  */
  76
  77       for (i = 0; i < ta->pthread_threads_max && num > 0; ++i)
  78         {
  79           if (handles[i].h_descr == NULL)
  80             /* No entry here.  */
  81             continue;
  82
  83           /* First count this active thread.  */
  84           --num;
  85
  86           if (handles[i].h_descr == addr)
  87             /* We already handled this.  */
  88             continue;
  89
  90           /* Read the event data for this thread.  */
  91           if (ps_pdread (ta->ph,
  92                          ((char *) handles[i].h_descr
  93                           + offsetof (struct _pthread_descr_struct,
  94                                       p_eventbuf)),
  95                          &event, sizeof (td_eventbuf_t)) != PS_OK)
  96             return TD_ERR;
  97
  98           if (event.eventnum != TD_EVENT_NONE)
  99             {
 100               /* We found a thread with an unreported event.  */
 101               addr = handles[i].h_descr;
 102               break;
 103             }
 104         }
 105
 106       /* If we haven't found any other event signal this to the user.  */
 107       if (event.eventnum == TD_EVENT_NONE)
 108         return TD_NOMSG;
 109     }
 110
 111   /* Generate the thread descriptor.  */
 112   th.th_ta_p = (td_thragent_t *) ta;
 113   th.th_unique = addr;
 114
 115   /* Fill the user's data structure.  */
 116   msg->event = event.eventnum;
 117   msg->th_p = &th;
 118   msg->msg.data = (uintptr_t) event.eventdata;
 119
 120   /* And clear the event message in the target.  */
 121   memset (&event, '\0', sizeof (td_eventbuf_t));
 122   if (ps_pdwrite (ta->ph,
 123                   ((char *) addr
 124                    + offsetof (struct _pthread_descr_struct, p_eventbuf)),
 125                   &event, sizeof (td_eventbuf_t)) != PS_OK)
 126     return TD_ERR;      /* XXX Other error value?  */
 127
 128   return TD_OK;
 129 }