libpthread/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, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <stddef.h>
  21 #include <string.h>
  22
  23 #include "thread_dbP.h"
  24
  25
  26 td_err_e
  27 td_ta_event_getmsg (const td_thragent_t *ta, td_event_msg_t *msg)
  28 {
  29   /* XXX I cannot think of another way but using a static variable.  */
  30   static td_thrhandle_t th;
  31   td_eventbuf_t event;
  32   psaddr_t addr;
  33
  34   LOG ("td_ta_event_getmsg");
  35
  36   /* Test whether the TA parameter is ok.  */
  37   if (! ta_ok (ta))
  38     return TD_BADTA;
  39
  40   /* Get the pointer to the thread descriptor with the last event.  */
  41   if (ps_pdread (ta->ph, ta->pthread_last_event,
  42                  &addr, sizeof (void *)) != PS_OK)
  43     return TD_ERR;      /* XXX Other error value?  */
  44
  45   /* If the pointer is NULL no event occurred.  */
  46   if (addr == 0)
  47     return TD_NOMSG;
  48
  49   /* Read the even structure from the target.  */
  50   if (ps_pdread (ta->ph,
  51                  ((char *) addr
  52                   + offsetof (struct _pthread_descr_struct, p_eventbuf)),
  53                  &event, sizeof (td_eventbuf_t)) != PS_OK)
  54     return TD_ERR;      /* XXX Other error value?  */
  55
  56   /* Check whether an event occurred.  */
  57   if (event.eventnum == TD_EVENT_NONE)
  58     {
  59       /* Oh well, this means the last event was already read.  So
  60          we have to look for any other event.  */
  61       struct pthread_handle_struct handles[ta->pthread_threads_max];
  62       int num;
  63       int i;
  64
  65       /* Read the number of currently active threads.  */
  66       if (ps_pdread (ta->ph, ta->pthread_handles_num, &num, sizeof (int))
  67           != PS_OK)
  68         return TD_ERR;  /* XXX Other error value?  */
  69
  70       /* Now read the handles.  */
  71       if (ps_pdread (ta->ph, ta->handles, handles,
  72                      ta->pthread_threads_max * sizeof (handles[0])) != PS_OK)
  73         return TD_ERR;  /* XXX Other error value?  */
  74
  75       for (i = 0; i < ta->pthread_threads_max && num > 0; ++i)
  76         {
  77           if (handles[i].h_descr == NULL)
  78             /* No entry here.  */
  79             continue;
  80
  81           /* First count this active thread.  */
  82           --num;
  83
  84           if (handles[i].h_descr == addr)
  85             /* We already handled this.  */
  86             continue;
  87
  88           /* Read the event data for this thread.  */
  89           if (ps_pdread (ta->ph,
  90                          ((char *) handles[i].h_descr
  91                           + offsetof (struct _pthread_descr_struct,
  92                                       p_eventbuf)),
  93                          &event, sizeof (td_eventbuf_t)) != PS_OK)
  94             return TD_ERR;
  95
  96           if (event.eventnum != TD_EVENT_NONE)
  97             {
  98               /* We found a thread with an unreported event.  */
  99               addr = handles[i].h_descr;
 100               break;
 101             }
 102         }
 103
 104       /* If we haven't found any other event signal this to the user.  */
 105       if (event.eventnum == TD_EVENT_NONE)
 106         return TD_NOMSG;
 107     }
 108
 109   /* Generate the thread descriptor.  */
 110   th.th_ta_p = (td_thragent_t *) ta;
 111   th.th_unique = addr;
 112
 113   /* Fill the user's data structure.  */
 114   msg->event = event.eventnum;
 115   msg->th_p = &th;
 116   msg->msg.data = (uintptr_t) event.eventdata;
 117
 118   /* And clear the event message in the target.  */
 119   memset (&event, '\0', sizeof (td_eventbuf_t));
 120   if (ps_pdwrite (ta->ph,
 121                   ((char *) addr
 122                    + offsetof (struct _pthread_descr_struct, p_eventbuf)),
 123                   &event, sizeof (td_eventbuf_t)) != PS_OK)
 124     return TD_ERR;      /* XXX Other error value?  */
 125
 126   return TD_OK;
 127 }