hurd/report-wait.c

   1 /* Report on what a thread in our task is waiting for.
   2    Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <hurd.h>
  21 #include <hurd/signal.h>
  22 #include <hurd/fd.h>
  23 #include <string.h>
  24 #include <assert.h>
  25 #include <hurd/msg_server.h>
  26 #include "thread_state.h"
  27 #include "intr-msg.h"
  28
  29 static void
  30 describe_number (string_t description, const char *flavor, unsigned long int i)
  31 {
  32   unsigned long int j;
  33   char *p = __stpcpy (description, flavor);
  34
  35   /* Allocate space for the number at the end of DESCRIPTION.  */
  36   for (j = i; j >= 10; j /= 10)
  37     p++;
  38   p[1] = '\0';
  39
  40   do
  41     {
  42       *p-- = '0' + i % 10;
  43       i /= 10;
  44     } while (i != 0);
  45   assert (*p == '#');
  46 }
  47
  48 static void
  49 describe_port (string_t description, mach_port_t port)
  50 {
  51   int i;
  52
  53   if (port == __mach_task_self ())
  54     {
  55       strcpy (description, "task-self");
  56       return;
  57     }
  58
  59   for (i = 0; i < _hurd_nports; ++i)
  60     if (port == _hurd_ports[i].port)
  61       {
  62         describe_number (description, "init#", i);
  63         return;
  64       }
  65
  66   if (_hurd_init_dtable)
  67     {
  68       for (i = 0; i < _hurd_init_dtablesize; ++i)
  69         if (port == _hurd_init_dtable[i])
  70           {
  71             describe_number (description, "fd#", i);
  72             return;
  73           }
  74     }
  75   else if (_hurd_dtable)
  76     {
  77       for (i = 0; i < _hurd_dtablesize; ++i)
  78         if (_hurd_dtable[i] == NULL)
  79           continue;
  80         else if (port == _hurd_dtable[i]->port.port)
  81           {
  82             describe_number (description, "fd#", i);
  83             return;
  84           }
  85         else if (port == _hurd_dtable[i]->ctty.port)
  86           {
  87             describe_number (description, "bgfd#", i);
  88             return;
  89           }
  90     }
  91
  92   describe_number (description, "port#", port);
  93 }
  94
  95
  96 /* We want _HURD_ITIMER_THREAD, but don't want to link in the itimer code
  97    unnecessarily.  */
  98 #if 0 /* libc.so.0.0 needs this defined, so make it a weak alias for now.  */
  99 extern thread_t _hurd_itimer_thread; /* XXX */
 100 weak_extern (_hurd_itimer_thread)
 101 #else
 102 static thread_t default_hurd_itimer_thread;
 103 weak_alias (default_hurd_itimer_thread, _hurd_itimer_thread)
 104 #endif
 105
 106 kern_return_t
 107 _S_msg_report_wait (mach_port_t msgport, thread_t thread,
 108                     string_t description, int *msgid)
 109 {
 110   *msgid = 0;
 111
 112   if (thread == _hurd_msgport_thread)
 113     /* Cute.  */
 114     strcpy (description, "msgport");
 115   else if (&_hurd_msgport_thread && thread == _hurd_itimer_thread)
 116     strcpy (description, "itimer");
 117   else
 118     {
 119       /* Make sure this is really one of our threads.  */
 120
 121       struct hurd_sigstate *ss;
 122
 123       __mutex_lock (&_hurd_siglock);
 124       for (ss = _hurd_sigstates; ss != NULL; ss = ss->next)
 125         if (ss->thread == thread)
 126           break;
 127       __mutex_unlock (&_hurd_siglock);
 128       if (ss == NULL)
 129         /* To hell with you.  */
 130         return EINVAL;
 131
 132       if (ss->suspended != MACH_PORT_NULL)
 133         strcpy (description, "sigsuspend");
 134       else
 135         {
 136           /* Examine the thread's state to see if it is blocked in an RPC.  */
 137
 138           struct machine_thread_state state;
 139           mach_msg_type_number_t count = MACHINE_THREAD_STATE_COUNT;
 140           error_t err;
 141
 142           err = __thread_get_state (thread, MACHINE_THREAD_STATE_FLAVOR,
 143                                     (integer_t *) &state, &count);
 144           if (err)
 145             return err;
 146           assert (count == MACHINE_THREAD_STATE_COUNT);
 147           if (SYSCALL_EXAMINE (&state, msgid))
 148             {
 149               /* Blocked in a system call.  */
 150               if (*msgid == -25)
 151                 /* mach_msg system call.  Examine its parameters.  */
 152                 describe_port (description, MSG_EXAMINE (&state, msgid));
 153               else
 154                 strcpy (description, "kernel");
 155             }
 156           else
 157             description[0] = '\0';
 158         }
 159     }
 160
 161   __mach_port_deallocate (__mach_task_self (), thread);
 162   return 0;
 163 }
 164
 165 kern_return_t
 166 _S_msg_describe_ports (mach_port_t msgport, mach_port_t refport,
 167                        mach_port_t *ports, mach_msg_type_number_t nports,
 168                        char **desc, mach_msg_type_number_t *desclen)
 169 {
 170   char *p, *end;
 171
 172   if (__USEPORT (AUTH, msgport != port))
 173     return EPERM;
 174
 175   end = *desc + *desclen;
 176   p = *desc;
 177   while (nports-- > 0)
 178     {
 179       char this[200];
 180       describe_port (this, *ports++);
 181       p = __stpncpy (p, this, end - p);
 182       if (p == end && p[-1] != '\0')
 183         return ENOMEM;
 184     }
 185
 186   *desclen = p - *desc;
 187   return 0;
 188 }