summaryrefslogtreecommitdiff
path: root/hurd/thread-cancel.c
blob: 9791268e33e1772f13c13720aa11feec5b2e8f86 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
/* Thread cancellation support.
   Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include <hurd/signal.h>
#include <hurd/interrupt.h>
#include <assert.h>
#include <thread_state.h>


/* See hurdsig.c.  */
extern mach_port_t _hurdsig_abort_rpcs (struct hurd_sigstate *ss,
					int signo, int sigthread,
					struct machine_thread_all_state *,
					int *state_change,
					mach_port_t *reply_port,
					mach_msg_type_name_t reply_port_type,
					int untraced);

error_t
hurd_thread_cancel (thread_t thread)
{
  struct hurd_sigstate *ss = _hurd_thread_sigstate (thread);
  struct machine_thread_all_state state;
  int state_change;
  error_t err;

  if (! ss)
    return EINVAL;
  if (ss == _hurd_self_sigstate ())
    return EINTR;		/* Bozo.  */

  assert (! __spin_lock_locked (&ss->critical_section_lock));
  __spin_lock (&ss->critical_section_lock);
  __spin_lock (&ss->lock);
  err = __thread_suspend (thread);
  __spin_unlock (&ss->lock);

  if (! err)
    {
      /* Set the flag telling the thread its operation is being cancelled.  */
      ss->cancel = 1;

      /* Interrupt any interruptible RPC now in progress.  */
      state.set = 0;
      _hurdsig_abort_rpcs (ss, 0, 0, &state, &state_change, NULL, 0, 0);
      if (state_change)
	err = __thread_set_state (thread, MACHINE_THREAD_STATE_FLAVOR,
				  (natural_t *) &state.basic,
				  MACHINE_THREAD_STATE_COUNT);

      if (ss->cancel_hook)
	/* The code being cancelled has a special wakeup function.
	   Calling this should make the thread wake up and check the
	   cancellation flag.  */
	(*ss->cancel_hook) ();

      __thread_resume (thread);
    }

  _hurd_critical_section_unlock (ss);
  return err;
}


int
hurd_check_cancel (void)
{
  struct hurd_sigstate *ss = _hurd_self_sigstate ();
  int cancel;

  __spin_lock (&ss->lock);
  assert (! __spin_lock_locked (&ss->critical_section_lock));
  cancel = ss->cancel;
  ss->cancel = 0;
  __spin_unlock (&ss->lock);

  return cancel;
}