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[glibc.git] / nptl / cancellation.c
blob1d28d383f9badafe75ee32e57a4d23bc8e306ae7
1 /* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
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 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <setjmp.h>
21 #include <stdlib.h>
22 #include "pthreadP.h"
25 /* The next two functions are similar to pthread_setcanceltype() but
26 more specialized for the use in the cancelable functions like write().
27 They do not need to check parameters etc. */
28 int
29 attribute_hidden
30 __pthread_enable_asynccancel (void)
32 struct pthread *self = THREAD_SELF;
33 int oldval = THREAD_GETMEM (self, cancelhandling);
35 while (1)
37 int newval = oldval | CANCELTYPE_BITMASK;
39 if (newval == oldval)
40 break;
42 int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,
43 oldval);
44 if (__builtin_expect (curval == oldval, 1))
46 if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval))
48 THREAD_SETMEM (self, result, PTHREAD_CANCELED);
49 __do_cancel ();
52 break;
55 /* Prepare the next round. */
56 oldval = curval;
59 return oldval;
63 void
64 internal_function attribute_hidden
65 __pthread_disable_asynccancel (int oldtype)
67 /* If asynchronous cancellation was enabled before we do not have
68 anything to do. */
69 if (oldtype & CANCELTYPE_BITMASK)
70 return;
72 struct pthread *self = THREAD_SELF;
73 int oldval = THREAD_GETMEM (self, cancelhandling);
75 while (1)
77 int newval = oldval & ~CANCELTYPE_BITMASK;
79 if (newval == oldval)
80 break;
82 int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,
83 oldval);
84 if (__builtin_expect (curval == oldval, 1))
85 break;
87 /* Prepare the next round. */
88 oldval = curval;