.
[glibc/history.git] / nptl / cancellation.c
blob81134a679a90f7b3b552d6155a8e5059f44edd02
1 /* Copyright (C) 2002, 2003, 2009 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;
74 #ifdef THREAD_ATOMIC_AND
75 THREAD_ATOMIC_AND (self, cancelhandling, ~CANCELTYPE_BITMASK);
76 #else
77 int oldval = THREAD_GETMEM (self, cancelhandling);
79 while (1)
81 int newval = oldval & ~CANCELTYPE_BITMASK;
83 if (newval == oldval)
84 break;
86 int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,
87 oldval);
88 if (__builtin_expect (curval == oldval, 1))
89 break;
91 /* Prepare the next round. */
92 oldval = curval;
94 #endif