Update.
[glibc.git] / nptl / libc-cancellation.c
blobc9237e0950553c0a1fa9e2afc8983cf89da35900
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"
23 #include "atomic.h"
24 #include <bits/libc-lock.h>
27 #ifndef NOT_IN_libc
29 /* The next two functions are similar to pthread_setcanceltype() but
30 more specialized for the use in the cancelable functions like write().
31 They do not need to check parameters etc. */
32 int
33 attribute_hidden
34 __libc_enable_asynccancel (void)
36 struct pthread *self = THREAD_SELF;
37 int oldval = THREAD_GETMEM (self, cancelhandling);
39 while (1)
41 int newval = oldval | CANCELTYPE_BITMASK;
43 if (__builtin_expect ((oldval & CANCELED_BITMASK) != 0, 0))
45 /* If we are already exiting or if PTHREAD_CANCEL_DISABLED,
46 stop right here. */
47 if ((oldval & (EXITING_BITMASK | CANCELSTATE_BITMASK)) != 0)
48 break;
50 int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
51 newval, oldval);
52 if (__builtin_expect (curval != oldval, 0))
54 /* Somebody else modified the word, try again. */
55 oldval = curval;
56 continue;
59 THREAD_SETMEM (self, result, PTHREAD_CANCELED);
61 __do_cancel ();
63 /* NOTREACHED */
66 int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,
67 oldval);
68 if (__builtin_expect (curval == oldval, 1))
69 break;
71 /* Prepare the next round. */
72 oldval = curval;
75 return oldval;
79 void
80 internal_function attribute_hidden
81 __libc_disable_asynccancel (int oldtype)
83 /* If asynchronous cancellation was enabled before we do not have
84 anything to do. */
85 if (oldtype & CANCELTYPE_BITMASK)
86 return;
88 struct pthread *self = THREAD_SELF;
89 int oldval = THREAD_GETMEM (self, cancelhandling);
91 while (1)
93 int newval = oldval & ~CANCELTYPE_BITMASK;
95 if (newval == oldval)
96 break;
98 int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,
99 oldval);
100 if (__builtin_expect (curval == oldval, 1))
101 break;
103 /* Prepare the next round. */
104 oldval = curval;
109 void
110 __libc_cleanup_routine (struct __pthread_cleanup_frame *f)
112 if (f->__do_it)
113 f->__cancel_routine (f->__cancel_arg);
116 #endif