projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| f7a9f785 | 1 | /* Copyright (C) 2002-2016 Free Software Foundation, Inc. |
| 76a50749 UD |
2 | This file is part of the GNU C Library. |
| 3 | Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. | |
| 4 | ||
| 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. | |
| 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 | Lesser General Public License for more details. | |
| 14 | ||
| 15 | You should have received a copy of the GNU Lesser General Public | |
| 59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
| 17 | <http://www.gnu.org/licenses/>. */ | |
| 76a50749 UD |
18 | |
| 19 | #include <errno.h> | |
| 20 | #include "pthreadP.h" | |
| 21 | #include <atomic.h> | |
| 22 | ||
| 23 | ||
| 24 | int | |
| 9d46370c | 25 | __pthread_setcancelstate (int state, int *oldstate) |
| 76a50749 UD |
26 | { |
| 27 | volatile struct pthread *self; | |
| 28 | ||
| 29 | if (state < PTHREAD_CANCEL_ENABLE || state > PTHREAD_CANCEL_DISABLE) | |
| 30 | return EINVAL; | |
| 31 | ||
| 32 | self = THREAD_SELF; | |
| 33 | ||
| b22d701b | 34 | int oldval = THREAD_GETMEM (self, cancelhandling); |
| 76a50749 UD |
35 | while (1) |
| 36 | { | |
| 76a50749 UD |
37 | int newval = (state == PTHREAD_CANCEL_DISABLE |
| 38 | ? oldval | CANCELSTATE_BITMASK | |
| 39 | : oldval & ~CANCELSTATE_BITMASK); | |
| 40 | ||
| 41 | /* Store the old value. */ | |
| 42 | if (oldstate != NULL) | |
| 43 | *oldstate = ((oldval & CANCELSTATE_BITMASK) | |
| 44 | ? PTHREAD_CANCEL_DISABLE : PTHREAD_CANCEL_ENABLE); | |
| 45 | ||
| 46 | /* Avoid doing unnecessary work. The atomic operation can | |
| 3335502b | 47 | potentially be expensive if the memory has to be locked and |
| 76a50749 UD |
48 | remote cache lines have to be invalidated. */ |
| 49 | if (oldval == newval) | |
| 50 | break; | |
| 51 | ||
| 52 | /* Update the cancel handling word. This has to be done | |
| 53 | atomically since other bits could be modified as well. */ | |
| b22d701b UD |
54 | int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval, |
| 55 | oldval); | |
| a1ffb40e | 56 | if (__glibc_likely (curval == oldval)) |
| 76a50749 UD |
57 | { |
| 58 | if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval)) | |
| 9ae0909b | 59 | __do_cancel (); |
| 76a50749 UD |
60 | |
| 61 | break; | |
| 62 | } | |
| b22d701b UD |
63 | |
| 64 | /* Prepare for the next round. */ | |
| 65 | oldval = curval; | |
| 76a50749 UD |
66 | } |
| 67 | ||
| 68 | return 0; | |
| 69 | } | |
| 83614008 | 70 | strong_alias (__pthread_setcancelstate, pthread_setcancelstate) |
| e5d19c08 | 71 | hidden_def (__pthread_setcancelstate) |