projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| 2b778ceb | 1 | /* Copyright (C) 2002-2021 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 | 16 | License along with the GNU C Library; if not, see |
| 5a82c748 | 17 | <https://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_setcanceltype (int type, int *oldtype) |
| 76a50749 | 26 | { |
| 76a50749 UD |
27 | if (type < PTHREAD_CANCEL_DEFERRED || type > PTHREAD_CANCEL_ASYNCHRONOUS) |
| 28 | return EINVAL; | |
| 29 | ||
| 2f531bbb | 30 | volatile struct pthread *self = THREAD_SELF; |
| 76a50749 | 31 | |
| b22d701b | 32 | int oldval = THREAD_GETMEM (self, cancelhandling); |
| 76a50749 UD |
33 | while (1) |
| 34 | { | |
| 76a50749 UD |
35 | int newval = (type == PTHREAD_CANCEL_ASYNCHRONOUS |
| 36 | ? oldval | CANCELTYPE_BITMASK | |
| 37 | : oldval & ~CANCELTYPE_BITMASK); | |
| 38 | ||
| 39 | /* Store the old value. */ | |
| 40 | if (oldtype != NULL) | |
| 41 | *oldtype = ((oldval & CANCELTYPE_BITMASK) | |
| 42 | ? PTHREAD_CANCEL_ASYNCHRONOUS : PTHREAD_CANCEL_DEFERRED); | |
| 43 | ||
| 44 | /* Avoid doing unnecessary work. The atomic operation can | |
| 3335502b | 45 | potentially be expensive if the memory has to be locked and |
| 76a50749 UD |
46 | remote cache lines have to be invalidated. */ |
| 47 | if (oldval == newval) | |
| 48 | break; | |
| 49 | ||
| 50 | /* Update the cancel handling word. This has to be done | |
| 51 | atomically since other bits could be modified as well. */ | |
| b22d701b UD |
52 | int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval, |
| 53 | oldval); | |
| a1ffb40e | 54 | if (__glibc_likely (curval == oldval)) |
| 76a50749 UD |
55 | { |
| 56 | if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval)) | |
| 57 | { | |
| 58 | THREAD_SETMEM (self, result, PTHREAD_CANCELED); | |
| 9ae0909b | 59 | __do_cancel (); |
| 76a50749 UD |
60 | } |
| 61 | ||
| 62 | break; | |
| 63 | } | |
| b22d701b UD |
64 | |
| 65 | /* Prepare for the next round. */ | |
| 66 | oldval = curval; | |
| 76a50749 UD |
67 | } |
| 68 | ||
| 69 | return 0; | |
| 70 | } | |
| 09efc3ba | 71 | strong_alias (__pthread_setcanceltype, pthread_setcanceltype) |