| 1 | /* Copyright (C) 1994-2022 Free Software Foundation, Inc. |
|---|---|
| 2 | This file is part of the GNU C Library. |
| 3 | |
| 4 | The GNU C Library is free software; you can redistribute it and/or |
| 5 | modify it under the terms of the GNU Lesser General Public |
| 6 | License as published by the Free Software Foundation; either |
| 7 | version 2.1 of the License, or (at your option) any later version. |
| 8 | |
| 9 | The GNU C Library is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | Lesser General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU Lesser General Public |
| 15 | License along with the GNU C Library; if not, see |
| 16 | <https://www.gnu.org/licenses/>. */ |
| 17 | |
| 18 | #include <hurd/sigpreempt.h> |
| 19 | #include <hurd/signal.h> |
| 20 | #include <assert.h> |
| 21 | |
| 22 | void |
| 23 | hurd_preempt_signals (struct hurd_signal_preemptor *preemptor) |
| 24 | { |
| 25 | __mutex_lock (&_hurd_siglock); |
| 26 | preemptor->next = _hurdsig_preemptors; |
| 27 | _hurdsig_preemptors = preemptor; |
| 28 | _hurdsig_preempted_set |= preemptor->signals; |
| 29 | __mutex_unlock (&_hurd_siglock); |
| 30 | } |
| 31 | |
| 32 | void |
| 33 | hurd_unpreempt_signals (struct hurd_signal_preemptor *preemptor) |
| 34 | { |
| 35 | struct hurd_signal_preemptor **p; |
| 36 | sigset_t preempted = 0; |
| 37 | |
| 38 | __mutex_lock (&_hurd_siglock); |
| 39 | |
| 40 | p = &_hurdsig_preemptors; |
| 41 | while (*p) |
| 42 | if (*p == preemptor) |
| 43 | { |
| 44 | /* Found it; take it off the chain. */ |
| 45 | *p = (*p)->next; |
| 46 | if ((preemptor->signals & preempted) != preemptor->signals) |
| 47 | { |
| 48 | /* This might have been the only preemptor for some |
| 49 | of those signals, so we must collect the full mask |
| 50 | from the others. */ |
| 51 | struct hurd_signal_preemptor *pp; |
| 52 | for (pp = *p; pp; pp = pp->next) |
| 53 | preempted |= pp->signals; |
| 54 | _hurdsig_preempted_set = preempted; |
| 55 | } |
| 56 | __mutex_unlock (&_hurd_siglock); |
| 57 | return; |
| 58 | } |
| 59 | else |
| 60 | { |
| 61 | preempted |= (*p)->signals; |
| 62 | p = &(*p)->next; |
| 63 | } |
| 64 | |
| 65 | __mutex_unlock (&_hurd_siglock); /* Avoid deadlock during death rattle. */ |
| 66 | assert (! "removing absent preemptor"); |
| 67 | } |
| 68 |