| 1 | /* Out-of-line notification function for the GSCOPE locking mechanism. |
|---|---|
| 2 | Copyright (C) 2007-2024 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 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 |
| 16 | License along with the GNU C Library; if not, see |
| 17 | <https://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #include <ldsodefs.h> |
| 20 | #include <pthread.h> |
| 21 | #include <htl/pt-internal.h> |
| 22 | |
| 23 | void |
| 24 | __thread_gscope_wait (void) |
| 25 | { |
| 26 | size_t i; |
| 27 | struct __pthread *t; |
| 28 | int *gscope_flagp; |
| 29 | |
| 30 | __libc_rwlock_rdlock (GL (dl_pthread_threads_lock)); |
| 31 | |
| 32 | /* Iterate over the list of threads. */ |
| 33 | for (i = 0; i < GL (dl_pthread_num_threads); ++i) |
| 34 | { |
| 35 | t = GL (dl_pthread_threads[i]); |
| 36 | if (t == NULL || t->tcb->gscope_flag == THREAD_GSCOPE_FLAG_UNUSED) |
| 37 | continue; |
| 38 | |
| 39 | gscope_flagp = &t->tcb->gscope_flag; |
| 40 | |
| 41 | /* We have to wait until this thread is done with the global |
| 42 | scope. First tell the thread that we are waiting and |
| 43 | possibly have to be woken. */ |
| 44 | if (atomic_compare_and_exchange_bool_acq (gscope_flagp, |
| 45 | THREAD_GSCOPE_FLAG_WAIT, |
| 46 | THREAD_GSCOPE_FLAG_USED)) |
| 47 | continue; |
| 48 | |
| 49 | do |
| 50 | lll_wait (gscope_flagp, THREAD_GSCOPE_FLAG_WAIT, LLL_PRIVATE); |
| 51 | while (*gscope_flagp == THREAD_GSCOPE_FLAG_WAIT); |
| 52 | } |
| 53 | |
| 54 | __libc_rwlock_unlock (GL (dl_pthread_threads_lock)); |
| 55 | } |
| 56 |