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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:24:08 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:24:08 +0000 |
commit | f449f278dd3c70e479a035f50a9bb817a9b433ba (patch) | |
tree | 8ca2bfb785dda9bb4d573acdf9b42aea9cd51383 /src/contrib/semaphore.c | |
parent | Initial commit. (diff) | |
download | knot-upstream.tar.xz knot-upstream.zip |
Adding upstream version 3.2.6.upstream/3.2.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/contrib/semaphore.c')
-rw-r--r-- | src/contrib/semaphore.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/src/contrib/semaphore.c b/src/contrib/semaphore.c new file mode 100644 index 0000000..ad50dcc --- /dev/null +++ b/src/contrib/semaphore.c @@ -0,0 +1,80 @@ +/* Copyright (C) 2019 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include "semaphore.h" + +#include <assert.h> +#include <stdlib.h> + +#if defined(__APPLE__) +#pragma clang diagnostic ignored "-Wdeprecated-declarations" +#endif + +void knot_sem_init(knot_sem_t *sem, unsigned int value) +{ + int ret = sem_init(&sem->semaphore, 1, value); + if (ret == 0) { + sem->status = -1; + } else { + sem->status = value; + sem->status_lock = malloc(sizeof(*sem->status_lock)); + pthread_mutex_init(&sem->status_lock->mutex, NULL); + pthread_cond_init(&sem->status_lock->cond, NULL); + } +} + +void knot_sem_wait(knot_sem_t *sem) +{ + if (sem->status < 0) { + int semret; + do { + semret = sem_wait(&sem->semaphore); + } while (semret != 0); // repeat wait as it might be interrupted by a signal + } else { + pthread_mutex_lock(&sem->status_lock->mutex); + while (sem->status == 0) { + pthread_cond_wait(&sem->status_lock->cond, &sem->status_lock->mutex); + } + sem->status--; + pthread_mutex_unlock(&sem->status_lock->mutex); + } +} + +void knot_sem_post(knot_sem_t *sem) +{ + if (sem->status < 0) { + int semret = sem_post(&sem->semaphore); + (void)semret; + assert(semret == 0); + } else { + pthread_mutex_lock(&sem->status_lock->mutex); + sem->status++; + pthread_cond_signal(&sem->status_lock->cond); + pthread_mutex_unlock(&sem->status_lock->mutex); + } +} + +void knot_sem_destroy(knot_sem_t *sem) +{ + knot_sem_wait(sem); + if (sem->status < 0) { + sem_destroy(&sem->semaphore); + } else { + pthread_cond_destroy(&sem->status_lock->cond); + pthread_mutex_destroy(&sem->status_lock->mutex); + free(sem->status_lock); + } +} |