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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:24:08 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:24:08 +0000
commitf449f278dd3c70e479a035f50a9bb817a9b433ba (patch)
tree8ca2bfb785dda9bb4d573acdf9b42aea9cd51383 /src/contrib/semaphore.c
parentInitial commit. (diff)
downloadknot-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 '')
-rw-r--r--src/contrib/semaphore.c80
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);
+ }
+}