Add semaphore wrapper

3 files changed, 44 insertions, 0 deletions

diff --git a/src/lib/core/CMakeLists.txt b/src/lib/core/CMakeLists.txt
index e3e3d4b..7b33cf9 100644
--- a/src/lib/core/CMakeLists.txt
+++ b/src/lib/core/CMakeLists.txt
@@ -21,6 +21,7 @@ add_library(stasis_core STATIC
         template_func_proto.c
         envctl.c
         multiprocessing.c
+        semaphore.c
 )
 target_include_directories(stasis_core PRIVATE
         ${core_INCLUDE}
diff --git a/src/lib/core/include/sem.h b/src/lib/core/include/sem.h
new file mode 100644
index 0000000..868f33d
--- /dev/null
+++ b/src/lib/core/include/sem.h
@@ -0,0 +1,17 @@
+#ifndef STASIS_SEMAPHORE_H
+#define STASIS_SEMAPHORE_H
+
+#include <semaphore.h>
+
+struct Semaphore {
+    sem_t *sem;
+    char name[255];
+};
+
+int semaphore_init(struct Semaphore *s, const char *name, int value);
+int semaphore_wait(struct Semaphore *s);
+int semaphore_post(struct Semaphore *s);
+
+void semaphore_destroy(struct Semaphore *s);
+
+#endif //STASIS_SEMAPHORE_H
\ No newline at end of file
diff --git a/src/lib/core/semaphore.c b/src/lib/core/semaphore.c
new file mode 100644
index 0000000..9ea4c9c
--- /dev/null
+++ b/src/lib/core/semaphore.c
@@ -0,0 +1,26 @@
+#include <stdio.h>
+#include <fcntl.h>
+#include "sem.h"
+
+int semaphore_init(struct Semaphore *s, const char *name, const int value) {
+    snprintf(s->name, sizeof(s->name), "/%s", name);
+    s->sem = sem_open(s->name, O_CREAT, 0644, value);
+    if (s->sem == SEM_FAILED) {
+        perror("sem_open");
+        return -1;
+    }
+    return 0;
+}
+
+int semaphore_wait(struct Semaphore *s) {
+    return sem_wait(s->sem);
+}
+
+int semaphore_post(struct Semaphore *s) {
+    return sem_post(s->sem);
+}
+
+void semaphore_destroy(struct Semaphore *s) {
+    sem_close(s->sem);
+    sem_unlink(s->name);
+}