From 4c67d0bba4347085ae71ff7d2ad57347e1d7c8ae Mon Sep 17 00:00:00 2001
From: Oleg Borodin <onborodin@gmail.com>
Date: Tue, 30 Aug 2022 16:26:29 +0200
Subject: [PATCH] added primitive semaphore

---
 semaphore.c | 23 +++++++++++++++++++++++
 semaphore.h | 12 ++++++++++++
 2 files changed, 35 insertions(+)
 create mode 100644 semaphore.c
 create mode 100644 semaphore.h

diff --git a/semaphore.c b/semaphore.c
new file mode 100644
index 0000000..f6b885a
--- /dev/null
+++ b/semaphore.c
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2022 Oleg Borodin  <borodin@unix7.org>
+ */
+
+#include "semaphore.h"
+
+typedef struct {
+    int value;
+} sem_t;
+
+int sem_init(sem_t* sem, int value) {
+    sem->value = value;
+}
+
+int sem_wait(sem_t* sem) {
+    while(sem->value > 0);
+    sem->value--;
+}
+
+
+int sem_post(sem_t* sem) {
+    sem->value++;
+}
diff --git a/semaphore.h b/semaphore.h
new file mode 100644
index 0000000..0cf2b8e
--- /dev/null
+++ b/semaphore.h
@@ -0,0 +1,12 @@
+/*
+ * Copyright 2022 Oleg Borodin  <borodin@unix7.org>
+ */
+
+
+typedef struct {
+    int value;
+} sem_t;
+
+int sem_init(sem_t* sem, int value);
+int sem_wait(sem_t* sem);
+int sem_post(sem_t* sem);