Initial commit: SUB-OS 64-Bit Production Monolithic Operating System with LazyBox userland suite

kernel/sync.c

@@ -0,0 +1,26 @@
+#include <kernel/sync.h>
+#include <kernel/sched.h>
+
+void sem_init(semaphore_t* sem, int value) {
+    spinlock_init(&sem->lock);
+    sem->count = value;
+}
+
+void sem_wait(semaphore_t* sem) {
+    while (1) {
+        spin_lock(&sem->lock);
+        if (sem->count > 0) {
+            sem->count--;
+            spin_unlock(&sem->lock);
+            return;
+        }
+        spin_unlock(&sem->lock);
+        sched_yield();
+    }
+}
+
+void sem_post(semaphore_t* sem) {
+    spin_lock(&sem->lock);
+    sem->count++;
+    spin_unlock(&sem->lock);
+}