wrap mutex type to enable future optimization

mutex.h

@@ -0,0 +1,28 @@
+#ifndef MUTEX_H
+#define MUTEX_H
+
+#include <pthread.h>
+
+#include "util.h"
+
+struct mutex {
+    pthread_mutex_t lock;
+};
+
+#define MUTEX_INITIALIZER (struct mutex){PTHREAD_MUTEX_INITIALIZER}
+
+static inline void mutex_init(struct mutex *m) {
+    if (unlikely(pthread_mutex_init(&m->lock, NULL))) {
+        fatal_error("mutex initialization failed");
+    }
+}
+
+static inline void mutex_lock(struct mutex *m) {
+    pthread_mutex_lock(&m->lock);
+}
+
+static inline void mutex_unlock(struct mutex *m) {
+    pthread_mutex_unlock(&m->lock);
+}
+
+#endif