From f5013449e113167e8a285d6c1e1b244568815403 Mon Sep 17 00:00:00 2001
From: Remzi Arpaci-Dusseau <remzi.arpacidusseau@gmail.com>
Date: Thu, 16 May 2019 16:09:52 -0500
Subject: [PATCH] nit

---
 threads-sema/zemaphore.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/threads-sema/zemaphore.h b/threads-sema/zemaphore.h
index 3b6639a..76f2222 100644
--- a/threads-sema/zemaphore.h
+++ b/threads-sema/zemaphore.h
@@ -28,10 +28,12 @@ void Zem_post(Zem_t *z) {
     Mutex_unlock(&z->lock);
 }
 
+#ifdef __APPLE__
 typedef Zem_t sem_t;
 
 #define Sem_wait(s)    Zem_wait(s)
 #define Sem_post(s)    Zem_post(s)
 #define Sem_init(s, v) Zem_init(s, v)
+#endif
 
 #endif // __zemaphore_h__