From 9da3fa0b23b6339e5ec8fd4497886690ce118926 Mon Sep 17 00:00:00 2001
From: 3DAlgoLab <83936830+3DAlgoLab@users.noreply.github.com>
Date: Fri, 18 Mar 2022 11:23:00 +0900
Subject: [PATCH 1/2] Update example3.py

After call apply_async, we shoud wait its result.
---
 Chapter15/example3.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Chapter15/example3.py b/Chapter15/example3.py
index d5b085b..d6f326a 100644
--- a/Chapter15/example3.py
+++ b/Chapter15/example3.py
@@ -43,8 +43,10 @@ def countdown(n):
 
     pool = Pool(processes=2)
     start = time.time()
-    pool.apply_async(countdown, args=(COUNT//2,))
-    pool.apply_async(countdown, args=(COUNT//2,))
+    r1 = pool.apply_async(countdown, args=(COUNT//2,))
+    r2 = pool.apply_async(countdown, args=(COUNT//2,))
+    r1.wait() # it should be wait to measure its completion time. 
+    r2.wait() 
     pool.close()
     pool.join()
 

From 48e4cb4878830b5f3e23346187ba8ada37f1dd2c Mon Sep 17 00:00:00 2001
From: 3DAlgoLab <83936830+3DAlgoLab@users.noreply.github.com>
Date: Fri, 18 Mar 2022 12:24:57 +0900
Subject: [PATCH 2/2] Update example3.py

fix a typo.
---
 Chapter15/example3.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Chapter15/example3.py b/Chapter15/example3.py
index d6f326a..77d1489 100644
--- a/Chapter15/example3.py
+++ b/Chapter15/example3.py
@@ -45,7 +45,7 @@ def countdown(n):
     start = time.time()
     r1 = pool.apply_async(countdown, args=(COUNT//2,))
     r2 = pool.apply_async(countdown, args=(COUNT//2,))
-    r1.wait() # it should be wait to measure its completion time. 
+    r1.wait() # it should wait to measure its completion time. 
     r2.wait() 
     pool.close()
     pool.join()