From b044c5bccace64c56522860528bf45144907c6bc Mon Sep 17 00:00:00 2001
From: qdo_ln <4yu@bk.ru>
Date: Mon, 22 Jul 2019 12:28:08 +0300
Subject: [PATCH] Java3 lesson 4 homework.

---
 src/lesson4/Main.java     | 18 +++++++++++++
 src/lesson4/MyThread.java | 55 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 73 insertions(+)
 create mode 100644 src/lesson4/Main.java
 create mode 100644 src/lesson4/MyThread.java

diff --git a/src/lesson4/Main.java b/src/lesson4/Main.java
new file mode 100644
index 0000000..e9ec098
--- /dev/null
+++ b/src/lesson4/Main.java
@@ -0,0 +1,18 @@
+package lesson4;
+
+public class Main {
+    public static void main(String[] args) {
+        MyThread mt = new MyThread();
+        new Thread(() -> {
+            mt.printA();
+        }).start();
+        new Thread(() -> {
+            mt.printB();
+        }).start();
+
+        new Thread(() -> {
+            mt.printC();
+        }).start();
+    }
+
+}
diff --git a/src/lesson4/MyThread.java b/src/lesson4/MyThread.java
new file mode 100644
index 0000000..f8aadd8
--- /dev/null
+++ b/src/lesson4/MyThread.java
@@ -0,0 +1,55 @@
+package lesson4;
+
+public class MyThread {
+    private Object monitor = new Object();
+    private volatile char currentLetter = 'A';
+
+    public void printA() {
+        synchronized (monitor) {
+            try {
+                for (int i = 5; i > 0; i--) {
+                    while (currentLetter != 'A')
+                        monitor.wait();
+                    System.out.print("A");
+                    currentLetter = 'B';
+                    monitor.notifyAll();
+                }
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
+    public void printB() {
+        synchronized (monitor) {
+            try {
+                for (int i = 5; i > 0; i--) {
+                    while (currentLetter != 'B')
+                        monitor.wait();
+                    System.out.print("B");
+                    currentLetter = 'C';
+                    monitor.notifyAll();
+                }
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
+    public void printC() {
+        synchronized (monitor) {
+            try {
+                for (int i = 5; i > 0; i--) {
+                    while (currentLetter != 'C')
+                        monitor.wait();
+                    System.out.print("C");
+                    currentLetter = 'A';
+                    monitor.notifyAll();
+                }
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
+}