From 9b85eed52885e86176d12dfcbdd15237dd399964 Mon Sep 17 00:00:00 2001
From: Fabio Scotto di Santolo <fabio.scottodisantolo@gmail.com>
Date: Sun, 10 May 2020 11:53:01 +0200
Subject: [PATCH] Esempi di sincronizzazione tra thread

---
 .gitignore                                    | 111 +++++++++++-
 .idea/workspace.xml                           | 167 ------------------
 OracleCertificationTest.iml                   |   2 +-
 .../java8/professional/ConcurrencyTest.java   |  51 ++++++
 .../professional/concurrency/BankAccount.java |  19 ++
 .../java8/professional/concurrency/Data.java  |  40 +++++
 .../professional/concurrency/PingPong.java    |  29 +++
 .../professional/concurrency/Receiver.java    |  31 ++++
 .../professional/concurrency/Sender.java      |  37 ++++
 9 files changed, 315 insertions(+), 172 deletions(-)
 delete mode 100644 .idea/workspace.xml
 create mode 100644 src/com/oracle/java8/professional/ConcurrencyTest.java
 create mode 100644 src/com/oracle/java8/professional/concurrency/BankAccount.java
 create mode 100644 src/com/oracle/java8/professional/concurrency/Data.java
 create mode 100644 src/com/oracle/java8/professional/concurrency/PingPong.java
 create mode 100644 src/com/oracle/java8/professional/concurrency/Receiver.java
 create mode 100644 src/com/oracle/java8/professional/concurrency/Sender.java

diff --git a/.gitignore b/.gitignore
index a2d3d1f..60b502d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,92 @@
-# Add any directories, files, or patterns you don't want to be tracked by version control
-# Created by https://www.gitignore.io/api/Java
-# Edit at https://www.gitignore.io/?templates=Java
+
+# Created by https://www.gitignore.io/api/java,maven,intellij,sonar
+# Edit at https://www.gitignore.io/?templates=java,maven,intellij,sonar
+
+### Intellij ###
+# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and WebStorm
+# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
+
+# User-specific stuff
+.idea/**/workspace.xml
+.idea/**/tasks.xml
+.idea/**/usage.statistics.xml
+.idea/**/dictionaries
+.idea/**/shelf
+
+# Generated files
+.idea/**/contentModel.xml
+
+# Sensitive or high-churn files
+.idea/**/dataSources/
+.idea/**/dataSources.ids
+.idea/**/dataSources.local.xml
+.idea/**/sqlDataSources.xml
+.idea/**/dynamic.xml
+.idea/**/uiDesigner.xml
+.idea/**/dbnavigator.xml
+
+# Gradle
+.idea/**/gradle.xml
+.idea/**/libraries
+
+# Gradle and Maven with auto-import
+# When using Gradle or Maven with auto-import, you should exclude module files,
+# since they will be recreated, and may cause churn.  Uncomment if using
+# auto-import.
+.idea/modules.xml
+.idea/*.iml
+.idea/modules
+*.iml
+*.ipr
+
+# CMake
+cmake-build-*/
+
+# Mongo Explorer plugin
+.idea/**/mongoSettings.xml
+
+# File-based project format
+*.iws
+
+# IntelliJ
+out/
+
+# mpeltonen/sbt-idea plugin
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Cursive Clojure plugin
+.idea/replstate.xml
+
+# Crashlytics plugin (for Android Studio and IntelliJ)
+com_crashlytics_export_strings.xml
+crashlytics.properties
+crashlytics-build.properties
+fabric.properties
+
+# Editor-based Rest Client
+.idea/httpRequests
+
+# Android studio 3.1+ serialized cache file
+.idea/caches/build_file_checksums.ser
+
+### Intellij Patch ###
+# Comment Reason: https://github.com/joeblau/gitignore.io/issues/186#issuecomment-215987721
+
+modules.xml
+.idea/misc.xml
+
+# Sonarlint plugin
+.idea/**/sonarlint/
+
+# SonarQube Plugin
+.idea/**/sonarIssues.xml
+
+# Markdown Navigator plugin
+.idea/**/markdown-navigator.xml
+.idea/**/markdown-navigator/
 
 ### Java ###
 # Compiled class file
@@ -27,4 +113,21 @@
 # virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
 hs_err_pid*
 
-# End of https://www.gitignore.io/api/Java
+### Maven ###
+target/
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+pom.xml.next
+release.properties
+dependency-reduced-pom.xml
+buildNumber.properties
+.mvn/timing.properties
+.mvn/wrapper/maven-wrapper.jar
+.flattened-pom.xml
+
+### Sonar ###
+#Sonar generated dir
+/.sonar/
+
+# End of https://www.gitignore.io/api/java,maven,intellij,sonar
diff --git a/.idea/workspace.xml b/.idea/workspace.xml
deleted file mode 100644
index a7b65c7..0000000
--- a/.idea/workspace.xml
+++ /dev/null
@@ -1,167 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="BranchesTreeState">
-    <expand>
-      <path>
-        <item name="ROOT" type="e8cecc67:BranchNodeDescriptor" />
-        <item name="LOCAL_ROOT" type="e8cecc67:BranchNodeDescriptor" />
-      </path>
-      <path>
-        <item name="ROOT" type="e8cecc67:BranchNodeDescriptor" />
-        <item name="REMOTE_ROOT" type="e8cecc67:BranchNodeDescriptor" />
-      </path>
-      <path>
-        <item name="ROOT" type="e8cecc67:BranchNodeDescriptor" />
-        <item name="REMOTE_ROOT" type="e8cecc67:BranchNodeDescriptor" />
-        <item name="GROUP_NODE:origin" type="e8cecc67:BranchNodeDescriptor" />
-      </path>
-    </expand>
-    <select />
-  </component>
-  <component name="ChangeListManager">
-    <list default="true" id="7689427a-6b8c-43cf-a2b5-7eb7ae541ad3" name="Default Changelist" comment="">
-      <change beforePath="$PROJECT_DIR$/.classpath" beforeDir="false" />
-      <change beforePath="$PROJECT_DIR$/.idea/sonarlint/issuestore/index.pb" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/sonarlint/issuestore/index.pb" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/.project" beforeDir="false" />
-      <change beforePath="$PROJECT_DIR$/.settings/org.eclipse.jdt.core.prefs" beforeDir="false" />
-      <change beforePath="$PROJECT_DIR$/.vscode/launch.json" beforeDir="false" />
-    </list>
-    <option name="SHOW_DIALOG" value="false" />
-    <option name="HIGHLIGHT_CONFLICTS" value="true" />
-    <option name="HIGHLIGHT_NON_ACTIVE_CHANGELIST" value="false" />
-    <option name="LAST_RESOLUTION" value="IGNORE" />
-  </component>
-  <component name="CodeStyleSettingsInfer">
-    <option name="done" value="true" />
-  </component>
-  <component name="FileTemplateManagerImpl">
-    <option name="RECENT_TEMPLATES">
-      <list>
-        <option value="Class" />
-      </list>
-    </option>
-  </component>
-  <component name="Git.Settings">
-    <option name="RECENT_GIT_ROOT_PATH" value="$PROJECT_DIR$" />
-  </component>
-  <component name="ProjectCodeStyleSettingsMigration">
-    <option name="version" value="1" />
-  </component>
-  <component name="ProjectId" id="1XtW4Cv6Jj7Gvlhk7hHpikOtIsR" />
-  <component name="ProjectViewState">
-    <option name="hideEmptyMiddlePackages" value="true" />
-    <option name="showLibraryContents" value="true" />
-  </component>
-  <component name="PropertiesComponent">
-    <property name="RunOnceActivity.OpenProjectViewOnStart" value="true" />
-    <property name="RunOnceActivity.ShowReadmeOnStart" value="true" />
-    <property name="WebServerToolWindowFactoryState" value="false" />
-    <property name="aspect.path.notification.shown" value="true" />
-    <property name="last_opened_file_path" value="$PROJECT_DIR$" />
-  </component>
-  <component name="RunManager">
-    <configuration name="InnerClassDemo" type="Application" factoryName="Application" temporary="true" nameIsGenerated="true">
-      <option name="MAIN_CLASS_NAME" value="com.oracle.java8.associate.InnerClassDemo" />
-      <module name="OracleCertificationTest" />
-      <extension name="coverage">
-        <pattern>
-          <option name="PATTERN" value="com.oracle.java8.associate.*" />
-          <option name="ENABLED" value="true" />
-        </pattern>
-      </extension>
-      <method v="2">
-        <option name="Make" enabled="true" />
-      </method>
-    </configuration>
-    <recent_temporary>
-      <list>
-        <item itemvalue="Application.InnerClassDemo" />
-      </list>
-    </recent_temporary>
-  </component>
-  <component name="SvnConfiguration">
-    <configuration />
-  </component>
-  <component name="TaskManager">
-    <task active="true" id="Default" summary="Default task">
-      <changelist id="7689427a-6b8c-43cf-a2b5-7eb7ae541ad3" name="Default Changelist" comment="" />
-      <created>1581865677580</created>
-      <option name="number" value="Default" />
-      <option name="presentableId" value="Default" />
-      <updated>1581865677580</updated>
-      <workItem from="1581865678731" duration="45000" />
-      <workItem from="1588399470293" duration="828000" />
-      <workItem from="1588406335490" duration="577000" />
-    </task>
-    <servers />
-  </component>
-  <component name="TypeScriptGeneratedFilesManager">
-    <option name="version" value="2" />
-  </component>
-  <component name="Vcs.Log.Tabs.Properties">
-    <option name="TAB_STATES">
-      <map>
-        <entry key="MAIN">
-          <value>
-            <State />
-          </value>
-        </entry>
-      </map>
-    </option>
-    <option name="oldMeFiltersMigrated" value="true" />
-  </component>
-  <component name="WindowStateProjectService">
-    <state x="745" y="478" key="#com.intellij.ide.util.projectWizard.JdkChooserPanel.MyDialog" timestamp="1581865697666">
-      <screen x="0" y="23" width="1792" height="1097" />
-    </state>
-    <state x="745" y="478" key="#com.intellij.ide.util.projectWizard.JdkChooserPanel.MyDialog/0.23.1792.1097@0.23.1792.1097" timestamp="1581865697666" />
-    <state width="1750" height="675" key="GridCell.Tab.0.bottom" timestamp="1588406643415">
-      <screen x="0" y="23" width="1792" height="1097" />
-    </state>
-    <state width="1750" height="675" key="GridCell.Tab.0.bottom/0.23.1792.1097@0.23.1792.1097" timestamp="1588406643415" />
-    <state width="1750" height="675" key="GridCell.Tab.0.center" timestamp="1588406643415">
-      <screen x="0" y="23" width="1792" height="1097" />
-    </state>
-    <state width="1750" height="675" key="GridCell.Tab.0.center/0.23.1792.1097@0.23.1792.1097" timestamp="1588406643415" />
-    <state width="1750" height="675" key="GridCell.Tab.0.left" timestamp="1588406643414">
-      <screen x="0" y="23" width="1792" height="1097" />
-    </state>
-    <state width="1750" height="675" key="GridCell.Tab.0.left/0.23.1792.1097@0.23.1792.1097" timestamp="1588406643414" />
-    <state width="1750" height="675" key="GridCell.Tab.0.right" timestamp="1588406643415">
-      <screen x="0" y="23" width="1792" height="1097" />
-    </state>
-    <state width="1750" height="675" key="GridCell.Tab.0.right/0.23.1792.1097@0.23.1792.1097" timestamp="1588406643415" />
-    <state width="1750" height="675" key="GridCell.Tab.1.bottom" timestamp="1588406643416">
-      <screen x="0" y="23" width="1792" height="1097" />
-    </state>
-    <state width="1750" height="675" key="GridCell.Tab.1.bottom/0.23.1792.1097@0.23.1792.1097" timestamp="1588406643416" />
-    <state width="1750" height="675" key="GridCell.Tab.1.center" timestamp="1588406643416">
-      <screen x="0" y="23" width="1792" height="1097" />
-    </state>
-    <state width="1750" height="675" key="GridCell.Tab.1.center/0.23.1792.1097@0.23.1792.1097" timestamp="1588406643416" />
-    <state width="1750" height="675" key="GridCell.Tab.1.left" timestamp="1588406643415">
-      <screen x="0" y="23" width="1792" height="1097" />
-    </state>
-    <state width="1750" height="675" key="GridCell.Tab.1.left/0.23.1792.1097@0.23.1792.1097" timestamp="1588406643415" />
-    <state width="1750" height="675" key="GridCell.Tab.1.right" timestamp="1588406643416">
-      <screen x="0" y="23" width="1792" height="1097" />
-    </state>
-    <state width="1750" height="675" key="GridCell.Tab.1.right/0.23.1792.1097@0.23.1792.1097" timestamp="1588406643416" />
-    <state x="561" y="268" key="search.everywhere.popup" timestamp="1588401428428">
-      <screen x="0" y="23" width="1792" height="1097" />
-    </state>
-    <state x="561" y="268" key="search.everywhere.popup/0.23.1792.1097@0.23.1792.1097" timestamp="1588401428428" />
-  </component>
-  <component name="XDebuggerManager">
-    <breakpoint-manager>
-      <breakpoints>
-        <line-breakpoint enabled="true" type="java-line">
-          <url>file://$PROJECT_DIR$/src/com/oracle/java8/associate/InnerClassDemo.java</url>
-          <line>10</line>
-          <option name="timeStamp" value="2" />
-        </line-breakpoint>
-      </breakpoints>
-    </breakpoint-manager>
-  </component>
-</project>
\ No newline at end of file
diff --git a/OracleCertificationTest.iml b/OracleCertificationTest.iml
index ea1542a..22eec9e 100644
--- a/OracleCertificationTest.iml
+++ b/OracleCertificationTest.iml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <module type="JAVA_MODULE" version="4">
   <component name="NewModuleRootManager">
-    <output url="file://$MODULE_DIR$/bin" />
+    <output url="file://$MODULE_DIR$/out" />
     <exclude-output />
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
diff --git a/src/com/oracle/java8/professional/ConcurrencyTest.java b/src/com/oracle/java8/professional/ConcurrencyTest.java
new file mode 100644
index 0000000..d96d04b
--- /dev/null
+++ b/src/com/oracle/java8/professional/ConcurrencyTest.java
@@ -0,0 +1,51 @@
+package com.oracle.java8.professional;
+
+import com.oracle.java8.professional.concurrency.BankAccount;
+import com.oracle.java8.professional.concurrency.Data;
+import com.oracle.java8.professional.concurrency.Receiver;
+import com.oracle.java8.professional.concurrency.Sender;
+
+public class ConcurrencyTest {
+
+    public static void main(String[] args) {
+        doBankAccoundDemo();
+        doSynchronizeThreadDemo();
+    }
+
+    private static void doBankAccoundDemo() {
+        BankAccount bankAccount = new BankAccount(1, 100);
+
+        Thread worker1 = new Thread(() -> {
+            System.out.printf("[Thread %s] read current balance = %d\n",
+                    Thread.currentThread().getName(), bankAccount.getBalance());
+            bankAccount.deposit(10);
+        });
+
+        Thread worker2 = new Thread(() -> {
+            System.out.printf("[Thread %s] read current balance = %d\n",
+                    Thread.currentThread().getName(), bankAccount.getBalance());
+            bankAccount.deposit(10000);
+        });
+
+        worker1.start();
+        worker2.start();
+
+        try {
+            worker1.join();
+            worker2.join();
+            System.out.println("Final balance is " + bankAccount.getBalance());
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+
+    private static void doSynchronizeThreadDemo() {
+        Data data = new Data();
+        Thread sender = new Thread(new Sender(data));
+        Thread receiver = new Thread(new Receiver(data));
+
+        sender.start();
+        receiver.start();
+    }
+
+}
diff --git a/src/com/oracle/java8/professional/concurrency/BankAccount.java b/src/com/oracle/java8/professional/concurrency/BankAccount.java
new file mode 100644
index 0000000..7d67cc9
--- /dev/null
+++ b/src/com/oracle/java8/professional/concurrency/BankAccount.java
@@ -0,0 +1,19 @@
+package com.oracle.java8.professional.concurrency;
+
+public class BankAccount {
+    private long number;
+    private long balance;
+
+    public BankAccount(long number, long balance) {
+        this.number = number;
+        this.balance = balance;
+    }
+
+    public synchronized long getBalance() {
+        return balance;
+    }
+
+    public synchronized void deposit(long amout) {
+        balance += amout;
+    }
+}
diff --git a/src/com/oracle/java8/professional/concurrency/Data.java b/src/com/oracle/java8/professional/concurrency/Data.java
new file mode 100644
index 0000000..55453ce
--- /dev/null
+++ b/src/com/oracle/java8/professional/concurrency/Data.java
@@ -0,0 +1,40 @@
+package com.oracle.java8.professional.concurrency;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class Data {
+    private String packet;
+    private boolean transfer = true;
+
+    public synchronized void send(String packet) {
+        while (!transfer) {
+            try {
+                wait();
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                Logger.getAnonymousLogger().log(Level.SEVERE, "Interrupted error", e);
+            }
+        }
+
+        transfer = false;
+        this.packet = packet;
+        notifyAll();
+    }
+
+    public synchronized String receive() {
+        while (transfer) {
+            try {
+                wait();
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                Logger.getAnonymousLogger().log(Level.SEVERE, "Interrupted error", e);
+            }
+        }
+
+        transfer = true;
+        notifyAll();
+        return packet;
+    }
+
+}
diff --git a/src/com/oracle/java8/professional/concurrency/PingPong.java b/src/com/oracle/java8/professional/concurrency/PingPong.java
new file mode 100644
index 0000000..d1c53f4
--- /dev/null
+++ b/src/com/oracle/java8/professional/concurrency/PingPong.java
@@ -0,0 +1,29 @@
+package com.oracle.java8.professional.concurrency;
+
+public class PingPong extends Thread {
+    private String word;
+    private int delay;
+
+    public PingPong(String whatToSay, int delayTime) {
+        this.word = whatToSay;
+        this.delay = delayTime;
+    }
+
+    @Override
+    public void run() {
+        try {
+            for (;;) {
+                System.out.println(word + " ");
+                Thread.sleep(delay);
+            }
+        } catch (InterruptedException e) {
+            return;
+        }
+    }
+
+    public static void main(String[] args) {
+        System.out.println(Thread.currentThread().getName());
+        new PingPong("ping", 33).start();
+        new PingPong("PONG", 100).start();
+    }
+}
diff --git a/src/com/oracle/java8/professional/concurrency/Receiver.java b/src/com/oracle/java8/professional/concurrency/Receiver.java
new file mode 100644
index 0000000..ee7735b
--- /dev/null
+++ b/src/com/oracle/java8/professional/concurrency/Receiver.java
@@ -0,0 +1,31 @@
+package com.oracle.java8.professional.concurrency;
+
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class Receiver implements Runnable {
+    private Data load;
+
+    public Receiver(Data data) {
+        this.load = data;
+    }
+
+    public void run() {
+        for (String receivedMessage = load.receive();
+             !"End".equals(receivedMessage);
+             receivedMessage = load.receive()) {
+
+            System.out.println(receivedMessage);
+
+            // ...
+            try {
+                Thread.sleep(ThreadLocalRandom.current().nextInt(1000, 5000));
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                Logger.getAnonymousLogger().log(Level.SEVERE, "Interrupted error", e);
+            }
+        }
+    }
+
+}
diff --git a/src/com/oracle/java8/professional/concurrency/Sender.java b/src/com/oracle/java8/professional/concurrency/Sender.java
new file mode 100644
index 0000000..41c75f0
--- /dev/null
+++ b/src/com/oracle/java8/professional/concurrency/Sender.java
@@ -0,0 +1,37 @@
+package com.oracle.java8.professional.concurrency;
+
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class Sender implements Runnable {
+    private Data data;
+
+    public Sender(Data data) {
+        this.data = data;
+    }
+
+    @Override
+    public void run() {
+        String packets[] = {
+                "First packet",
+                "Second packet",
+                "Third packet",
+                "Fourth packet",
+                "End"
+        };
+
+        for (String packet : packets) {
+            data.send(packet);
+
+            // Thread.sleep() to mimic heavy server-side processing
+            try {
+                Thread.sleep(ThreadLocalRandom.current().nextInt(1000, 5000));
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+                Logger.getAnonymousLogger().log(Level.SEVERE, "Interrupted error", e);
+            }
+        }
+    }
+
+}