From 1e53e7b61bda1de8cce14fa887ee48f842be7500 Mon Sep 17 00:00:00 2001
From: stedS <sven.steddin@reutlingen-university.de>
Date: Mon, 25 Jan 2021 20:33:05 +0100
Subject: [PATCH] Ergaenzung Beispiele zur Verwendung von Thread Monitoren mit
wait() und notify()
---
VL04_09/ThreadsMonitor2/.classpath | 6 +++
VL04_09/ThreadsMonitor2/.gitignore | 1 +
VL04_09/ThreadsMonitor2/.project | 17 ++++++++
.../.settings/org.eclipse.jdt.core.prefs | 11 +++++
.../src/inf3/Thread_TextAusgabe.java | 42 +++++++++++++++++++
.../src/inf3/ThreadsMonitor2.java | 33 +++++++++++++++
6 files changed, 110 insertions(+)
create mode 100644 VL04_09/ThreadsMonitor2/.classpath
create mode 100644 VL04_09/ThreadsMonitor2/.gitignore
create mode 100644 VL04_09/ThreadsMonitor2/.project
create mode 100644 VL04_09/ThreadsMonitor2/.settings/org.eclipse.jdt.core.prefs
create mode 100644 VL04_09/ThreadsMonitor2/src/inf3/Thread_TextAusgabe.java
create mode 100644 VL04_09/ThreadsMonitor2/src/inf3/ThreadsMonitor2.java
diff --git a/VL04_09/ThreadsMonitor2/.classpath b/VL04_09/ThreadsMonitor2/.classpath
new file mode 100644
index 0000000..fceb480
--- /dev/null
+++ b/VL04_09/ThreadsMonitor2/.classpath
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+ <classpathentry kind="src" path="src"/>
+ <classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8"/>
+ <classpathentry kind="output" path="bin"/>
+</classpath>
diff --git a/VL04_09/ThreadsMonitor2/.gitignore b/VL04_09/ThreadsMonitor2/.gitignore
new file mode 100644
index 0000000..ae3c172
--- /dev/null
+++ b/VL04_09/ThreadsMonitor2/.gitignore
@@ -0,0 +1 @@
+/bin/
diff --git a/VL04_09/ThreadsMonitor2/.project b/VL04_09/ThreadsMonitor2/.project
new file mode 100644
index 0000000..df49c09
--- /dev/null
+++ b/VL04_09/ThreadsMonitor2/.project
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+ <name>ThreadsMonitor2</name>
+ <comment></comment>
+ <projects>
+ </projects>
+ <buildSpec>
+ <buildCommand>
+ <name>org.eclipse.jdt.core.javabuilder</name>
+ <arguments>
+ </arguments>
+ </buildCommand>
+ </buildSpec>
+ <natures>
+ <nature>org.eclipse.jdt.core.javanature</nature>
+ </natures>
+</projectDescription>
diff --git a/VL04_09/ThreadsMonitor2/.settings/org.eclipse.jdt.core.prefs b/VL04_09/ThreadsMonitor2/.settings/org.eclipse.jdt.core.prefs
new file mode 100644
index 0000000..3a21537
--- /dev/null
+++ b/VL04_09/ThreadsMonitor2/.settings/org.eclipse.jdt.core.prefs
@@ -0,0 +1,11 @@
+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
+org.eclipse.jdt.core.compiler.compliance=1.8
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
+org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
+org.eclipse.jdt.core.compiler.source=1.8
diff --git a/VL04_09/ThreadsMonitor2/src/inf3/Thread_TextAusgabe.java b/VL04_09/ThreadsMonitor2/src/inf3/Thread_TextAusgabe.java
new file mode 100644
index 0000000..d326d85
--- /dev/null
+++ b/VL04_09/ThreadsMonitor2/src/inf3/Thread_TextAusgabe.java
@@ -0,0 +1,42 @@
+package inf3;
+public class Thread_TextAusgabe extends Thread {
+ char c;
+ Object consoleLock;
+ Thread_TextAusgabe (char c, Object consoleLock) {
+ this.c = c;
+ this.consoleLock = consoleLock;
+ }
+
+ void SchreibeZeile (char c) {
+ for (int ii=0; ii< 20; ii++) {
+ System.out.print(c + " ");
+ //busy waiting ... keine gute Idee!
+// for (int ll=0; ll< 1000000; ll++) {
+// Double kk = Math.sqrt(ll);
+// }
+ try {
+ Thread.sleep(20);
+ } catch (InterruptedException e) {
+ System.out.println("interrupted while sleeping");
+ }
+ }
+ System.out.println();
+ }
+
+ public void run() {
+ synchronized (consoleLock) {
+ for (int ii=0; ii<5; ii++) {
+ SchreibeZeile(c);
+ consoleLock.notifyAll();
+ try {
+ consoleLock.wait();
+ } catch (InterruptedException e) {
+ ;
+ }
+ }
+ consoleLock.notifyAll();
+ }
+ }
+}
+
+
diff --git a/VL04_09/ThreadsMonitor2/src/inf3/ThreadsMonitor2.java b/VL04_09/ThreadsMonitor2/src/inf3/ThreadsMonitor2.java
new file mode 100644
index 0000000..0fff649
--- /dev/null
+++ b/VL04_09/ThreadsMonitor2/src/inf3/ThreadsMonitor2.java
@@ -0,0 +1,33 @@
+/** Programm zur Demonstration der Threadsynchronisation
+ * durch den Einsatz eines Monitors: Zwei Threads sollen
+ * jeweils 10 mal die im Konstruktor übergebene Ziffer in eine
+ * Zeile schreiben.
+ *
+ * Durch Verwendung der Methoden wait() und notify() zusamen mit
+ * einem gemeinsam genutzten Lock-Objekt kann erzwungen werden, dass
+ * sich die Threads bei der Textausgabe abwechseln.
+ *
+ * @author stedS
+ * @version 1.0 (2021-01-25)
+ */
+package inf3;
+public class ThreadsMonitor2 {
+ char c;
+
+ public static void main(String[] args) {
+ Object console = new Object();
+ Thread_TextAusgabe th1 = new Thread_TextAusgabe('1', console);
+ Thread_TextAusgabe th2 = new Thread_TextAusgabe('2', console);
+ th1.start();
+ th2.start();
+ try {
+ th1.join();
+ th2.join();
+ } catch (InterruptedException e) {
+ System.out.println("join interrupted");
+ }
+ System.out.println("Programmende");
+ }
+}
+
+
--
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