From 0cda89930a26b696713255b927a2da3e617bfdd7 Mon Sep 17 00:00:00 2001
From: stedS <sven.steddin@reutlingen-university.de>
Date: Tue, 26 Jan 2021 00:54:03 +0100
Subject: [PATCH] Zusaetzliches Beispiel zum Thema Circular Wait / Deadlock
---
VL04_09/ThreadDeadlock/.classpath | 6 ++++
VL04_09/ThreadDeadlock/.gitignore | 1 +
VL04_09/ThreadDeadlock/.project | 17 +++++++++++
.../.settings/org.eclipse.jdt.core.prefs | 11 +++++++
.../src/inf3/ThreadDeadlock.java | 30 +++++++++++++++++++
.../ThreadDeadlock/src/inf3/Thread_Koch1.java | 25 ++++++++++++++++
.../ThreadDeadlock/src/inf3/Thread_Koch2.java | 25 ++++++++++++++++
7 files changed, 115 insertions(+)
create mode 100644 VL04_09/ThreadDeadlock/.classpath
create mode 100644 VL04_09/ThreadDeadlock/.gitignore
create mode 100644 VL04_09/ThreadDeadlock/.project
create mode 100644 VL04_09/ThreadDeadlock/.settings/org.eclipse.jdt.core.prefs
create mode 100644 VL04_09/ThreadDeadlock/src/inf3/ThreadDeadlock.java
create mode 100644 VL04_09/ThreadDeadlock/src/inf3/Thread_Koch1.java
create mode 100644 VL04_09/ThreadDeadlock/src/inf3/Thread_Koch2.java
diff --git a/VL04_09/ThreadDeadlock/.classpath b/VL04_09/ThreadDeadlock/.classpath
new file mode 100644
index 0000000..fceb480
--- /dev/null
+++ b/VL04_09/ThreadDeadlock/.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/ThreadDeadlock/.gitignore b/VL04_09/ThreadDeadlock/.gitignore
new file mode 100644
index 0000000..ae3c172
--- /dev/null
+++ b/VL04_09/ThreadDeadlock/.gitignore
@@ -0,0 +1 @@
+/bin/
diff --git a/VL04_09/ThreadDeadlock/.project b/VL04_09/ThreadDeadlock/.project
new file mode 100644
index 0000000..6e4548f
--- /dev/null
+++ b/VL04_09/ThreadDeadlock/.project
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+ <name>ThreadDeadlock</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/ThreadDeadlock/.settings/org.eclipse.jdt.core.prefs b/VL04_09/ThreadDeadlock/.settings/org.eclipse.jdt.core.prefs
new file mode 100644
index 0000000..3a21537
--- /dev/null
+++ b/VL04_09/ThreadDeadlock/.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/ThreadDeadlock/src/inf3/ThreadDeadlock.java b/VL04_09/ThreadDeadlock/src/inf3/ThreadDeadlock.java
new file mode 100644
index 0000000..1994fdd
--- /dev/null
+++ b/VL04_09/ThreadDeadlock/src/inf3/ThreadDeadlock.java
@@ -0,0 +1,30 @@
+/** Programm zur Demonstration ein Deadlocks
+ *
+ * Greifen unterschiedliche Threads auf mehrere gemeinsam genutzte Resourcen zu, dann
+ * kann dies zu Verklemmungen führen. Durch vorgegebene Reihenfolge beim Zugriff lässt sich
+ * das Problem beheben.
+ *
+ * @author stedS
+ * @version 2.0 (2021-01-25)
+ */
+package inf3;
+public class ThreadDeadlock {
+ public static void main(String[] args) {
+ Object teigschuessel = new Object();
+ Object ruehrgeraet = new Object();
+ Thread_Koch1 kochA = new Thread_Koch1(teigschuessel, ruehrgeraet);
+ Thread_Koch2 kochB = new Thread_Koch2(teigschuessel, ruehrgeraet);
+ //Thread_Koch1 kochB = new Thread_Koch1(teigschuessel, ruehrgeraet);
+ kochA.start();
+ kochB.start();
+ try {
+ kochA.join();
+ kochB.join();
+ } catch (InterruptedException e) {
+ System.out.println("join interrupted");
+ }
+ System.out.println("Kuchen fertig");
+ }
+}
+
+
diff --git a/VL04_09/ThreadDeadlock/src/inf3/Thread_Koch1.java b/VL04_09/ThreadDeadlock/src/inf3/Thread_Koch1.java
new file mode 100644
index 0000000..00f9a26
--- /dev/null
+++ b/VL04_09/ThreadDeadlock/src/inf3/Thread_Koch1.java
@@ -0,0 +1,25 @@
+package inf3;
+public class Thread_Koch1 extends Thread {
+ Object teigschuessel;
+ Object ruehrgeraet;
+ Thread_Koch1 (Object teigschuessel, Object ruehrgeraet) {
+ this.teigschuessel = teigschuessel;
+ this.ruehrgeraet = ruehrgeraet;
+ }
+
+ public void run() {
+ synchronized (teigschuessel) {
+ System.out.println(this.getName() + " hat Teigschüssel und wartet auf Rührgerät");
+ try {
+ Thread.sleep(200);
+ } catch (InterruptedException e) { }
+ synchronized (ruehrgeraet) {
+ System.out.println(this.getName() + " rührt Teig");
+ try {
+ Thread.sleep(200);
+ } catch (InterruptedException e) { }
+ }
+ }
+ }
+}
+
diff --git a/VL04_09/ThreadDeadlock/src/inf3/Thread_Koch2.java b/VL04_09/ThreadDeadlock/src/inf3/Thread_Koch2.java
new file mode 100644
index 0000000..34ce58a
--- /dev/null
+++ b/VL04_09/ThreadDeadlock/src/inf3/Thread_Koch2.java
@@ -0,0 +1,25 @@
+package inf3;
+public class Thread_Koch2 extends Thread {
+ Object teigschuessel;
+ Object ruehrgeraet;
+ Thread_Koch2 (Object teigschuessel, Object ruehrgeraet) {
+ this.teigschuessel = teigschuessel;
+ this.ruehrgeraet = ruehrgeraet;
+ }
+
+ public void run() {
+ synchronized (ruehrgeraet) {
+ System.out.println(this.getName() + " hat Rührgerät und wartet auf Teigschüssel");
+ try {
+ Thread.sleep(200);
+ } catch (InterruptedException e) { }
+ synchronized (teigschuessel) {
+ System.out.println(this.getName() + " rührt Teig");
+ try {
+ Thread.sleep(200);
+ } catch (InterruptedException e) { }
+ }
+ }
+ }
+}
+
--
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