Paralelismus. Březen 2008

Size: px
Start display at page:

Download "Paralelismus. Březen 2008"

Transcription

1 Seminář Java Paralelismus Radek Kočí Fakulta informačních technologií VUT Březen 2008 Radek Kočí Seminář Java Paralelismus 1/ 55

2 Obsah Vlákna Multithreading Sdílení prostředků Synchronizace Radek Kočí Seminář Java Paralelismus 2/ 55

3 Pojmy Proces spuštěný program s vlastním adresovým prostorem Vlákno (podproces) nezávislá vedlejší úloha spuštěná v kontextu procesu sdílí adresový prostor procesu Multithreading technika rozdělění běhu programu na více podprocesů typicky pro oddělení částí programu, které jsou vázané na prostředky Radek Kočí Seminář Java Paralelismus 3/ 55

4 Proces a vlákna Process Threads Radek Kočí Seminář Java Paralelismus 4/ 55

5 Vlákna vlákna jsou reprezentována objekty každé vlákno má svůj jedinečný identifikátor (přidělen při vytvoření) vlákno může mít svůj název Radek Kočí Seminář Java Paralelismus 5/ 55

6 Práce s vlákny Balík java.lang Thread Runnable Reprezentace vlákna instance třídy Thread (ev. odvozených tříd) Vytvoření objektu, který reprezentuje běh vlákna rozšířením (dědičnost) třídy Thread implementací rozhraní Runnable Radek Kočí Seminář Java Paralelismus 6/ 55

7 Třída Thread Metody start() inicializace vlákna volá metodu run() odvozená třída nepřekrývá tuto metodu! run() kód vlákna odvozená třída překrývá tuto metodu sleep(long millis) uspání vlákna na daný počet milisekund výjimka InterruptedException Radek Kočí Seminář Java Paralelismus 7/ 55

8 Ukázka SimpleThread public class SimpleThread extends Thread { public SimpleThread(String str) { super(str); public void run() { for (int i = 0; i < 10; i++) { System.out.println(i + " " + getname()); try { sleep((long)(math.random() * 1000)); catch (InterruptedException e) { System.out.println("DONE! " + getname()); Radek Kočí Seminář Java Paralelismus 8/ 55

9 Ukázka SimpleThread public class TwoThreadsDemo { public static void main (String[] args) { new SimpleThread("Jamaica").start(); new SimpleThread("Fiji").start(); Radek Kočí Seminář Java Paralelismus 9/ 55

10 Rozhraní Runnable Metody run() kód vlákna implementující třída musí implementovat tuto metodu Implementující třída není vlákno informace, že instance třídy definuje chování vlákna pro spuštění vlákna potřebuje třídu Thread Radek Kočí Seminář Java Paralelismus 10/ 55

11 Ukázka Clock public class Clock extends Applet implements Runnable { private Thread clockthread = null; public void start() { if (clockthread == null) { clockthread = new Thread(this, "Clock"); clockthread.start(); public void paint(graphics g) {... //get the time and convert it to a date... g.drawstring(dateformatter.format(date), 5, 10); Radek Kočí Seminář Java Paralelismus 11/ 55

12 Ukázka Clock public void run() { Thread mythread = Thread.currentThread(); while (clockthread == mythread) { repaint(); try { Thread.sleep(1000); catch (InterruptedException e) { //the VM doesn t want us to sleep anymore, //so get back to work //overrides Applet s stop method, not Thread s public void stop() { clockthread = null; Radek Kočí Seminář Java Paralelismus 12/ 55

13 Třída Thread nebo rozhraní Runnable hodně tříd potřebuje dědit (rozšiřovat) jinou třídu public class Clock extends Applet implements Runnable {... Java neumožňuje vícenásobnou dědičnost rozhraní Runnable clockthread = new Thread(this, "Clock"); clockthread.start(); Radek Kočí Seminář Java Paralelismus 13/ 55

14 Životní cyklus vlákna runnable yield New Thread start Runnable Not Runnable The run method terminates Dead Radek Kočí Seminář Java Paralelismus 14/ 55

15 Životní cyklus vlákna Vytvoření Spuštění new Thread(this, "Clock") start() kód vlákna v metodě run() (Thread nebo Runnable) Ukončení přirozeným doběhnutím metody run() existují i jiné metody, ty se ale nedoporučují (deprecated) stop() destroy() suspend(), resume() Radek Kočí Seminář Java Paralelismus 15/ 55

16 Životní cyklus vlákna Test stavu vlákna isalive() true pokud bylo vlákno spuštěno a nebylo ukončeno (není dead) false pokud vlákno nebylo spuštěno, nebo bylo ukončeno (je dead) Radek Kočí Seminář Java Paralelismus 16/ 55

17 Životní cyklus vlákna Pozastavení (stav not runnable) sleep(...) wait() při i/o operaci Uvolnění (stav runnable) uplynutí doby čekání (viz sleep(...)) notify(), notifyall() dokončení při i/o operace Radek Kočí Seminář Java Paralelismus 17/ 55

18 Vlákna Chování vláken závisí na jejich interní reprezentaci. Native threads vlákna operačního systému více procesorů preemtivní plánování Green threads vlákna na úrovni JVM jeden procesor vlákno se musí přepnout samo již nejsou moc běžná Radek Kočí Seminář Java Paralelismus 18/ 55

19 Plánování vláken Jedna CPU Priorita provádění vláken se musí plánovat plánovač v Javě je fixed-priority scheduling plánuje vlákna na základě jejich priority relativně k ostatním vláknům vlákno dědí prioritu vlákna, ve kterém bylo vytvořeno čtení/změna priority: getpriority(), setpriority() rozsah: Thread.MIN PRIORITY Thread.MAX PRIORITY Radek Kočí Seminář Java Paralelismus 19/ 55

20 Plánování vláken Plánovač vybere vlákno (runnable) s nejvyšší prioritou pokud je jich více se stejnou prioritou, vybere náhodně/spravedlivě Vlákno běží dokud se nestane: na systému s time-slicing uběhne přidělené časové kvantum jiné vlákno s vyšší prioritou přejde do stavu runnable skončí metoda run() vlákno se vzdá procesoru vlákno se dobrovolně vzdá procesoru zpráva yield() šance pro ostatní vlákna na stejné prioritě Radek Kočí Seminář Java Paralelismus 20/ 55

21 Thread Thread Thread.currentThread() vrátí právě běžící vlákno (objekt) setname / getname každé vlákno může mít své jméno long getid() každé vlákno má svůj jedinečný identifikátor Thread.State getstate() vrací stav vlákna enum Thread.State Radek Kočí Seminář Java Paralelismus 21/ 55

22 Thread enum Thread.State NEW vlákno pouze vytvořeno RUNNABLE běžící vlákno BLOCKED vlákno čeká na monitoru WAITING vlákno čeká na jiné vlákno / operaci (časově neomezeno) TIMED WAITING vlákno čeká na jiné vlákno (časově omezeno) TERMINATED vlákno bylo ukončeno Radek Kočí Seminář Java Paralelismus 22/ 55

23 Thread stavy vlákna WAITING Object.wait() Thread.join() LockSupport.park() I/O operace TIMED WAITING Object.wait(long) Thread.join(long) Thread.sleep(long) LockSupport.parkNanos(long) LockSupport.parkUntil(long) java.util.concurrent.locks.locksupport Radek Kočí Seminář Java Paralelismus 23/ 55

24 Skupina vláken java.lang.threadgroup vlákno patří vždy k nějaké skupině existuje implicitní systémová skupina skupiny tvoří stromovou hierarchii příslušnost ke skupině je neměnná vlákno implicitně dědí skupinu vytvářejícího vlákna Thread.currentThread().getThreadGroup() Radek Kočí Seminář Java Paralelismus 24/ 55

25 Synchronizace vláken Problém producent konzument jedno vlákno (producent) zapisuje na sdílené místo data druhé vlákno (konzument) tato data čte operace zápis/čtení se musí střídat! Ukázkový příklad třída Producer producent třída Consumer konzument třída CubbyHole sdílený prostor (metody get a put) Radek Kočí Seminář Java Paralelismus 25/ 55

26 Producent konzument: Producent public class Producer extends Thread { private CubbyHole cubbyhole; public Producer(CubbyHole c) { cubbyhole = c; public void run() { for (int i = 0; i < 10; i++) { cubbyhole.put(i); try { sleep((int)(math.random() * 100)); catch (InterruptedException e) { Radek Kočí Seminář Java Paralelismus 26/ 55

27 Producent konzument: Konzument public class Consumer extends Thread { private CubbyHole cubbyhole; public Consumer(CubbyHole c) { cubbyhole = c; public void run() { int value = 0; for (int i = 0; i < 10; i++) { value = cubbyhole.get(); Radek Kočí Seminář Java Paralelismus 27/ 55

28 Producent konzument: CubbyHole public class CubbyHole { private int contents; public int get() { return contents; public int put(int value) { contents = value; Radek Kočí Seminář Java Paralelismus 28/ 55

29 Producent konzument: možné problémy Producent je rychlejší konzument může propásnout čísla Konzumer je rychlejší konzument čte stejné číslo vícekrát race condition dvě (příp. více) vlákna čtou/zapisují sdílená data; výsledek zavisí na časování (jak jsou vlákna plánována) Radek Kočí Seminář Java Paralelismus 29/ 55

30 Producent konzument: možné problémy race condition dvě (příp. více) vlákna čtou/zapisují sdílená data; výsledek zavisí na časování (jak jsou vlákna plánována) Nutná synchronizace: vlákna nesmí současně přistoupit ke sdílenému objektu producent musí indikovat, že hodnota je připravena; nezapisuje dokud si hodnotu nepřečte konzument konzument musí indikovat, že přečetl hodnotu; nečte dokud producent nezapíše novou hodnotu Radek Kočí Seminář Java Paralelismus 29/ 55

31 Monitor Monitor kritické sekce uzamčení objektu při přístupu ke kritické sekci pokud je objekt uzamčen, nikdo jiný nemůže přistupovat je kritickým sekcím objektu odemknutí objektu při výstupu z kritické sekce Monitor v Javě (intrinsic lock) součástí každého objektu (třída Object) klíčové slovo synchronized Kritická sekce v Javě metoda blok Radek Kočí Seminář Java Paralelismus 30/ 55

32 Producent konzument: CubbyHole public class CubbyHole { private int contents; private boolean available = false; public synchronized int get() { //CubbyHole locked by the Producer... // CubbyHole unlocked by the Producer public synchronized int put(int value) { // CubbyHole locked by the Consumer... // CubbyHole unlocked by the Consumer Radek Kočí Seminář Java Paralelismus 31/ 55

33 Zámek: reentrantní public class Reentrant { public synchronized void a() { b(); System.out.println("here I am, in a()"); public synchronized void b() { System.out.println("here I am, in b()"); Radek Kočí Seminář Java Paralelismus 32/ 55

34 Producent konzument: CubbyHole public class CubbyHole { private int contents; private boolean available = false; public synchronized int get() { if (available == true) { available = false; return contents; public synchronized int put(int value) { if (available == false) { available = true; contents = value; Radek Kočí Seminář Java Paralelismus 33/ 55

35 Producent konzument: synchronizace Nutná synchronizace: vlákna nesmí současně přistoupit ke sdílenému objektu producent musí indikovat, že hodnota je připravena konzument musí indikovat, že přečetl hodnotu producent nezapisuje dokud si hodnotu nepřečte konzument konzument nečte dokud producent nezapíše novou hodnotu Radek Kočí Seminář Java Paralelismus 34/ 55

36 Producent konzument: synchronizace Nutná synchronizace: vlákna nesmí současně přistoupit ke sdílenému objektu producent musí indikovat, že hodnota je připravena konzument musí indikovat, že přečetl hodnotu producent nezapisuje dokud si hodnotu nepřečte konzument konzument nečte dokud producent nezapíše novou hodnotu Radek Kočí Seminář Java Paralelismus 34/ 55

37 Synchronizace vláken (třída Object) wait() aktuální vlákno bude čekat, dokud se nezavolá notify() (notifyall()) nad objektem wait(long timeout)... nebo neuplyne timeout notify() vzbudí jedno vlákno čekající na monitoru objektu notifyall() vzbudí všechna vlákna čekající na monitoru objektu Radek Kočí Seminář Java Paralelismus 35/ 55

38 Synchronizace vláken (třída Object) wait(),... před suspendováním vlákna se odemkne monitor pokud vlákno vlastní více monitorů, odemkne se pouze monitor daného objektu notify(),... řízení není okamžitě předáno vzbuzenému vláknu Tyto metody může volat pouze to vlákno, které je vlastníkem monitoru vstoupení do kritické sekce (synchronized) metoda, blok Radek Kočí Seminář Java Paralelismus 36/ 55

39 Producent konzument: CubbyHole public synchronized int get() { while (available == false) { try { // wait for Producer to put value wait(); catch (InterruptedException e) { available = false; // notify Producer that value has been // retrieved notifyall(); return contents; Radek Kočí Seminář Java Paralelismus 37/ 55

40 Producent konzument: CubbyHole public synchronized void put(int value) { while (available == true) { try { // wait for Consumer to get value wait(); catch (InterruptedException e) { contents = value; available = true; // notify Consumer that value has been set notifyall(); Radek Kočí Seminář Java Paralelismus 38/ 55

41 Synchronizace vláken efektivita Při uzamčení objektu se zvýší náklady na režii uvážit změnu návrhu použít zámek (synchronized) na konkrétní objekt neodbýt souběžný přístup synchronizací všech metod Radek Kočí Seminář Java Paralelismus 39/ 55

42 Synchronizace vláken Blok jako kritická sekce stejný princip synchronizace metody se nemusí deklarovat jako synchronizované deklaruje se objekt, jehož monitor se použije při obsluze kritické sekce synchronized(cybbyhole) { cybbyhole.put(i); synchronized(cybbyhole) { value = cybbyhole.get(); Radek Kočí Seminář Java Paralelismus 40/ 55

43 Přerušení vlákna Operace interrupt() (Thread) je nastaven příznak přerušitelné operace (sleep(),...) testují tento příznak Vlákno je běžící pouze se nastaví příznak lze otestovat (isinterrupted()) Vlákno je čekající je nastaven příznak vlákno se rozběhne a vygeneruje se výjimka (InterruptedException) Radek Kočí Seminář Java Paralelismus 41/ 55

44 Viditelnost proměnné Viditelnost sdílené proměnné změna hodnoty se nemusí projevit okamžitě (optimalizace) klíčové slovo volatile Radek Kočí Seminář Java Paralelismus 42/ 55

45 Proč nepoužívat stop() a suspend()? stop() uvolní všechny monitory blokované vláknem nebezpečí přístupu k objektům v nekonzistentním stavu přirozené ukončení metody run() suspend(), resume() suspenduje/uvolní vlákno suspendované vlákno drží monitor (viz kritická sekce); vlákno, které ho má uvolnit (viz resume), musí vstoupit do této sekce dead-lock wait(), notify() více na threadprimitivedeprecation.html Radek Kočí Seminář Java Paralelismus 43/ 55

46 Explicitní zámky java.util.concurrent.locks rozhraní Lock, Condition, ReadWriteLock třídy ReentrantLock, ReentrantReadWriteLock třída ReentrantReadWriteLock.ReadLock třída ReentrantReadWriteLock.WriteLock Radek Kočí Seminář Java Paralelismus 44/ 55

47 Lock public interface Lock { void lock(); void lockinterruptibly() throws InterruptedException; boolean trylock(); boolean trylock(long timeout, TimeUnit unit) throws InterruptedException; void unlock(); Condition newcondition(); Radek Kočí Seminář Java Paralelismus 45/ 55

48 ReentrantLock implements Lock Lock lock = new ReentrantLock(); lock.lock(); try {... finally { lock.unlock(); Radek Kočí Seminář Java Paralelismus 46/ 55

49 Lock a Condition public interface Condition { void await() throws InterruptedException; boolean await(long time, TimeUnit unit) throws InterruptedException; long awaitnanos(long nanostimeout) throws InterruptedException; void awaituninterruptibly() throws InterruptedException; long awaituntil(date deadline) throws InterruptedException; void signal(); void signalall(); Radek Kočí Seminář Java Paralelismus 47/ 55

50 Vztah zámků a JVM Intrinsic locks méně flexibilní JVM ví o vztahu vlákna a zámku Explicit locks flexibilní JVM neví o vztahu vlákna a zámku Radek Kočí Seminář Java Paralelismus 48/ 55

51 Synchronizované struktury java.util.concurrent BlockingQueue SynchronousQueue Semaphore... private BlockingQueue cubbyhole; cubbyhole.put(i);... Radek Kočí Seminář Java Paralelismus 49/ 55

52 Synchronizované kolekce Statické metody třídy Collections XXX synchronizedxxx(xxx c); Collection synchronizedset(collection c); Map synchronizedmap(map c);... Radek Kočí Seminář Java Paralelismus 50/ 55

53 Synchronizované kolekce public class SynchronDemo { public static void main(string[] args) { List seznam = new ArrayList(); seznam.add(new Integer(20));... Iterator i = seznam.iterator(); // Simulace soubezne akce jineho vlakna!! seznam.remove(new Integer(20)); //... Integer c = (Integer) i.next(); Vyjimka ConcurrentModificationException Radek Kočí Seminář Java Paralelismus 51/ 55

54 Synchronizované kolekce Synchronization wrapper public class SynchronDemo2 { public static void main(string[] args) { List seznam = Collections. synchronizedlist(new ArrayList()); seznam.add(new Integer(20)); synchronized(seznam) { Iterator i = seznam.iterator(); Integer c = (Integer) i.next(); Radek Kočí Seminář Java Paralelismus 52/ 55

55 SynchronizedCollection static class SynchronizedCollection<E>... { Collection<E> c; // Backing Collection Object mutex; // Object on which to // synchronize SynchronizedCollection(Collection<E> c) { this.c = c; mutex = this; SynchronizedCollection(Collection<E> c, Object mutex) { this.c = c; this.mutex = mutex; Radek Kočí Seminář Java Paralelismus 53/ 55

56 SynchronizedCollection public boolean add(e o) { synchronized(mutex) {return c.add(o); public Iterator<E> iterator() { return c.iterator(); // Must be manually synchronized by user! Radek Kočí Seminář Java Paralelismus 54/ 55

57 Zdroje informací brian-goetz.html Radek Kočí Seminář Java Paralelismus 55/ 55

Lecture 5-1. Java Threads I

Lecture 5-1. Java Threads I Java Programming Lecture 5-1. I Cheng-Chia Chen Transparency No. 1 Contents 1. What is a thread? 2. Define and launch a thread 3. The life-cycle of a thread 4. interrupt a thread 5. thread synchronization

More information

Outline of this lecture G52CON: Concepts of Concurrency

Outline of this lecture G52CON: Concepts of Concurrency Outline of this lecture G52CON: Concepts of Concurrency Lecture 10 Synchronisation in Java Natasha Alechina School of Computer Science nza@cs.nott.ac.uk mutual exclusion in Java condition synchronisation

More information

CS11 Java. Fall 2014-2015 Lecture 7

CS11 Java. Fall 2014-2015 Lecture 7 CS11 Java Fall 2014-2015 Lecture 7 Today s Topics! All about Java Threads! Some Lab 7 tips Java Threading Recap! A program can use multiple threads to do several things at once " A thread can have local

More information

Topics. Producing Production Quality Software. Concurrent Environments. Why Use Concurrency? Models of concurrency Concurrency in Java

Topics. Producing Production Quality Software. Concurrent Environments. Why Use Concurrency? Models of concurrency Concurrency in Java Topics Producing Production Quality Software Models of concurrency Concurrency in Java Lecture 12: Concurrent and Distributed Programming Prof. Arthur P. Goldberg Fall, 2005 2 Why Use Concurrency? Concurrent

More information

JAVA - MULTITHREADING

JAVA - MULTITHREADING JAVA - MULTITHREADING http://www.tutorialspoint.com/java/java_multithreading.htm Copyright tutorialspoint.com Java is amulti threaded programming language which means we can develop multi threaded program

More information

Deadlock Victim. dimanche 6 mai 12

Deadlock Victim. dimanche 6 mai 12 Deadlock Victim by Dr Heinz Kabutz && Olivier Croisier The Java Specialists Newsletter && The Coder's Breakfast heinz@javaspecialists.eu && olivier.croisier@zenika.com 1 You discover a race condition 2

More information

OBJECT ORIENTED PROGRAMMING LANGUAGE

OBJECT ORIENTED PROGRAMMING LANGUAGE UNIT-6 (MULTI THREADING) Multi Threading: Java Language Classes The java.lang package contains the collection of base types (language types) that are always imported into any given compilation unit. This

More information

Monitors & Condition Synchronization

Monitors & Condition Synchronization Chapter 5 Monitors & Condition Synchronization 1 monitors & condition synchronization Concepts: monitors: encapsulated data + access procedures mutual exclusion + condition synchronization nested monitors

More information

Java Memory Model: Content

Java Memory Model: Content Java Memory Model: Content Memory Models Double Checked Locking Problem Java Memory Model: Happens Before Relation Volatile: in depth 16 March 2012 1 Java Memory Model JMM specifies guarantees given by

More information

Concurrent Programming

Concurrent Programming Concurrent Programming Shared Memory Passing the baton Monitors Verónica Gaspes www.hh.se/staff/vero CERES, November 2, 2007 ceres Outline 1 Recap 2 Readers & Writers Readers & writers (mutual exclusion)

More information

Built-in Concurrency Primitives in Java Programming Language. by Yourii Martiak and Mahir Atmis

Built-in Concurrency Primitives in Java Programming Language. by Yourii Martiak and Mahir Atmis Built-in Concurrency Primitives in Java Programming Language by Yourii Martiak and Mahir Atmis Overview One of the many strengths of Java is the built into the programming language support for concurrency

More information

Jazyk C# (seminář 8)

Jazyk C# (seminář 8) Jazyk C# (seminář 8) Pavel Procházka KMI 12. listopadu 2014 Na co je dobré XML? Deklarativní jazyk reprezentující čitelně data Snadná práce s konfiguračními soubory a ukládání do souboru Human readeble

More information

Unit 6: Conditions, Barriers, and RendezVous

Unit 6: Conditions, Barriers, and RendezVous SPP (Synchro et Prog Parallèle) Unit 6: Conditions, Barriers, and RendezVous François Taïani So far We have seen several synchronisation mechanisms locks (plain, re-entrant, read/write) semaphores monitors

More information

Kontejnery. Březen 2008

Kontejnery. Březen 2008 Seminář Java Kontejnery Radek Kočí Fakulta informačních technologií VUT Březen 2008 Radek Kočí Seminář Java Kontejnery 1/ 53 Téma přednášky Kontejnery For-each loop Autoboxing Radek Kočí Seminář Java Kontejnery

More information

Threads 1. When writing games you need to do more than one thing at once.

Threads 1. When writing games you need to do more than one thing at once. Threads 1 Threads Slide 1 When writing games you need to do more than one thing at once. Threads offer a way of automatically allowing more than one thing to happen at the same time. Java has threads as

More information

BIRD Internet Routing Daemon

BIRD Internet Routing Daemon BIRD Internet Routing Daemon Ondřej Zajíček CZ.NIC z.s.p.o. IT 13 Úvod I Úvod do dynamického routování I Představení démona BIRD I OSPF a BIRD I BGP a BIRD Dynamické routování I Sestavení routovacích tabulek

More information

8. Condition Objects. Prof. O. Nierstrasz. Selected material 2005 Bowbeer, Goetz, Holmes, Lea and Peierls

8. Condition Objects. Prof. O. Nierstrasz. Selected material 2005 Bowbeer, Goetz, Holmes, Lea and Peierls 8. Condition Objects Prof. O. Nierstrasz Selected material 2005 Bowbeer, Goetz, Holmes, Lea and Peierls Roadmap > Condition Objects Simple Condition Objects The Nested Monitor Problem Permits and Semaphores

More information

Threads & Tasks: Executor Framework

Threads & Tasks: Executor Framework Threads & Tasks: Executor Framework Introduction & Motivation WebServer Executor Framework Callable and Future 12 April 2012 1 Threads & Tasks Motivations for using threads Actor-based Goal: Create an

More information

Traditional Software Development. Model Requirements and JAVA Programs. Formal Verification & Validation. What is a state?

Traditional Software Development. Model Requirements and JAVA Programs. Formal Verification & Validation. What is a state? Mel Requirements and JAVA Programs MVP The Waterfall Mel Problem Area Traditional Software Develoment Analysis REVIEWS Design Costly wrt time and money. Errors are found too late (or maybe never). SPIN/PROMELA

More information

Overview. CMSC 330: Organization of Programming Languages. Synchronization Example (Java 1.5) Lock Interface (Java 1.5) ReentrantLock Class (Java 1.

Overview. CMSC 330: Organization of Programming Languages. Synchronization Example (Java 1.5) Lock Interface (Java 1.5) ReentrantLock Class (Java 1. CMSC 330: Organization of Programming Languages Java 1.5, Ruby, and MapReduce Overview Java 1.5 ReentrantLock class Condition interface - await( ), signalall( ) Ruby multithreading Concurrent programming

More information

Java Concurrency Framework. Sidartha Gracias

Java Concurrency Framework. Sidartha Gracias Java Concurrency Framework Sidartha Gracias Executive Summary This is a beginners introduction to the java concurrency framework Some familiarity with concurrent programs is assumed However the presentation

More information

SSC - Concurrency and Multi-threading Java multithreading programming - Synchronisation (I)

SSC - Concurrency and Multi-threading Java multithreading programming - Synchronisation (I) SSC - Concurrency and Multi-threading Java multithreading programming - Synchronisation (I) Shan He School for Computational Science University of Birmingham Module 06-19321: SSC Outline Outline of Topics

More information

aneb Perfekt perfektně.

aneb Perfekt perfektně. aneb Perfekt perfektně. 2013 se v angličtině nazývá Present Perfect, tedy Přítomný perfekt. Patří k časům přítomným, ačkoliv se jistě nejedná o klasický přítomný čas tak, jak jsme zvykĺı z češtiny. jistým

More information

Crash Course in Java

Crash Course in Java Crash Course in Java Based on notes from D. Hollinger Based in part on notes from J.J. Johns also: Java in a Nutshell Java Network Programming and Distributed Computing Netprog 2002 Java Intro 1 What is

More information

JAVA Program For Processing SMS Messages

JAVA Program For Processing SMS Messages JAVA Program For Processing SMS Messages Krishna Akkulu The paper describes the Java program implemented for the MultiModem GPRS wireless modem. The MultiModem offers standards-based quad-band GSM/GPRS

More information

Java Coding Practices for Improved Application Performance

Java Coding Practices for Improved Application Performance 1 Java Coding Practices for Improved Application Performance Lloyd Hagemo Senior Director Application Infrastructure Management Group Candle Corporation In the beginning, Java became the language of the

More information

Chapter 8 Implementing FSP Models in Java

Chapter 8 Implementing FSP Models in Java Chapter 8 Implementing FSP Models in Java 1 8.1.1: The Carpark Model A controller is required for a carpark, which only permits cars to enter when the carpark is not full and does not permit cars to leave

More information

Concurrent programming in Java

Concurrent programming in Java Concurrent programming in Java INF4140 04.10.12 Lecture 5 0 Book: Andrews - ch.05 (5.4) Book: Magee & Kramer ch.04 - ch.07 INF4140 (04.10.12) Concurrent programming in Java Lecture 5 1 / 33 Outline 1 Monitors:

More information

1.1. Over view. 1.2. Example 1: CPU Slot Distribution A example to test the distribution of cpu slot.

1.1. Over view. 1.2. Example 1: CPU Slot Distribution A example to test the distribution of cpu slot. 1. JVM, Threads, and Monitors See also: http://java.sun.com/docs/books/vmspec/2nd-edition/html/vmspec- TOC.doc.html I have copied material from there. Thanks to Tim Lindholm Frank Yellin. 1.1. Over view

More information

Lecture 6: Introduction to Monitors and Semaphores

Lecture 6: Introduction to Monitors and Semaphores Concurrent Programming 19530-V (WS01) Lecture 6: Introduction to Monitors and Semaphores Dr. Richard S. Hall rickhall@inf.fu-berlin.de Concurrent programming November 27, 2001 Abstracting Locking Details

More information

Last Class: Semaphores

Last Class: Semaphores Last Class: Semaphores A semaphore S supports two atomic operations: S Wait(): get a semaphore, wait if busy semaphore S is available. S Signal(): release the semaphore, wake up a process if one is waiting

More information

Monitor Object. An Object Behavioral Pattern for Concurrent Programming. Douglas C. Schmidt

Monitor Object. An Object Behavioral Pattern for Concurrent Programming. Douglas C. Schmidt Monitor Object An Object Behavioral Pattern for Concurrent Programming Douglas C. Schmidt schmidt@cs.wustl.edu Department of Computer Science Washington University, St. Louis 1 Intent The Monitor Object

More information

SYSTEM ecos Embedded Configurable Operating System

SYSTEM ecos Embedded Configurable Operating System BELONGS TO THE CYGNUS SOLUTIONS founded about 1989 initiative connected with an idea of free software ( commercial support for the free software ). Recently merged with RedHat. CYGNUS was also the original

More information

Monitors, Java, Threads and Processes

Monitors, Java, Threads and Processes Monitors, Java, Threads and Processes 185 An object-oriented view of shared memory A semaphore can be seen as a shared object accessible through two methods: wait and signal. The idea behind the concept

More information

Multithreaded Programming

Multithreaded Programming Java Multithreaded Programming This chapter presents multithreading, which is one of the core features supported by Java. The chapter introduces the need for expressing concurrency to support simultaneous

More information

Java Virtual Machine Locks

Java Virtual Machine Locks Java Virtual Machine Locks SS 2008 Synchronized Gerald SCHARITZER (e0127228) 2008-05-27 Synchronized 1 / 13 Table of Contents 1 Scope...3 1.1 Constraints...3 1.2 In Scope...3 1.3 Out of Scope...3 2 Logical

More information

Parallel Programming

Parallel Programming Parallel Programming 0024 Recitation Week 7 Spring Semester 2010 R 7 :: 1 0024 Spring 2010 Today s program Assignment 6 Review of semaphores Semaphores Semaphoren and (Java) monitors Semaphore implementation

More information

4. Monitors. Monitors support data encapsulation and information hiding and are easily adapted to an object-oriented environment.

4. Monitors. Monitors support data encapsulation and information hiding and are easily adapted to an object-oriented environment. 4. Monitors Problems with semaphores: - shared variables and the semaphores that protect them are global variables - Operations on shared variables and semaphores distributed throughout program - difficult

More information

First Java Programs. V. Paúl Pauca. CSC 111D Fall, 2015. Department of Computer Science Wake Forest University. Introduction to Computer Science

First Java Programs. V. Paúl Pauca. CSC 111D Fall, 2015. Department of Computer Science Wake Forest University. Introduction to Computer Science First Java Programs V. Paúl Pauca Department of Computer Science Wake Forest University CSC 111D Fall, 2015 Hello World revisited / 8/23/15 The f i r s t o b l i g a t o r y Java program @author Paul Pauca

More information

An Overview of Java. overview-1

An Overview of Java. overview-1 An Overview of Java overview-1 Contents What is Java Major Java features Java virtual machine Java programming language Java class libraries (API) GUI Support in Java Networking and Threads in Java overview-2

More information

Shared Address Space Computing: Programming

Shared Address Space Computing: Programming Shared Address Space Computing: Programming Alistair Rendell See Chapter 6 or Lin and Synder, Chapter 7 of Grama, Gupta, Karypis and Kumar, and Chapter 8 of Wilkinson and Allen Fork/Join Programming Model

More information

Tutorial: Getting Started

Tutorial: Getting Started 9 Tutorial: Getting Started INFRASTRUCTURE A MAKEFILE PLAIN HELLO WORLD APERIODIC HELLO WORLD PERIODIC HELLO WORLD WATCH THOSE REAL-TIME PRIORITIES THEY ARE SERIOUS SUMMARY Getting started with a new platform

More information

CONCURRENT PROGRAMMING WITH THREADS R I C K M E R C E R, R I C K S N O D G R A S S, I V A N V A S Q U E Z W I T H H E L P F R O M J O S H B L O C K

CONCURRENT PROGRAMMING WITH THREADS R I C K M E R C E R, R I C K S N O D G R A S S, I V A N V A S Q U E Z W I T H H E L P F R O M J O S H B L O C K CONCURRENT PROGRAMMING WITH THREADS R I C K M E R C E R, R I C K S N O D G R A S S, I V A N V A S Q U E Z W I T H H E L P F R O M J O S H B L O C K OUTLINE Basic concepts Processes Threads Java: Thread

More information

Scheduling recurring tasks in Java applications

Scheduling recurring tasks in Java applications Introducing a simple generalisation of the Java language's Timer class Skill Level: Intermediate Tom White Lead Java Developer Kizoom 04 Nov 2003 All manner of Java applications commonly need to schedule

More information

Performance Improvement In Java Application

Performance Improvement In Java Application Performance Improvement In Java Application Megha Fulfagar Accenture Delivery Center for Technology in India Accenture, its logo, and High Performance Delivered are trademarks of Accenture. Agenda Performance

More information

Introduction to Java threads

Introduction to Java threads Introduction to Java threads ibm.com/developerworks Table of Contents If you're viewing this document online, you can click any of the topics below to link directly to that section. 1. About this tutorial...

More information

Replication on Virtual Machines

Replication on Virtual Machines Replication on Virtual Machines Siggi Cherem CS 717 November 23rd, 2004 Outline 1 Introduction The Java Virtual Machine 2 Napper, Alvisi, Vin - DSN 2003 Introduction JVM as state machine Addressing non-determinism

More information

STORM. Simulation TOol for Real-time Multiprocessor scheduling. Designer Guide V3.3.1 September 2009

STORM. Simulation TOol for Real-time Multiprocessor scheduling. Designer Guide V3.3.1 September 2009 STORM Simulation TOol for Real-time Multiprocessor scheduling Designer Guide V3.3.1 September 2009 Richard Urunuela, Anne-Marie Déplanche, Yvon Trinquet This work is part of the project PHERMA supported

More information

14/05/2013 Ed Merks EDL V1.0 1

14/05/2013 Ed Merks EDL V1.0 1 14/05/2013 Ed Merks EDL V1.0 1 Java Performance is Complex Write once run everywhere Java is slow because it s interpreted No, there are Just In Time (JIT) compilers Different hardware and platforms Different

More information

Platform-wide Deadlock Immunity for Mobile Phones

Platform-wide Deadlock Immunity for Mobile Phones Platform-wide Deadlock Immunity for Mobile Phones Horatiu Jula, Thomas Rensch, George Candea School of Computer and Communication Sciences École Polytechnique Fédérale de Lausanne (EPFL), Switzerland Abstract

More information

3C03 Concurrency: Condition Synchronisation

3C03 Concurrency: Condition Synchronisation 3C03 Concurrency: Condition Synchronisation Mark Handley 1 Goals n Introduce concepts of Condition synchronisation Fairness Starvation n Modelling: Relationship between guarded actions and condition synchronisation?

More information

Massachusetts Institute of Technology 6.005: Elements of Software Construction Fall 2011 Quiz 2 November 21, 2011 SOLUTIONS.

Massachusetts Institute of Technology 6.005: Elements of Software Construction Fall 2011 Quiz 2 November 21, 2011 SOLUTIONS. Massachusetts Institute of Technology 6.005: Elements of Software Construction Fall 2011 Quiz 2 November 21, 2011 Name: SOLUTIONS Athena* User Name: Instructions This quiz is 50 minutes long. It contains

More information

Chapter 1 Java Program Design and Development

Chapter 1 Java Program Design and Development presentation slides for JAVA, JAVA, JAVA Object-Oriented Problem Solving Third Edition Ralph Morelli Ralph Walde Trinity College Hartford, CT published by Prentice Hall Java, Java, Java Object Oriented

More information

www.virtualians.pk CS506 Web Design and Development Solved Online Quiz No. 01 www.virtualians.pk

www.virtualians.pk CS506 Web Design and Development Solved Online Quiz No. 01 www.virtualians.pk CS506 Web Design and Development Solved Online Quiz No. 01 Which of the following is a general purpose container? JFrame Dialog JPanel JApplet Which of the following package needs to be import while handling

More information

Java TM & Real-Time Advantages, Limitations, & RTSJ

Java TM & Real-Time Advantages, Limitations, & RTSJ Java TM & Real-Time Advantages, Limitations, & Christos.Kloukinas@imag.fr Verimag (http://www-verimag.imag.fr/) Grenoble, France École IN2P3 d informatique: Temps Réel 29 May 2003 p.1/56 Java is a language

More information

Background Tasks and Blackboard Building Blocks TM. Two great tastes that taste great together

Background Tasks and Blackboard Building Blocks TM. Two great tastes that taste great together Background Tasks and Blackboard Building Blocks TM Two great tastes that taste great together Why? Recurring tasks? Processing-intensive tasks? Secret, shameful tasks! Considerations Basic Java Thread

More information

How to Write AllSeen Alliance Self- Certification Test Cases September 25, 2014

How to Write AllSeen Alliance Self- Certification Test Cases September 25, 2014 How to Write AllSeen Alliance Self- Certification Test Cases September 25, 2014 This work is licensed under a Creative Commons Attribution 4.0 International License. http://creativecommons.org/licenses/by/4.0/

More information

Enterprise Java (BI-EJA) Technologie programování v jazyku Java (X36TJV)

Enterprise Java (BI-EJA) Technologie programování v jazyku Java (X36TJV) Příprava studijního programu Informatika je podporována projektem financovaným z Evropského sociálního fondu a rozpočtu hlavního města Prahy. Praha & EU: Investujeme do vaší budoucnosti Enterprise Java

More information

Socket-based Network Communication in J2SE and J2ME

Socket-based Network Communication in J2SE and J2ME Socket-based Network Communication in J2SE and J2ME 1 C/C++ BSD Sockets in POSIX POSIX functions allow to access network connection in the same way as regular files: There are special functions for opening

More information

Chapter 2 Introduction to Java programming

Chapter 2 Introduction to Java programming Chapter 2 Introduction to Java programming 1 Keywords boolean if interface class true char else package volatile false byte final switch while throws float private case return native void protected break

More information

Fundamentals of Java Programming

Fundamentals of Java Programming Fundamentals of Java Programming This document is exclusive property of Cisco Systems, Inc. Permission is granted to print and copy this document for non-commercial distribution and exclusive use by instructors

More information

pavlix@pavlix.net pavlix@pavlix.net

pavlix@pavlix.net pavlix@pavlix.net Evolution of Linux network management InstallFest 2013, Praha http://data.pavlix.net/installfest/2013/ 1/12 From: Dan Williams To: networkmanager-list gnome org Subject: ANN: released

More information

aneb Co bylo, bylo, co zbylo, zbylo.

aneb Co bylo, bylo, co zbylo, zbylo. aneb Co bylo, bylo, co zbylo, zbylo. 2013 Minulé časy Minulý čas se vyznačuje především tím, že jím popisované děje jsou již ukončeny a dále neprobíhají. Často jsou tyto skutečnosti naznačeny signálním

More information

CS5233 Components Models and Engineering

CS5233 Components Models and Engineering Prof. Dr. Th. Letschert CS5233 Components Models and Engineering - Komponententechnologien Master of Science (Informatik) Java Management Extensions: JMX Seite 1 JMX http://download.oracle.com/javase/tutorial/jmx/index.html

More information

CSE 1223: Introduction to Computer Programming in Java Chapter 7 File I/O

CSE 1223: Introduction to Computer Programming in Java Chapter 7 File I/O CSE 1223: Introduction to Computer Programming in Java Chapter 7 File I/O 1 Sending Output to a (Text) File import java.util.scanner; import java.io.*; public class TextFileOutputDemo1 public static void

More information

Monitors and Semaphores

Monitors and Semaphores Monitors and Semaphores Annotated Condition Variable Example Condition *cv; Lock* cvmx; int waiter = 0; await() { cvmx->lock(); waiter = waiter + 1; /* I m sleeping */ cv->wait(cvmx); /* sleep */ cvmx->unlock();

More information

! Past few lectures: Ø Locks: provide mutual exclusion Ø Condition variables: provide conditional synchronization

! Past few lectures: Ø Locks: provide mutual exclusion Ø Condition variables: provide conditional synchronization 1 Synchronization Constructs! Synchronization Ø Coordinating execution of multiple threads that share data structures Semaphores and Monitors: High-level Synchronization Constructs! Past few lectures:

More information

Mutual Exclusion using Monitors

Mutual Exclusion using Monitors Mutual Exclusion using Monitors Some programming languages, such as Concurrent Pascal, Modula-2 and Java provide mutual exclusion facilities called monitors. They are similar to modules in languages that

More information

aneb Perfektní minulost.

aneb Perfektní minulost. aneb Perfektní minulost. 2013 se v angličtině nazývá Past Perfect. Používáme jej tehdy, potřebujeme-li jasně vyjádřit, že nějaký děj proběhl ještě dříve než minulý děj, o kterém hovoříme. Podívejme se

More information

16.1 DataFlavor. 16.1.1 DataFlavor Methods. Variables

16.1 DataFlavor. 16.1.1 DataFlavor Methods. Variables In this chapter: DataFlavor Transferable Interface ClipboardOwner Interface Clipboard StringSelection UnsupportedFlavorException Reading and Writing the Clipboard 16 Data Transfer One feature that was

More information

Java Interview Questions and Answers

Java Interview Questions and Answers 1. What is the most important feature of Java? Java is a platform independent language. 2. What do you mean by platform independence? Platform independence means that we can write and compile the java

More information

WK29B / WK29W. Bluetooth Wireless Slim Keyboard. User manual ( 2 5 ) Uživatelský manuál ( 6 10) Užívateľský manuál (11 15)

WK29B / WK29W. Bluetooth Wireless Slim Keyboard. User manual ( 2 5 ) Uživatelský manuál ( 6 10) Užívateľský manuál (11 15) WK29B / WK29W Bluetooth Wireless Slim Keyboard User manual ( 2 5 ) Uživatelský manuál ( 6 10) Užívateľský manuál (11 15) 1. Installing the batteries The EVOLVEO WK29B / WK29W keyboard uses two AAA alkaline

More information

Lecture 8: Safety and Liveness Properties

Lecture 8: Safety and Liveness Properties Concurrent Programming 19530-V (WS01) 1 Lecture 8: Safety and Liveness Properties Dr. Richard S. Hall rickhall@inf.fu-berlin.de Concurrent programming December 11, 2001 Safety Properties 2 A safety property

More information

Monitors and Exceptions : How to Implement Java efficiently. Andreas Krall and Mark Probst Technische Universitaet Wien

Monitors and Exceptions : How to Implement Java efficiently. Andreas Krall and Mark Probst Technische Universitaet Wien Monitors and Exceptions : How to Implement Java efficiently Andreas Krall and Mark Probst Technische Universitaet Wien 1 Outline Exceptions in CACAO Exception implementation techniques CACAO s implementation

More information

GP webpay System Administration Role: MerchantAdmin

GP webpay System Administration Role: MerchantAdmin Role: MerchantAdmin User s Guide, July 2013 TABLE OF CONTENTS: INTRODUCTION... 3 LOGING IN TO GP WEBPAY... 3 MAIN MENU FOR THE MERCHANTADMIN ROLE... 4 ADMINISTRATION... 6 Change password... 6 Contact info...

More information

Java SE 8 Programming

Java SE 8 Programming Oracle University Contact Us: 1.800.529.0165 Java SE 8 Programming Duration: 5 Days What you will learn This Java SE 8 Programming training covers the core language features and Application Programming

More information

Capabilities of a Java Test Execution Framework by Erick Griffin

Capabilities of a Java Test Execution Framework by Erick Griffin Capabilities of a Java Test Execution Framework by Erick Griffin Here we discuss key properties and capabilities of a Java Test Execution Framework for writing and executing discrete Java tests for testing

More information

Creating a Simple, Multithreaded Chat System with Java

Creating a Simple, Multithreaded Chat System with Java Creating a Simple, Multithreaded Chat System with Java Introduction by George Crawford III In this edition of Objective Viewpoint, you will learn how to develop a simple chat system. The program will demonstrate

More information

race conditions Image courtesy of photostock / FreeDigitalPhotos.net Flavia Rainone - Principal Software Engineer

race conditions Image courtesy of photostock / FreeDigitalPhotos.net Flavia Rainone - Principal Software Engineer Boston race conditions? Image courtesy of photostock / FreeDigitalPhotos.net 2 race conditions Race conditions arise in software when separate computer processes or threads of execution depend on some

More information

A Comparison of the Concurrency and Real-Time Features of Ada 95 and Java

A Comparison of the Concurrency and Real-Time Features of Ada 95 and Java A Comparison of the Concurrency and Real-Time Features of Ada 95 and Java Benjamin M. Brosgol Ada Core Technologies 79 Tobey Road Belmont, MA 02478 USA +1.617.489.4027 (Phone) +1.617.489.4009 (FAX) brosgol@gnat.com

More information

e ag u g an L g ter lvin v E ram Neal G g ro va P Ja

e ag u g an L g ter lvin v E ram Neal G g ro va P Ja Evolving the Java Programming Language Neal Gafter Overview The Challenge of Evolving a Language Design Principles Design Goals JDK7 and JDK8 Challenge: Evolving a Language What is it like trying to extend

More information

Hoare-Style Monitors for Java

Hoare-Style Monitors for Java Hoare-Style Monitors for Java Theodore S Norvell Electrical and Computer Engineering Memorial University February 17, 2006 1 Hoare-Style Monitors Coordinating the interactions of two or more threads can

More information

Semaphores and Monitors: High-level Synchronization Constructs

Semaphores and Monitors: High-level Synchronization Constructs Semaphores and Monitors: High-level Synchronization Constructs 1 Synchronization Constructs Synchronization Coordinating execution of multiple threads that share data structures Past few lectures: Locks:

More information

Animazione in Java. Animazione in Java. Problemi che possono nascere, e loro soluzione. Marco Ronchetti Lezione 1

Animazione in Java. Animazione in Java. Problemi che possono nascere, e loro soluzione. Marco Ronchetti Lezione 1 Animazione in Java Problemi che possono nascere, e loro soluzione Animazione in Java Application MyFrame (JFrame) ClockPanel (JPanel) 1 public class ClockPanel extends JPanel { public ClockPanel void paintcomponent(graphics

More information

3. Java Nuggets in a Nutshell

3. Java Nuggets in a Nutshell 3. Java Nuggets in a Nutshell 3. Java Nuggets in a Nutshell Sequential Java Programming Shared Memory Multi-Threading in Java 43 / 303 3. Java Nuggets in a Nutshell Help Yourself Java Language and Standard

More information

Free Java textbook available online. Introduction to the Java programming language. Compilation. A simple java program

Free Java textbook available online. Introduction to the Java programming language. Compilation. A simple java program Free Java textbook available online "Thinking in Java" by Bruce Eckel, 4th edition, 2006, ISBN 0131872486, Pearson Education Introduction to the Java programming language CS 4354 Summer II 2015 The third

More information

Free Java textbook available online. Introduction to the Java programming language. Compilation. A simple java program

Free Java textbook available online. Introduction to the Java programming language. Compilation. A simple java program Free Java textbook available online "Thinking in Java" by Bruce Eckel, 4th edition, 2006, ISBN 0131872486, Pearson Education Introduction to the Java programming language CS 4354 Summer II 2014 Jill Seaman

More information

Getting Started with the Internet Communications Engine

Getting Started with the Internet Communications Engine Getting Started with the Internet Communications Engine David Vriezen April 7, 2014 Contents 1 Introduction 2 2 About Ice 2 2.1 Proxies................................. 2 3 Setting Up ICE 2 4 Slices 2

More information

YOUTUBE 4.0. Postup upgrade Youtube z Youtube 3.1 na Youtube 4.0 pro produkty EAGET X5R, M6, M7 a M9:

YOUTUBE 4.0. Postup upgrade Youtube z Youtube 3.1 na Youtube 4.0 pro produkty EAGET X5R, M6, M7 a M9: YOUTUBE 4.0 Postup upgrade Youtube z Youtube 3.1 na Youtube 4.0 pro produkty EAGET X5R, M6, M7 a M9: 1) V puštěném přehrávači EAGET zjistěte IP adresu vašeho zařízení (Nastavení - Systém - Síť - "IP adresa

More information

A Thread Monitoring System for Multithreaded Java Programs

A Thread Monitoring System for Multithreaded Java Programs A Thread Monitoring System for Multithreaded Java Programs Sewon Moon and Byeong-Mo Chang Department of Computer Science Sookmyung Women s University, Seoul 140-742, Korea wonsein@nate.com, chang@sookmyung.ac.kr

More information

Distributed Systems [Fall 2012]

Distributed Systems [Fall 2012] Distributed Systems [Fall 2012] [W4995-2] Lec 6: YFS Lab Introduction and Local Synchronization Primitives Slide acks: Jinyang Li, Dave Andersen, Randy Bryant (http://www.news.cs.nyu.edu/~jinyang/fa10/notes/ds-lec2.ppt,

More information

Pemrograman Dasar. Basic Elements Of Java

Pemrograman Dasar. Basic Elements Of Java Pemrograman Dasar Basic Elements Of Java Compiling and Running a Java Application 2 Portable Java Application 3 Java Platform Platform: hardware or software environment in which a program runs. Oracle

More information

CPU Scheduling. Dr. Yingwu Zhu

CPU Scheduling. Dr. Yingwu Zhu CPU Scheduling Dr. Yingwu Zhu Overview In discussing process/threads management and synchronization, we talked about context switching among processes/threads on the ready queue But we have not glossed

More information

Chapter 6 Concurrent Programming

Chapter 6 Concurrent Programming Chapter 6 Concurrent Programming Outline 6.1 Introduction 6.2 Monitors 6.2.1 Condition Variables 6.2.2 Simple Resource Allocation with Monitors 6.2.3 Monitor Example: Circular Buffer 6.2.4 Monitor Example:

More information

Mobile App Sensor Documentation (English Version)

Mobile App Sensor Documentation (English Version) Mobile App Sensor Documentation (English Version) Mobile App Sensor Documentation (English Version) Version: 1.2.1 Date: 2015-03-25 Author: email: Kantar Media spring support@spring.de Content Mobile App

More information

JAVA INTERVIEW QUESTIONS

JAVA INTERVIEW QUESTIONS JAVA INTERVIEW QUESTIONS http://www.tutorialspoint.com/java/java_interview_questions.htm Copyright tutorialspoint.com Dear readers, these Java Interview Questions have been designed especially to get you

More information

Port of the Java Virtual Machine Kaffe to DROPS by using L4Env

Port of the Java Virtual Machine Kaffe to DROPS by using L4Env Port of the Java Virtual Machine Kaffe to DROPS by using L4Env Alexander Böttcher ab764283@os.inf.tu-dresden.de Technische Universität Dresden Faculty of Computer Science Operating System Group July 2004

More information

How to program a MapReduce cluster

How to program a MapReduce cluster How to program a MapReduce cluster TF-IDF step by step Ján Súkeník xsukenik@is.stuba.sk sukenik08@student.fiit.stuba.sk TF-IDF potrebujeme pre každý dokument počet slov frekvenciu každého slova pre každé

More information

11. Applets, normal window applications, packaging and sharing your work

11. Applets, normal window applications, packaging and sharing your work 11. Applets, normal window applications, packaging and sharing your work In this chapter Converting Full Screen experiments into normal window applications, Packaging and sharing applications packaging

More information

The Sun Certified Associate for the Java Platform, Standard Edition, Exam Version 1.0

The Sun Certified Associate for the Java Platform, Standard Edition, Exam Version 1.0 The following applies to all exams: Once exam vouchers are purchased you have up to one year from the date of purchase to use it. Each voucher is valid for one exam and may only be used at an Authorized

More information