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Split or move core-java-modules/core-java-concurrency-basic module (#7799)

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This commit is contained in:
Catalin Burcea
2019-09-23 16:55:02 +03:00
committed by Josh Cummings
parent dac59fbec2
commit 6073d2d451
30 changed files with 114 additions and 42 deletions
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93
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/delay/Delay.java Normal file
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package com.baeldung.concurrent.delay;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
public class Delay {
public static void main(String args[]) throws InterruptedException {
threadSleep(4, 1);
timeunitSleep(4, 1);
delayedServiceTask(5);
fixedRateServiceTask(5);
System.out.println("Done.");
return;
}
private static void threadSleep(Integer iterations, Integer secondsToSleep) {
for (Integer i = 0; i < iterations; i++) {
System.out.println("This is loop iteration number " + i.toString());
try {
Thread.sleep(secondsToSleep * 1000);
} catch (InterruptedException ie) {
Thread.currentThread().interrupt();
}
}
}
private static void timeunitSleep(Integer iterations, Integer secondsToSleep) {
for (Integer i = 0; i < iterations; i++) {
System.out.println("This is loop iteration number " + i.toString());
try {
TimeUnit.SECONDS.sleep(secondsToSleep);
} catch (InterruptedException ie) {
Thread.currentThread().interrupt();
}
}
}
private static void delayedServiceTask(Integer delayInSeconds) {
ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor();
executorService.schedule(Delay::someTask1, delayInSeconds, TimeUnit.SECONDS);
executorService.shutdown();
}
private static void fixedRateServiceTask(Integer delayInSeconds) {
ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor();
ScheduledFuture<?> sf = executorService.scheduleAtFixedRate(Delay::someTask2, 0, delayInSeconds,
TimeUnit.SECONDS);
try {
TimeUnit.SECONDS.sleep(20);
} catch (InterruptedException ie) {
Thread.currentThread().interrupt();
}
sf.cancel(true);
executorService.shutdown();
}
private static void someTask1() {
System.out.println("Task 1 completed.");
}
private static void someTask2() {
System.out.println("Task 2 completed.");
}
}

27
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/sleepwait/ThreadA.java Normal file
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package com.baeldung.concurrent.sleepwait;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/***
* Example of waking up a waiting thread
*/
public class ThreadA {
private static final Logger LOG = LoggerFactory.getLogger(ThreadA.class);
private static final ThreadB b = new ThreadB();
public static void main(String... args) throws InterruptedException {
b.start();
synchronized (b) {
while (b.sum == 0) {
LOG.debug("Waiting for ThreadB to complete...");
b.wait();
}
LOG.debug("ThreadB has completed. Sum from that thread is: " + b.sum);
}
}
}

20
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/sleepwait/ThreadB.java Normal file
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package com.baeldung.concurrent.sleepwait;
/***
* Example of waking up a waiting thread
*/
class ThreadB extends Thread {
int sum;
@Override
public void run() {
synchronized (this) {
int i = 0;
while (i < 100000) {
sum += i;
i++;
}
notify();
}
}
}

29
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/sleepwait/WaitSleepExample.java Normal file
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package com.baeldung.concurrent.sleepwait;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/***
* Example of wait() and sleep() methods
*/
public class WaitSleepExample {
private static final Logger LOG = LoggerFactory.getLogger(WaitSleepExample.class);
private static final Object LOCK = new Object();
public static void main(String... args) throws InterruptedException {
sleepWaitInSynchronizedBlocks();
}
private static void sleepWaitInSynchronizedBlocks() throws InterruptedException {
Thread.sleep(1000); // called on the thread
LOG.debug("Thread '" + Thread.currentThread().getName() + "' is woken after sleeping for 1 second");
synchronized (LOCK) {
LOCK.wait(1000); // called on the object, synchronization required
LOG.debug("Object '" + LOCK + "' is woken after waiting for 1 second");
}
}
}

35
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/synchronize/BaeldungSynchronizedBlocks.java Normal file
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package com.baeldung.concurrent.synchronize;
public class BaeldungSynchronizedBlocks {
private int count = 0;
private static int staticCount = 0;
void performSynchronisedTask() {
synchronized (this) {
setCount(getCount() + 1);
}
}
static void performStaticSyncTask() {
synchronized (BaeldungSynchronizedBlocks.class) {
setStaticCount(getStaticCount() + 1);
}
}
public int getCount() {
return count;
}
public void setCount(int count) {
this.count = count;
}
static int getStaticCount() {
return staticCount;
}
private static void setStaticCount(int staticCount) {
BaeldungSynchronizedBlocks.staticCount = staticCount;
}
}

37
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/synchronize/BaeldungSynchronizedMethods.java Normal file
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package com.baeldung.concurrent.synchronize;
public class BaeldungSynchronizedMethods {
private int sum = 0;
private int syncSum = 0;
static int staticSum = 0;
void calculate() {
setSum(getSum() + 1);
}
synchronized void synchronisedCalculate() {
setSyncSum(getSyncSum() + 1);
}
static synchronized void syncStaticCalculate() {
staticSum = staticSum + 1;
}
public int getSum() {
return sum;
}
public void setSum(int sum) {
this.sum = sum;
}
int getSyncSum() {
return syncSum;
}
private void setSyncSum(int syncSum) {
this.syncSum = syncSum;
}
}

31
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/threadlifecycle/BlockedState.java Normal file
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package com.baeldung.concurrent.threadlifecycle;
public class BlockedState {
public static void main(String[] args) throws InterruptedException {
Thread t1 = new Thread(new DemoThreadB());
Thread t2 = new Thread(new DemoThreadB());
t1.start();
t2.start();
Thread.sleep(1000);
System.out.println(t2.getState());
System.exit(0);
}
}
class DemoThreadB implements Runnable {
@Override
public void run() {
commonResource();
}
public static synchronized void commonResource() {
while(true) {
// Infinite loop to mimic heavy processing
// Thread 't1' won't leave this method
// when Thread 't2' enters this
}
}
}

14
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/threadlifecycle/NewState.java Normal file
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package com.baeldung.concurrent.threadlifecycle;
public class NewState implements Runnable {
public static void main(String[] args) {
Runnable runnable = new NewState();
Thread t = new Thread(runnable);
System.out.println(t.getState());
}
@Override
public void run() {
}
}

15
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/threadlifecycle/RunnableState.java Normal file
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package com.baeldung.concurrent.threadlifecycle;
public class RunnableState implements Runnable {
public static void main(String[] args) {
Runnable runnable = new NewState();
Thread t = new Thread(runnable);
t.start();
System.out.println(t.getState());
}
@Override
public void run() {
}
}

15
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/threadlifecycle/TerminatedState.java Normal file
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package com.baeldung.concurrent.threadlifecycle;
public class TerminatedState implements Runnable {
public static void main(String[] args) throws InterruptedException {
Thread t1 = new Thread(new TerminatedState());
t1.start();
Thread.sleep(1000);
System.out.println(t1.getState());
}
@Override
public void run() {
// No processing in this block
}
}

25
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/threadlifecycle/TimedWaitingState.java Normal file
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package com.baeldung.concurrent.threadlifecycle;
public class TimedWaitingState {
public static void main(String[] args) throws InterruptedException {
DemoThread obj1 = new DemoThread();
Thread t1 = new Thread(obj1);
t1.start();
// The following sleep will give enough time for ThreadScheduler
// to start processing of thread t1
Thread.sleep(1000);
System.out.println(t1.getState());
}
}
class DemoThread implements Runnable {
@Override
public void run() {
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
e.printStackTrace();
}
}
}

35
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/threadlifecycle/WaitingState.java Normal file
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package com.baeldung.concurrent.threadlifecycle;
public class WaitingState implements Runnable {
public static Thread t1;
public static void main(String[] args) {
t1 = new Thread(new WaitingState());
t1.start();
}
public void run() {
Thread t2 = new Thread(new DemoThreadWS());
t2.start();
try {
t2.join();
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
e.printStackTrace();
}
}
}
class DemoThreadWS implements Runnable {
public void run() {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
e.printStackTrace();
}
System.out.println(WaitingState.t1.getState());
}
}

39
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/waitandnotify/Data.java Normal file
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package com.baeldung.concurrent.waitandnotify;
public class Data {
private String packet;
// True if receiver should wait
// False if sender should wait
private boolean transfer = true;
public synchronized String receive() {
while (transfer) {
try {
wait();
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
System.out.println("Thread Interrupted");
}
}
transfer = true;
notifyAll();
return packet;
}
public synchronized void send(String packet) {
while (!transfer) {
try {
wait();
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
System.out.println("Thread Interrupted");
}
}
transfer = false;
this.packet = packet;
notifyAll();
}
}

12
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/waitandnotify/NetworkDriver.java Normal file
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package com.baeldung.concurrent.waitandnotify;
public class NetworkDriver {
public static void main(String[] args) {
Data data = new Data();
Thread sender = new Thread(new Sender(data));
Thread receiver = new Thread(new Receiver(data));
sender.start();
receiver.start();
}
}

28
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/waitandnotify/Receiver.java Normal file
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package com.baeldung.concurrent.waitandnotify;
import java.util.concurrent.ThreadLocalRandom;
public class Receiver implements Runnable {
private Data load;
public Receiver(Data load) {
this.load = load;
}
public void run() {
for(String receivedMessage = load.receive();
!"End".equals(receivedMessage) ;
receivedMessage = load.receive()) {
System.out.println(receivedMessage);
//Thread.sleep() to mimic heavy server-side processing
try {
Thread.sleep(ThreadLocalRandom.current().nextInt(1000, 5000));
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
System.out.println("Thread Interrupted");
}
}
}
}

33
core-java-modules/core-java-concurrency-basic-2/src/main/java/com/baeldung/concurrent/waitandnotify/Sender.java Normal file
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package com.baeldung.concurrent.waitandnotify;
import java.util.concurrent.ThreadLocalRandom;
public class Sender implements Runnable {
private Data data;
public Sender(Data data) {
this.data = data;
}
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();
System.out.println("Thread Interrupted");
}
}
}
}

19
core-java-modules/core-java-concurrency-basic-2/src/main/resources/logback.xml Normal file
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<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
</pattern>
</encoder>
</appender>
<logger name="org.springframework" level="WARN" />
<logger name="org.springframework.transaction" level="WARN" />
<!-- in order to debug some marshalling issues, this needs to be TRACE -->
<logger name="org.springframework.web.servlet.mvc" level="WARN" />
<root level="INFO">
<appender-ref ref="STDOUT" />
</root>
</configuration>

37
core-java-modules/core-java-concurrency-basic-2/src/test/java/com/baeldung/concurrent/synchronize/BaeldungSychronizedBlockUnitTest.java Normal file
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package com.baeldung.concurrent.synchronize;
import org.junit.Test;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.stream.IntStream;
import static org.junit.Assert.assertEquals;
public class BaeldungSychronizedBlockUnitTest {
@Test
public void givenMultiThread_whenBlockSync() throws InterruptedException {
ExecutorService service = Executors.newFixedThreadPool(3);
BaeldungSynchronizedBlocks synchronizedBlocks = new BaeldungSynchronizedBlocks();
IntStream.range(0, 1000)
.forEach(count -> service.submit(synchronizedBlocks::performSynchronisedTask));
service.awaitTermination(500, TimeUnit.MILLISECONDS);
assertEquals(1000, synchronizedBlocks.getCount());
}
@Test
public void givenMultiThread_whenStaticSyncBlock() throws InterruptedException {
ExecutorService service = Executors.newCachedThreadPool();
IntStream.range(0, 1000)
.forEach(count -> service.submit(BaeldungSynchronizedBlocks::performStaticSyncTask));
service.awaitTermination(500, TimeUnit.MILLISECONDS);
assertEquals(1000, BaeldungSynchronizedBlocks.getStaticCount());
}
}

51
core-java-modules/core-java-concurrency-basic-2/src/test/java/com/baeldung/concurrent/synchronize/BaeldungSynchronizeMethodsUnitTest.java Normal file
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package com.baeldung.concurrent.synchronize;
import org.junit.Ignore;
import org.junit.Test;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.stream.IntStream;
import static org.junit.Assert.assertEquals;
public class BaeldungSynchronizeMethodsUnitTest {
@Test
@Ignore
public void givenMultiThread_whenNonSyncMethod() throws InterruptedException {
ExecutorService service = Executors.newFixedThreadPool(3);
BaeldungSynchronizedMethods method = new BaeldungSynchronizedMethods();
IntStream.range(0, 1000)
.forEach(count -> service.submit(method::calculate));
service.awaitTermination(100, TimeUnit.MILLISECONDS);
assertEquals(1000, method.getSum());
}
@Test
public void givenMultiThread_whenMethodSync() throws InterruptedException {
ExecutorService service = Executors.newFixedThreadPool(3);
BaeldungSynchronizedMethods method = new BaeldungSynchronizedMethods();
IntStream.range(0, 1000)
.forEach(count -> service.submit(method::synchronisedCalculate));
service.awaitTermination(100, TimeUnit.MILLISECONDS);
assertEquals(1000, method.getSyncSum());
}
@Test
public void givenMultiThread_whenStaticSyncMethod() throws InterruptedException {
ExecutorService service = Executors.newCachedThreadPool();
IntStream.range(0, 1000)
.forEach(count -> service.submit(BaeldungSynchronizedMethods::syncStaticCalculate));
service.awaitTermination(100, TimeUnit.MILLISECONDS);
assertEquals(1000, BaeldungSynchronizedMethods.staticSum);
}
}

66
core-java-modules/core-java-concurrency-basic-2/src/test/java/com/baeldung/concurrent/waitandnotify/NetworkIntegrationTest.java Normal file
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package com.baeldung.concurrent.waitandnotify;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import static org.junit.Assert.assertEquals;
public class NetworkIntegrationTest {
private final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
private final ByteArrayOutputStream errContent = new ByteArrayOutputStream();
private String expected;
@Before
public void setUpStreams() {
System.setOut(new PrintStream(outContent));
System.setErr(new PrintStream(errContent));
}
@Before
public void setUpExpectedOutput() {
StringWriter expectedStringWriter = new StringWriter();
PrintWriter printWriter = new PrintWriter(expectedStringWriter);
printWriter.println("First packet");
printWriter.println("Second packet");
printWriter.println("Third packet");
printWriter.println("Fourth packet");
printWriter.close();
expected = expectedStringWriter.toString();
}
@After
public void cleanUpStreams() {
System.setOut(null);
System.setErr(null);
}
@Test
public void givenSenderAndReceiver_whenSendingPackets_thenNetworkSynchronized() {
Data data = new Data();
Thread sender = new Thread(new Sender(data));
Thread receiver = new Thread(new Receiver(data));
sender.start();
receiver.start();
//wait for sender and receiver to finish before we test against expected
try {
sender.join();
receiver.join();
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
System.out.println("Thread Interrupted");
}
assertEquals(expected, outContent.toString());
}
}