diff --git a/guest/thread-pools/pom.xml b/guest/thread-pools/pom.xml new file mode 100644 index 0000000000..72a10213c4 --- /dev/null +++ b/guest/thread-pools/pom.xml @@ -0,0 +1,28 @@ + + 4.0.0 + com.stackify + thread-pools + 0.0.1-SNAPSHOT + + + + ch.qos.logback + logback-classic + 1.2.3 + + + + + + + maven-compiler-plugin + 3.5.1 + + 1.8 + 1.8 + + + + + \ No newline at end of file diff --git a/guest/thread-pools/src/main/java/com/stackify/models/Employee.java b/guest/thread-pools/src/main/java/com/stackify/models/Employee.java new file mode 100644 index 0000000000..65661f38d5 --- /dev/null +++ b/guest/thread-pools/src/main/java/com/stackify/models/Employee.java @@ -0,0 +1,28 @@ +package com.stackify.models; + +public class Employee { + private String name; + private double salary; + + public String getName() { + return name; + } + + public void setName(String name) { + this.name = name; + } + + public double getSalary() { + return salary; + } + + public void setSalary(double salary) { + this.salary = salary; + } + + public Employee(String name, double salary) { + super(); + this.name = name; + this.salary = salary; + } +} diff --git a/guest/thread-pools/src/main/java/com/stackify/services/EmployeeService.java b/guest/thread-pools/src/main/java/com/stackify/services/EmployeeService.java new file mode 100644 index 0000000000..824f87a625 --- /dev/null +++ b/guest/thread-pools/src/main/java/com/stackify/services/EmployeeService.java @@ -0,0 +1,9 @@ +package com.stackify.services; + +import com.stackify.models.Employee; + +public class EmployeeService { + public double calculateBonus(Employee employee) { + return 0.1 * employee.getSalary(); + } +} diff --git a/guest/thread-pools/src/main/java/com/stackify/threadpools/FactorialTask.java b/guest/thread-pools/src/main/java/com/stackify/threadpools/FactorialTask.java new file mode 100644 index 0000000000..2dd83d9b20 --- /dev/null +++ b/guest/thread-pools/src/main/java/com/stackify/threadpools/FactorialTask.java @@ -0,0 +1,64 @@ +package com.stackify.threadpools; + +import java.math.BigInteger; +import java.util.ArrayList; +import java.util.Collection; +import java.util.List; +import java.util.concurrent.ForkJoinTask; +import java.util.concurrent.RecursiveTask; +import java.util.stream.IntStream; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +public class FactorialTask extends RecursiveTask { + + private static final Logger logger = LoggerFactory.getLogger(Logger.ROOT_LOGGER_NAME); + + private static final long serialVersionUID = 1L; + + private int start = 1; + private int n; + + private static final int THRESHOLD = 20; + + public FactorialTask(int n) { + this.n = n; + } + + public FactorialTask(int start, int n) { + logger.info("New FactorialTask Created"); + this.start = start; + this.n = n; + } + + @Override + protected BigInteger compute() { + if ((n - start) >= THRESHOLD) { + return ForkJoinTask.invokeAll(createSubtasks()) + .stream() + .map(ForkJoinTask::join) + .reduce(BigInteger.ONE, BigInteger::multiply); + } else { + return calculate(start, n); + } + } + + private Collection createSubtasks() { + List dividedTasks = new ArrayList<>(); + + int mid = (start + n) / 2; + + dividedTasks.add(new FactorialTask(start, mid)); + dividedTasks.add(new FactorialTask(mid + 1, n)); + return dividedTasks; + } + + private BigInteger calculate(int start, int n) { + logger.info("Calculate factorial from " + start + " to " + n); + return IntStream.rangeClosed(start, n) + .mapToObj(BigInteger::valueOf) + .reduce(BigInteger.ONE, BigInteger::multiply); + } + +} diff --git a/guest/thread-pools/src/main/java/com/stackify/threadpools/ThreadsApplication.java b/guest/thread-pools/src/main/java/com/stackify/threadpools/ThreadsApplication.java new file mode 100644 index 0000000000..cc9048eee7 --- /dev/null +++ b/guest/thread-pools/src/main/java/com/stackify/threadpools/ThreadsApplication.java @@ -0,0 +1,102 @@ +package com.stackify.threadpools; + +import java.math.BigInteger; +import java.util.concurrent.Callable; +import java.util.concurrent.ExecutionException; +import java.util.concurrent.Executor; +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Executors; +import java.util.concurrent.ForkJoinPool; +import java.util.concurrent.Future; +import java.util.concurrent.LinkedBlockingQueue; +import java.util.concurrent.ScheduledExecutorService; +import java.util.concurrent.ScheduledThreadPoolExecutor; +import java.util.concurrent.ThreadPoolExecutor; +import java.util.concurrent.TimeUnit; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import com.stackify.models.Employee; +import com.stackify.services.EmployeeService; + +public class ThreadsApplication { + + private static final Logger logger = LoggerFactory.getLogger(Logger.ROOT_LOGGER_NAME); + + public static void main(String[] args) { + testExecutor(); + testExecutorService(); + testScheduledExecutorService(); + testThreadPoolExecutor(); + testForkJoinPool(); + } + + private static EmployeeService employeeService = new EmployeeService(); + + public static void testExecutor() { + Executor executor = Executors.newSingleThreadExecutor(); + executor.execute(() -> System.out.println("Single thread pool test")); + } + + public static void testExecutorService() { + + Employee employee = new Employee("John", 2000); + + ExecutorService executor = Executors.newFixedThreadPool(10); + + Callable callableTask = () -> { + return employeeService.calculateBonus(employee); + }; + Future future = executor.submit(callableTask); + + try { + if (future.isDone()) { + double result = future.get(); + System.out.println("Bonus is:" + result); + } + } catch (InterruptedException | ExecutionException e) { + e.printStackTrace(); + } + + executor.shutdown(); + } + + public static void testScheduledExecutorService() { + Employee employee = new Employee("John", 2000); + + ScheduledExecutorService executor = Executors.newScheduledThreadPool(10); + + Callable callableTask = () -> { + return employeeService.calculateBonus(employee); + }; + + Future futureScheduled = executor.schedule(callableTask, 2, TimeUnit.MILLISECONDS); + + try { + System.out.println("Bonus:" + futureScheduled.get()); + } catch (InterruptedException | ExecutionException e) { + e.printStackTrace(); + } + + executor.scheduleAtFixedRate(() -> System.out.println("Fixed Rate Scheduled"), 2, 2000, TimeUnit.MILLISECONDS); + executor.scheduleWithFixedDelay(() -> System.out.println("Fixed Delay Scheduled"), 2, 2000, TimeUnit.MILLISECONDS); + } + + public static void testThreadPoolExecutor() { + ThreadPoolExecutor fixedPoolExecutor = (ThreadPoolExecutor) Executors.newFixedThreadPool(10); + ThreadPoolExecutor cachedPoolExecutor = (ThreadPoolExecutor) Executors.newCachedThreadPool(); + + ThreadPoolExecutor executor = new ThreadPoolExecutor(4, 6, 60, TimeUnit.SECONDS, new LinkedBlockingQueue()); + executor.setMaximumPoolSize(8); + + ScheduledThreadPoolExecutor scheduledExecutor = (ScheduledThreadPoolExecutor) Executors.newScheduledThreadPool(5); + } + + public static void testForkJoinPool() { + ForkJoinPool pool = ForkJoinPool.commonPool(); + logger.info("Thread Pool Created"); + BigInteger result = pool.invoke(new FactorialTask(100)); + System.out.println(result.toString()); + } +}