diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..d669585
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,203 @@
+
+ Apache License
+ Version 2.0, January 2004
+ http://www.apache.org/licenses/
+
+ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
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\ No newline at end of file
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..0d88f95
--- /dev/null
+++ b/README.md
@@ -0,0 +1,146 @@
+# ConcuSim: Concurrency Simulator Testing Tool
+
+ConcuSim is a \[very\] simple tool for simulate thread interleaving in test cases.
+
+Latest release: 1.0.0
+
+## Getting Started
+
+You could find complete example [here](https://github.com/IlyaAI/concusim4j)
+
+#### Step 1. Add Maven or Gradle dependency
+
+```groovy
+dependencies {
+ compile 'com.github.concusim:concusim4j:1.0.0'
+}
+```
+
+#### Step 2. Add concurrency checkpoints in your code
+
+```java
+/**
+ * This is example of some domain service.
+ */
+public final class MyService {
+ static final String CHECKPOINT_BEFORE_COMMIT = "beforeCommit";
+
+ private final EntityManagerFactory emf;
+
+ public MyService(EntityManagerFactory emf) {
+ this.emf = emf;
+ }
+
+ /**
+ * Some method which operates on MyEntity and might be executed concurrently.
+ *
+ * @param id entity id
+ * @param value some input
+ * @return modified entity
+ */
+ public MyEntity serve(long id, String value) {
+ EntityManager em = emf.createEntityManager();
+ em.getTransaction().begin();
+ try {
+ MyEntity entity = MyEntity.getById(em, id);
+
+ /* some long processing here */
+
+ entity.setValue(value);
+
+ /*
+ * We would like to simulate concurrent modification of the same entity by another transaction,
+ * so we place checkpoint before commit. This allows to pause one thread here while another one
+ * performs a commit first. Then we resume and should get OptimisticLockException.
+ */
+ Concurrency.checkpoint(getClass(), CHECKPOINT_BEFORE_COMMIT); // <<<===
+ em.flush();
+ em.getTransaction().commit();
+
+ return entity;
+ } catch (RuntimeException e) {
+ if (em.getTransaction().isActive()) {
+ em.getTransaction().rollback();
+ }
+ throw e;
+ } finally {
+ em.close();
+ }
+ }
+}
+```
+
+#### Step 3. Write a test
+
+The following test checks that concurrent modification of versioned JPA entity throws an OptimisticLockException.
+
+```java
+public class MyServiceTest {
+ private EntityManagerFactory emf;
+
+ @Before
+ public void setUp() {
+ emf = Persistence.createEntityManagerFactory("sample-db");
+ Concurrency.enableCheckpoints();
+ }
+
+ @After
+ public void tearDown() {
+ Concurrency.disableCheckpoints();
+ if (emf != null) {
+ emf.close();
+ emf = null;
+ }
+ }
+
+ @Test
+ public void myService_server_should_throw_optimistic_lock_exception_if_concurrent_modification() throws Exception {
+ // arrange
+ long entityId;
+
+ EntityManager em = emf.createEntityManager();
+ em.getTransaction().begin();
+ try {
+ MyEntity entity = MyEntity.newOne("key", "value");
+ em.persist(entity);
+ em.getTransaction().commit();
+
+ entityId = entity.getId();
+ } finally {
+ em.close();
+ }
+
+ MyService svc = new MyService(emf);
+
+ // act concurrently
+ Runnable requestA = () -> svc.serve(entityId, "new-value-A");
+ Runnable requestB = () -> svc.serve(entityId, "new-value-B");
+
+ ConcurrencySimulator simulator = new ConcurrencySimulator()
+ .withStepTimeoutSec(1)
+ .withConcurrentWorker(requestA, "A")
+ .withConcurrentWorker(requestB, "B");
+
+ simulator.start();
+ try {
+ simulator
+ .run(requestA).till(MyService.class, MyService.CHECKPOINT_BEFORE_COMMIT)
+ .run(requestB).tillEnd()
+ .go();
+
+ try {
+ simulator
+ .run(requestA).tillEnd()
+ .go();
+
+ fail("AggregatedException is expected.");
+ } catch (AggregatedException e) {
+ // assert
+ assertThat(e.getCauseFor(requestA), instanceOf(OptimisticLockException.class));
+ }
+ } finally {
+ simulator.stop();
+ }
+ }
+}
+```
diff --git a/build.gradle b/build.gradle
new file mode 100644
index 0000000..2fd432a
--- /dev/null
+++ b/build.gradle
@@ -0,0 +1,46 @@
+subprojects {
+ repositories {
+ jcenter()
+ }
+
+ apply plugin: 'java'
+
+ group = 'com.github.concusim'
+ version = '1.0'
+
+ sourceCompatibility = 1.8
+ targetCompatibility = 1.8
+
+ ext {
+ versions = [
+ slf4j: '1.7.12',
+ log4j: '1.2.17',
+ jbAnnotations: '15.0',
+
+ junit: '4.12',
+ hamcrest: '1.3'
+ ]
+ }
+
+ dependencies {
+ // logging
+ compile "org.slf4j:slf4j-api:${versions.slf4j}"
+
+ // @Nullable and @NotNull
+ compile "org.jetbrains:annotations:${versions.jbAnnotations}"
+
+ // testing
+ testCompile "junit:junit:${versions.junit}"
+ testCompile "org.hamcrest:hamcrest-all:${versions.hamcrest}"
+ testCompile "org.slf4j:slf4j-log4j12:${versions.slf4j}"
+ testCompile "log4j:log4j:${versions.log4j}"
+ }
+
+ compileJava {
+ options.encoding = 'UTF-8'
+ }
+
+ compileTestJava {
+ options.encoding = 'UTF-8'
+ }
+}
\ No newline at end of file
diff --git a/concusim-sample/build.gradle b/concusim-sample/build.gradle
new file mode 100644
index 0000000..8990904
--- /dev/null
+++ b/concusim-sample/build.gradle
@@ -0,0 +1,6 @@
+dependencies {
+ compile project(':concusim')
+ compile 'org.hibernate:hibernate-entitymanager:5.0.6.Final'
+ compile 'org.hsqldb:hsqldb:2.3.3'
+ compile 'javax.transaction:jta:1.1'
+}
\ No newline at end of file
diff --git a/concusim-sample/src/main/java/com/github/concusim/sample/MyEntity.java b/concusim-sample/src/main/java/com/github/concusim/sample/MyEntity.java
new file mode 100644
index 0000000..f9fa7cd
--- /dev/null
+++ b/concusim-sample/src/main/java/com/github/concusim/sample/MyEntity.java
@@ -0,0 +1,66 @@
+package com.github.concusim.sample;
+
+import javax.persistence.*;
+
+/**
+ * Example of some domain entity.
+ */
+@Entity
+public class MyEntity {
+ @Id
+ @GeneratedValue
+ @Access(AccessType.PROPERTY)
+ private long id;
+
+ @Column(length = 32, nullable = false)
+ private String name;
+
+ @Column(length = 64)
+ private String value;
+
+ @Version
+ private int revision;
+
+ protected MyEntity() {
+ }
+
+ public long getId() {
+ return id;
+ }
+
+ protected void setId(long id) {
+ this.id = id;
+ }
+
+ public String getName() {
+ return name;
+ }
+
+ public String getValue() {
+ return value;
+ }
+
+ public void setValue(String value) {
+ this.value = value;
+ }
+
+ public int getRevision() {
+ return revision;
+ }
+
+ public static MyEntity getById(EntityManager entityManager, long id) {
+ MyEntity entity = entityManager.find(MyEntity.class, id);
+ if (entity == null)
+ throw new EntityNotFoundException();
+
+ return entity;
+ }
+
+ public static MyEntity newOne(String name, String value) {
+ MyEntity entity = new MyEntity();
+ entity.name = name;
+ entity.value = value;
+
+ return entity;
+ }
+}
diff --git a/concusim-sample/src/main/java/com/github/concusim/sample/MyService.java b/concusim-sample/src/main/java/com/github/concusim/sample/MyService.java
new file mode 100644
index 0000000..7bcb389
--- /dev/null
+++ b/concusim-sample/src/main/java/com/github/concusim/sample/MyService.java
@@ -0,0 +1,56 @@
+package com.github.concusim.sample;
+
+import com.github.concusim.Concurrency;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+
+/**
+ * This is example of some domain service.
+ */
+public final class MyService {
+ static final String CHECKPOINT_BEFORE_COMMIT = "beforeCommit";
+
+ private final EntityManagerFactory emf;
+
+ public MyService(EntityManagerFactory emf) {
+ this.emf = emf;
+ }
+
+ /**
+ * Some method which operates on MyEntity and might be executed concurrently.
+ *
+ * @param id entity id
+ * @param value some input
+ * @return modified entity
+ */
+ public MyEntity serve(long id, String value) {
+ EntityManager em = emf.createEntityManager();
+ em.getTransaction().begin();
+ try {
+ MyEntity entity = MyEntity.getById(em, id);
+
+ /* some long processing here */
+
+ entity.setValue(value);
+
+ /*
+ * We would like to simulate concurrent modification of the same entity by another transaction,
+ * so we place checkpoint before commit. This allows to pause one thread here while another one
+ * performs a commit first. Then we resume and should get OptimisticLockException.
+ */
+ Concurrency.checkpoint(getClass(), CHECKPOINT_BEFORE_COMMIT);
+ em.flush();
+ em.getTransaction().commit();
+
+ return entity;
+ } catch (RuntimeException e) {
+ if (em.getTransaction().isActive()) {
+ em.getTransaction().rollback();
+ }
+ throw e;
+ } finally {
+ em.close();
+ }
+ }
+}
diff --git a/concusim-sample/src/main/resources/META-INF/persistence.xml b/concusim-sample/src/main/resources/META-INF/persistence.xml
new file mode 100644
index 0000000..4e07c5c
--- /dev/null
+++ b/concusim-sample/src/main/resources/META-INF/persistence.xml
@@ -0,0 +1,26 @@
+
+
+
+
+
+ com.github.concusim.sample.MyEntity
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
\ No newline at end of file
diff --git a/concusim-sample/src/test/java/com/github/concusim/sample/MyServiceTest.java b/concusim-sample/src/test/java/com/github/concusim/sample/MyServiceTest.java
new file mode 100644
index 0000000..317d002
--- /dev/null
+++ b/concusim-sample/src/test/java/com/github/concusim/sample/MyServiceTest.java
@@ -0,0 +1,86 @@
+package com.github.concusim.sample;
+
+import com.github.concusim.Concurrency;
+import com.github.concusim.testing.AggregatedException;
+import com.github.concusim.testing.ConcurrencySimulator;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.OptimisticLockException;
+import javax.persistence.Persistence;
+
+import static org.hamcrest.CoreMatchers.instanceOf;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.fail;
+
+public class MyServiceTest {
+ private EntityManagerFactory emf;
+
+ @Before
+ public void setUp() {
+ emf = Persistence.createEntityManagerFactory("sample-db");
+ Concurrency.enableCheckpoints();
+ }
+
+ @After
+ public void tearDown() {
+ Concurrency.disableCheckpoints();
+ if (emf != null) {
+ emf.close();
+ emf = null;
+ }
+ }
+
+ @Test
+ public void myService_server_should_throw_optimistic_lock_exception_if_concurrent_modification() throws Exception {
+ // arrange
+ long entityId;
+
+ EntityManager em = emf.createEntityManager();
+ em.getTransaction().begin();
+ try {
+ MyEntity entity = MyEntity.newOne("key", "value");
+ em.persist(entity);
+ em.getTransaction().commit();
+
+ entityId = entity.getId();
+ } finally {
+ em.close();
+ }
+
+ MyService svc = new MyService(emf);
+
+ // act concurrently
+ Runnable requestA = () -> svc.serve(entityId, "new-value-A");
+ Runnable requestB = () -> svc.serve(entityId, "new-value-B");
+
+ ConcurrencySimulator simulator = new ConcurrencySimulator()
+ .withStepTimeoutSec(1)
+ .withConcurrentWorker(requestA, "A")
+ .withConcurrentWorker(requestB, "B");
+
+ simulator.start();
+ try {
+ simulator
+ .run(requestA).till(MyService.class, MyService.CHECKPOINT_BEFORE_COMMIT)
+ .run(requestB).tillEnd()
+ .go();
+
+ try {
+ simulator
+ .run(requestA).tillEnd()
+ .go();
+
+ fail("AggregatedException is expected.");
+ } catch (AggregatedException e) {
+ // assert
+ assertThat(e.getCauseFor(requestA), instanceOf(OptimisticLockException.class));
+ }
+ } finally {
+ simulator.stop();
+ }
+ }
+}
diff --git a/concusim-sample/src/test/resources/log4j.properties b/concusim-sample/src/test/resources/log4j.properties
new file mode 100644
index 0000000..98874df
--- /dev/null
+++ b/concusim-sample/src/test/resources/log4j.properties
@@ -0,0 +1,7 @@
+log4j.rootCategory=off, console
+
+log4j.appender.console=org.apache.log4j.ConsoleAppender
+log4j.appender.console.layout=org.apache.log4j.PatternLayout
+log4j.appender.console.layout.ConversionPattern= %p %c: %m%n
+
+log4j.logger.com.github.concusim=debug
diff --git a/concusim/build.gradle b/concusim/build.gradle
new file mode 100644
index 0000000..1b8a904
--- /dev/null
+++ b/concusim/build.gradle
@@ -0,0 +1,46 @@
+buildscript {
+ repositories {
+ jcenter()
+ }
+ dependencies {
+ classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.6'
+ }
+}
+
+apply plugin: 'maven'
+apply plugin: 'maven-publish'
+apply plugin: 'com.jfrog.bintray'
+
+bintray {
+ user = System.getProperty('bintrayUser')
+ key = System.getProperty('bintrayApiKey')
+ pkg {
+ repo = 'maven'
+ name = project.name
+ desc = 'Concurrency Simulator Testing Tool for Java'
+ licenses = ['Apache-2.0']
+ vcsUrl = 'https://github.com/IlyaAI/concusim4j.git'
+ labels = ['concusim4j', 'concurrency', 'test']
+ }
+ publications = ['bintray']
+}
+
+task sourceJar(type: Jar) {
+ from sourceSets.main.allSource
+}
+
+publishing {
+ publications {
+ bintray (MavenPublication) {
+ from components.java
+
+ artifact sourceJar {
+ classifier "sources"
+ }
+
+ groupId project.group
+ artifactId project.name
+ version project.version
+ }
+ }
+}
diff --git a/concusim/src/main/java/com/github/concusim/Concurrency.java b/concusim/src/main/java/com/github/concusim/Concurrency.java
new file mode 100644
index 0000000..cedf2f5
--- /dev/null
+++ b/concusim/src/main/java/com/github/concusim/Concurrency.java
@@ -0,0 +1,50 @@
+package com.github.concusim;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import static com.github.concusim.testing.CheckpointUtils.getFullName;
+
+/**
+ * Concurrency testing helper. Provides facilities to model threads interleaving based on checkpoints.
+ *
+ * Use Concurrency.checkpoint("name") in production code in "interesting" places and then use ConcurrentRunner
+ * in test to model specific interleaving cases.
+ *
+ * By default method checkpoint does nothing and has minimal overhead (just one check which should be in-lined by JIT).
+ */
+public final class Concurrency {
+ private static final ThreadLocal interceptor = new ThreadLocal<>();
+ private static boolean enabled = false;
+
+ /**
+ * Denotes "interesting" place in concurrent code.
+ *
+ * @param clazz owning class
+ * @param name checkpoint name
+ */
+ public static void checkpoint(@NotNull Class> clazz, @NotNull String name) {
+ if (!enabled)
+ return;
+
+ if (interceptor.get() != null) {
+ interceptor.get().onCheckpoint(getFullName(clazz, name));
+ }
+ }
+
+ public static boolean isCheckpointsEnabled() {
+ return enabled;
+ }
+
+ public static void enableCheckpoints() {
+ enabled = true;
+ }
+
+ public static void disableCheckpoints() {
+ enabled = false;
+ }
+
+ public static void setInterceptor(@Nullable ICheckpointInterceptor interceptor) {
+ Concurrency.interceptor.set(interceptor);
+ }
+}
diff --git a/concusim/src/main/java/com/github/concusim/ICheckpointInterceptor.java b/concusim/src/main/java/com/github/concusim/ICheckpointInterceptor.java
new file mode 100644
index 0000000..b8a97a6
--- /dev/null
+++ b/concusim/src/main/java/com/github/concusim/ICheckpointInterceptor.java
@@ -0,0 +1,19 @@
+package com.github.concusim;
+
+import com.github.concusim.testing.ConcurrencySimulator;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Concurrency checkpoint interceptor.
+ *
+ * This interface is used by {@link ConcurrencySimulator} to simulate threads interleaving.
+ */
+public interface ICheckpointInterceptor {
+
+ /**
+ * Called when executing thread reaches {@code Concurrency.checkpoint(name)}.
+ *
+ * @param name checkpoint name
+ */
+ void onCheckpoint(@NotNull String name);
+}
diff --git a/concusim/src/main/java/com/github/concusim/testing/AggregatedException.java b/concusim/src/main/java/com/github/concusim/testing/AggregatedException.java
new file mode 100644
index 0000000..c6f2b3e
--- /dev/null
+++ b/concusim/src/main/java/com/github/concusim/testing/AggregatedException.java
@@ -0,0 +1,67 @@
+package com.github.concusim.testing;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public final class AggregatedException extends RuntimeException {
+ private static final class CauseEntry {
+ final NamedWorker worker;
+ final Throwable cause;
+
+ CauseEntry(NamedWorker worker, Throwable cause) {
+ this.worker = worker;
+ this.cause = cause;
+ }
+ }
+ static final class Builder {
+ private final List causes = new ArrayList<>();
+
+ @SuppressWarnings("ThrowableResultOfMethodCallIgnored")
+ Builder addCauseIfAny(@NotNull WorkerThread thread) {
+ Throwable cause = thread.getCause();
+ if (cause != null) {
+ causes.add(new CauseEntry(thread.getNamedWorker(), cause));
+ }
+ return this;
+ }
+
+ void throwIfAny() throws AggregatedException {
+ if (!causes.isEmpty()) {
+ CauseEntry[] entries = new CauseEntry[causes.size()];
+ throw new AggregatedException(causes.toArray(entries));
+ }
+ }
+ }
+
+ private final CauseEntry[] causes;
+
+ private AggregatedException(CauseEntry[] causes) {
+ this.causes = causes;
+ }
+
+ @Override
+ public String getMessage() {
+ StringBuilder sb = new StringBuilder(512);
+
+ sb.append("The following exceptions were thrown:\n");
+ for (CauseEntry entry: causes) {
+ sb.append(" ").append(entry.worker)
+ .append(":: ").append(entry.cause)
+ .append("\n");
+ }
+
+ return sb.toString();
+ }
+
+ public @Nullable Throwable getCauseFor(@NotNull Runnable worker) {
+ for (CauseEntry entry: causes) {
+ if (entry.worker.getRunnable() == worker)
+ return entry.cause;
+ }
+
+ return null;
+ }
+}
diff --git a/concusim/src/main/java/com/github/concusim/testing/CheckpointException.java b/concusim/src/main/java/com/github/concusim/testing/CheckpointException.java
new file mode 100644
index 0000000..7af1bf2
--- /dev/null
+++ b/concusim/src/main/java/com/github/concusim/testing/CheckpointException.java
@@ -0,0 +1,9 @@
+package com.github.concusim.testing;
+
+import org.jetbrains.annotations.NotNull;
+
+public final class CheckpointException extends RuntimeException {
+ public CheckpointException(@NotNull String msg) {
+ super(msg);
+ }
+}
diff --git a/concusim/src/main/java/com/github/concusim/testing/CheckpointUtils.java b/concusim/src/main/java/com/github/concusim/testing/CheckpointUtils.java
new file mode 100644
index 0000000..c8d63bf
--- /dev/null
+++ b/concusim/src/main/java/com/github/concusim/testing/CheckpointUtils.java
@@ -0,0 +1,9 @@
+package com.github.concusim.testing;
+
+import org.jetbrains.annotations.NotNull;
+
+public final class CheckpointUtils {
+ public static @NotNull String getFullName(@NotNull Class> clazz, @NotNull String name) {
+ return clazz.getName() + "#" + name;
+ }
+}
diff --git a/concusim/src/main/java/com/github/concusim/testing/ConcurrencySimulator.java b/concusim/src/main/java/com/github/concusim/testing/ConcurrencySimulator.java
new file mode 100644
index 0000000..3a720b4
--- /dev/null
+++ b/concusim/src/main/java/com/github/concusim/testing/ConcurrencySimulator.java
@@ -0,0 +1,211 @@
+package com.github.concusim.testing;
+
+import com.github.concusim.Concurrency;
+import org.jetbrains.annotations.NotNull;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+import static com.github.concusim.testing.CheckpointUtils.getFullName;
+
+/**
+ * Concurrency testing helper. Provides facilities to model threads interleaving based on checkpoints.
+ *
+ * @see com.github.concusim.Concurrency
+ */
+public final class ConcurrencySimulator {
+ private static final Logger log = LoggerFactory.getLogger(ConcurrencySimulator.class);
+
+ @SuppressWarnings("WeakerAccess")
+ public final class StepBuilder {
+ private final WorkerThread thread;
+ private boolean concurrent = false;
+
+ StepBuilder(@NotNull WorkerThread thread) {
+ this.thread = thread;
+ }
+
+ /**
+ * Specifies to run this step concurrently.
+ *
+ * @return step builder
+ */
+ public @NotNull StepBuilder parallel() {
+ this.concurrent = true;
+ return this;
+ }
+
+ /**
+ * Specifies checkpoint till run step to and finishes step creation.
+ *
+ * @param checkpoint checkpoint name
+ * @return original concurrent runner
+ */
+ public @NotNull ConcurrencySimulator till(@NotNull Class> clazz, @NotNull String checkpoint) {
+ if (checkpoint.isEmpty())
+ throw new IllegalArgumentException("checkpoint must not be empty");
+
+ if (!Concurrency.isCheckpointsEnabled())
+ throw new IllegalStateException("Checkpoints are disabled. Forget to call Concurrency.enableCheckpoints?");
+
+ steps.add(new Step(thread, getFullName(clazz, checkpoint), concurrent));
+ return ConcurrencySimulator.this;
+ }
+
+ /**
+ * Specifies run step till doer's end and finishes step creation.
+ *
+ * @return original concurrent runner
+ */
+ public @NotNull ConcurrencySimulator tillEnd() {
+ steps.add(new Step(thread, null, concurrent));
+ return ConcurrencySimulator.this;
+ }
+ }
+
+ private final List threads = new ArrayList<>();
+ private final List steps = new ArrayList<>();
+ private long stepTimeout;
+
+ /**
+ * Constructs new ConcurrencySimulator with default step timeout (5sec).
+ */
+ public ConcurrencySimulator() {
+ stepTimeout = 5000;
+ }
+
+ /**
+ * Sets new step timeout in seconds.
+ *
+ * @param seconds step timeout in seconds
+ * @return this
+ */
+ public @NotNull ConcurrencySimulator withStepTimeoutSec(int seconds) {
+ if (seconds < 0)
+ throw new IllegalArgumentException("seconds must be non-negative");
+
+ stepTimeout = seconds * 1000;
+ return this;
+ }
+
+ /**
+ * Sets new step timeout in milliseconds.
+ *
+ * @param milliseconds step timeout in milliseconds
+ * @return this
+ */
+ public @NotNull ConcurrencySimulator withStepTimeoutMillis(long milliseconds) {
+ if (milliseconds < 0)
+ throw new IllegalArgumentException("milliseconds must be non-negative");
+
+ stepTimeout = milliseconds;
+ return this;
+ }
+
+ /**
+ * Adds new concurrent worker with specified body (as runnable) and name.
+ * Each worker will run in separate thread.
+ *
+ * @param worker worker body
+ * @param name worker name
+ * @return this
+ */
+ public @NotNull ConcurrencySimulator withConcurrentWorker(@NotNull Runnable worker, @NotNull String name) {
+ NamedWorker namedWorker = new NamedWorker(worker, name);
+ threads.add(new WorkerThread(namedWorker, stepTimeout));
+ return this;
+ }
+
+ /**
+ * Adds new concurrent worker with specified body (as runnable).
+ * Each worker will run in separate thread.
+ *
+ * @param worker worker body
+ * @return this
+ */
+ public @NotNull ConcurrencySimulator withConcurrentWorker(@NotNull Runnable worker) {
+ return withConcurrentWorker(worker, worker.toString());
+ }
+
+ /**
+ * Constructs step for specified worker. By default steps are executed sequentially,
+ * use StepBuilder.parallel() to override this behavior.
+ *
+ * @param worker worker to be run
+ * @return step builder
+ */
+ public @NotNull StepBuilder run(@NotNull Runnable worker) {
+ return new StepBuilder(getThreadOf(worker));
+ }
+
+ /**
+ * Starts all worker's threads and pauses them just before entering to worker's body.
+ */
+ public void start() {
+ threads.forEach(Thread::start);
+ }
+
+ /**
+ * Executes step sequence defined via run() method. Throws an exception if at least one thread is thrown.
+ * If method returned normally it is possible to define next sub-sequence and call go() again.
+ * If method threw exception then it IS NOT possible to call go() again.
+ *
+ * @throws AggregatedException if at least one thread failed during it step
+ */
+ public void go() throws
+ InterruptedException, TimeoutException,
+ AggregatedException, CheckpointException
+ {
+ for (int index = 0; index < steps.size(); ) {
+ int count = 1;
+ for (int i = index + 1; i < steps.size() && steps.get(i).isConcurrent(); i++) {
+ count++;
+ }
+
+ CountDownLatch latch = new CountDownLatch(count);
+
+ for (; count > 0; index++, count--) {
+ steps.get(index).doIt(latch);
+ }
+
+ if (!latch.await(stepTimeout, TimeUnit.MILLISECONDS))
+ throw new TimeoutException();
+
+ AggregatedException.Builder builder = new AggregatedException.Builder();
+ threads.forEach(builder::addCauseIfAny);
+ builder.throwIfAny();
+ }
+
+ steps.forEach(Step::validate);
+ steps.clear();
+ }
+
+ /**
+ * Signals all worker's threads to interrupt and tries to join.
+ */
+ public void stop() {
+ threads.forEach(Thread::interrupt);
+
+ for (WorkerThread t: threads) {
+ try {
+ t.join(stepTimeout);
+ } catch (InterruptedException e) {
+ log.info("{} => JOIN TIMED-OUT", t);
+ }
+ }
+ }
+
+ private @NotNull WorkerThread getThreadOf(@NotNull Runnable worker) {
+ for (WorkerThread t: threads) {
+ if (t.getNamedWorker().getRunnable() == worker)
+ return t;
+ }
+
+ throw new IllegalStateException(String.format("No thread bound to '%s'.", worker));
+ }
+}
diff --git a/concusim/src/main/java/com/github/concusim/testing/NamedWorker.java b/concusim/src/main/java/com/github/concusim/testing/NamedWorker.java
new file mode 100644
index 0000000..ee7d055
--- /dev/null
+++ b/concusim/src/main/java/com/github/concusim/testing/NamedWorker.java
@@ -0,0 +1,44 @@
+package com.github.concusim.testing;
+
+import org.jetbrains.annotations.NotNull;
+
+final class NamedWorker implements Runnable {
+ private final Runnable target;
+ private final String name;
+
+ NamedWorker(@NotNull Runnable target, @NotNull String name) {
+ this.target = target;
+ this.name = name;
+ }
+
+ @Override
+ public void run() {
+ target.run();
+ }
+
+ @Override
+ public String toString() {
+ return name;
+ }
+
+ @Override
+ public boolean equals(Object other) {
+ return
+ this == other ||
+ other != null && other.getClass() == getClass() &&
+ target == ((NamedWorker) other).target;
+ }
+
+ @Override
+ public int hashCode() {
+ return target.hashCode();
+ }
+
+ @NotNull Runnable getRunnable() {
+ return target;
+ }
+
+ @NotNull String getName() {
+ return name;
+ }
+}
diff --git a/concusim/src/main/java/com/github/concusim/testing/Step.java b/concusim/src/main/java/com/github/concusim/testing/Step.java
new file mode 100644
index 0000000..ddccafd
--- /dev/null
+++ b/concusim/src/main/java/com/github/concusim/testing/Step.java
@@ -0,0 +1,53 @@
+package com.github.concusim.testing;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.concurrent.CountDownLatch;
+
+final class Step {
+ private final WorkerThread thread;
+ private final String checkpoint;
+ private final boolean concurrent;
+ private volatile boolean checkpointReached;
+ private volatile boolean workerFinished;
+
+ Step(@NotNull WorkerThread thread, @Nullable String checkpoint, boolean concurrent) {
+ this.thread = thread;
+ this.checkpoint = checkpoint;
+ this.concurrent = concurrent;
+ }
+
+ void doIt(@NotNull CountDownLatch latch) {
+ thread.doStep(this, latch);
+ }
+
+ boolean hasCheckpoint() {
+ return checkpoint != null;
+ }
+
+ @Nullable String getCheckpoint() {
+ return checkpoint;
+ }
+
+ boolean isConcurrent() {
+ return concurrent;
+ }
+
+ void checkpointReached() {
+ checkpointReached = true;
+ }
+
+ void workerFinished() {
+ workerFinished = true;
+ }
+
+ void validate() throws CheckpointException {
+ if (checkpoint != null && !checkpointReached)
+ throw new CheckpointException(
+ String.format("Worker '%s' didn't reach checkpoint '%s' as expected.", thread, checkpoint));
+
+ if (checkpoint == null && !workerFinished)
+ throw new CheckpointException(String.format("Worker '%s' didn't finished as expected.", thread));
+ }
+}
diff --git a/concusim/src/main/java/com/github/concusim/testing/Trigger.java b/concusim/src/main/java/com/github/concusim/testing/Trigger.java
new file mode 100644
index 0000000..6dfafb2
--- /dev/null
+++ b/concusim/src/main/java/com/github/concusim/testing/Trigger.java
@@ -0,0 +1,32 @@
+package com.github.concusim.testing;
+
+final class Trigger {
+ private volatile boolean fired;
+
+ void fire() {
+ if (fired)
+ return;
+
+ synchronized (this) {
+ fired = true;
+ notify();
+ }
+ }
+
+ boolean await(long timeout) throws InterruptedException {
+ boolean ret = true;
+
+ if (!fired) {
+ synchronized (this) {
+ if (!fired)
+ wait(timeout);
+
+ ret = fired;
+ }
+ }
+
+ fired = false;
+
+ return ret;
+ }
+}
diff --git a/concusim/src/main/java/com/github/concusim/testing/WorkerThread.java b/concusim/src/main/java/com/github/concusim/testing/WorkerThread.java
new file mode 100644
index 0000000..dcf339a
--- /dev/null
+++ b/concusim/src/main/java/com/github/concusim/testing/WorkerThread.java
@@ -0,0 +1,117 @@
+package com.github.concusim.testing;
+
+import com.github.concusim.Concurrency;
+import com.github.concusim.ICheckpointInterceptor;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeoutException;
+
+final class WorkerThread extends Thread implements ICheckpointInterceptor {
+ private static final Logger log = LoggerFactory.getLogger(WorkerThread.class);
+
+ private final Trigger trigger = new Trigger();
+ private final NamedWorker worker;
+ private final long timeout;
+ private volatile Step step;
+ private volatile CountDownLatch latch;
+ private volatile Throwable cause;
+
+ WorkerThread(@NotNull NamedWorker worker, long timeout) {
+ this.worker = worker;
+ this.timeout = timeout;
+ }
+
+ @Override
+ public void run() {
+ Concurrency.setInterceptor(this);
+ log.info("{} => started", worker);
+
+ try {
+ await();
+
+ worker.run();
+
+ log.info("{} => finished", worker);
+ } catch (InterruptedException e) {
+ log.info("{} => interrupted", worker);
+ } catch (Throwable t) {
+ cause = t;
+ log.error("{} => threw '{}'", worker, t.getMessage(), t);
+ } finally {
+ if (step != null) {
+ step.workerFinished();
+ }
+ Concurrency.setInterceptor(null);
+ if (latch != null)
+ latch.countDown();
+ }
+ }
+
+ @Override
+ public void onCheckpoint(@NotNull String name) {
+ log.info("{} => @{}", worker, name);
+
+ if (isInterrupted())
+ throw new RuntimeException("Thread has been interrupted.");
+
+ if (!step.hasCheckpoint() || !name.equals(step.getCheckpoint()))
+ return;
+
+ step.checkpointReached();
+ step = null;
+
+ latch.countDown();
+ try {
+ await();
+ } catch (InterruptedException | TimeoutException e) {
+ throw new RuntimeException(e);
+ }
+ }
+
+ @Override
+ public String toString() {
+ return worker.getName();
+ }
+
+ @NotNull NamedWorker getNamedWorker() {
+ return worker;
+ }
+
+ void doStep(@NotNull Step step, @NotNull CountDownLatch latch) {
+ if (this.step != null)
+ throw new IllegalStateException(String.format("Thread of '%s' already in use.", worker));
+
+ this.step = step;
+ this.latch = latch;
+
+ fire();
+ }
+
+ @Nullable Throwable getCause() {
+ return cause;
+ }
+
+ private void await() throws InterruptedException, TimeoutException {
+ log.info("{} => waiting", worker);
+
+ boolean fired;
+ long start = System.currentTimeMillis();
+
+ //noinspection StatementWithEmptyBody
+ while (!(fired = trigger.await(timeout)) && (System.currentTimeMillis() - start < timeout));
+
+ if (!fired)
+ throw new TimeoutException();
+
+ log.info("{} => resumed", worker);
+ }
+
+ private void fire() {
+ log.info("{} => fired", worker);
+ trigger.fire();
+ }
+}
diff --git a/concusim/src/test/java/com/github/concusim/testing/ConcurrencySimulatorTest.java b/concusim/src/test/java/com/github/concusim/testing/ConcurrencySimulatorTest.java
new file mode 100644
index 0000000..92e99e5
--- /dev/null
+++ b/concusim/src/test/java/com/github/concusim/testing/ConcurrencySimulatorTest.java
@@ -0,0 +1,151 @@
+package com.github.concusim.testing;
+
+import com.github.concusim.Concurrency;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.instanceOf;
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.fail;
+
+public class ConcurrencySimulatorTest {
+
+ private static class StepByStepWorker implements Runnable {
+ private final String name;
+ private volatile String currentStep = "init";
+
+ StepByStepWorker(String name) {
+ this.name = name;
+ }
+
+ @Override
+ public void run() {
+ currentStep = "foo";
+ Concurrency.checkpoint(getClass(), "foo");
+
+ currentStep = "bar";
+ Concurrency.checkpoint(getClass(), "bar");
+
+ currentStep = "end";
+ }
+
+ @Override
+ public String toString() {
+ return name;
+ }
+
+ String getCurrentStep() {
+ return currentStep;
+ }
+ }
+
+ @Before
+ public void setUp() throws Exception {
+ Concurrency.enableCheckpoints();
+ }
+
+ @After
+ public void tearDown() throws Exception {
+ Concurrency.disableCheckpoints();
+ }
+
+ @Test
+ public void concurrencySimulator_should_control_thread_execution() throws Exception {
+ StepByStepWorker workerA = new StepByStepWorker("A");
+ StepByStepWorker workerB = new StepByStepWorker("B");
+
+ ConcurrencySimulator simulator = new ConcurrencySimulator()
+ .withConcurrentWorker(workerA)
+ .withConcurrentWorker(workerB);
+
+ simulator.start();
+ try {
+ assertThat(workerA.getCurrentStep(), is("init"));
+ assertThat(workerB.getCurrentStep(), is("init"));
+
+ simulator
+ .run(workerA).till(StepByStepWorker.class, "foo")
+ .go();
+
+ assertThat(workerA.getCurrentStep(), is("foo"));
+ assertThat(workerB.getCurrentStep(), is("init"));
+
+ simulator
+ .run(workerB).till(StepByStepWorker.class, "foo")
+ .go();
+
+ assertThat(workerA.getCurrentStep(), is("foo"));
+ assertThat(workerB.getCurrentStep(), is("foo"));
+
+ simulator
+ .run(workerA).till(StepByStepWorker.class, "bar")
+ .run(workerB).tillEnd()
+ .go();
+
+ assertThat(workerA.getCurrentStep(), is("bar"));
+ assertThat(workerB.getCurrentStep(), is("end"));
+
+ simulator
+ .run(workerA).tillEnd()
+ .go();
+
+ assertThat(workerA.getCurrentStep(), is("end"));
+ assertThat(workerB.getCurrentStep(), is("end"));
+ } finally {
+ simulator.stop();
+ }
+ }
+
+ @Test
+ public void concurrencySimulator_go_should_throw_if_worker_threw() throws Exception {
+ Runnable worker = () -> {
+ throw new RuntimeException("Error");
+ };
+
+ ConcurrencySimulator simulator = new ConcurrencySimulator()
+ .withConcurrentWorker(worker, "worker");
+
+ simulator.start();
+ try {
+ simulator
+ .run(worker).tillEnd()
+ .go();
+
+ fail("AggregatedException is expected.");
+ } catch (AggregatedException e) {
+ assertThat(e.getCauseFor(worker), instanceOf(RuntimeException.class));
+ } finally {
+ simulator.stop();
+ }
+ }
+
+ @Test
+ public void concurrencySimulator_go_should_throw_if_non_visited_checkpoint_exists() throws Exception {
+ Runnable worker = new Runnable() {
+ @Override
+ public void run() {
+ Concurrency.checkpoint(getClass(), "foo");
+ }
+ };
+
+ ConcurrencySimulator simulator = new ConcurrencySimulator()
+ .withConcurrentWorker(worker, "fooWorker");
+
+ simulator.start();
+ try {
+ simulator
+ .run(worker).till(worker.getClass(), "bar")
+ .go();
+
+ fail("CheckpointException is expected.");
+ } catch (CheckpointException e) {
+ assertThat(e.getMessage(), containsString("bar"));
+ assertThat(e.getMessage(), containsString("fooWorker"));
+ } finally {
+ simulator.stop();
+ }
+ }
+}
diff --git a/concusim/src/test/resources/log4j.properties b/concusim/src/test/resources/log4j.properties
new file mode 100644
index 0000000..98874df
--- /dev/null
+++ b/concusim/src/test/resources/log4j.properties
@@ -0,0 +1,7 @@
+log4j.rootCategory=off, console
+
+log4j.appender.console=org.apache.log4j.ConsoleAppender
+log4j.appender.console.layout=org.apache.log4j.PatternLayout
+log4j.appender.console.layout.ConversionPattern= %p %c: %m%n
+
+log4j.logger.com.github.concusim=debug
diff --git a/gradle.properties b/gradle.properties
new file mode 100644
index 0000000..848966e
--- /dev/null
+++ b/gradle.properties
@@ -0,0 +1 @@
+file.encoding=UTF-8
\ No newline at end of file
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..e8c6bf7
Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..b476807
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Thu Sep 17 10:21:05 GMT+06:00 2015
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.14.1-all.zip
diff --git a/gradlew b/gradlew
new file mode 100644
index 0000000..97fac78
--- /dev/null
+++ b/gradlew
@@ -0,0 +1,160 @@
+#!/usr/bin/env bash
+
+##############################################################################
+##
+## Gradle start up script for UN*X
+##
+##############################################################################
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn ( ) {
+ echo "$*"
+}
+
+die ( ) {
+ echo
+ echo "$*"
+ echo
+ exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+case "`uname`" in
+ CYGWIN* )
+ cygwin=true
+ ;;
+ Darwin* )
+ darwin=true
+ ;;
+ MINGW* )
+ msys=true
+ ;;
+esac
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+ ls=`ls -ld "$PRG"`
+ link=`expr "$ls" : '.*-> \(.*\)$'`
+ if expr "$link" : '/.*' > /dev/null; then
+ PRG="$link"
+ else
+ PRG=`dirname "$PRG"`"/$link"
+ fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >&-
+APP_HOME="`pwd -P`"
+cd "$SAVED" >&-
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+ if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+ # IBM's JDK on AIX uses strange locations for the executables
+ JAVACMD="$JAVA_HOME/jre/sh/java"
+ else
+ JAVACMD="$JAVA_HOME/bin/java"
+ fi
+ if [ ! -x "$JAVACMD" ] ; then
+ die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+ fi
+else
+ JAVACMD="java"
+ which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" ] ; then
+ MAX_FD_LIMIT=`ulimit -H -n`
+ if [ $? -eq 0 ] ; then
+ if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+ MAX_FD="$MAX_FD_LIMIT"
+ fi
+ ulimit -n $MAX_FD
+ if [ $? -ne 0 ] ; then
+ warn "Could not set maximum file descriptor limit: $MAX_FD"
+ fi
+ else
+ warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+ fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+ GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+ APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+ CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+ JAVACMD=`cygpath --unix "$JAVACMD"`
+
+ # We build the pattern for arguments to be converted via cygpath
+ ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+ SEP=""
+ for dir in $ROOTDIRSRAW ; do
+ ROOTDIRS="$ROOTDIRS$SEP$dir"
+ SEP="|"
+ done
+ OURCYGPATTERN="(^($ROOTDIRS))"
+ # Add a user-defined pattern to the cygpath arguments
+ if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+ OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+ fi
+ # Now convert the arguments - kludge to limit ourselves to /bin/sh
+ i=0
+ for arg in "$@" ; do
+ CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+ CHECK2=`echo "$arg"|egrep -c "^-"` ### Determine if an option
+
+ if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then ### Added a condition
+ eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+ else
+ eval `echo args$i`="\"$arg\""
+ fi
+ i=$((i+1))
+ done
+ case $i in
+ (0) set -- ;;
+ (1) set -- "$args0" ;;
+ (2) set -- "$args0" "$args1" ;;
+ (3) set -- "$args0" "$args1" "$args2" ;;
+ (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+ (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+ (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+ (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+ (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+ (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+ esac
+fi
+
+# Split up the JVM_OPTS And GRADLE_OPTS values into an array, following the shell quoting and substitution rules
+function splitJvmOpts() {
+ JVM_OPTS=("$@")
+}
+eval splitJvmOpts $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS
+JVM_OPTS[${#JVM_OPTS[*]}]="-Dorg.gradle.appname=$APP_BASE_NAME"
+
+exec "$JAVACMD" "${JVM_OPTS[@]}" -classpath "$CLASSPATH" org.gradle.wrapper.GradleWrapperMain "$@"
diff --git a/gradlew.bat b/gradlew.bat
new file mode 100644
index 0000000..8a0b282
--- /dev/null
+++ b/gradlew.bat
@@ -0,0 +1,90 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windowz variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+if "%@eval[2+2]" == "4" goto 4NT_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+goto execute
+
+:4NT_args
+@rem Get arguments from the 4NT Shell from JP Software
+set CMD_LINE_ARGS=%$
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/settings.gradle b/settings.gradle
new file mode 100644
index 0000000..d3dc43f
--- /dev/null
+++ b/settings.gradle
@@ -0,0 +1,4 @@
+rootProject.name = 'concusim4j'
+
+include 'concusim'
+include 'concusim-sample'