http://nurkiewicz.blogspot.com/2011/01/activiti-processes-and-executions.html

ActivitiTestCase-context.xml

<bean id="dataSource" class="org.springframework.jdbc.datasource.TransactionAwareDataSourceProxy">
    <property name="targetDataSource">
        <bean class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
            <property name="driverClassName" value="org.h2.Driver" />
            <property name="url" value="jdbc:h2:~/workspace/h2/activiti;DB_CLOSE_ON_EXIT=FALSE;TRACE_LEVEL_FILE=4" />
            <property name="username" value="sa" />
            <property name="password" value="" />
        </bean>
    </property>
</bean>

<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource" />
</bean>

<!-- Workaround to http://jira.codehaus.org/browse/ACT-473 -->
<bean id="initProcessEngines" class="org.springframework.beans.factory.config.MethodInvokingFactoryBean">
    <property name="staticMethod" value="org.activiti.engine.ProcessEngines.init"/>
</bean>
<bean id="processEngine" class="org.activiti.spring.ProcessEngineFactoryBean" depends-on="initProcessEngines">
    <property name="processEngineConfiguration">
        <bean class="org.activiti.spring.SpringProcessEngineConfiguration">
            <property name="databaseType" value="h2" />
            <property name="dataSource" ref="dataSource" />
            <property name="transactionManager" ref="transactionManager" />
            <property name="databaseSchemaUpdate" value="none" />
            <property name="jobExecutorActivate" value="false" />
            <property name="deploymentResources" value="classpath*:/com/blogspot/nurkiewicz/tryipad2/bpmn20/*.bpmn20.xml" />
        </bean>
    </property>
</bean>

ActivitiTestCase2-context.xml

<bean id="repositoryService" factory-bean="processEngine" factory-method="getRepositoryService" />
<bean id="runtimeService" factory-bean="processEngine" factory-method="getRuntimeService" />
<bean id="taskService" factory-bean="processEngine" factory-method="getTaskService" />
<bean id="historyService" factory-bean="processEngine" factory-method="getHistoryService" />
<bean id="managementService" factory-bean="processEngine" factory-method="getManagementService" />

ForkJoin.bpmn20.xml

<process name="ForkJoin" id="ForkJoin" isExecutable="false">
    <startEvent id="Start" name="Start"/>
    <userTask id="Task_0" name="Task 0"/>
    <parallelGateway gatewayDirection="Diverging" id="Fork_AB" name="Fork AB"/>
    <userTask id="Task_A" name="Task A"/>
    <userTask id="Task_B" name="Task B"/>
    <parallelGateway gatewayDirection="Diverging" id="Fork_B" name="Fork B"/>
    <userTask id="Task_B1" name="Task B1"/>
    <parallelGateway gatewayDirection="Converging" id="Join_B" name="Join B"/>
    <userTask id="Task_B2" name="Task B2"/>
    <parallelGateway gatewayDirection="Converging" id="Join_AB" name="Join AB"/>
    <userTask id="Task_C" name="Task C"/>
    <endEvent id="End" name="End"/>

    <sequenceFlow id="Flow_2" name="" sourceRef="Fork_AB" targetRef="Task_A" />
    <sequenceFlow id="Flow_5" name="" sourceRef="Fork_AB" targetRef="Task_B" />
    <sequenceFlow id="Flow_7" name="" sourceRef="Task_B" targetRef="Fork_B" />
    <sequenceFlow id="Flow_0" name="" sourceRef="Fork_B" targetRef="Task_B1" />
    <sequenceFlow id="Flow_1" name="" sourceRef="Fork_B" targetRef="Task_B2" />
    <sequenceFlow id="Flow_11" name="" sourceRef="Task_B1" targetRef="Join_AB" />
    <sequenceFlow id="Flow_10" name="" sourceRef="Task_B2" targetRef="Join_AB" />
    <sequenceFlow id="Flow_4" name="" sourceRef="Task_A" targetRef="Join_AB" />
    <sequenceFlow id="Flow_8" name="" sourceRef="Join_AB" targetRef="Task_C" />
    <sequenceFlow id="Flow_12" name="" sourceRef="Task_C" targetRef="End" />
    <sequenceFlow id="Flow_9" name="" sourceRef="Start" targetRef="Task_0" />
    <sequenceFlow id="Flow_6" name="" sourceRef="Task_0" targetRef="Fork_AB" />
</process>

ForkJoinTest.java

import static org.fest.assertions.Assertions.assertThat;
import org.activiti.engine.RuntimeService;
import org.activiti.engine.runtime.ProcessInstance;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:/com/blogspot/nurkiewicz/tryipad2/activiti/ActivitiTestCase-context.xml")
public class ForkJoinTest {

    @Resource
    private RuntimeService runtimeService;

    @Test
    public void shouldRunConcurrently() throws Exception {
        final ProcessInstance process = runtimeService.startProcessInstanceByKey("ForkJoin");
        final String pid = process.getId();
        //...
    }
}

ForkJoinTest2.java

log.debug("Waiting in Task 0");
assertThat(runtimeService.getActiveActivityIds(pid)).containsOnly("Task_0");

ForkJoinTest3.java

//only one execution
assertThat(
        runtimeService
                .createExecutionQuery()
                .processInstanceId(pid)
                .list()
).hasSize(1);

ForkJoinTest4.java

log.debug("Signaling advances to Task A and B concurrently");
runtimeService.signal(pid);
assertThat(runtimeService.getActiveActivityIds(pid)).containsOnly("Task_A", "Task_B");

//three execution
assertThat(
        runtimeService
                .createExecutionQuery()
                .processInstanceId(pid)
                .list()
).hasSize(3);

ForkJoinTest5.java

final Execution forkA = runtimeService
        .createExecutionQuery()
        .activityId("Task_A")
        .processInstanceId(pid)
        .singleResult();
log.debug("Found forked execution {} in Task A activity for process {}", forkA, pid);

runtimeService.signal(forkA.getId());
log.debug("Advanced fork A, waiting in Join AB");
assertThat(runtimeService.getActiveActivityIds(pid)).containsOnly("Task_B");

//no active activities in fork A since waiting in join
assertThat(runtimeService.getActiveActivityIds(forkA.getId())).isEmpty();

gistfile10.sh

svn co http://svn.codehaus.org/activiti/activiti/tags/activiti-5.1
cd activiti-5.1
mvn install source:jar -DskipTests -Pdistro

gistfile9.txt

Leaving activity 'Task_A'
ConcurrentExecution[12256734] takes transition (Task_A)--Flow_4-->(Join_AB)
ConcurrentExecution[12256734] executes Activity(Join_AB): org.activiti.engine.impl.bpmn.ParallelGatewayActivity
parallel gateway 'Join_AB' does not activate: 1 of 3 joined