Performing tasks in parallel with different priorities
The BackgroundExecutor component is able to run different functional interfaces in parallel by setting the priority of the thread they will be assigned to. There is also the option to wait for them start or finish.
For obtaining threads this component uses the ThreadSupplier that is also used by the IterableObjectHelper to iterate collections or arrays in parallel. The ThreadSupplier can be customized in the burningwave.static.properties file and it provides a fixed number of reusable threads indicated by the thread-supplier.max-poolable-thread-count property and, if these threads have already been assigned, new non-reusable threads will be created whose quantity maximum is indicated by the thread-supplier.max-detached-thread-count property. Once this limit is reached if the request for a new thread exceeds the waiting time indicated by the thread-supplier.poolable-thread-request-timeout property, the ThreadSupplier will proceed to increase the limit indicated by the 'thread-supplier.max-detached-thread-count' property for the quantity indicated by the thread-supplier.max-detached-thread-count.increasing-step property. Resetting the 'thread-supplier.max-detached-thread-count' property to its initial value, will occur gradually only when there have been no more waits on thread requests for an amount of time indicated by the thread-supplier.max-detached-thread-count.elapsed-time-threshold-from-last-increase-for-gradual-decreasing-to-initial-value property.
import static org.burningwave.core.assembler.StaticComponentContainer.BackgroundExecutor;
import org.burningwave.core.ManagedLogger;
import org.burningwave.core.concurrent.QueuedTasksExecutor.ProducerTask;
import org.burningwave.core.concurrent.QueuedTasksExecutor.Task;
public class TaskLauncher implements ManagedLogger {
public void launch() {
ProducerTask<Long> taskOne = BackgroundExecutor.createProducerTask(task -> {
Long startTime = System.currentTimeMillis();
logInfo("task one started");
synchronized (this) {
wait(5000);
}
Task internalTask = BackgroundExecutor.createTask(tsk -> {
logInfo("internal task started");
synchronized (this) {
wait(5000);
}
logInfo("internal task finished");
}, Thread.MAX_PRIORITY).submit();
internalTask.waitForFinish();
logInfo("task one finished");
return startTime;
}, Thread.MAX_PRIORITY);
taskOne.submit();
Task taskTwo = BackgroundExecutor.createTask(task -> {
logInfo("task two started and wait for task one finishing");
taskOne.waitForFinish();
logInfo("task two finished");
}, Thread.NORM_PRIORITY);
taskTwo.submit();
ProducerTask<Long> taskThree = BackgroundExecutor.createProducerTask(task -> {
logInfo("task three started and wait for task two finishing");
taskTwo.waitForFinish();
logInfo("task two finished");
return System.currentTimeMillis();
}, Thread.MIN_PRIORITY);
taskThree.submit();
taskThree.waitForFinish();
logInfo("Elapsed time: {}ms", taskThree.join() - taskOne.join());
}
public static void main(String[] args) {
new TaskLauncher().launch();
}
}ClassFactory
ClassHunter
- In depth look to and configuration guide
- USE CASE: retrieving all classes of the classpath
- USE CASE: retrieving all classes that implement one or more interfaces
- USE CASE: finding all classes that extend a base class
- USE CASE: searching for all classes that have package name that matches a regex
- USE CASE: finding all classes for module name (Java 9 and later)
- USE CASE: finding all annotated classes
- USE CASE: how to scan classes for specific annotations and collect its values
- USE CASE: searching for all classes with a constructor that takes a specific type as first parameter and with at least 2 methods that begin for a given string
- USE CASE: searching for all classes with methods whose name begins for a given string and that takes a specific type as its first parameter
- USE CASE: finding all classes that have at least 2 protected fields