I have a queue of running threads and would like to expose some of its data while it is executed, to monitor the process.
ThreadPoolExecutor
provides access to its queue and I can iterate through these objects to call my overridden toString()
method, but these are only threads that are waiting for execution.
Is there a way to access threads that are currently running to call my method? Or maybe there's a better approach for this task in general?
To clarify a bit more about the purpose, here's some code of general idea:
public class GetDataTask implements Runnable {
private String pageNumber;
private int dataBlocksParsed;
private String source;
private String dataType;
public GetDataTask(String source, String dataType) {
this.source = source;
this.dataType = dataType;
}
@Override
public void run() {
//do stuff that affects pageNumber and dataBlocksParsed
}
@Override
public String toString() {
return "GetDataTask{" +
"source=" + source +
", dataType=" + dataType +
", pageNumber=" + pageNumber +
", dataBlocksParsed=" + dataBlocksParsed +
'}';
}
}
and a class holding the executor:
public class DataParseManager {
private static ThreadPoolExecutor executor = new ThreadPoolExecutor(100, 100, 20, TimeUnit.SECONDS, new ArrayBlockingQueue<>(300));
public void addParseDataTask(String source, String dataType) {
executor.execute(new GetDataTask(source, dataType));
}
// here's the method that I need
public String getInfo() {
StringBuilder info = new StringBuilder();
//and here's the method that I'm missing - executor.getActiveThreads()
for (Runnable r : executor.getActiveThreads()) {
info.append(((GetDataTask) r).toString()).append('\n');
}
return info.append(executor.toString()).toString();
}
}
How about wrap Runnable like this.
static class MonitorRunnable implements Runnable {
static final List<Runnable> activeTasks = Collections.synchronizedList(new ArrayList<>());
private final Runnable runnable;
public MonitorRunnable(Runnable runnable) {
this.runnable = runnable;
}
@Override
public void run() {
activeTasks.add(runnable);
runnable.run();
activeTasks.remove(runnable);
}
}
and
public class DataParseManager {
private static ThreadPoolExecutor executor = new ThreadPoolExecutor(100, 100, 20, TimeUnit.SECONDS, new ArrayBlockingQueue<>(300));
public void addParseDataTask(String source, String dataType) {
executor.execute(new MonitorRunnable(new GetDataTask(source, dataType)));
}
// here's the method that I need
public String getInfo() {
StringBuilder info = new StringBuilder();
//and here's the method that I'm missing - executor.getActiveThreads()
synchronized (MonitorRunnable.activeTasks) {
for (Runnable r : MonitorRunnable.activeTasks) {
info.append(((GetDataTask) r).toString()).append('\n');
}
}
return info.append(executor.toString()).toString();
}
}