Class AbstractTask

server/src/main/java/io/crate/execution/jobs/AbstractTask.java:28–105

import java.util.function.BiConsumer;

public abstract class AbstractTask implements Task {

    protected final int id;

    private final AtomicBoolean firstClose = new AtomicBoolean(false);
    private final CompletableFuture<Void> future = new CompletableFuture<>();

    protected AbstractTask(int id) {
        this.id = id;
    }

    public int id() {
        return id;
    }

    protected static BiConsumer<? super Object, Throwable> closeOrKill(AbstractTask t) {
        return (result, err) -> {
            if (err == null) {
                t.close();
            } else {
                t.kill(err);
            }
        };
    }

    protected CompletableFuture<Void> innerStart() {
        return null;
    }

    @Override
    public final CompletableFuture<Void> start() {
        if (!firstClose.get()) {
            try {
                return innerStart();
            } catch (Throwable t) {
                kill(t);
            }
        }
        return null;
    }

    protected void innerClose() {
    }

    protected void close() {
        if (firstClose.compareAndSet(false, true)) {
            try {
                innerClose();
                future.complete(null);
            } catch (Throwable t) {
                future.completeExceptionally(t);
            }
        }
    }

    protected void innerKill(Throwable t) {
    }