DimensionalRipper/tests/ManagedFutureAwaitRegression.java

import dev.modzuozhi.core.compat.ManagedFutureAwait;
import java.util.concurrent.*;

/** Standalone regression: dimension work needs a callback on the waiting server thread. */
public final class ManagedFutureAwaitRegression {
    public static void main(String[] args) throws Exception {
        Thread serverThread = Thread.currentThread();
        BlockingQueue<Runnable> serverTasks = new LinkedBlockingQueue<>();
        CompletableFuture<Integer> chunk = new CompletableFuture<>();
        Thread worker = new Thread(() -> {
            try {
                CompletableFuture<Void> physics = new CompletableFuture<>();
                serverTasks.add(() -> {
                    if (Thread.currentThread() != serverThread) {
                        physics.completeExceptionally(new AssertionError("wrong callback thread"));
                    } else {
                        physics.complete(null);
                    }
                });
                physics.get(3, TimeUnit.SECONDS);
                chunk.complete(42);
            } catch (Throwable failure) {
                chunk.completeExceptionally(failure);
            }
        }, "test-dimension-worker");
        worker.start();
        int value = ManagedFutureAwait.join(chunk, done -> {
            long deadline = System.nanoTime() + TimeUnit.SECONDS.toNanos(5);
            while (!done.getAsBoolean()) {
                if (System.nanoTime() > deadline) throw new AssertionError("circular wait");
                try {
                    Runnable task = serverTasks.poll(10, TimeUnit.MILLISECONDS);
                    if (task != null) task.run();
                } catch (InterruptedException failure) {
                    throw new AssertionError(failure);
                }
            }
        });
        worker.join(1000);
        if (value != 42 || worker.isAlive()) throw new AssertionError("request did not finish");
        if (ManagedFutureAwait.join(CompletableFuture.completedFuture(7), done -> {
            throw new AssertionError("completed future pumped callbacks");
        }) != 7) throw new AssertionError("wrong result");
        RuntimeException failure = new RuntimeException("expected");
        try {
            ManagedFutureAwait.join(CompletableFuture.failedFuture(failure), done -> {});
            throw new AssertionError("exception swallowed");
        } catch (CompletionException expected) {
            if (expected.getCause() != failure) throw new AssertionError("exception changed");
        }
        CompletableFuture<Object> cancelled = new CompletableFuture<>();
        cancelled.cancel(false);
        try {
            ManagedFutureAwait.join(cancelled, done -> {});
            throw new AssertionError("cancellation swallowed");
        } catch (CancellationException expected) {}
        // An apparently server-owned cache can switch owner after the entry check.
        // The request must remain queued regardless; an inline-capable execute() is unsafe.
        BlockingQueue<Runnable> chunkTasks = new LinkedBlockingQueue<>();
        java.util.concurrent.atomic.AtomicReference<Thread> owner =
                new java.util.concurrent.atomic.AtomicReference<>(serverThread);
        java.util.concurrent.atomic.AtomicBoolean executed = new java.util.concurrent.atomic.AtomicBoolean();
        int queued = ManagedFutureAwait.callQueued(() -> {
            if (owner.get() != Thread.currentThread()) throw new AssertionError("wrong chunk owner");
            executed.set(true);
            return 19;
        }, task -> {
            chunkTasks.add(task);
            if (executed.get()) throw new AssertionError("request executed inline");
        }, done -> {
            Thread dimension = new Thread(() -> {
                owner.set(Thread.currentThread());
                chunkTasks.remove().run();
            });
            dimension.start();
            try { dimension.join(2000); } catch (InterruptedException e) { throw new AssertionError(e); }
            if (!done.getAsBoolean()) throw new AssertionError("queued request stuck");
        });
        if (queued != 19 || !executed.get()) throw new AssertionError("lost queued result");
        System.out.println("PASS: callback handoff, completion, failure and cancellation");
        System.out.println("PASS: unconditional enqueue survives owner switch after entry");
    }
}