Tests.java

package com.tigerbeetle;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.UUID;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;

import org.junit.Test;
import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotEquals;
import static org.junit.Assert.assertTrue;

/**
 * Integration tests using a TigerBeetle instance.
 */
public class Tests {   
  
    /**
     * This test asserts that async tasks will respect client's maxConcurrency.
     */
    @Test
    public void testAsyncTasks() throws Throwable {

        try (var server = new Server()) {

            // Defining the maxConcurrency greater than tasks_qty
            // The goal here is to allow to all requests being submitted at once simultaneously
            final int tasks_qty = 64;
            final int max_concurrency = tasks_qty;

            try (var client = new Client(0, new String[] {Server.TB_PORT}, max_concurrency)) {

                var errors = client.createAccounts(accounts);
                assertTrue(errors.getLength() == 0);

                final var tasks = new CompletableFuture[tasks_qty];
                for (int i = 0; i < tasks_qty; i++) {

                    final var transfers = new TransferBatch(1);
                    transfers.add();

                    transfers.setId(UInt128.asBytes(UUID.randomUUID()));
                    transfers.setCreditAccountId(account1Id);
                    transfers.setDebitAccountId(account2Id);
                    transfers.setLedger(720);
                    transfers.setCode((short) 1);
                    transfers.setAmount(100);

                    // Starting async batch
                    tasks[i] = client.createTransfersAsync(transfers);
                }

                // Wait for all tasks, it hangs here.
                for (int i = 0; i < tasks_qty; i++) {
                    @SuppressWarnings("unchecked")
                    final var future = (CompletableFuture<CreateTransferResultBatch>) tasks[i];
                    final var result = future.get();
                    assertEquals(0, result.getLength());
                }

            } catch (Throwable any) {
                throw any;
            }

        } catch (Throwable any) {
            throw any;
        }
    }
}