package com.datastax.driver.core;
import java.util.List;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import com.google.common.collect.Lists;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.ListeningExecutorService;
import com.google.common.util.concurrent.MoreExecutors;
import org.testng.annotations.Test;
import static org.testng.Assert.assertEquals;
import static org.testng.Assert.assertTrue;
import static org.testng.Assert.fail;
public class ThreadLocalMonotonicTimestampGeneratorTest {
@Test(groups = "unit")
public void should_generate_incrementing_timestamps_for_each_thread() throws InterruptedException {
// Create a generator with a fixed millisecond value
final long fixedTime = 1;
final ThreadLocalMonotonicTimestampGenerator generator = new ThreadLocalMonotonicTimestampGenerator();
generator.clock = new MockClocks.FixedTimeClock(fixedTime);
// Generate 1000 timestamps on each thread
int testThreadsCount = 2;
ListeningExecutorService executor = MoreExecutors.listeningDecorator(Executors.newFixedThreadPool(testThreadsCount));
List<ListenableFuture<?>> futures = Lists.newArrayListWithExpectedSize(testThreadsCount);
for (int i = 0; i < testThreadsCount; i++) {
futures.add(executor.submit(
new Runnable() {
@Override
public void run() {
// Ensure that each thread gets the 1000 microseconds for the mocked millisecond value,
// in order
for (int i = 0; i < 1000; i++)
assertEquals(generator.next(), fixedTime * 1000 + i);
}
}));
}
executor.shutdown();
executor.awaitTermination(1, TimeUnit.SECONDS);
try {
Futures.allAsList(futures).get();
} catch (ExecutionException e) {
Throwable cause = e.getCause();
if (cause instanceof AssertionError)
throw (AssertionError)cause;
else
fail("Error in a test thread", cause);
}
}
@Test(groups = "unit")
public void should_generate_incrementing_timestamps_on_clock_resync() {
ThreadLocalMonotonicTimestampGenerator generator = new ThreadLocalMonotonicTimestampGenerator();
generator.clock = new MockClocks.BackInTimeClock();
long beforeClockResync = generator.next();
long afterClockResync = generator.next();
assertTrue(beforeClockResync < afterClockResync, "The generated timestamps are not increasing on block resync");
}
}