/*
* Copyright (c) 2018-Present Pivotal Software Inc, All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package reactor.pool;
import java.time.Duration;
import java.util.Arrays;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.Consumer;
import org.assertj.core.data.Offset;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Tag;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.CsvSource;
import org.reactivestreams.Subscription;
import reactor.core.Disposable;
import reactor.core.Disposables;
import reactor.core.publisher.BaseSubscriber;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import reactor.core.scheduler.Scheduler;
import reactor.core.scheduler.Schedulers;
import reactor.pool.TestUtils.PoolableTest;
import reactor.test.util.RaceTestUtils;
import reactor.util.function.Tuple2;
import static org.assertj.core.api.Assertions.assertThat;
import static org.awaitility.Awaitility.await;
import static reactor.pool.PoolBuilder.from;
/**
* @author Simon Baslé
*/
class SimpleFifoPoolTest {
private Disposable.Composite disposeList;
@BeforeEach
void initComposite() {
disposeList = Disposables.composite();
}
@AfterEach
void cleanup() {
disposeList.dispose();
}
<T extends Disposable> T autoDispose(T toDispose) {
disposeList.add(toDispose);
return toDispose;
}
//==utils for package-private config==
static final PoolConfig<PoolableTest> poolableTestConfig(int minSize, int maxSize, Mono<PoolableTest> allocator) {
return from(allocator)
.sizeBetween(minSize, maxSize)
.releaseHandler(pt -> Mono.fromRunnable(pt::clean))
.evictionPredicate((value, metadata) -> !value.isHealthy())
.buildConfig();
}
static final PoolConfig<PoolableTest> poolableTestConfig(int minSize, int maxSize, Mono<PoolableTest> allocator, Scheduler deliveryScheduler) {
return from(allocator)
.sizeBetween(minSize, maxSize)
.sizeBetween(0, maxSize)
.releaseHandler(pt -> Mono.fromRunnable(pt::clean))
.evictionPredicate((value, metadata) -> !value.isHealthy())
.acquisitionScheduler(deliveryScheduler)
.buildConfig();
}
static final PoolConfig<PoolableTest> poolableTestConfig(int minSize, int maxSize, Mono<PoolableTest> allocator,
Consumer<? super PoolableTest> additionalCleaner) {
return from(allocator)
.sizeBetween(minSize, maxSize)
.releaseHandler(poolableTest -> Mono.fromRunnable(() -> {
poolableTest.clean();
additionalCleaner.accept(poolableTest);
}))
.evictionPredicate((value, metadata) -> !value.isHealthy())
.buildConfig();
}
//======
@Test
void demonstrateAcquireInScopePipeline() throws InterruptedException {
AtomicInteger counter = new AtomicInteger();
AtomicReference<String> releaseRef = new AtomicReference<>();
SimpleFifoPool<String> pool = new SimpleFifoPool<>(
from(Mono.just("Hello Reactive World"))
.sizeBetween(0, 1)
.releaseHandler(s -> Mono.fromRunnable(()-> releaseRef.set(s)))
.buildConfig());
Flux<String> words = pool.withPoolable(poolable -> Mono.just(poolable)
//simulate deriving a value from the resource (ie. query from DB connection)
.map(resource -> resource.split(" "))
//then further process the derived value to produce multiple values (ie. rows from a query)
.flatMapIterable(Arrays::asList)
//and all that with latency
.delayElements(Duration.ofMillis(500)));
words.subscribe(v -> counter.incrementAndGet());
assertThat(counter).hasValue(0);
Thread.sleep(1100);
//we're in the middle of processing the "rows"
assertThat(counter).as("before all emitted").hasValue(2);
assertThat(releaseRef).as("still acquiring").hasValue(null);
Thread.sleep(500);
//we've finished processing, let's check resource has been automatically released
assertThat(counter).as("after all emitted").hasValue(3);
assertThat(pool.poolConfig.allocationStrategy().estimatePermitCount()).as("allocation permits").isZero();
assertThat(pool.elements).as("available").hasSize(1);
assertThat(releaseRef).as("released").hasValue("Hello Reactive World");
}
@Nested
@DisplayName("Tests around the acquire() manual mode of acquiring")
@SuppressWarnings("ClassCanBeStatic")
class AcquireTest {
@Test
@Tag("loops")
void allocatedReleasedOrAbortedIfCancelRequestRace_loop() throws InterruptedException {
AtomicInteger newCount = new AtomicInteger();
AtomicInteger releasedCount = new AtomicInteger();
for (int i = 0; i < 100; i++) {
allocatedReleasedOrAbortedIfCancelRequestRace(i, newCount, releasedCount, i % 2 == 0);
}
System.out.println("Total release of " + releasedCount.get() + " for " + newCount.get() + " created over 100 rounds");
}
@Test
void allocatedReleasedOrAbortedIfCancelRequestRace() throws InterruptedException {
allocatedReleasedOrAbortedIfCancelRequestRace(0, new AtomicInteger(), new AtomicInteger(), true);
allocatedReleasedOrAbortedIfCancelRequestRace(1, new AtomicInteger(), new AtomicInteger(), false);
}
@SuppressWarnings("FutureReturnValueIgnored")
void allocatedReleasedOrAbortedIfCancelRequestRace(int round, AtomicInteger newCount, AtomicInteger releasedCount, boolean cancelFirst) throws InterruptedException {
Scheduler scheduler = Schedulers.newParallel("poolable test allocator");
final ExecutorService executorService = Executors.newFixedThreadPool(2);
try {
PoolConfig<PoolableTest> testConfig = poolableTestConfig(0, 1,
Mono.defer(() -> Mono.delay(Duration.ofMillis(50)).thenReturn(new PoolableTest(newCount.incrementAndGet())))
.subscribeOn(scheduler),
pt -> releasedCount.incrementAndGet());
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//acquire the only element and capture the subscription, don't request just yet
CountDownLatch latch = new CountDownLatch(1);
final BaseSubscriber<PooledRef<PoolableTest>> baseSubscriber = new BaseSubscriber<PooledRef<PoolableTest>>() {
@Override
protected void hookOnSubscribe(Subscription subscription) {
//don't request
latch.countDown();
}
};
pool.acquire().subscribe(baseSubscriber);
latch.await();
if (cancelFirst) {
executorService.submit(baseSubscriber::cancel);
executorService.submit(baseSubscriber::requestUnbounded);
}
else {
executorService.submit(baseSubscriber::requestUnbounded);
executorService.submit(baseSubscriber::cancel);
}
//release due to cancel is async, give it ample time
await().atMost(200, TimeUnit.MILLISECONDS).with().pollInterval(10, TimeUnit.MILLISECONDS)
.untilAsserted(() -> assertThat(releasedCount)
.as("released vs created in round " + round + (cancelFirst? " (cancel first)" : " (request first)"))
.hasValue(newCount.get()));
}
finally {
scheduler.dispose();
executorService.shutdownNow();
}
}
@Test
void defaultThreadDeliveringWhenHasElements() throws InterruptedException {
AtomicReference<String> threadName = new AtomicReference<>();
Scheduler acquireScheduler = Schedulers.newSingle("acquire");
PoolConfig<PoolableTest> testConfig = poolableTestConfig(1, 1,
Mono.fromCallable(PoolableTest::new)
.subscribeOn(Schedulers.newParallel("poolable test allocator")));
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
pool.warmup().block();
//the pool is started and warmed up with one available element
//we prepare to acquire it
Mono<PooledRef<PoolableTest>> borrower = pool.acquire();
CountDownLatch latch = new CountDownLatch(1);
//we actually request the acquire from a separate thread and see from which thread the element was delivered
acquireScheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName()), e -> latch.countDown(), latch::countDown));
latch.await(1, TimeUnit.SECONDS);
assertThat(threadName.get())
.startsWith("acquire-");
}
@Test
void defaultThreadDeliveringWhenNoElementsButNotFull() throws InterruptedException {
AtomicReference<String> threadName = new AtomicReference<>();
Scheduler acquireScheduler = Schedulers.newSingle("acquire");
PoolConfig<PoolableTest> testConfig = poolableTestConfig(0, 1,
Mono.fromCallable(PoolableTest::new)
.subscribeOn(Schedulers.newParallel("poolable test allocator")));
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//the pool is started with no elements, and has capacity for 1
//we prepare to acquire, which would allocate the element
Mono<PooledRef<PoolableTest>> borrower = pool.acquire();
CountDownLatch latch = new CountDownLatch(1);
//we actually request the acquire from a separate thread, but the allocation also happens in a dedicated thread
//we look at which thread the element was delivered from
acquireScheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName()), e -> latch.countDown(), latch::countDown));
latch.await(1, TimeUnit.SECONDS);
assertThat(threadName.get())
.startsWith("poolable test allocator-");
}
@Test
void defaultThreadDeliveringWhenNoElementsAndFull() throws InterruptedException {
AtomicReference<String> threadName = new AtomicReference<>();
Scheduler acquireScheduler = Schedulers.newSingle("acquire");
Scheduler releaseScheduler = Schedulers.fromExecutorService(
Executors.newSingleThreadScheduledExecutor((r -> new Thread(r,"release"))));
PoolConfig<PoolableTest> testConfig = poolableTestConfig(1, 1,
Mono.fromCallable(PoolableTest::new)
.subscribeOn(Schedulers.newParallel("poolable test allocator")));
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//the pool is started with one elements, and has capacity for 1.
//we actually first acquire that element so that next acquire will wait for a release
PooledRef<PoolableTest> uniqueSlot = pool.acquire().block();
assertThat(uniqueSlot).isNotNull();
//we prepare next acquire
Mono<PooledRef<PoolableTest>> borrower = pool.acquire();
CountDownLatch latch = new CountDownLatch(1);
//we actually perform the acquire from its dedicated thread, capturing the thread on which the element will actually get delivered
acquireScheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName()),
e -> latch.countDown(), latch::countDown));
//after a short while, we release the acquired unique element from a third thread
releaseScheduler.schedule(uniqueSlot.release()::block, 500, TimeUnit.MILLISECONDS);
latch.await(1, TimeUnit.SECONDS);
assertThat(threadName.get())
.isEqualTo("release");
}
@Test
@Tag("loops")
void defaultThreadDeliveringWhenNoElementsAndFullAndRaceDrain_loop() throws InterruptedException {
AtomicInteger releaserWins = new AtomicInteger();
AtomicInteger borrowerWins = new AtomicInteger();
for (int i = 0; i < 100; i++) {
defaultThreadDeliveringWhenNoElementsAndFullAndRaceDrain(i, releaserWins, borrowerWins);
}
//look at the stats and show them in case of assertion error. We expect all deliveries to be on either of the racer threads.
//we expect a subset of the deliveries to happen on the second borrower's thread
String stats = "releaser won " + releaserWins.get() + ", borrower won " + borrowerWins.get();
assertThat(releaserWins.get()).as("releaser should win some. " + stats).isPositive();
assertThat(releaserWins.get() + borrowerWins.get()).as(stats).isEqualTo(100);
}
@Test
void defaultThreadDeliveringWhenNoElementsAndFullAndRaceDrain() throws InterruptedException {
AtomicInteger releaserWins = new AtomicInteger();
AtomicInteger borrowerWins = new AtomicInteger();
defaultThreadDeliveringWhenNoElementsAndFullAndRaceDrain(0, releaserWins, borrowerWins);
assertThat(releaserWins.get() + borrowerWins.get()).isEqualTo(1);
}
void defaultThreadDeliveringWhenNoElementsAndFullAndRaceDrain(int round, AtomicInteger releaserWins, AtomicInteger borrowerWins) throws InterruptedException {
AtomicReference<String> threadName = new AtomicReference<>();
AtomicInteger newCount = new AtomicInteger();
Scheduler acquire1Scheduler = Schedulers.newSingle("acquire1");
Scheduler racerReleaseScheduler = Schedulers.fromExecutorService(
Executors.newSingleThreadScheduledExecutor((r -> new Thread(r,"racerRelease"))));
Scheduler racerAcquireScheduler = Schedulers.fromExecutorService(
Executors.newSingleThreadScheduledExecutor((r -> new Thread(r,"racerAcquire"))));
PoolConfig<PoolableTest> testConfig = poolableTestConfig(1, 1,
Mono.fromCallable(() -> new PoolableTest(newCount.getAndIncrement()))
.subscribeOn(Schedulers.newParallel("poolable test allocator")));
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//the pool is started with one elements, and has capacity for 1.
//we actually first acquire that element so that next acquire will wait for a release
PooledRef<PoolableTest> uniqueSlot = pool.acquire().block();
assertThat(uniqueSlot).isNotNull();
//we prepare next acquire
Mono<PooledRef<PoolableTest>> borrower = pool.acquire();
CountDownLatch latch = new CountDownLatch(1);
//we actually perform the acquire from its dedicated thread, capturing the thread on which the element will actually get delivered
acquire1Scheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName())
, e -> latch.countDown(), latch::countDown));
//in parallel, we'll both attempt concurrent acquire AND release the unique element (each on their dedicated threads)
racerAcquireScheduler.schedule(pool.acquire()::block, 100, TimeUnit.MILLISECONDS);
racerReleaseScheduler.schedule(uniqueSlot.release()::block, 100, TimeUnit.MILLISECONDS);
latch.await(1, TimeUnit.SECONDS);
assertThat(newCount).as("created 1 poolable in round " + round).hasValue(1);
//we expect that sometimes the race will let the second borrower thread drain, which would mean first borrower
//will get the element delivered from racerAcquire thread. Yet the rest of the time it would get drained by racerRelease.
if (threadName.get().startsWith("racerRelease")) releaserWins.incrementAndGet();
else if (threadName.get().startsWith("racerAcquire")) borrowerWins.incrementAndGet();
else System.out.println(threadName.get());
}
@Test
void consistentThreadDeliveringWhenHasElements() throws InterruptedException {
Scheduler deliveryScheduler = Schedulers.newSingle("delivery");
AtomicReference<String> threadName = new AtomicReference<>();
Scheduler acquireScheduler = Schedulers.newSingle("acquire");
PoolConfig<PoolableTest> testConfig = poolableTestConfig(1, 1,
Mono.fromCallable(PoolableTest::new)
.subscribeOn(Schedulers.newParallel("poolable test allocator")),
deliveryScheduler);
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//the pool is started with one available element
//we prepare to acquire it
Mono<PooledRef<PoolableTest>> borrower = pool.acquire();
CountDownLatch latch = new CountDownLatch(1);
//we actually request the acquire from a separate thread and see from which thread the element was delivered
acquireScheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName()), e -> latch.countDown(), latch::countDown));
latch.await(1, TimeUnit.SECONDS);
assertThat(threadName.get())
.startsWith("delivery-");
}
@Test
void consistentThreadDeliveringWhenNoElementsButNotFull() throws InterruptedException {
Scheduler deliveryScheduler = Schedulers.newSingle("delivery");
AtomicReference<String> threadName = new AtomicReference<>();
Scheduler acquireScheduler = Schedulers.newSingle("acquire");
PoolConfig<PoolableTest> testConfig = poolableTestConfig(0, 1,
Mono.fromCallable(PoolableTest::new)
.subscribeOn(Schedulers.newParallel("poolable test allocator")),
deliveryScheduler);
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//the pool is started with no elements, and has capacity for 1
//we prepare to acquire, which would allocate the element
Mono<PooledRef<PoolableTest>> borrower = pool.acquire();
CountDownLatch latch = new CountDownLatch(1);
//we actually request the acquire from a separate thread, but the allocation also happens in a dedicated thread
//we look at which thread the element was delivered from
acquireScheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName()), e -> latch.countDown(), latch::countDown));
latch.await(1, TimeUnit.SECONDS);
assertThat(threadName.get())
.startsWith("delivery-");
}
@Test
void consistentThreadDeliveringWhenNoElementsAndFull() throws InterruptedException {
Scheduler deliveryScheduler = Schedulers.newSingle("delivery");
AtomicReference<String> threadName = new AtomicReference<>();
Scheduler acquireScheduler = Schedulers.newSingle("acquire");
Scheduler releaseScheduler = Schedulers.fromExecutorService(
Executors.newSingleThreadScheduledExecutor((r -> new Thread(r,"release"))));
PoolConfig<PoolableTest> testConfig = poolableTestConfig(1, 1,
Mono.fromCallable(PoolableTest::new)
.subscribeOn(Schedulers.newParallel("poolable test allocator")),
deliveryScheduler);
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//the pool is started with one elements, and has capacity for 1.
//we actually first acquire that element so that next acquire will wait for a release
PooledRef<PoolableTest> uniqueSlot = pool.acquire().block();
assertThat(uniqueSlot).isNotNull();
//we prepare next acquire
Mono<PooledRef<PoolableTest>> borrower = pool.acquire();
CountDownLatch latch = new CountDownLatch(1);
//we actually perform the acquire from its dedicated thread, capturing the thread on which the element will actually get delivered
acquireScheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName()),
e -> latch.countDown(), latch::countDown));
//after a short while, we release the acquired unique element from a third thread
releaseScheduler.schedule(uniqueSlot.release()::block, 500, TimeUnit.MILLISECONDS);
latch.await(1, TimeUnit.SECONDS);
assertThat(threadName.get())
.startsWith("delivery-");
}
@Test
@Tag("loops")
void consistentThreadDeliveringWhenNoElementsAndFullAndRaceDrain_loop() throws InterruptedException {
for (int i = 0; i < 100; i++) {
consistentThreadDeliveringWhenNoElementsAndFullAndRaceDrain(i);
}
}
@Test
void consistentThreadDeliveringWhenNoElementsAndFullAndRaceDrain() throws InterruptedException {
consistentThreadDeliveringWhenNoElementsAndFullAndRaceDrain(0);
}
void consistentThreadDeliveringWhenNoElementsAndFullAndRaceDrain(int i) throws InterruptedException {
Scheduler deliveryScheduler = Schedulers.newSingle("delivery");
AtomicReference<String> threadName = new AtomicReference<>();
AtomicInteger newCount = new AtomicInteger();
Scheduler acquire1Scheduler = Schedulers.newSingle("acquire1");
Scheduler racerReleaseScheduler = Schedulers.fromExecutorService(
Executors.newSingleThreadScheduledExecutor((r -> new Thread(r,"racerRelease"))));
Scheduler racerAcquireScheduler = Schedulers.newSingle("racerAcquire");
PoolConfig<PoolableTest> testConfig = poolableTestConfig(1, 1,
Mono.fromCallable(() -> new PoolableTest(newCount.getAndIncrement()))
.subscribeOn(Schedulers.newParallel("poolable test allocator")),
deliveryScheduler);
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//the pool is started with one elements, and has capacity for 1.
//we actually first acquire that element so that next acquire will wait for a release
PooledRef<PoolableTest> uniqueSlot = pool.acquire().block();
assertThat(uniqueSlot).isNotNull();
//we prepare next acquire
Mono<PooledRef<PoolableTest>> borrower = pool.acquire();
CountDownLatch latch = new CountDownLatch(1);
//we actually perform the acquire from its dedicated thread, capturing the thread on which the element will actually get delivered
acquire1Scheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName())
, e -> latch.countDown(), latch::countDown));
//in parallel, we'll both attempt a second acquire AND release the unique element (each on their dedicated threads
Mono<PooledRef<PoolableTest>> otherBorrower = pool.acquire();
racerAcquireScheduler.schedule(() -> otherBorrower.subscribe().dispose(), 100, TimeUnit.MILLISECONDS);
racerReleaseScheduler.schedule(uniqueSlot.release()::block, 100, TimeUnit.MILLISECONDS);
latch.await(1, TimeUnit.SECONDS);
//we expect that, consistently, the poolable is delivered on a `delivery` thread
assertThat(threadName.get()).as("round #" + i).startsWith("delivery-");
//we expect that only 1 element was created
assertThat(newCount).as("elements created in round " + i).hasValue(1);
}
@Test
@Tag("loops")
void acquireReleaseRaceWithMinSize_loop() {
final Scheduler racer = Schedulers.fromExecutorService(Executors.newFixedThreadPool(2));
AtomicInteger newCount = new AtomicInteger();
try {
PoolConfig<PoolableTest> testConfig = from(Mono.fromCallable(() -> new PoolableTest(newCount.getAndIncrement())))
.sizeBetween(4, 5)
.buildConfig();
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
for (int i = 0; i < 100; i++) {
RaceTestUtils.race(() -> pool.acquire().block().release().block(),
() -> pool.acquire().block().release().block(),
racer);
}
//we expect that only 3 element was created
assertThat(newCount).as("elements created in total").hasValue(4);
}
finally {
racer.dispose();
}
}
}
@Nested
@DisplayName("Tests around the withPoolable(Function) mode of acquiring")
@SuppressWarnings("ClassCanBeStatic")
class AcquireInScopeTest {
@Test
@DisplayName("acquire delays instead of allocating past maxSize")
void acquireDelaysNotAllocate() {
AtomicInteger newCount = new AtomicInteger();
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(poolableTestConfig(2, 3,
Mono.defer(() -> Mono.just(new PoolableTest(newCount.incrementAndGet())))));
pool.withPoolable(poolable -> Mono.just(poolable).delayElement(Duration.ofMillis(500))).subscribe();
pool.withPoolable(poolable -> Mono.just(poolable).delayElement(Duration.ofMillis(500))).subscribe();
pool.withPoolable(poolable -> Mono.just(poolable).delayElement(Duration.ofMillis(500))).subscribe();
final Tuple2<Long, PoolableTest> tuple2 = pool.withPoolable(Mono::just).elapsed().blockLast();
assertThat(tuple2).isNotNull();
assertThat(tuple2.getT1()).as("pending for 500ms").isCloseTo(500L, Offset.offset(50L));
assertThat(tuple2.getT2().usedUp).as("discarded twice").isEqualTo(2);
assertThat(tuple2.getT2().id).as("id").isLessThan(4);
}
@Test
@Tag("loops")
void allocatedReleasedOrAbortedIfCancelRequestRace_loop() throws InterruptedException {
AtomicInteger newCount = new AtomicInteger();
AtomicInteger releasedCount = new AtomicInteger();
for (int i = 0; i < 100; i++) {
allocatedReleasedOrAbortedIfCancelRequestRace(i, newCount, releasedCount, i % 2 == 0);
}
System.out.println("Total release of " + releasedCount.get() + " for " + newCount.get() + " created over 100 rounds");
}
@Test
void allocatedReleasedOrAbortedIfCancelRequestRace() throws InterruptedException {
allocatedReleasedOrAbortedIfCancelRequestRace(0, new AtomicInteger(), new AtomicInteger(), true);
allocatedReleasedOrAbortedIfCancelRequestRace(1, new AtomicInteger(), new AtomicInteger(), false);
}
@SuppressWarnings("FutureReturnValueIgnored")
void allocatedReleasedOrAbortedIfCancelRequestRace(int round, AtomicInteger newCount, AtomicInteger releasedCount, boolean cancelFirst) throws InterruptedException {
Scheduler scheduler = Schedulers.newParallel("poolable test allocator");
PoolConfig<PoolableTest> testConfig = poolableTestConfig(0, 1,
Mono.defer(() -> Mono.delay(Duration.ofMillis(50)).thenReturn(new PoolableTest(newCount.incrementAndGet())))
.subscribeOn(scheduler),
pt -> releasedCount.incrementAndGet());
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//acquire the only element and capture the subscription, don't request just yet
CountDownLatch latch = new CountDownLatch(1);
final BaseSubscriber<PoolableTest> baseSubscriber = new BaseSubscriber<PoolableTest>() {
@Override
protected void hookOnSubscribe(Subscription subscription) {
//don't request
latch.countDown();
}
};
pool.withPoolable(Mono::just).subscribe(baseSubscriber);
latch.await();
final ExecutorService executorService = Executors.newFixedThreadPool(2);
if (cancelFirst) {
executorService.submit(baseSubscriber::cancel);
executorService.submit(baseSubscriber::requestUnbounded);
}
else {
executorService.submit(baseSubscriber::requestUnbounded);
executorService.submit(baseSubscriber::cancel);
}
//release due to cancel is async, give it a bit of time
await().atMost(100, TimeUnit.MILLISECONDS).with().pollInterval(10, TimeUnit.MILLISECONDS)
.untilAsserted(() -> assertThat(releasedCount)
.as("released vs created in round " + round + (cancelFirst? " (cancel first)" : " (request first)"))
.hasValue(newCount.get()));
}
@Test
void defaultThreadDeliveringWhenHasElements() throws InterruptedException {
AtomicReference<String> threadName = new AtomicReference<>();
Scheduler acquireScheduler = Schedulers.newSingle("acquire");
PoolConfig<PoolableTest> testConfig = poolableTestConfig(1, 1,
Mono.fromCallable(PoolableTest::new)
.subscribeOn(Schedulers.newParallel("poolable test allocator")));
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
pool.warmup().block();
//the pool is started and warmed up with one available element
//we prepare to acquire it
Mono<PoolableTest> borrower = Mono.fromDirect(pool.withPoolable(Mono::just));
CountDownLatch latch = new CountDownLatch(1);
//we actually request the acquire from a separate thread and see from which thread the element was delivered
acquireScheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName()), e -> latch.countDown(), latch::countDown));
latch.await(1, TimeUnit.SECONDS);
assertThat(threadName.get())
.startsWith("acquire-");
}
@Test
void defaultThreadDeliveringWhenNoElementsButNotFull() throws InterruptedException {
AtomicReference<String> threadName = new AtomicReference<>();
Scheduler acquireScheduler = Schedulers.newSingle("acquire");
PoolConfig<PoolableTest> testConfig = poolableTestConfig(0, 1,
Mono.fromCallable(PoolableTest::new)
.subscribeOn(Schedulers.newParallel("poolable test allocator")));
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//the pool is started with no elements, and has capacity for 1
//we prepare to acquire, which would allocate the element
Mono<PoolableTest> borrower = Mono.fromDirect(pool.withPoolable(Mono::just));
CountDownLatch latch = new CountDownLatch(1);
//we actually request the acquire from a separate thread, but the allocation also happens in a dedicated thread
//we look at which thread the element was delivered from
acquireScheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName()), e -> latch.countDown(), latch::countDown));
latch.await(1, TimeUnit.SECONDS);
assertThat(threadName.get())
.startsWith("poolable test allocator-");
}
@Test
void defaultThreadDeliveringWhenNoElementsAndFull() throws InterruptedException {
AtomicReference<String> threadName = new AtomicReference<>();
Scheduler acquireScheduler = Schedulers.newSingle("acquire");
Scheduler releaseScheduler = Schedulers.fromExecutorService(
Executors.newSingleThreadScheduledExecutor((r -> new Thread(r,"release"))));
PoolConfig<PoolableTest> testConfig = poolableTestConfig(1, 1,
Mono.fromCallable(PoolableTest::new)
.subscribeOn(Schedulers.newParallel("poolable test allocator")));
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//the pool is started with one elements, and has capacity for 1.
//we actually first acquire that element so that next acquire will wait for a release
PooledRef<PoolableTest> uniqueSlot = pool.acquire().block();
assertThat(uniqueSlot).isNotNull();
//we prepare next acquire
Mono<PoolableTest> borrower = Mono.fromDirect(pool.withPoolable(Mono::just));
CountDownLatch latch = new CountDownLatch(1);
//we actually perform the acquire from its dedicated thread, capturing the thread on which the element will actually get delivered
acquireScheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName()),
e -> latch.countDown(), latch::countDown));
//after a short while, we release the acquired unique element from a third thread
releaseScheduler.schedule(uniqueSlot.release()::block, 500, TimeUnit.MILLISECONDS);
latch.await(1, TimeUnit.SECONDS);
assertThat(threadName.get())
.isEqualTo("release");
}
@Test
@Tag("loops")
void defaultThreadDeliveringWhenNoElementsAndFullAndRaceDrain_loop() throws InterruptedException {
AtomicInteger releaserWins = new AtomicInteger();
AtomicInteger borrowerWins = new AtomicInteger();
for (int i = 0; i < 100; i++) {
defaultThreadDeliveringWhenNoElementsAndFullAndRaceDrain(i, releaserWins, borrowerWins);
}
//look at the stats and show them in case of assertion error. We expect all deliveries to be on either of the racer threads.
//we expect a subset of the deliveries to happen on the second borrower's thread
String stats = "releaser won " + releaserWins.get() + ", borrower won " + borrowerWins.get();
assertThat(releaserWins.get()).as("releaser should win some. " + stats).isPositive();
assertThat(releaserWins.get() + borrowerWins.get()).as(stats).isEqualTo(100);
}
@Test
void defaultThreadDeliveringWhenNoElementsAndFullAndRaceDrain() throws InterruptedException {
AtomicInteger releaserWins = new AtomicInteger();
AtomicInteger borrowerWins = new AtomicInteger();
defaultThreadDeliveringWhenNoElementsAndFullAndRaceDrain(0, releaserWins, borrowerWins);
assertThat(releaserWins.get() + borrowerWins.get()).isEqualTo(1);
}
void defaultThreadDeliveringWhenNoElementsAndFullAndRaceDrain(int round, AtomicInteger releaserWins, AtomicInteger borrowerWins) throws InterruptedException {
AtomicReference<String> threadName = new AtomicReference<>();
AtomicInteger newCount = new AtomicInteger();
Scheduler acquire1Scheduler = Schedulers.newSingle("acquire1");
Scheduler racerReleaseScheduler = Schedulers.fromExecutorService(
Executors.newSingleThreadScheduledExecutor((r -> new Thread(r,"racerRelease"))));
Scheduler racerAcquireScheduler = Schedulers.fromExecutorService(
Executors.newSingleThreadScheduledExecutor((r -> new Thread(r,"racerAcquire"))));
Scheduler allocatorScheduler = Schedulers.newParallel("poolable test allocator");
try {
PoolConfig<PoolableTest> testConfig = poolableTestConfig(1, 1,
Mono.fromCallable(() -> new PoolableTest(newCount.getAndIncrement()))
.subscribeOn(allocatorScheduler));
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//the pool is started with one elements, and has capacity for 1.
//we actually first acquire that element so that next acquire will wait for a release
PooledRef<PoolableTest> uniqueSlot = pool.acquire().block();
assertThat(uniqueSlot).isNotNull();
//we prepare next acquire
Mono<PoolableTest> borrower = Mono.fromDirect(pool.withPoolable(Mono::just));
CountDownLatch latch = new CountDownLatch(3);
//we actually perform the acquire from its dedicated thread, capturing the thread on which the element will actually get delivered
acquire1Scheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName())
, e -> latch.countDown(), latch::countDown));
//in parallel, we'll both attempt concurrent acquire AND release the unique element (each on their dedicated threads)
racerAcquireScheduler.schedule(() -> {
pool.acquire().block();
latch.countDown();
}, 100, TimeUnit.MILLISECONDS);
racerReleaseScheduler.schedule(() -> {
uniqueSlot.release().block();
latch.countDown();
}, 100, TimeUnit.MILLISECONDS);
assertThat(latch.await(1, TimeUnit.SECONDS)).as("1s").isTrue();
assertThat(newCount).as("created 1 poolable in round " + round).hasValue(1);
//we expect that sometimes the race will let the second borrower thread drain, which would mean first borrower
//will get the element delivered from racerAcquire thread. Yet the rest of the time it would get drained by racerRelease.
if (threadName.get().startsWith("racerRelease")) releaserWins.incrementAndGet();
else if (threadName.get().startsWith("racerAcquire")) borrowerWins.incrementAndGet();
else System.out.println(threadName.get());
}
finally {
acquire1Scheduler.dispose();
racerAcquireScheduler.dispose();
racerReleaseScheduler.dispose();
allocatorScheduler.dispose();
}
}
@Test
void consistentThreadDeliveringWhenHasElements() throws InterruptedException {
Scheduler deliveryScheduler = Schedulers.newSingle("delivery");
AtomicReference<String> threadName = new AtomicReference<>();
Scheduler acquireScheduler = Schedulers.newSingle("acquire");
PoolConfig<PoolableTest> testConfig = poolableTestConfig(1, 1,
Mono.fromCallable(PoolableTest::new)
.subscribeOn(Schedulers.newParallel("poolable test allocator")),
deliveryScheduler);
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//the pool is started with one available element
//we prepare to acquire it
Mono<PoolableTest> borrower = Mono.fromDirect(pool.withPoolable(Mono::just));
CountDownLatch latch = new CountDownLatch(1);
//we actually request the acquire from a separate thread and see from which thread the element was delivered
acquireScheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName()), e -> latch.countDown(), latch::countDown));
latch.await(1, TimeUnit.SECONDS);
assertThat(threadName.get())
.startsWith("delivery-");
}
@Test
void consistentThreadDeliveringWhenNoElementsButNotFull() throws InterruptedException {
Scheduler deliveryScheduler = Schedulers.newSingle("delivery");
AtomicReference<String> threadName = new AtomicReference<>();
Scheduler acquireScheduler = Schedulers.newSingle("acquire");
PoolConfig<PoolableTest> testConfig = poolableTestConfig(0, 1,
Mono.fromCallable(PoolableTest::new)
.subscribeOn(Schedulers.newParallel("poolable test allocator")),
deliveryScheduler);
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//the pool is started with no elements, and has capacity for 1
//we prepare to acquire, which would allocate the element
Mono<PoolableTest> borrower = Mono.fromDirect(pool.withPoolable(Mono::just));
CountDownLatch latch = new CountDownLatch(1);
//we actually request the acquire from a separate thread, but the allocation also happens in a dedicated thread
//we look at which thread the element was delivered from
acquireScheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName()), e -> latch.countDown(), latch::countDown));
latch.await(1, TimeUnit.SECONDS);
assertThat(threadName.get())
.startsWith("delivery-");
}
@Test
void consistentThreadDeliveringWhenNoElementsAndFull() throws InterruptedException {
Scheduler deliveryScheduler = Schedulers.newSingle("delivery");
AtomicReference<String> threadName = new AtomicReference<>();
Scheduler acquireScheduler = Schedulers.newSingle("acquire");
Scheduler releaseScheduler = Schedulers.fromExecutorService(
Executors.newSingleThreadScheduledExecutor((r -> new Thread(r,"release"))));
PoolConfig<PoolableTest> testConfig = poolableTestConfig(1, 1,
Mono.fromCallable(PoolableTest::new)
.subscribeOn(Schedulers.newParallel("poolable test allocator")),
deliveryScheduler);
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//the pool is started with one elements, and has capacity for 1.
//we actually first acquire that element so that next acquire will wait for a release
PooledRef<PoolableTest> uniqueSlot = pool.acquire().block();
assertThat(uniqueSlot).isNotNull();
//we prepare next acquire
Mono<PoolableTest> borrower = Mono.fromDirect(pool.withPoolable(Mono::just));
CountDownLatch latch = new CountDownLatch(1);
//we actually perform the acquire from its dedicated thread, capturing the thread on which the element will actually get delivered
acquireScheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName()),
e -> latch.countDown(), latch::countDown));
//after a short while, we release the acquired unique element from a third thread
releaseScheduler.schedule(uniqueSlot.release()::block, 500, TimeUnit.MILLISECONDS);
latch.await(1, TimeUnit.SECONDS);
assertThat(threadName.get())
.startsWith("delivery-");
}
@Test
@Tag("loops")
void consistentThreadDeliveringWhenNoElementsAndFullAndRaceDrain_loop() throws InterruptedException {
for (int i = 0; i < 100; i++) {
consistentThreadDeliveringWhenNoElementsAndFullAndRaceDrain(i);
}
}
@Test
void consistentThreadDeliveringWhenNoElementsAndFullAndRaceDrain() throws InterruptedException {
consistentThreadDeliveringWhenNoElementsAndFullAndRaceDrain(0);
}
void consistentThreadDeliveringWhenNoElementsAndFullAndRaceDrain(int i) throws InterruptedException {
Scheduler deliveryScheduler = Schedulers.newSingle("delivery");
AtomicReference<String> threadName = new AtomicReference<>();
AtomicInteger newCount = new AtomicInteger();
Scheduler acquire1Scheduler = Schedulers.newSingle("acquire1");
Scheduler racerReleaseScheduler = Schedulers.fromExecutorService(
Executors.newSingleThreadScheduledExecutor((r -> new Thread(r,"racerRelease"))));
Scheduler racerAcquireScheduler = Schedulers.newSingle("racerAcquire");
PoolConfig<PoolableTest> testConfig = poolableTestConfig(1, 1,
Mono.fromCallable(() -> new PoolableTest(newCount.getAndIncrement()))
.subscribeOn(Schedulers.newParallel("poolable test allocator")),
deliveryScheduler);
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(testConfig);
//the pool is started with one elements, and has capacity for 1.
//we actually first acquire that element so that next acquire will wait for a release
PooledRef<PoolableTest> uniqueSlot = pool.acquire().block();
assertThat(uniqueSlot).isNotNull();
//we prepare next acquire
Mono<PoolableTest> borrower = Mono.fromDirect(pool.withPoolable(Mono::just));
CountDownLatch latch = new CountDownLatch(1);
//we actually perform the acquire from its dedicated thread, capturing the thread on which the element will actually get delivered
acquire1Scheduler.schedule(() -> borrower.subscribe(v -> threadName.set(Thread.currentThread().getName())
, e -> latch.countDown(), latch::countDown));
//in parallel, we'll both attempt a second acquire AND release the unique element (each on their dedicated threads
Mono<PooledRef<PoolableTest>> otherBorrower = pool.acquire();
racerAcquireScheduler.schedule(() -> otherBorrower.subscribe().dispose(), 100, TimeUnit.MILLISECONDS);
racerReleaseScheduler.schedule(uniqueSlot.release()::block, 100, TimeUnit.MILLISECONDS);
latch.await(1, TimeUnit.SECONDS);
//we expect that, consistently, the poolable is delivered on a `delivery` thread
assertThat(threadName.get()).as("round #" + i).startsWith("delivery-");
//we expect that only 1 element was created
assertThat(newCount).as("elements created in round " + i).hasValue(1);
}
}
@Test
void stillacquiredAfterPoolDisposedMaintainsCount() {
AtomicInteger cleanerCount = new AtomicInteger();
SimpleFifoPool<PoolableTest> pool = new SimpleFifoPool<>(
from(Mono.fromCallable(PoolableTest::new))
.sizeBetween(3, 3)
.releaseHandler(p -> Mono.fromRunnable(cleanerCount::incrementAndGet))
.evictionPredicate((value, metadata) -> !value.isHealthy())
.buildConfig());
PooledRef<PoolableTest> acquired1 = pool.acquire().block();
PooledRef<PoolableTest> acquired2 = pool.acquire().block();
PooledRef<PoolableTest> acquired3 = pool.acquire().block();
assertThat(acquired1).as("acquired1").isNotNull();
assertThat(acquired2).as("acquired2").isNotNull();
assertThat(acquired3).as("acquired3").isNotNull();
pool.dispose();
assertThat(pool.acquired).as("before releases").isEqualTo(3);
acquired1.release().block();
acquired2.release().block();
acquired3.release().block();
assertThat(pool.acquired).as("after releases").isEqualTo(0);
}
@SuppressWarnings("FutureReturnValueIgnored")
@ParameterizedTest
@CsvSource({"4, 1", "4, 100000", "10, 1", "10, 100000"})
//see https://github.com/reactor/reactor-pool/issues/65
void concurrentAcquireCorrectlyAccountsAll(int parallelism, int loops) throws InterruptedException {
final ScheduledExecutorService executorService = Executors.newScheduledThreadPool(parallelism);
autoDispose(executorService::shutdownNow);
for (int l = 0; l < loops; l++) {
PoolConfig<String> config = PoolBuilder.from(Mono.just("foo"))
.sizeBetween(0, 100)
.buildConfig();
SimpleFifoPool<String> fifoPool = autoDispose(new SimpleFifoPool<>(config));
CountDownLatch latch = new CountDownLatch(parallelism);
for (int i = 0; i < parallelism; i++) {
executorService.submit(() -> {
fifoPool.acquire()
.block();
latch.countDown();
});
}
boolean awaited = latch.await(1, TimeUnit.SECONDS);
assertThat(awaited).as("all concurrent acquire served in loop #" + l).isTrue();
}
}
}
