Fix flaky DefaultPooledConnectionProviderTest#testDisposeInactivePool…

…sInBackground (#3237)

There are random DefaultPooledConnectionProviderTest#testDisposeInactivePoolsInBackground failures

DefaultPooledConnectionProviderTest > testDisposeInactivePoolsInBackground(boolean, boolean, boolean) > [5] enableEvictInBackground=true, isHttp2=false, isBuiltInMetrics=false FAILED
    org.opentest4j.AssertionFailedError:
    expected: true
     but was: false
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at reactor.netty.resources.DefaultPooledConnectionProviderTest.testDisposeInactivePoolsInBackground(DefaultPooledConnectionProviderTest.java:729)

DefaultPooledConnectionProviderTest > testDisposeInactivePoolsInBackground(boolean, boolean, boolean) > [8] enableEvictInBackground=true, isHttp2=true, isBuiltInMetrics=true FAILED
    org.opentest4j.AssertionFailedError:
    expected: null
     but was: io.micrometer.core.instrument.internal.DefaultGauge@78e01239
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at reactor.netty.resources.DefaultPooledConnectionProviderTest.testDisposeInactivePoolsInBackground(DefaultPooledConnectionProviderTest.java:733)

reactor-netty-http/src/test/java/reactor/netty/resources/DefaultPooledConnectionProviderTest.java

@@ -669,12 +669,20 @@ void testDisposeInactivePoolsInBackground(boolean enableEvictInBackground, boole
  }
 
  MeterRegistrarImpl meterRegistrar;
- String metricsName = "";
+ CountDownLatch meterRemoved = new CountDownLatch(1);
+ String metricsName = CONNECTION_PROVIDER_PREFIX + ACTIVE_CONNECTIONS;
+ String metricsTagName = "";
  if (isBuiltInMetrics) {
  meterRegistrar = null;
  builder.metrics(true);
 
- metricsName = isHttp2 ? "http2.testDisposeInactivePoolsInBackground" : "testDisposeInactivePoolsInBackground";
+ metricsTagName = isHttp2 ? "http2.testDisposeInactivePoolsInBackground" : "testDisposeInactivePoolsInBackground";
+
+ registry.config().onMeterRemoved(meter -> {
+ if (metricsName.equals(meter.getId().getName())) {
+ meterRemoved.countDown();
+ }
+ });
  }
  else {
  meterRegistrar = new MeterRegistrarImpl();
@@ -711,7 +719,7 @@ void testDisposeInactivePoolsInBackground(boolean enableEvictInBackground, boole
  assertThat(meterRegistrar.registered.get()).isTrue();
  }
  else {
- assertGauge(registry, CONNECTION_PROVIDER_PREFIX + ACTIVE_CONNECTIONS, NAME, metricsName).isNotNull();
+ assertGauge(registry, metricsName, NAME, metricsTagName).isNotNull();
  }
 
  if (enableEvictInBackground) {
@@ -726,14 +734,18 @@ void testDisposeInactivePoolsInBackground(boolean enableEvictInBackground, boole
 
  assertThat(provider.isDisposed()).isEqualTo(enableEvictInBackground);
  if (meterRegistrar != null) {
+ if (enableEvictInBackground) {
+ assertThat(meterRegistrar.latch.await(30, TimeUnit.SECONDS)).isTrue();
+ }
  assertThat(meterRegistrar.deRegistered.get()).isEqualTo(enableEvictInBackground);
  }
  else {
  if (enableEvictInBackground) {
- assertGauge(registry, CONNECTION_PROVIDER_PREFIX + ACTIVE_CONNECTIONS, NAME, metricsName).isNull();
+ assertThat(meterRemoved.await(30, TimeUnit.SECONDS)).isTrue();
+ assertGauge(registry, metricsName, NAME, metricsTagName).isNull();
  }
  else {
- assertGauge(registry, CONNECTION_PROVIDER_PREFIX + ACTIVE_CONNECTIONS, NAME, metricsName).isNotNull();
+ assertGauge(registry, metricsName, NAME, metricsTagName).isNotNull();
  }
  }
  }
@@ -869,6 +881,7 @@ void testHttp2PoolAndGoAway() {
  static final class MeterRegistrarImpl implements ConnectionProvider.MeterRegistrar {
  AtomicBoolean registered = new AtomicBoolean();
  AtomicBoolean deRegistered = new AtomicBoolean();
+ final CountDownLatch latch = new CountDownLatch(1);
 
  MeterRegistrarImpl() {
  }
@@ -881,6 +894,7 @@ public void registerMetrics(String poolName, String id, SocketAddress remoteAddr
  @Override
  public void deRegisterMetrics(String poolName, String id, SocketAddress remoteAddress) {
  deRegistered.compareAndSet(false, true);
+ latch.countDown();
  }
  }
 }