Migrate DynamicConfigurationManager to use java.util.concurrent

service/src/main/java/org/whispersystems/textsecuregcm/WhisperServerService.java

@@ -315,11 +315,14 @@ public class WhisperServerService extends Application<WhisperServerConfiguration
 
     UncaughtExceptionHandler.register();
 
+    ScheduledExecutorService dynamicConfigurationExecutor = environment.lifecycle()
+        .scheduledExecutorService(name(getClass(), "dynamicConfiguration-%d")).threads(1).build();
+
     DynamicConfigurationManager<DynamicConfiguration> dynamicConfigurationManager =
         new DynamicConfigurationManager<>(config.getAppConfig().getApplication(),
             config.getAppConfig().getEnvironment(),
             config.getAppConfig().getConfigurationName(),
-            DynamicConfiguration.class);
+            DynamicConfiguration.class, dynamicConfigurationExecutor);
     dynamicConfigurationManager.start();
 
     MetricsUtil.configureRegistries(config, environment, dynamicConfigurationManager);

service/src/main/java/org/whispersystems/textsecuregcm/storage/DynamicConfigurationManager.java

@@ -13,6 +13,9 @@ import io.micrometer.core.instrument.Metrics;
 import java.time.Duration;
 import java.util.Optional;
 import java.util.Set;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 import javax.validation.ConstraintViolation;
 import javax.validation.Validation;
@@ -38,8 +41,9 @@ public class DynamicConfigurationManager<T> {
 
   // Set on initial config fetch
   private final AtomicReference<T> configuration = new AtomicReference<>();
+  private final CountDownLatch initialized = new CountDownLatch(1);
+  private final ScheduledExecutorService scheduledExecutorService;
   private String configurationToken = null;
-  private boolean initialized = false;
 
   private static final Validator VALIDATOR = Validation.buildDefaultValidatorFactory().getValidator();
 
@@ -50,61 +54,48 @@ public class DynamicConfigurationManager<T> {
   private static final Logger logger = LoggerFactory.getLogger(DynamicConfigurationManager.class);
 
   public DynamicConfigurationManager(String application, String environment, String configurationName,
-      Class<T> configurationClass) {
+      Class<T> configurationClass, ScheduledExecutorService scheduledExecutorService) {
     this(AppConfigDataClient
             .builder()
             .overrideConfiguration(ClientOverrideConfiguration.builder()
                 .apiCallTimeout(Duration.ofSeconds(10))
                 .apiCallAttemptTimeout(Duration.ofSeconds(10)).build())
             .build(),
-        application, environment, configurationName, configurationClass);
+        application, environment, configurationName, configurationClass, scheduledExecutorService);
   }
 
   @VisibleForTesting
   DynamicConfigurationManager(AppConfigDataClient appConfigClient, String application, String environment,
-      String configurationName, Class<T> configurationClass) {
+      String configurationName, Class<T> configurationClass, ScheduledExecutorService scheduledExecutorService) {
     this.appConfigClient = appConfigClient;
     this.application = application;
     this.environment = environment;
     this.configurationName = configurationName;
     this.configurationClass = configurationClass;
+    this.scheduledExecutorService = scheduledExecutorService;
   }
 
   public T getConfiguration() {
-    synchronized (this) {
-      while (!initialized) {
-        try {
-          this.wait();
-        } catch (final InterruptedException e) {
-          logger.warn("Interrupted while waiting for initial configuration", e);
-          throw new RuntimeException(e);
-        }
-      }
+    try {
+      initialized.await();
+    } catch (InterruptedException e) {
+      logger.warn("Interrupted while waiting for initial configuration", e);
+      throw new RuntimeException(e);
     }
     return configuration.get();
   }
 
   public void start() {
     configuration.set(retrieveInitialDynamicConfiguration());
-    synchronized (this) {
-      this.initialized = true;
-      this.notifyAll();
-    }
+    initialized.countDown();
 
-    final Thread workerThread = new Thread(() -> {
-      while (true) {
-        try {
-          retrieveDynamicConfiguration().ifPresent(configuration::set);
-        } catch (Exception e) {
-          logger.warn("Error retrieving dynamic configuration", e);
-        }
-
-        Util.sleep(5000);
+    scheduledExecutorService.scheduleWithFixedDelay(() -> {
+      try {
+        retrieveDynamicConfiguration().ifPresent(configuration::set);
+      } catch (Exception e) {
+        logger.warn("Error retrieving dynamic configuration", e);
       }
-    }, "DynamicConfigurationManagerWorker");
-
-    workerThread.setDaemon(true);
-    workerThread.start();
+    }, 0, 5, TimeUnit.SECONDS);
   }
 
   private Optional<T> retrieveDynamicConfiguration() throws JsonProcessingException {

service/src/main/java/org/whispersystems/textsecuregcm/workers/AssignUsernameCommand.java

@@ -98,6 +98,14 @@ public class AssignUsernameCommand extends EnvironmentCommand<WhisperServerConfi
       throws Exception {
     environment.getObjectMapper().configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
 
+    ScheduledExecutorService dynamicConfigurationExecutor = environment.lifecycle()
+        .scheduledExecutorService(name(getClass(), "dynamicConfiguration-%d")).threads(1).build();
+
+    DynamicConfigurationManager<DynamicConfiguration> dynamicConfigurationManager = new DynamicConfigurationManager<>(
+        configuration.getAppConfig().getApplication(), configuration.getAppConfig().getEnvironment(),
+        configuration.getAppConfig().getConfigurationName(), DynamicConfiguration.class, dynamicConfigurationExecutor);
+    dynamicConfigurationManager.start();
+
     ClientResources redisClusterClientResources = ClientResources.builder().build();
 
     FaultTolerantRedisCluster cacheCluster = new FaultTolerantRedisCluster("main_cache_cluster",
@@ -128,11 +136,6 @@ public class AssignUsernameCommand extends EnvironmentCommand<WhisperServerConfi
     ExternalServiceCredentialsGenerator secureValueRecoveryCredentialsGenerator = SecureValueRecovery2Controller.credentialsGenerator(
         configuration.getSvr2Configuration());
 
-    DynamicConfigurationManager<DynamicConfiguration> dynamicConfigurationManager = new DynamicConfigurationManager<>(
-        configuration.getAppConfig().getApplication(), configuration.getAppConfig().getEnvironment(),
-        configuration.getAppConfig().getConfigurationName(), DynamicConfiguration.class);
-    dynamicConfigurationManager.start();
-
     ExperimentEnrollmentManager experimentEnrollmentManager = new ExperimentEnrollmentManager(
         dynamicConfigurationManager);
 

service/src/main/java/org/whispersystems/textsecuregcm/workers/CommandDependencies.java

@@ -72,9 +72,12 @@ record CommandDependencies(
 
     environment.getObjectMapper().configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
 
+    ScheduledExecutorService dynamicConfigurationExecutor = environment.lifecycle()
+        .scheduledExecutorService(name(name, "dynamicConfiguration-%d")).threads(1).build();
+
     DynamicConfigurationManager<DynamicConfiguration> dynamicConfigurationManager = new DynamicConfigurationManager<>(
         configuration.getAppConfig().getApplication(), configuration.getAppConfig().getEnvironment(),
-        configuration.getAppConfig().getConfigurationName(), DynamicConfiguration.class);
+        configuration.getAppConfig().getConfigurationName(), DynamicConfiguration.class, dynamicConfigurationExecutor);
     dynamicConfigurationManager.start();
 
     MetricsUtil.configureRegistries(configuration, environment, dynamicConfigurationManager);

service/src/test/java/org/whispersystems/textsecuregcm/storage/DynamicConfigurationManagerTest.java

@@ -6,6 +6,9 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 import java.time.Duration;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledThreadPoolExecutor;
+import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicConfiguration;
@@ -27,12 +30,13 @@ class DynamicConfigurationManagerTest {
   private DynamicConfigurationManager<DynamicConfiguration> dynamicConfigurationManager;
   private AppConfigDataClient appConfig;
   private StartConfigurationSessionRequest startConfigurationSession;
+  private final ScheduledExecutorService scheduledExecutorService = new ScheduledThreadPoolExecutor(1);
 
   @BeforeEach
   void setup() {
     this.appConfig = mock(AppConfigDataClient.class);
     this.dynamicConfigurationManager = new DynamicConfigurationManager<>(
-        appConfig, "foo", "bar", "baz", DynamicConfiguration.class);
+        appConfig, "foo", "bar", "baz", DynamicConfiguration.class, scheduledExecutorService);
     this.startConfigurationSession = StartConfigurationSessionRequest.builder()
         .applicationIdentifier("foo")
         .environmentIdentifier("bar")
@@ -40,6 +44,11 @@ class DynamicConfigurationManagerTest {
         .build();
   }
 
+  @AfterEach
+  void teardown() {
+    scheduledExecutorService.shutdown();
+  }
+
   @Test
   void testGetInitialConfig() {
     when(appConfig.startConfigurationSession(startConfigurationSession))