Add logic to clear data structures between same-JVM TCK tests (essent…

…ially no-ops during normal usage)

metrics/metrics/src/main/java/io/helidon/metrics/MicrometerPrometheusFormatter.java

@@ -65,13 +65,13 @@ public static Builder builder() {
 
     private final String scopeTagName;
     private final Iterable<String> scopeSelection;
-    private final Iterable<String> meterSelection;
+    private final Iterable<String> meterNameSelection;
     private final MediaType resultMediaType;
 
     private MicrometerPrometheusFormatter(Builder builder) {
         scopeTagName = builder.scopeTagName;
         scopeSelection = builder.scopeSelection;
-        meterSelection = builder.meterNameSelection;
+        meterNameSelection = builder.meterNameSelection;
         resultMediaType = builder.resultMediaType;
     }
 
@@ -82,28 +82,7 @@ private MicrometerPrometheusFormatter(Builder builder) {
      * @return filtered Prometheus output
      */
     public Optional<String> filteredOutput() {
-        return formattedOutput(prometheusMeterRegistry(),
-                               resultMediaType,
-                               scopeTagName,
-                               scopeSelection,
-                               meterSelection);
-    }
-
-    /**
-     * Retrieves the Prometheus-format report from the specified registry, according to the specified media type,
-     * filtered by the specified scope and meter name, and returns the filtered Prometheus-format output.
-     *
-     * @param prometheusMeterRegistry registry to query
-     * @param resultMediaType media type which controls the exact output format
-     * @param scopeSelection scope to select; null if no scope selection required
-     * @param meterNameSelection meter name to select; null if no meter name selection required
-     * @return filtered output
-     */
-    Optional<String> formattedOutput(PrometheusMeterRegistry prometheusMeterRegistry,
-                                  MediaType resultMediaType,
-                                  String scopeTagName,
-                                  Iterable<String> scopeSelection,
-                                  Iterable<String> meterNameSelection) {
+        PrometheusMeterRegistry prometheusMeterRegistry = prometheusMeterRegistry();
         Set<String> meterNamesOfInterest = meterNamesOfInterest(prometheusMeterRegistry,
                                                                           scopeSelection,
                                                                           meterNameSelection);

metrics/metrics/src/main/java/io/helidon/metrics/RegistryFactory.java

@@ -19,6 +19,7 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
+import java.util.concurrent.Callable;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
 
@@ -80,6 +81,17 @@ private void accessMetricsSettings(Runnable operation) {
         }
     }
 
+    private <T> T accessMetricsSettings(Callable<T> callable) {
+        metricsSettingsAccess.lock();
+        try {
+            return callable.call();
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        } finally {
+            metricsSettingsAccess.unlock();
+        }
+    }
+
 
     /**
      * Create a new factory with default configuration, with pre-filled
@@ -137,9 +149,6 @@ public static RegistryFactory getInstance(Config config) {
     }
 
     Registry getARegistry(String scope) {
-        if (Registry.BASE_SCOPE.equals(scope)) {
-            ensureBase();
-        }
         return registries.get(scope);
     }
 
@@ -151,10 +160,10 @@ Registry getARegistry(String scope) {
      */
     @Override
     public io.helidon.metrics.api.Registry getRegistry(String scope) {
-        if (Registry.BASE_SCOPE.equals(scope)) {
-            ensureBase();
-        }
-        return registries.computeIfAbsent(scope, s -> Registry.create(s, metricsSettings.registrySettings(s)));
+        return accessMetricsSettings(() -> registries.computeIfAbsent(scope, s ->
+                s.equals(Registry.BASE_SCOPE)
+                        ? BaseRegistry.create(metricsSettings)
+                        : Registry.create(s, metricsSettings.registrySettings(s))));
     }
 
     @Override
@@ -204,21 +213,20 @@ public Iterable<String> scopes() {
 
     @Override
     public void start() {
+        /*
+            Primarily for successive tests (e.g., in the TCK) which might share the same VM, delete each metric individually
+            (which will trickle down into the delegate meter registry) and also clear out the collection of registries.
+         */
+        registries.values()
+                .forEach(r -> r.getMetrics()
+                        .forEach((id, m) -> r.remove(id)));
+        registries.clear();
         PeriodicExecutor.start();
     }
 
     @Override
     public void stop() {
         PeriodicExecutor.stop();
     }
-
-    private void ensureBase() {
-        if (null == registries.get(Registry.BASE_SCOPE)) {
-            accessMetricsSettings(() -> {
-                Registry registry = BaseRegistry.create(metricsSettings);
-                registries.put(Registry.BASE_SCOPE, registry);
-            });
-        }
-    }
 }
 

microprofile/tests/tck/tck-metrics/src/test/java/io/helidon/microprofile/metrics/tck/MetricsTckCdiExtension.java

@@ -15,13 +15,16 @@
  */
 package io.helidon.microprofile.metrics.tck;
 
+import io.helidon.metrics.api.RegistryFactory;
+
 import jakarta.enterprise.event.Observes;
 import jakarta.enterprise.inject.spi.BeforeBeanDiscovery;
 import jakarta.enterprise.inject.spi.Extension;
 
 public class MetricsTckCdiExtension implements Extension {
 
     void before(@Observes BeforeBeanDiscovery discovery) {
+        RegistryFactory.getInstance().start();
         discovery.addAnnotatedType(ArrayParamConverterProvider.class, ArrayParamConverterProvider.class.getSimpleName());
     }
 }