fixes

Author: hmottestad

core/http/client/src/main/java/org/eclipse/rdf4j/http/client/QueryCircuitBreakerHandle.java

@@ -14,6 +14,7 @@
 import java.util.Objects;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicLong;
+import java.util.concurrent.atomic.AtomicReference;
 
 import org.eclipse.rdf4j.repository.RepositoryConnection;
 import org.slf4j.Logger;
@@ -39,14 +40,12 @@ public enum Source {
 	private final long startTimeMillis;
 	private final Runnable remoteCancel;
 	private final AtomicBoolean active = new AtomicBoolean(true);
-	private final AtomicBoolean cancelRequested = new AtomicBoolean(false);
+	private final AtomicReference<Cancellation> cancellation = new AtomicReference<>();
 	private final AtomicLong lastHeavyCheckpointMillis = new AtomicLong(-1);
 
 	private volatile Thread workerThread;
 	private volatile RepositoryConnection repositoryConnection;
 	private volatile String lastHeavyOperator;
-	private volatile QueryPressureState cancellationState = QueryPressureState.NORMAL;
-	private volatile String cancellationReason;
 
 	QueryCircuitBreakerHandle(String executionId, Source source, String repositoryId, String queryHash,
 			long startTimeMillis, Runnable remoteCancel) {
@@ -83,7 +82,7 @@ public boolean isActive() {
 	}
 
 	public boolean isCancelRequested() {
-		return cancelRequested.get();
+		return cancellation.get() != null;
 	}
 
 	public long getLastHeavyCheckpointMillis() {
@@ -95,11 +94,13 @@ public String getLastHeavyOperator() {
 	}
 
 	public QueryPressureState getCancellationState() {
-		return cancellationState;
+		Cancellation current = cancellation.get();
+		return current != null ? current.state : QueryPressureState.NORMAL;
 	}
 
 	public String getCancellationReason() {
-		return cancellationReason;
+		Cancellation current = cancellation.get();
+		return current != null ? current.reason : null;
 	}
 
 	public boolean hasHeavyCheckpoint() {
@@ -125,13 +126,10 @@ void markHeavy(String operator, long checkpointTimeMillis) {
 	}
 
 	boolean requestCancel(QueryPressureState state, String reason) {
-		if (!active.get() || !cancelRequested.compareAndSet(false, true)) {
+		if (!active.get() || !cancellation.compareAndSet(null, new Cancellation(state, reason))) {
 			return false;
 		}
 
-		cancellationState = state;
-		cancellationReason = reason;
-
 		Thread activeWorker = workerThread;
 		if (activeWorker != null && activeWorker != Thread.currentThread()) {
 			activeWorker.interrupt();
@@ -168,4 +166,15 @@ private void runRemoteCancel() {
 			LOGGER.debug("Error while forwarding breaker-triggered cancellation", e);
 		}
 	}
+
+	private static final class Cancellation {
+
+		private final QueryPressureState state;
+		private final String reason;
+
+		private Cancellation(QueryPressureState state, String reason) {
+			this.state = state;
+			this.reason = reason;
+		}
+	}
 }

core/http/client/src/test/java/org/eclipse/rdf4j/http/client/QueryCircuitBreakerTest.java

@@ -133,6 +133,12 @@ void shouldNotLeaveCurrentThreadInterruptedWhenSelfCancelling() {
 		}
 	}
 
+	@Test
+	void shouldPublishCancellationDetailsAndCancelRequestAsSingleState() {
+		assertThrows(NoSuchFieldException.class,
+				() -> QueryCircuitBreakerHandle.class.getDeclaredField("cancelRequested"));
+	}
+
 	@Test
 	void shouldIgnoreCheckpointStrideOnlyAtHighOrAbove() throws Exception {
 		PropertiesScope properties = new PropertiesScope()

tools/server-spring/src/test/java/org/eclipse/rdf4j/common/webapp/system/QueryCircuitBreakerStatusControllerTest.java

@@ -30,8 +30,10 @@ class QueryCircuitBreakerStatusControllerTest {
 	void shouldMapSystemBreakerStatusEndpoint() throws Exception {
 		String servletConfig = Files.readString(
 				Path.of("..", "server", "src", "main", "webapp", "WEB-INF", "common-webapp-system-servlet.xml"));
+		String webXml = Files.readString(Path.of("..", "server", "src", "main", "webapp", "WEB-INF", "web.xml"));
 
-		assertThat(servletConfig).contains("/system/breaker/status");
+		assertThat(servletConfig).contains("/system/breaker/status.view");
+		assertThat(webXml).contains("<url-pattern>*.view</url-pattern>");
 	}
 
 	@Test

tools/server/src/main/webapp/WEB-INF/common-webapp-system-servlet.xml

@@ -35,7 +35,7 @@
 				<prop key="/system/overview.view">commonWebappSystemOverviewController</prop>
 				<prop key="/system/info/overview.view">commonWebappSystemInfoController</prop>
 				<prop key="/system/info/debug.view">filenameViewController</prop>
-				<prop key="/system/breaker/status">commonWebappQueryCircuitBreakerStatusController</prop>
+				<prop key="/system/breaker/status.view">commonWebappQueryCircuitBreakerStatusController</prop>
 				<prop key="/system/logging/overview.view">commonWebappLoggingOverviewController</prop>
 			</props>
 		</property>