Forbid non-named threads

This commit forbids the use of Thread constructors that do not take a
name. In general nameless threads are more difficult to understand their
purpose when debugging. Note that this is only added to production
signatures. Tests are not forbidden here so as not to be pedantic (or
require a larger change since many tests create anonymous threads).

relates elastic#101628

build-tools-internal/src/main/resources/forbidden/es-server-signatures.txt

@@ -160,3 +160,7 @@ org.elasticsearch.cluster.ClusterState#compatibilityVersions()
 org.elasticsearch.cluster.ClusterFeatures#nodeFeatures()
 @defaultMessage ClusterFeatures#clusterHasFeature is for internal use only. Use FeatureService#clusterHasFeature to determine if a feature is present on the cluster.
 org.elasticsearch.cluster.ClusterFeatures#clusterHasFeature(org.elasticsearch.features.NodeFeature)
+
+@defaultMessage Use a Thread constructor with a name, anonymous threads are more difficult to debug
+java.lang.Thread#<init>(java.lang.Runnable)
+java.lang.Thread#<init>(java.lang.ThreadGroup, java.lang.Runnable)

distribution/tools/cli-launcher/src/main/java/org/elasticsearch/launcher/CliToolLauncher.java

@@ -94,7 +94,7 @@ static Thread createShutdownHook(Terminal terminal, Closeable closeable) {
                 e.printStackTrace(terminal.getErrorWriter());
             }
             terminal.flush(); // make sure to flush whatever the close or error might have written
-        });
+        }, "elasticsearch-cli-shutdown");
 
     }
 

server/src/main/java/org/elasticsearch/ExceptionsHelper.java

@@ -257,7 +257,7 @@ public static void maybeDieOnAnotherThread(final Throwable throwable) {
                 final String formatted = ExceptionsHelper.formatStackTrace(Thread.currentThread().getStackTrace());
                 logger.error("fatal error {}: {}\n{}", error.getClass().getCanonicalName(), error.getMessage(), formatted);
             } finally {
-                new Thread(() -> { throw error; }).start();
+                new Thread(() -> { throw error; }, "elasticsearch-error-rethrower").start();
             }
         });
     }

server/src/main/java/org/elasticsearch/bootstrap/Elasticsearch.java

@@ -174,7 +174,7 @@ private static void initPhase2(Bootstrap bootstrap) throws IOException {
         // initialize probes before the security manager is installed
         initializeProbes();
 
-        Runtime.getRuntime().addShutdownHook(new Thread(Elasticsearch::shutdown));
+        Runtime.getRuntime().addShutdownHook(new Thread(Elasticsearch::shutdown, "elasticsearch-shutdown"));
 
         // look for jar hell
         final Logger logger = LogManager.getLogger(JarHell.class);
@@ -376,7 +376,7 @@ private static void startCliMonitorThread(InputStream stdin) {
                     Bootstrap.exit(1);
                 }
             }
-        }).start();
+        }, "elasticsearch-cli-monitor-thread").start();
     }
 
     /**