Ignore Intellij idea rmi/jmx threads (attached debugger/ ctrl-c watcher/ thread dumper) (#26)

* Ignore intellij debugger threads.

* Detect and ignore intellij rmi threads.

Author: dweiss

randomizedtesting-jupiter/src/main/java/com/carrotsearch/randomizedtesting/jupiter/DetectThreadLeaks.java

@@ -57,6 +57,10 @@ enum Scope {
    * <p>Annotations are collected hierarchically from the class and its superclasses, and the
    * filters from all levels are combined.
    *
+   * <p>The default value of this annotation is {@link SystemThreadFilter} which excludes many known
+   * system and other ignorable threads. Add this filter explicitly when you redeclare the
+   * exclusions or omit it if you'd like to detect those system threads.
+   *
    * @see SystemThreadFilter
    */
   @Target({ElementType.TYPE})

randomizedtesting-jupiter/src/main/java/com/carrotsearch/randomizedtesting/jupiter/SystemThreadFilter.java

@@ -22,8 +22,18 @@ public boolean test(Thread t) {
       return true;
     }
 
-    // These are some of the "known" threads that should be ignored.
     var tName = t.getName();
+
+    // Intellij Idea attaches to forked test processes using jmx/rmi. This is asynchronous and
+    // unpredictable.
+    if (Boolean.getBoolean("intellij.debug.agent")) {
+      // JMX server connection timeout
+      if (tName.startsWith("JMX server connection timeout") || tName.startsWith("RMI TCP")) {
+        return true;
+      }
+    }
+
+    // These are some of the "known" threads that should be ignored.
     return switch (tName) {
       case "JFR request timer",
           "YJPAgent-Telemetry",

randomizedtesting-jupiter/src/test/java/com/carrotsearch/randomizedtesting/tests/F005_ThreadLeaks.java

@@ -5,6 +5,8 @@
 import static org.junit.platform.testkit.engine.TestExecutionResultConditions.*;
 
 import com.carrotsearch.randomizedtesting.jupiter.DetectThreadLeaks;
+import com.carrotsearch.randomizedtesting.jupiter.Randomized;
+import com.carrotsearch.randomizedtesting.jupiter.SystemThreadFilter;
 import com.carrotsearch.randomizedtesting.tests.infra.IgnoreInStandaloneRuns;
 import java.time.Duration;
 import java.util.ArrayList;
@@ -387,6 +389,25 @@ void testMethod() {
       }
     }
 
+    @Test
+    void intellijJmxThreads() {
+      collectExecutionResults(testKitBuilder(IntellijThreads.class))
+          .results()
+          .allEvents()
+          .assertThatEvents()
+          .doNotHave(event(finishedWithFailure()));
+    }
+
+    @DetectThreadLeaks(scope = DetectThreadLeaks.Scope.SUITE)
+    @DetectThreadLeaks.ExcludeThreads(value = {SystemThreadFilter.class})
+    @Randomized
+    static class IntellijThreads { // extends IgnoreInStandaloneRuns {
+      @Test
+      void testMethod() throws Exception {
+        Thread.sleep(1000);
+      }
+    }
+
     @DetectThreadLeaks(scope = DetectThreadLeaks.Scope.SUITE)
     @DetectThreadLeaks.ExcludeThreads(ExcludeNamedAFilter.class)
     static class ExcludedByClassFilter extends IgnoreInStandaloneRuns {