Report deadlocks when running in sharedthreadpool

CHANGES.txt

@@ -1,4 +1,5 @@
 Current (7.11.0)
+Fixed: GITHUB-3028: Execution stalls when using "use-global-thread-pool" (Krishnan Mahadevan)
 
 7.10.2
 Fixed: GITHUB-3117: ListenerComparator doesn't work (Krishnan Mahadevan)

testng-core-api/src/main/java/org/testng/internal/TestNGDeadLockException.java

@@ -0,0 +1,10 @@
+package org.testng.internal;
+
+import org.testng.TestNGException;
+
+/** Represents a deadlock condition in TestNG wherein execution can get stalled. */
+public class TestNGDeadLockException extends TestNGException {
+  public TestNGDeadLockException(String string) {
+    super(string);
+  }
+}

testng-core/src/main/java/org/testng/TestRunner.java

@@ -47,6 +47,7 @@
 import org.testng.internal.TestMethodComparator;
 import org.testng.internal.TestMethodContainer;
 import org.testng.internal.TestNGClassFinder;
+import org.testng.internal.TestNGDeadLockException;
 import org.testng.internal.TestNGMethodFinder;
 import org.testng.internal.Utils;
 import org.testng.internal.XmlMethodSelector;
@@ -63,6 +64,7 @@
 import org.testng.util.TimeUtils;
 import org.testng.xml.XmlClass;
 import org.testng.xml.XmlPackage;
+import org.testng.xml.XmlSuite;
 import org.testng.xml.XmlTest;
 
 /** This class takes care of running one Test. */
@@ -807,9 +809,34 @@ public List<IWorker<ITestNGMethod>> createWorkers(List<ITestNGMethod> methods) {
             .testContext(this)
             .listeners(this.m_classListeners.values())
             .build();
-    return AbstractParallelWorker.newWorker(
-            m_xmlTest.getParallel(), m_xmlTest.getGroupByInstances())
-        .createWorkers(args);
+    List<IWorker<ITestNGMethod>> result =
+        AbstractParallelWorker.newWorker(m_xmlTest.getParallel(), m_xmlTest.getGroupByInstances())
+            .createWorkers(args);
+    long dataDrivenTestCount =
+        result.stream()
+            .flatMap(it -> it.getTasks().stream())
+            .filter(ITestNGMethod::isDataDriven)
+            .count();
+    int threads = getCurrentXmlTest().getThreadCount();
+    XmlSuite.ParallelMode parallelMode = getCurrentXmlTest().getParallel();
+    XmlSuite suite = getSuite().getXmlSuite();
+    if (suite.useGlobalThreadPool()
+        && parallelMode.isParallel()
+        && dataDrivenTestCount >= threads) {
+      String msg =
+          "[Deadlock condition detected] "
+              + "Cannot run "
+              + dataDrivenTestCount
+              + " data driven tests on just "
+              + threads
+              + " threads when "
+              + "using common thread pool. "
+              + "Please increase the number of threads to at-least "
+              + (dataDrivenTestCount + 1)
+              + ".";
+      throw new TestNGDeadLockException(msg);
+    }
+    return result;
   }
 
   private void afterRun() {

testng-core/src/test/java/test/thread/SharedThreadPoolTest.java

@@ -8,10 +8,15 @@
 import java.util.stream.Collectors;
 import org.testng.TestNG;
 import org.testng.annotations.AfterMethod;
+import org.testng.annotations.DataProvider;
 import org.testng.annotations.Test;
+import org.testng.internal.TestNGDeadLockException;
 import org.testng.xml.XmlSuite;
 import test.SimpleBaseTest;
 import test.thread.issue2019.TestClassSample;
+import test.thread.issue3028.AnotherDataDrivenTestSample;
+import test.thread.issue3028.DataDrivenTestSample;
+import test.thread.issue3028.FactoryPoweredDataDrivenTestSample;
 
 public class SharedThreadPoolTest extends SimpleBaseTest {
 
@@ -68,6 +73,27 @@ public void ensureCommonThreadPoolIsNotUsedWhenUsedWithSuiteFiles() {
         .hasSizeBetween(4, 10);
   }
 
+  @Test(expectedExceptions = TestNGDeadLockException.class, dataProvider = "modes")
+  public void ensureDeadLocksAreDetectedForDataDrivenTestsRunningInParallel(
+      XmlSuite.ParallelMode mode, Class<?>... classes) {
+    TestNG testng = create(classes);
+    testng.shouldUseGlobalThreadPool(true);
+    testng.setParallel(mode);
+    testng.setThreadCount(2);
+    testng.run();
+  }
+
+  @DataProvider(name = "modes")
+  public Object[][] parallelModes() {
+    return new Object[][] {
+      {XmlSuite.ParallelMode.METHODS, DataDrivenTestSample.class},
+      {XmlSuite.ParallelMode.INSTANCES, FactoryPoweredDataDrivenTestSample.class},
+      {
+        XmlSuite.ParallelMode.CLASSES, DataDrivenTestSample.class, AnotherDataDrivenTestSample.class
+      },
+    };
+  }
+
   private static List<Long> runSimpleTest(String suite) {
     TestNG testng = create();
     testng.setTestSuites(Collections.singletonList(suite));

testng-core/src/test/java/test/thread/issue3028/AnotherDataDrivenTestSample.java

@@ -0,0 +1,30 @@
+package test.thread.issue3028;
+
+import org.testng.ITestResult;
+import org.testng.Reporter;
+import org.testng.annotations.DataProvider;
+import org.testng.annotations.Test;
+
+public class AnotherDataDrivenTestSample {
+
+  @Test(dataProvider = "dp")
+  public void a(int ignored) {
+    log();
+  }
+
+  @Test(dataProvider = "dp")
+  public void b(int ignored) {
+    log();
+  }
+
+  private void log() {
+    ITestResult itr = Reporter.getCurrentTestResult();
+    long id = Thread.currentThread().getId();
+    Reporter.log("Running " + itr.toString() + " on Thread " + id);
+  }
+
+  @DataProvider(name = "dp", parallel = true)
+  public Object[][] getData() {
+    return new Object[][] {{1}, {2}, {3}, {4}, {5}};
+  }
+}

testng-core/src/test/java/test/thread/issue3028/DataDrivenTestSample.java

@@ -0,0 +1,29 @@
+package test.thread.issue3028;
+
+import org.testng.ITestResult;
+import org.testng.Reporter;
+import org.testng.annotations.*;
+
+public class DataDrivenTestSample {
+
+  @Test(dataProvider = "dp")
+  public void a(int ignored) {
+    log();
+  }
+
+  @Test(dataProvider = "dp")
+  public void b(int ignored) {
+    log();
+  }
+
+  private void log() {
+    ITestResult itr = Reporter.getCurrentTestResult();
+    long id = Thread.currentThread().getId();
+    Reporter.log("Running " + itr.toString() + " on Thread " + id);
+  }
+
+  @DataProvider(name = "dp", parallel = true)
+  public Object[][] getData() {
+    return new Object[][] {{1}, {2}, {3}, {4}, {5}};
+  }
+}

testng-core/src/test/java/test/thread/issue3028/FactoryPoweredDataDrivenTestSample.java

@@ -0,0 +1,38 @@
+package test.thread.issue3028;
+
+import org.testng.ITestResult;
+import org.testng.Reporter;
+import org.testng.annotations.DataProvider;
+import org.testng.annotations.Factory;
+import org.testng.annotations.Test;
+
+public class FactoryPoweredDataDrivenTestSample {
+
+  @Factory
+  public static Object[] objects() {
+    return new Object[] {
+      new FactoryPoweredDataDrivenTestSample(), new FactoryPoweredDataDrivenTestSample()
+    };
+  }
+
+  @Test(dataProvider = "dp")
+  public void a(int ignored) {
+    log();
+  }
+
+  @Test(dataProvider = "dp")
+  public void b(int ignored) {
+    log();
+  }
+
+  private void log() {
+    ITestResult itr = Reporter.getCurrentTestResult();
+    long id = Thread.currentThread().getId();
+    Reporter.log("Running " + itr.toString() + " on Thread " + id);
+  }
+
+  @DataProvider(name = "dp", parallel = true)
+  public Object[][] getData() {
+    return new Object[][] {{1}, {2}, {3}, {4}, {5}};
+  }
+}