Added comment and removed redundant virtual thread starvation test

Author: dplyukhin

.github/workflows/ci.yml

@@ -147,7 +147,7 @@ jobs:
           USER: unittest
           TEMPORAL_SERVICE_ADDRESS: localhost:7233
           USE_EXTERNAL_SERVICE: true
-        run: ./gradlew --no-daemon :temporal-sdk:virtualThreadTests :temporal-sdk:virtualThreadStarvationTests -x spotlessCheck -x spotlessApply -x spotlessJava -PtestJavaVersion=21
+        run: ./gradlew --no-daemon :temporal-sdk:virtualThreadTests -x spotlessCheck -x spotlessApply -x spotlessJava -PtestJavaVersion=21
 
       - name: Publish Test Report
         uses: mikepenz/action-junit-report@bccf2e31636835cf0874589931c4116687171386 # v6

temporal-sdk/build.gradle

@@ -256,23 +256,6 @@ testing {
             }
         }
 
-        virtualThreadStarvationTests(JvmTestSuite) {
-            targets {
-                all {
-                    testTask.configure {
-                        jvmArgs '-Djdk.virtualThreadScheduler.parallelism=1',
-                                '-Djdk.virtualThreadScheduler.maxPoolSize=1'
-                        if (project.hasProperty("testJavaVersion")) {
-                            javaLauncher = javaToolchains.launcherFor {
-                                languageVersion = JavaLanguageVersion.of(project.property("testJavaVersion") as int)
-                            }
-                        }
-                        shouldRunAfter(virtualThreadTests)
-                    }
-                }
-            }
-        }
-
         // Run the same test as the normal test task with virtual threads
         testsWithVirtualThreads(JvmTestSuite) {
             // Use the same source and resources as the main test set
@@ -304,5 +287,4 @@ testing {
 tasks.named('check') {
     dependsOn(testing.suites.jackson3Tests)
     dependsOn(testing.suites.virtualThreadTests)
-    dependsOn(testing.suites.virtualThreadStarvationTests)
 }

temporal-sdk/src/test/java/io/temporal/internal/sync/DeterministicRunnerTest.java

@@ -842,6 +842,8 @@ public void testThreadStarvationBeforeWorkflowThreadStarts() throws InterruptedE
             () -> fail("workflow code should not start while the executor thread is occupied"));
 
     try {
+      // Try starting the root workflow thread, but it won't run because the executor is tied up.
+      // We should detect this and throw a PotentialDeadlockException.
       PotentialDeadlockException e =
           Assert.assertThrows(
               PotentialDeadlockException.class, () -> runner.runUntilAllBlocked(10));