Fix Java CI failure (#4995)

java/api/src/main/java/org/ray/api/id/BaseId.java

@@ -48,7 +48,7 @@ public abstract class BaseId implements Serializable {
           break;
         }
       }
-    isNilCache = localIsNil;
+      isNilCache = localIsNil;
     }
     return isNilCache;
   }

java/test/src/main/java/org/ray/api/TestUtils.java

@@ -1,8 +1,10 @@
 package org.ray.api;
 
 import java.util.function.Supplier;
+import org.ray.api.annotation.RayRemote;
 import org.ray.runtime.AbstractRayRuntime;
 import org.ray.runtime.config.RunMode;
+import org.testng.Assert;
 import org.testng.SkipException;
 
 public class TestUtils {
@@ -42,4 +44,17 @@ public class TestUtils {
     }
     return false;
   }
+
+  @RayRemote
+  private static String hi() {
+    return "hi";
+  }
+
+  /**
+   * Warm up the cluster.
+   */
+  public static void warmUpCluster() {
+    RayObject<String> obj = Ray.call(TestUtils::hi);
+    Assert.assertEquals(obj.get(), "hi");
+  }
 }

java/test/src/main/java/org/ray/api/test/DynamicResourceTest.java

@@ -23,6 +23,10 @@ public class DynamicResourceTest extends BaseTest {
   @Test
   public void testSetResource() {
     TestUtils.skipTestUnderSingleProcess();
+
+    // Call a task in advance to warm up the cluster to avoid being too slow to start workers.
+    TestUtils.warmUpCluster();
+
     CallOptions op1 =
         new CallOptions.Builder().setResources(ImmutableMap.of("A", 10.0)).createCallOptions();
     RayObject<String> obj = Ray.call(DynamicResourceTest::sayHi, op1);
@@ -30,16 +34,21 @@ public class DynamicResourceTest extends BaseTest {
     Assert.assertEquals(result.getReady().size(), 0);
 
     Ray.setResource("A", 10.0);
+    boolean resourceReady = TestUtils.waitForCondition(() -> {
+      List<NodeInfo> nodes = Ray.getRuntimeContext().getAllNodeInfo();
+      if (nodes.size() != 1) {
+        return false;
+      }
+      return (0 == Double.compare(10.0, nodes.get(0).resources.get("A")));
+    }, 2000);
 
-    // Assert node info.
-    List<NodeInfo> nodes = Ray.getRuntimeContext().getAllNodeInfo();
-    Assert.assertEquals(nodes.size(), 1);
-    Assert.assertEquals(nodes.get(0).resources.get("A"), 10.0);
+    Assert.assertTrue(resourceReady);
 
     // Assert ray call result.
     result = Ray.wait(ImmutableList.of(obj), 1, 1000);
     Assert.assertEquals(result.getReady().size(), 1);
     Assert.assertEquals(Ray.get(obj.getId()), "hi");
+
   }
 
 }

java/test/src/main/java/org/ray/api/test/WaitTest.java

@@ -5,6 +5,7 @@ import java.util.ArrayList;
 import java.util.List;
 import org.ray.api.Ray;
 import org.ray.api.RayObject;
+import org.ray.api.TestUtils;
 import org.ray.api.WaitResult;
 import org.ray.api.annotation.RayRemote;
 import org.testng.Assert;
@@ -28,6 +29,9 @@ public class WaitTest extends BaseTest {
   }
 
   private static void testWait() {
+    // Call a task in advance to warm up the cluster to avoid being too slow to start workers.
+    TestUtils.warmUpCluster();
+
     RayObject<String> obj1 = Ray.call(WaitTest::hi);
     RayObject<String> obj2 = Ray.call(WaitTest::delayedHi);
 
@@ -71,4 +75,5 @@ public class WaitTest extends BaseTest {
       Assert.assertTrue(true);
     }
   }
+
 }