[Java] Dynamic resource API in Java (#4824)

java/api/src/main/java/org/ray/api/Ray.java

@@ -123,6 +123,21 @@ public final class Ray extends RayCall {
     return runtime;
   }
 
+  /**
+   * Update the resource for the specified client.
+   * Set the resource for the specific node.
+   */
+  public static void setResource(UniqueId nodeId, String resourceName, double capacity) {
+    runtime.setResource(resourceName, capacity, nodeId);
+  }
+
+  /**
+   * Set the resource for local node.
+   */
+  public static void setResource(String resourceName, double capacity) {
+    runtime.setResource(resourceName, capacity, UniqueId.NIL);
+  }
+
   /**
    * Get the runtime context.
    */

java/api/src/main/java/org/ray/api/runtime/RayRuntime.java

@@ -65,6 +65,15 @@ public interface RayRuntime {
    */
   void free(List<UniqueId> objectIds, boolean localOnly, boolean deleteCreatingTasks);
 
+  /**
+   * Set the resource for the specific node.
+   *
+   * @param resourceName The name of resource.
+   * @param capacity The capacity of the resource.
+   * @param nodeId The node that we want to set its resource.
+   */
+  void setResource(String resourceName, double capacity, UniqueId nodeId);
+
   /**
    * Invoke a remote function.
    *

java/runtime/src/main/java/org/ray/runtime/AbstractRayRuntime.java

@@ -210,6 +210,15 @@ public abstract class AbstractRayRuntime implements RayRuntime {
     rayletClient.freePlasmaObjects(objectIds, localOnly, deleteCreatingTasks);
   }
 
+  @Override
+  public void setResource(String resourceName, double capacity, UniqueId nodeId) {
+    Preconditions.checkArgument(Double.compare(capacity, 0) >= 0);
+    if (nodeId == null) {
+      nodeId = UniqueId.NIL;
+    }
+    rayletClient.setResource(resourceName, capacity, nodeId);
+  }
+
   private List<List<UniqueId>> splitIntoBatches(List<UniqueId> objectIds) {
     List<List<UniqueId>> batches = new ArrayList<>();
     int objectsSize = objectIds.size();

java/runtime/src/main/java/org/ray/runtime/raylet/MockRayletClient.java

@@ -209,6 +209,11 @@ public class MockRayletClient implements RayletClient {
     throw new NotImplementedException("Not implemented.");
   }
 
+  @Override
+  public void setResource(String resourceName, double capacity, UniqueId nodeId) {
+    LOGGER.error("Not implemented under SINGLE_PROCESS mode.");
+  }
+
   @Override
   public void destroy() {
     exec.shutdown();

java/runtime/src/main/java/org/ray/runtime/raylet/RayletClient.java

@@ -30,5 +30,7 @@ public interface RayletClient {
 
   void notifyActorResumedFromCheckpoint(UniqueId actorId, UniqueId checkpointId);
 
+  void setResource(String resourceName, double capacity, UniqueId nodeId);
+
   void destroy();
 }

java/runtime/src/main/java/org/ray/runtime/raylet/RayletClientImpl.java

@@ -308,6 +308,10 @@ public class RayletClientImpl implements RayletClient {
     return buffer;
   }
 
+  public void setResource(String resourceName, double capacity, UniqueId nodeId) {
+    nativeSetResource(client, resourceName, capacity, nodeId.getBytes());
+  }
+
   public void destroy() {
     nativeDestroy(client);
   }
@@ -357,4 +361,7 @@ public class RayletClientImpl implements RayletClient {
 
   private static native void nativeNotifyActorResumedFromCheckpoint(long conn, byte[] actorId,
       byte[] checkpointId);
+
+  private static native void nativeSetResource(long conn, String resourceName, double capacity,
+                                               byte[] nodeId) throws RayException;
 }

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

@@ -0,0 +1,44 @@
+package org.ray.api.test;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+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.ray.api.options.CallOptions;
+import org.ray.api.runtimecontext.NodeInfo;
+import org.testng.Assert;
+import org.testng.annotations.Test;
+
+public class DynamicResourceTest extends BaseTest {
+
+  @RayRemote
+  public static String sayHi() {
+    return "hi";
+  }
+
+  @Test
+  public void testSetResource() {
+    TestUtils.skipTestUnderSingleProcess();
+    CallOptions op1 = new CallOptions(ImmutableMap.of("A", 10.0));
+    RayObject<String> obj = Ray.call(DynamicResourceTest::sayHi, op1);
+    WaitResult<String> result = Ray.wait(ImmutableList.of(obj), 1, 1000);
+    Assert.assertEquals(result.getReady().size(), 0);
+
+    Ray.setResource("A", 10.0);
+
+    // 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 ray call result.
+    result = Ray.wait(ImmutableList.of(obj), 1, 1000);
+    Assert.assertEquals(result.getReady().size(), 1);
+    Assert.assertEquals(Ray.get(obj.getId()), "hi");
+  }
+
+}