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

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;
 }