Merge pull request #2901 from jembishop/PV-completablefuture

implement completable future on PV class

core/pv/src/main/java/org/phoebus/pv/PV.java

@@ -10,7 +10,6 @@
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CopyOnWriteArrayList;
-import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
@@ -236,17 +235,17 @@ public VType read()
 
     /** Issue a read request
      *
-     *  <p>{@link Future} allows waiting for
+     *  <p>{@link CompletableFuture} allows waiting for
      *  and obtaining the result, or its <code>get()</code>
      *  calls will provide an error.
      *
      *  <p>As a side effect, registered listeners will
      *  also receive the value obtained by this call.
      *
-     *  @return {@link Future} for obtaining the result or Exception
+     *  @return {@link CompletableFuture} for obtaining the result or Exception
      *  @exception Exception on error
      */
-    public Future<VType> asyncRead() throws Exception
+    public CompletableFuture<VType> asyncRead() throws Exception
     {
         // Default: Return last known value
         return CompletableFuture.completedFuture(last_value);
@@ -270,17 +269,17 @@ public void write(final Object new_value) throws Exception
 
     /** Write value with confirmation
      *
-     *  <p>{@link Future} can be used to await completion
+     *  <p>{@link CompletableFuture} can be used to await completion
      *  of the write.
      *  The <code>get()</code> will not return a useful value (null),
      *  but they will throw an error if the write failed.
      *
      *  @param new_value Value to write to the PV
-     *  @return {@link Future} for awaiting completion or exception
+     *  @return {@link CompletableFuture} for awaiting completion or exception
      *  @exception Exception on error
      *  @see #write(Object)
      */
-    public Future<?> asyncWrite(final Object new_value) throws Exception
+    public CompletableFuture<?> asyncWrite(final Object new_value) throws Exception
     {   // Default: Normal write, declare 'done' right away
         write(new_value);
         return CompletableFuture.completedFuture(null);

core/pv/src/main/java/org/phoebus/pv/ca/JCA_PV.java

@@ -420,7 +420,7 @@ public void getCompleted(final GetEvent ev)
     }
 
     @Override
-    public Future<VType> asyncRead() throws Exception
+    public CompletableFuture<VType> asyncRead() throws Exception
     {
         final DBRType type = channel.getFieldType();
         if (type == null   ||  type == DBRType.UNKNOWN)
@@ -453,7 +453,7 @@ public void write(final Object new_value) throws Exception
     }
 
     @Override
-    public Future<?> asyncWrite(final Object new_value) throws Exception
+    public CompletableFuture<?> asyncWrite(final Object new_value) throws Exception
     {
         final PutCallbackFuture result = new PutCallbackFuture();
         performWrite(new_value, result);

core/pv/src/main/java/org/phoebus/pv/opva/PVA_PV.java

@@ -8,6 +8,7 @@
 package org.phoebus.pv.opva;
 
 import java.util.List;
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.Future;
 import java.util.logging.Level;
 
@@ -249,7 +250,7 @@ public void unlisten(final Monitor monitor)
 
     /** {@inheritDoc} */
     @Override
-    public Future<VType> asyncRead() throws Exception
+    public CompletableFuture<VType> asyncRead() throws Exception
     {
         final PVGetHandler result = new PVGetHandler(this);
         channel.createChannelGet(result, read_request);
@@ -265,7 +266,7 @@ public void write(final Object new_value) throws Exception
 
     /** {@inheritDoc} */
     @Override
-    public Future<?> asyncWrite(Object new_value) throws Exception
+    public CompletableFuture<?> asyncWrite(Object new_value) throws Exception
     {
         if (enum_labels != null  &&  new_value instanceof String)
         {   // Convert string-for-enum into index of corresponding label

core/pv/src/main/java/org/phoebus/pv/opva/PVGetHandler.java

@@ -27,7 +27,7 @@
  *  @author Kay Kasemir
  */
 @SuppressWarnings("nls")
-class PVGetHandler extends PVRequester implements ChannelGetRequester, Future<VType>
+class PVGetHandler extends PVRequester implements ChannelGetRequester
 {
     final private PVA_PV pv;
 

core/pv/src/main/java/org/phoebus/pv/opva/PVPutHandler.java

@@ -25,14 +25,15 @@
 import org.epics.pvdata.pv.Status;
 import org.epics.pvdata.pv.Structure;
 import org.phoebus.pv.PV;
+import org.epics.vtype.VType;
 
 /** A {@link ChannelPutRequester} for writing a value to a {@link PVA_PV},
  *  indicating completion via a {@link Future}
  *
  *  @author Kay Kasemir
  */
 @SuppressWarnings("nls")
-class PVPutHandler extends PVRequester implements ChannelPutRequester, Future<Object>
+class PVPutHandler extends PVRequester implements ChannelPutRequester
 {
     final private PV pv;
     final private Object new_value;
@@ -136,7 +137,7 @@ public boolean isDone()
 
     // Future
     @Override
-    public Object get() throws InterruptedException, ExecutionException
+    public VType get() throws InterruptedException, ExecutionException
     {
         updates.await();
         if (error != null)
@@ -146,7 +147,7 @@ public Object get() throws InterruptedException, ExecutionException
 
     // Future
     @Override
-    public Object get(final long timeout, final TimeUnit unit) throws InterruptedException,
+    public VType get(final long timeout, final TimeUnit unit) throws InterruptedException,
             ExecutionException, TimeoutException
     {
         if (! updates.await(timeout, unit))

core/pv/src/main/java/org/phoebus/pv/opva/PVRequester.java

@@ -9,15 +9,17 @@
 
 import static org.phoebus.pv.PV.logger;
 
+import java.util.concurrent.CompletableFuture;
 import java.util.logging.Level;
 
 import org.epics.pvdata.pv.MessageType;
 import org.epics.pvdata.pv.Requester;
+import org.epics.vtype.VType;
 
 /** Base for PVAccess {@link Requester}
  *  @author Kay Kasemir
  */
-class PVRequester implements Requester
+class PVRequester extends CompletableFuture<VType> implements Requester
 {
     @Override
     public String getRequesterName()

core/pv/src/main/java/org/phoebus/pv/pva/PVA_PV.java

@@ -8,6 +8,7 @@
 package org.phoebus.pv.pva;
 
 import java.util.BitSet;
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
@@ -96,11 +97,11 @@ private void handleMonitor(final PVAChannel channel,
         }
 
     @Override
-    public Future<VType> asyncRead() throws Exception
+    public CompletableFuture<VType> asyncRead() throws Exception
     {
         final Future<PVAStructure> data = channel.read(name_helper.getRequest());
         // Wrap into Future that converts PVAStructure into VType
-        return new Future<>()
+        return new CompletableFuture<>()
         {
             @Override
             public boolean cancel(final boolean mayInterruptIfRunning)
@@ -190,7 +191,7 @@ public void write(final Object new_value) throws Exception
     }
 
     @Override
-    public Future<?> asyncWrite(final Object new_value) throws Exception
+    public CompletableFuture<?> asyncWrite(final Object new_value) throws Exception
     {
         // Perform a put with completion,
         // i.e., process target and block until processing completes,