update OrchestratorBlockedEvent and TaskFailedException to be uncheck… (#89)

* update OrchestratorBlockedEvent and TaskFailedException to be unchecked exception

* update CHANGELOG.md

Author: kaibocai

CHANGELOG.md

@@ -10,6 +10,7 @@
 
 * Updated package version to v1.0.0 - to be updated
 * update DataConverterException with detail error message ([#78](https://github.com/microsoft/durabletask-java/issues/78))
+* update OrchestratorBlockedEvent and TaskFailedException to be unchecked exceptions ([#88](https://github.com/microsoft/durabletask-java/issues/88))
 
 ### Breaking changes
 

client/src/main/java/com/microsoft/durabletask/OrchestratorBlockedEvent.java renamed to client/src/main/java/com/microsoft/durabletask/OrchestratorBlockedException.java

@@ -6,13 +6,13 @@
  * Control flow {@code Throwable} class for orchestrator functions. This {@code Throwable} must never be caught by user
  * code.
  * <p>
- * {@code OrchestratorBlockedEvent} is thrown when an orchestrator calls {@link Task#await} on an uncompleted task. The
+ * {@code OrchestratorBlockedException} is thrown when an orchestrator calls {@link Task#await} on an uncompleted task. The
  * purpose of throwing in this way is to halt execution of the orchestrator to save the current state and commit any
- * side effects. Catching {@code OrchestratorBlockedEvent} in user code could prevent the orchestration from saving
+ * side effects. Catching {@code OrchestratorBlockedException} in user code could prevent the orchestration from saving
  * state and scheduling new tasks, resulting in the orchestration getting stuck.
  */
-public final class OrchestratorBlockedEvent extends Throwable {
-    OrchestratorBlockedEvent(String message) {
+public final class OrchestratorBlockedException extends RuntimeException {
+    OrchestratorBlockedException(String message) {
         super(message);
     }
 }

client/src/main/java/com/microsoft/durabletask/OrchestratorFunction.java

@@ -18,8 +18,6 @@ public interface OrchestratorFunction<R> {
      * @param ctx the orchestration context, which provides access to additional context for the current orchestration
      *            execution
      * @return the serializable output of the orchestrator function
-     * @throws OrchestratorBlockedEvent when the orchestrator blocks on an uncompleted task, which is a normal occurrence
-     * @throws TaskFailedException when a task fails with an unhandled exception
      */
-    R apply(TaskOrchestrationContext ctx) throws OrchestratorBlockedEvent, TaskFailedException;
+    R apply(TaskOrchestrationContext ctx);
 }

client/src/main/java/com/microsoft/durabletask/Task.java

@@ -3,8 +3,6 @@
 package com.microsoft.durabletask;
 
 import java.util.concurrent.CompletableFuture;
-import java.util.function.Consumer;
-import java.util.function.Function;
 
 /**
  * Represents an asynchronous operation in a durable orchestration.
@@ -16,13 +14,13 @@
  * </pre>
  * <p>
  * Orchestrator code uses the {@link #await()} method to block on the completion of the task and retrieve the result.
- * If the task is not yet complete, the {@code await()} method will throw an {@link OrchestratorBlockedEvent}, which
+ * If the task is not yet complete, the {@code await()} method will throw an {@link OrchestratorBlockedException}, which
  * pauses the orchestrator's execution so that it can save its progress into durable storage and schedule any
  * outstanding work. When the task is complete, the orchestrator will run again from the beginning and the next time
  * the task's {@code await()} method is called, the result will be returned, or a {@link TaskFailedException} will be
  * thrown if the result of the task was an unhandled exception.
  * <p>
- * Note that orchestrator code must never catch {@code OrchestratorBlockedEvent} because doing so can cause the
+ * Note that orchestrator code must never catch {@code OrchestratorBlockedException} because doing so can cause the
  * orchestration instance to get permanently stuck.
  *
  * @param <V> the return type of the task
@@ -54,9 +52,6 @@ public boolean isCancelled() {
      * Blocks the orchestrator until this task to complete, and then returns its result.
      *
      * @return the result of the task
-     * @throws TaskFailedException if the task failed with an unhandled exception
-     * @throws OrchestratorBlockedEvent if the task has not yet been scheduled, which is a normal occurrence.
-     *                                  This {@code Throwable} must never be caught in user code.
      */
-    public abstract V await() throws TaskFailedException, OrchestratorBlockedEvent;
+    public abstract V await();
 }

client/src/main/java/com/microsoft/durabletask/TaskFailedException.java

@@ -9,7 +9,7 @@
  * Detailed information associated with a particular task failure can be retrieved using the {@link #getErrorDetails()}
  * method.
  */
-public class TaskFailedException extends Exception {
+public class TaskFailedException extends RuntimeException {
     private final FailureDetails details;
     private final String taskName;
     private final int taskId;

client/src/main/java/com/microsoft/durabletask/TaskOrchestration.java

@@ -66,8 +66,6 @@ public interface TaskOrchestration {
      *
      * @param ctx provides access to methods for scheduling durable tasks and getting information about the current
      *            orchestration instance.
-     * @throws TaskFailedException when an orchestrator fails with an unhandled exception
-     * @throws OrchestratorBlockedEvent when the orchestrator blocks on an uncompleted task, which is a normal occurrence
      */
-    void run(TaskOrchestrationContext ctx) throws TaskFailedException, OrchestratorBlockedEvent;
+    void run(TaskOrchestrationContext ctx);
 }

client/src/main/java/com/microsoft/durabletask/TaskOrchestrationExecutor.java

@@ -42,13 +42,13 @@ public TaskOrchestratorResult execute(List<HistoryEvent> pastEvents, List<Histor
             // or we receive a yield signal
             while (context.processNextEvent()) { /* no method body */ }
             completed = true;
+        } catch (OrchestratorBlockedException orchestratorBlockedException) {
+            logger.fine("The orchestrator has yielded and will await for new events.");
         } catch (Exception e) {
             // The orchestrator threw an unhandled exception - fail it
             // TODO: What's the right way to log this?
             logger.warning("The orchestrator failed with an unhandled exception: " + e.toString());
             context.fail(new FailureDetails(e));
-        } catch (OrchestratorBlockedEvent orchestratorBlockedEvent) {
-            logger.fine("The orchestrator has yielded and will await for new events.");
         }
 
         if (context.continuedAsNew || (completed && context.pendingActions.isEmpty() && !context.waitingForEvents())) {
@@ -712,11 +712,11 @@ private boolean waitingForEvents() {
             return this.outstandingEvents.size() > 0;
         }
 
-        private boolean processNextEvent() throws TaskFailedException, OrchestratorBlockedEvent {
+        private boolean processNextEvent() {
             return this.historyEventPlayer.moveNext();
         }
 
-        private void processEvent(HistoryEvent e) throws TaskFailedException, OrchestratorBlockedEvent {
+        private void processEvent(HistoryEvent e) {
             switch (e.getEventTypeCase()) {
                 case ORCHESTRATORSTARTED:
                     Instant instant = DataConverter.getInstantFromTimestamp(e.getTimestamp());
@@ -826,7 +826,7 @@ public OrchestrationHistoryIterator(List<HistoryEvent> pastEvents, List<HistoryE
                 this.currentHistoryList = pastEvents;
             }
 
-            public boolean moveNext() throws TaskFailedException, OrchestratorBlockedEvent {
+            public boolean moveNext() {
                 if (this.currentHistoryList == pastEvents && this.currentHistoryIndex >= pastEvents.size()) {
                     // Move forward to the next list
                     this.currentHistoryList = this.newEvents;
@@ -860,7 +860,7 @@ public ExternalEventTask(String eventName, int taskId, Duration timeout) {
 
             // TODO: Shouldn't this be throws TaskCanceledException?
             @Override
-            protected void handleException(Throwable e) throws TaskFailedException {
+            protected void handleException(Throwable e) {
                 // Cancellation is caused by user-specified timeouts
                 if (e instanceof CancellationException) {
                     String message = String.format(
@@ -910,7 +910,7 @@ private RetriableTask(
             }
 
             @Override
-            public V await() throws TaskFailedException, OrchestratorBlockedEvent {
+            public V await() {
                 Instant startTime = this.context.getCurrentInstant();
                 while (true) {
                     Task<V> currentTask = this.taskFactory.create();
@@ -1024,7 +1024,7 @@ public CompletableTask() {
             }
 
             @Override
-            public V await() throws TaskFailedException, OrchestratorBlockedEvent {
+            public V await() {
                 do {
                     // If the future is done, return its value right away
                     if (this.future.isDone()) {
@@ -1039,14 +1039,14 @@ public V await() throws TaskFailedException, OrchestratorBlockedEvent {
                 } while (ContextImplTask.this.processNextEvent());
 
                 // There's no more history left to replay and the current task is still not completed. This is normal.
-                // The OrchestratorBlockedEvent throwable allows us to yield the current thread back to the executor so
+                // The OrchestratorBlockedException exception allows us to yield the current thread back to the executor so
                 // that we can send the current set of actions back to the worker and wait for new events to come in.
                 // This is *not* an exception - it's a normal part of orchestrator control flow.
-                throw new OrchestratorBlockedEvent(
+                throw new OrchestratorBlockedException(
                         "The orchestrator is blocked and waiting for new inputs. This Throwable should never be caught by user code.");
             }
 
-            protected void handleException(Throwable e) throws TaskFailedException {
+            protected void handleException(Throwable e) {
                 if (e instanceof TaskFailedException) {
                     throw (TaskFailedException)e;
                 }