Changed FailsafeExecutor.getAsyncExecution to accept an AsyncRunnable

Author: jhalterman

CHANGELOG.md

@@ -2,9 +2,10 @@
 
 ### API Changes
 
-- Added a generic result type `R` to `ExecutionContext`, `Execution` and `AsyncExecution`. This ensures that result types are unified across the API. It does mean that there are a few minor breaking changes to the API:
-  - `ContextualSupplier` and `AsyncSupplier` now have an additional result type parameter `R`. Normally these types are used as lambda parameters where the type is inferred, so most users should not be impacted. But any explicit generic declaration of these types will not compile until the new parameter is added.
+- Added a generic result type `R` to `ExecutionContext`, `Execution`, `AsyncExecution`, and `AsyncRunnable`. This ensures that result types are unified across the API. It does mean that there are a few minor breaking changes to the API:
+  - `ContextualSupplier` now has an additional result type parameter `R`. Normally this type is used as lambda parameters where the type is inferred, so most users should not be impacted. But any explicit generic declaration of this type will not compile until the new parameter is added.
   - `PolicyExecutor`, which is part of the SPI, now accepts an additional result type parameter `R`. This is only relevant for SPI users who are implementing their own Policies.
+- Changed `FailsafeExecutor.getAsyncExecution` to accept `AsyncRunnable` instead of `AsyncSupplier`. This is a breaking change for any `getAsyncExecution` calls, but the fix is to simply remove any `return` statement. The reason for this change is that the provided object does not need to return a result since the result will already be passed asynchronously to one of the `AsyncExecution` `complete` or `retry` methods.
 
 # 2.4.3
 

src/main/java/net/jodah/failsafe/FailsafeExecutor.java

@@ -135,8 +135,8 @@ public <T extends R> CompletableFuture<T> getAsync(ContextualSupplier<T, T> supp
    * @throws NullPointerException if the {@code supplier} is null
    * @throws RejectedExecutionException if the {@code supplier} cannot be scheduled for execution
    */
-  public <T extends R> CompletableFuture<T> getAsyncExecution(AsyncSupplier<T, T> supplier) {
-    return callAsync(execution -> getPromiseExecution(supplier, execution), true);
+  public <T extends R> CompletableFuture<T> getAsyncExecution(AsyncRunnable<T> runnable) {
+    return callAsync(execution -> getPromiseExecution(runnable, execution), true);
   }
 
   /**
@@ -277,8 +277,8 @@ public CompletableFuture<Void> runAsync(ContextualRunnable runnable) {
    * @throws NullPointerException if the {@code runnable} is null
    * @throws RejectedExecutionException if the {@code runnable} cannot be scheduled for execution
    */
-  public CompletableFuture<Void> runAsyncExecution(AsyncRunnable runnable) {
-    return callAsync(execution -> getPromiseExecution(toAsyncSupplier(runnable), execution), true);
+  public CompletableFuture<Void> runAsyncExecution(AsyncRunnable<Void> runnable) {
+    return callAsync(execution -> getPromiseExecution(runnable, execution), true);
   }
 
   /**

src/main/java/net/jodah/failsafe/Functions.java

@@ -132,21 +132,21 @@ static <R> Supplier<CompletableFuture<ExecutionResult>> getPromiseAsync(
   }
 
   /**
-   * Returns a Supplier that pre-executes the {@code execution}, applies the {@code supplier}, and attempts to complete
-   * the {@code execution} if a failure occurs. Locks to ensure the resulting supplier cannot be applied multiple times
+   * Returns a Supplier that pre-executes the {@code execution}, runs the {@code runnable}, and attempts to complete the
+   * {@code execution} if a failure occurs. Locks to ensure the resulting supplier cannot be applied multiple times
    * concurrently.
    *
    * @param <R> result type
    */
-  static <R> Supplier<CompletableFuture<ExecutionResult>> getPromiseExecution(AsyncSupplier<R, R> supplier,
+  static <R> Supplier<CompletableFuture<ExecutionResult>> getPromiseExecution(AsyncRunnable<R> runnable,
     AsyncExecution<R> execution) {
-    Assert.notNull(supplier, "supplier");
+    Assert.notNull(runnable, "runnable");
     return new Supplier<CompletableFuture<ExecutionResult>>() {
       @Override
       public synchronized CompletableFuture<ExecutionResult> get() {
         try {
           execution.preExecute();
-          supplier.get(execution);
+          runnable.run(execution);
         } catch (Throwable e) {
           execution.completeOrHandle(null, e);
         }
@@ -229,14 +229,6 @@ static <R> Supplier<CompletableFuture<ExecutionResult>> getPromiseOfStageExecuti
     };
   }
 
-  static AsyncSupplier<Void, Void> toAsyncSupplier(AsyncRunnable runnable) {
-    Assert.notNull(runnable, "runnable");
-    return execution -> {
-      runnable.run(execution);
-      return null;
-    };
-  }
-
   /**
    * Returns a SettableSupplier that supplies the set value once then uses the {@code supplier} for subsequent calls.
    *

src/main/java/net/jodah/failsafe/function/AsyncRunnable.java

@@ -19,10 +19,11 @@
 
 /**
  * A Runnable that manually triggers asynchronous retries or completion via an asynchronous execution.
- * 
+ *
+ * @param <R> result type
  * @author Jonathan Halterman
  */
 @FunctionalInterface
-public interface AsyncRunnable {
-  void run(AsyncExecution<Void> execution) throws Exception;
+public interface AsyncRunnable<R> {
+  void run(AsyncExecution<R> execution) throws Exception;
 }

src/test/java/net/jodah/failsafe/AsyncFailsafeTest.java

@@ -178,19 +178,17 @@ public void shouldGetAsyncContextual() throws Throwable {
   }
 
   public void shouldGetAsyncExecution() throws Throwable {
-    assertGetAsync((AsyncSupplier<?, ?>) exec -> {
+    assertGetAsync((AsyncRunnable<?>) exec -> {
       try {
         boolean result = service.connect();
         if (!exec.complete(result))
           exec.retry();
-        return result;
       } catch (Exception failure) {
         // Alternate between automatic and manual retries
         if (exec.getAttemptCount() % 2 == 0)
           throw failure;
         if (!exec.retryOn(failure))
           throw failure;
-        return null;
       }
     });
   }
@@ -389,10 +387,9 @@ public void shouldCancelOnGetAsyncWithTimeout() throws Throwable {
   }
 
   public void shouldCancelOnGetAsyncExecution() throws Throwable {
-    assertCancel(executor -> getAsync(executor, (AsyncSupplier<?, ?>) (e) -> {
+    assertCancel(executor -> getAsync(executor, (AsyncRunnable<?>) (e) -> {
       Thread.sleep(1000);
       e.complete();
-      return null;
     }), retryAlways);
   }
 
@@ -435,7 +432,6 @@ public void shouldManuallyRetryAndComplete() throws Throwable {
         exec.retryOn(new ConnectException());
       else
         exec.complete(true);
-      return true;
     });
     waiter.await(3000);
   }
@@ -504,7 +500,6 @@ public void shouldTimeoutAndRetry() throws Throwable {
       Thread.sleep(100);
       if (!exec.complete(false))
         exec.retry();
-      return null;
     });
 
     waiter.await(1000);
@@ -593,13 +588,14 @@ public void shouldSupportCovariance() {
       .getAsync(() -> fastService);
   }
 
+  @SuppressWarnings("unchecked")
   private Future<?> runAsync(FailsafeExecutor<?> failsafe, Object runnable) {
     if (runnable instanceof CheckedRunnable)
       return failsafe.runAsync((CheckedRunnable) runnable);
     else if (runnable instanceof ContextualRunnable)
       return failsafe.runAsync((ContextualRunnable) runnable);
     else
-      return failsafe.runAsyncExecution((AsyncRunnable) runnable);
+      return failsafe.runAsyncExecution((AsyncRunnable<Void>) runnable);
   }
 
   @SuppressWarnings("unchecked")
@@ -609,7 +605,7 @@ private <T> Future<T> getAsync(FailsafeExecutor<T> failsafe, Object supplier) {
     else if (supplier instanceof ContextualSupplier)
       return failsafe.getAsync((ContextualSupplier<T, T>) supplier);
     else
-      return failsafe.getAsyncExecution((AsyncSupplier<T, T>) supplier);
+      return failsafe.getAsyncExecution((AsyncRunnable<T>) supplier);
   }
 
   @SuppressWarnings({ "unchecked", "rawtypes" })

src/test/java/net/jodah/failsafe/Testing.java

@@ -389,10 +389,10 @@ private static <T> void testSyncAndAsyncInternal(boolean testSync, FailsafeExecu
       if (given != null)
         given.run();
       if (expectedExceptions.length == 0) {
-        T result = Testing.unwrapExceptions(() -> failsafe.onComplete(setCompletedEventFn::accept).get(when));
+        T result = Testing.unwrapExceptions(() -> failsafe.onComplete(setCompletedEventFn).get(when));
         assertEquals(result, expectedResult);
       } else
-        Asserts.assertThrows(() -> failsafe.onComplete(setCompletedEventFn::accept).get(when), expectedExceptions);
+        Asserts.assertThrows(() -> failsafe.onComplete(setCompletedEventFn).get(when), expectedExceptions);
       postTestFn.run();
     }
 
@@ -401,47 +401,28 @@ private static <T> void testSyncAndAsyncInternal(boolean testSync, FailsafeExecu
     if (given != null)
       given.run();
     if (expectedExceptions.length == 0) {
-      T result = Testing.unwrapExceptions(() -> failsafe.onComplete(setCompletedEventFn::accept).getAsync(when).get());
+      T result = Testing.unwrapExceptions(() -> failsafe.onComplete(setCompletedEventFn).getAsync(when).get());
       assertEquals(result, expectedResult);
     } else {
       expected.add(0, ExecutionException.class);
-      Asserts.assertThrows(() -> failsafe.onComplete(setCompletedEventFn::accept).getAsync(when).get(), expected);
+      Asserts.assertThrows(() -> failsafe.onComplete(setCompletedEventFn).getAsync(when).get(), expected);
     }
     postTestFn.run();
   }
 
-  public static <T> void testAsyncExecutionSuccess(FailsafeExecutor<T> failsafe, AsyncRunnable when,
-    Consumer<ExecutionCompletedEvent<T>> then, T expectedResult) {
-    AsyncSupplier supplier = ex -> {
-      when.run(ex);
-      return null;
-    };
-    testAsyncExecutionInternal(failsafe, supplier, then, expectedResult);
-  }
-
-  public static <T> void testAsyncExecutionSuccess(FailsafeExecutor<T> failsafe, AsyncSupplier<T, T> when,
+  public static <T> void testAsyncExecutionSuccess(FailsafeExecutor<T> failsafe, AsyncRunnable<T> when,
     Consumer<ExecutionCompletedEvent<T>> then, T expectedResult) {
     testAsyncExecutionInternal(failsafe, when, then, expectedResult);
   }
 
   @SafeVarargs
-  public static <T> void testAsyncExecutionFailure(FailsafeExecutor<T> failsafe, AsyncRunnable when,
-    Consumer<ExecutionCompletedEvent<T>> then, Class<? extends Throwable>... expectedExceptions) {
-    AsyncSupplier supplier = ex -> {
-      when.run(ex);
-      return null;
-    };
-    testAsyncExecutionInternal(failsafe, supplier, then, null, expectedExceptions);
-  }
-
-  @SafeVarargs
-  public static <T> void testAsyncExecutionFailure(FailsafeExecutor<T> failsafe, AsyncSupplier<T, T> when,
+  public static <T> void testAsyncExecutionFailure(FailsafeExecutor<T> failsafe, AsyncRunnable<T> when,
     Consumer<ExecutionCompletedEvent<T>> then, Class<? extends Throwable>... expectedExceptions) {
     testAsyncExecutionInternal(failsafe, when, then, null, expectedExceptions);
   }
 
   @SafeVarargs
-  private static <T> void testAsyncExecutionInternal(FailsafeExecutor<T> failsafe, AsyncSupplier<T, T> when,
+  private static <T> void testAsyncExecutionInternal(FailsafeExecutor<T> failsafe, AsyncRunnable<T> when,
     Consumer<ExecutionCompletedEvent<T>> then, T expectedResult, Class<? extends Throwable>... expectedExceptions) {
 
     AtomicReference<ExecutionCompletedEvent<T>> completedEventRef = new AtomicReference<>();
@@ -459,13 +440,13 @@ private static <T> void testAsyncExecutionInternal(FailsafeExecutor<T> failsafe,
     System.out.println("\nRunning async execution test");
     if (expectedExceptions.length == 0) {
       T result = Testing.unwrapExceptions(
-        () -> failsafe.onComplete(setCompletedEventFn::accept).getAsyncExecution(when).get());
+        () -> failsafe.onComplete(setCompletedEventFn).getAsyncExecution(when).get());
       assertEquals(result, expectedResult);
     } else {
       List<Class<? extends Throwable>> expected = new LinkedList<>();
       Collections.addAll(expected, expectedExceptions);
       expected.add(0, ExecutionException.class);
-      Asserts.assertThrows(() -> failsafe.onComplete(setCompletedEventFn::accept).getAsyncExecution(when).get(),
+      Asserts.assertThrows(() -> failsafe.onComplete(setCompletedEventFn).getAsyncExecution(when).get(),
         expected);
     }
     postTestFn.run();