[ONOS-6267] Support configurable Executors for primitives
- Support user-provided Executors in primitive builders
- Implement default per-partition per-primitive serial executor using a shared thread pool
- Implement Executor wrappers for all primitive types
Change-Id: I53acfb173a9b49a992a9a388983791d9735ed54a
diff --git a/utils/misc/src/main/java/org/onlab/util/Tools.java b/utils/misc/src/main/java/org/onlab/util/Tools.java
index cc769c4..883a7c8 100644
--- a/utils/misc/src/main/java/org/onlab/util/Tools.java
+++ b/utils/misc/src/main/java/org/onlab/util/Tools.java
@@ -39,6 +39,7 @@
import java.util.Set;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
@@ -642,6 +643,32 @@
}
/**
+ * Returns a future that's completed using the given {@link Executor} once the given {@code future} is completed.
+ * <p>
+ * {@link CompletableFuture}'s async methods cannot be relied upon to complete futures on an executor thread. If a
+ * future is completed synchronously, {@code CompletableFuture} async methods will often complete the future on the
+ * current thread, ignoring the provided {@code Executor}. This method ensures a more reliable and consistent thread
+ * model by ensuring that futures are always completed using the provided {@code Executor}.
+ *
+ * @param future the future to convert into an asynchronous future
+ * @param executor the executor with which to complete the returned future
+ * @param <T> future value type
+ * @return a new completable future to be completed using the provided {@code executor} once the provided
+ * {@code future} is complete
+ */
+ public static <T> CompletableFuture<T> asyncFuture(CompletableFuture<T> future, Executor executor) {
+ CompletableFuture<T> newFuture = new CompletableFuture<T>();
+ future.whenComplete((result, error) -> executor.execute(() -> {
+ if (future.isCompletedExceptionally()) {
+ newFuture.completeExceptionally(error);
+ } else {
+ newFuture.complete(result);
+ }
+ }));
+ return newFuture;
+ }
+
+ /**
* Returns a new CompletableFuture completed with a list of computed values
* when all of the given CompletableFuture complete.
*