From 1c9efd6a0f77ac71bceac2f93ea487d3d5d9258c Mon Sep 17 00:00:00 2001
From: cpovirk <cpovirk@google.com>
Date: Wed, 18 Jan 2023 03:29:01 -0800
Subject: [PATCH] Document ForwardingExecutorService behavior for default
 methods.

Currently, Guava is built with Java 9 and `ExecutorService` has no
default methods. This changes in Java 19, where `ExecutorService.close`
is added. Ensure users have right expectations about future evolution of
the `ForwardingExecutorService` and its compatibility with newer Java
versions.

Fixes #6296
Fixes #6299

RELNOTES=n/a
PiperOrigin-RevId: 502827344
---
 .../common/util/concurrent/ForwardingExecutorService.java     | 4 ++++
 .../util/concurrent/ForwardingListeningExecutorService.java   | 4 ++++
 .../common/util/concurrent/ForwardingExecutorService.java     | 4 ++++
 .../util/concurrent/ForwardingListeningExecutorService.java   | 4 ++++
 4 files changed, 16 insertions(+)

diff --git a/android/guava/src/com/google/common/util/concurrent/ForwardingExecutorService.java b/android/guava/src/com/google/common/util/concurrent/ForwardingExecutorService.java
index 9a87b5c981ad..e9a1c4ec0a4f 100644
--- a/android/guava/src/com/google/common/util/concurrent/ForwardingExecutorService.java
+++ b/android/guava/src/com/google/common/util/concurrent/ForwardingExecutorService.java
@@ -33,6 +33,10 @@
  * should override one or more methods to modify the behavior of the backing executor service as
  * desired per the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
  *
+ * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
+ * default} methods. Instead, it inherits their default implementations. When those implementations
+ * invoke methods, they invoke methods on the {@code ForwardingExecutorService}.
+ *
  * @author Kurt Alfred Kluever
  * @since 10.0
  */
diff --git a/android/guava/src/com/google/common/util/concurrent/ForwardingListeningExecutorService.java b/android/guava/src/com/google/common/util/concurrent/ForwardingListeningExecutorService.java
index 592a9f5eed74..47f7b1d5d235 100644
--- a/android/guava/src/com/google/common/util/concurrent/ForwardingListeningExecutorService.java
+++ b/android/guava/src/com/google/common/util/concurrent/ForwardingListeningExecutorService.java
@@ -24,6 +24,10 @@
  * executor service as desired per the <a
  * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
  *
+ * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
+ * default} methods. Instead, it inherits their default implementations. When those implementations
+ * invoke methods, they invoke methods on the {@code ForwardingListeningExecutorService}.
+ *
  * @author Isaac Shum
  * @since 10.0
  */
diff --git a/guava/src/com/google/common/util/concurrent/ForwardingExecutorService.java b/guava/src/com/google/common/util/concurrent/ForwardingExecutorService.java
index 9a87b5c981ad..e9a1c4ec0a4f 100644
--- a/guava/src/com/google/common/util/concurrent/ForwardingExecutorService.java
+++ b/guava/src/com/google/common/util/concurrent/ForwardingExecutorService.java
@@ -33,6 +33,10 @@
  * should override one or more methods to modify the behavior of the backing executor service as
  * desired per the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
  *
+ * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
+ * default} methods. Instead, it inherits their default implementations. When those implementations
+ * invoke methods, they invoke methods on the {@code ForwardingExecutorService}.
+ *
  * @author Kurt Alfred Kluever
  * @since 10.0
  */
diff --git a/guava/src/com/google/common/util/concurrent/ForwardingListeningExecutorService.java b/guava/src/com/google/common/util/concurrent/ForwardingListeningExecutorService.java
index 592a9f5eed74..47f7b1d5d235 100644
--- a/guava/src/com/google/common/util/concurrent/ForwardingListeningExecutorService.java
+++ b/guava/src/com/google/common/util/concurrent/ForwardingListeningExecutorService.java
@@ -24,6 +24,10 @@
  * executor service as desired per the <a
  * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
  *
+ * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
+ * default} methods. Instead, it inherits their default implementations. When those implementations
+ * invoke methods, they invoke methods on the {@code ForwardingListeningExecutorService}.
+ *
  * @author Isaac Shum
  * @since 10.0
  */