From d2bea3023fc9e7a2f43ed700f9b16f2de9f577f9 Mon Sep 17 00:00:00 2001
From: Larry Safran <lsafran@google.com>
Date: Wed, 12 Feb 2025 15:16:14 -0800
Subject: [PATCH] don't process resourceDoesNotExist for watchers that have
 been cancelled.

---
 .../java/io/grpc/xds/XdsDependencyManager.java   | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/xds/src/main/java/io/grpc/xds/XdsDependencyManager.java b/xds/src/main/java/io/grpc/xds/XdsDependencyManager.java
index 4adfebfe74d..7eff0c549e2 100644
--- a/xds/src/main/java/io/grpc/xds/XdsDependencyManager.java
+++ b/xds/src/main/java/io/grpc/xds/XdsDependencyManager.java
@@ -149,6 +149,7 @@ private <T extends ResourceUpdate> void cancelWatcher(XdsWatcherBase<T> watcher)
       throwIfParentContextsNotEmpty(watcher);
     }
 
+    watcher.cancelled = true;
     XdsResourceType<T> type = watcher.type;
     String resourceName = watcher.resourceName;
 
@@ -597,6 +598,8 @@ private abstract static class XdsWatcherBase<T extends ResourceUpdate>
       implements ResourceWatcher<T> {
     private final XdsResourceType<T> type;
     private final String resourceName;
+    boolean cancelled;
+
     @Nullable
     private StatusOr<T> data;
 
@@ -693,6 +696,10 @@ public void onError(Status error) {
 
     @Override
     public void onResourceDoesNotExist(String resourceName) {
+      if (cancelled) {
+        return;
+      }
+
       handleDoesNotExist(resourceName);
       xdsConfigWatcher.onResourceDoesNotExist(toContextString());
     }
@@ -752,6 +759,9 @@ public void onError(Status error) {
 
     @Override
     public void onResourceDoesNotExist(String resourceName) {
+      if (cancelled) {
+        return;
+      }
       handleDoesNotExist(checkNotNull(resourceName, "resourceName"));
       xdsConfigWatcher.onResourceDoesNotExist(toContextString());
     }
@@ -836,6 +846,9 @@ public void onChanged(XdsClusterResource.CdsUpdate update) {
 
     @Override
     public void onResourceDoesNotExist(String resourceName) {
+      if (cancelled) {
+        return;
+      }
       handleDoesNotExist(checkNotNull(resourceName, "resourceName"));
       maybePublishConfig();
     }
@@ -857,6 +870,9 @@ public void onChanged(XdsEndpointResource.EdsUpdate update) {
 
     @Override
     public void onResourceDoesNotExist(String resourceName) {
+      if (cancelled) {
+        return;
+      }
       handleDoesNotExist(checkNotNull(resourceName, "resourceName"));
       maybePublishConfig();
     }