From 4b87e757975ce62f42e3acad91717a31d4df3fd8 Mon Sep 17 00:00:00 2001
From: Jonathan Giles <jonathan@jonathangiles.net>
Date: Fri, 12 Jul 2024 19:42:24 +1200
Subject: [PATCH] Fix issue with lifecycle hooks concurrently modifying the
 underlying resources list.

---
 .../microsoft/aspire/ManifestGenerator.java   | 23 ++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/aspire4j/aspire4j/src/main/java/com/microsoft/aspire/ManifestGenerator.java b/aspire4j/aspire4j/src/main/java/com/microsoft/aspire/ManifestGenerator.java
index 95b44d8..ac08540 100644
--- a/aspire4j/aspire4j/src/main/java/com/microsoft/aspire/ManifestGenerator.java
+++ b/aspire4j/aspire4j/src/main/java/com/microsoft/aspire/ManifestGenerator.java
@@ -6,6 +6,7 @@
 import java.io.IOException;
 import java.io.PrintStream;
 import java.nio.file.*;
+import java.util.HashSet;
 import java.util.Set;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -61,7 +62,7 @@ private ObjectMapper prepareObjectMapper(DistributedApplication app) {
         }
 
         // run the precommit lifecycle hook on all resources
-        app.manifest.getResources().values().iterator().forEachRemaining(ResourceWithLifecycle::onResourcePrecommit);
+        callLifecyclePrecommitHook(app);
 
         LOGGER.info("Validating models...");
         // Firstly, disable the info logging messages that are printed by Hibernate Validator
@@ -134,6 +135,26 @@ private void writeTemplateFile(TemplateFileOutput templateFile) {
         }
     }
 
+    private void callLifecyclePrecommitHook(DistributedApplication app) {
+        Set<ResourceWithLifecycle> processedResources = new HashSet<>();
+        Set<ResourceWithLifecycle> currentResources = new HashSet<>(app.manifest.getResources().values());
+
+        while (!currentResources.isEmpty()) {
+            // Create a snapshot of current resources to iterate over
+            Set<ResourceWithLifecycle> snapshot = new HashSet<>(currentResources);
+            for (ResourceWithLifecycle resource : snapshot) {
+                if (!processedResources.contains(resource)) {
+                    resource.onResourcePrecommit();
+                    processedResources.add(resource);
+                }
+                currentResources.remove(resource);
+            }
+            // Update currentResources to include only new resources added during processing
+            currentResources.addAll(app.manifest.getResources().values());
+            currentResources.removeAll(processedResources);
+        }
+    }
+
     private void printAnnotations(PrintStream out, DistributedApplication app) {
         app.manifest.getResources().values().forEach(resource -> {
             out.println("Resource: " + resource.getName());