From fe5ce630159138441898329ceb5c381e22c09fe0 Mon Sep 17 00:00:00 2001
From: James Nord <jtnord@users.noreply.github.com>
Date: Tue, 14 May 2024 13:42:02 +0100
Subject: [PATCH 1/2] pass through the remote ClassLoaders name

add getName to the IClassloader and set a name in the RemoteClassLoader

This improves the debugability from RemoteClassloaders to understand any
classloading related issues.
---
 .../remoting/DumbClassLoaderBridge.java       |  6 ++++
 .../hudson/remoting/RemoteClassLoader.java    | 34 +++++++++++++++++--
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/src/main/java/hudson/remoting/DumbClassLoaderBridge.java b/src/main/java/hudson/remoting/DumbClassLoaderBridge.java
index 090a60171..4dd43aee9 100644
--- a/src/main/java/hudson/remoting/DumbClassLoaderBridge.java
+++ b/src/main/java/hudson/remoting/DumbClassLoaderBridge.java
@@ -79,4 +79,10 @@ public ResourceFile[] getResources2(String name) throws IOException {
         }
         return res;
     }
+
+    @Override
+    public String getName() throws IOException {
+        return base.getName();
+    }
+
 }
diff --git a/src/main/java/hudson/remoting/RemoteClassLoader.java b/src/main/java/hudson/remoting/RemoteClassLoader.java
index 84518a82c..06db8e6b3 100644
--- a/src/main/java/hudson/remoting/RemoteClassLoader.java
+++ b/src/main/java/hudson/remoting/RemoteClassLoader.java
@@ -170,11 +170,18 @@ public static ClassLoader create(@CheckForNull ClassLoader parent, @NonNull ICla
             // actually our classloader that we exported to the other side.
             return ((ClassLoaderProxy) proxy).cl;
         }
-        return new RemoteClassLoader(parent, proxy);
+
+        String name;
+        try {
+            name = proxy.getName();
+        } catch(IOException ignored) {
+            name = "unknown-due-to-io-error";
+        }
+        return new RemoteClassLoader(name, parent, proxy);
     }
 
-    private RemoteClassLoader(@CheckForNull ClassLoader parent, @NonNull IClassLoader proxy) {
-        super(new URL[0], parent);
+    private RemoteClassLoader(String name, @CheckForNull ClassLoader parent, @NonNull IClassLoader proxy) {
+        super(name, new URL[0], parent);
         final Channel channel = RemoteInvocationHandler.unwrap(proxy);
         this.channel = channel == null ? null : channel.ref();
         this.underlyingProxy = proxy;
@@ -887,6 +894,12 @@ public interface IClassLoader {
          */
         @NonNull
         ResourceFile[] getResources2(String name) throws IOException;
+
+        /**
+         * Name of the classLoader
+         * @since 3242
+         */
+        String getName() throws IOException;
     }
 
     /**
@@ -1178,6 +1191,11 @@ public ResourceFile[] getResources2(String name) throws IOException {
             return r;
         }
 
+        @Override
+        public String getName() throws IOException {
+            return cl.getName();
+        }
+
         @Override
         public boolean equals(Object that) {
             if (this == that) {
@@ -1276,6 +1294,11 @@ public ResourceFile[] getResources2(String name) throws IOException {
             return proxy.getResources2(name);
         }
 
+        @Override
+        public String getName() throws IOException {
+            return proxy.getName();
+        }
+
         private Object readResolve() throws ObjectStreamException {
             try {
                 return getChannelForSerialization().getExportedObject(oid);
@@ -1336,6 +1359,11 @@ public ResourceFile[] getResources2(String name) throws IOException {
             throw new IOException("Cannot get " + name, cause);
         }
 
+        @Override
+        public String getName() throws IOException {
+            throw new IOException("Cannot getName", cause);
+        }
+
     }
 
     private static Iterable<String> analyze(InputStream bytecode) {

From 98cc05c5d792aa27fb19cb80a3f00b401d165b1b Mon Sep 17 00:00:00 2001
From: James Nord <jtnord@users.noreply.github.com>
Date: Wed, 15 May 2024 14:45:44 +0100
Subject: [PATCH 2/2] Make "unknown" classloader unique

If we can not obtain the name of the classloader then add the proxies
identityHashCode so they will be unique amongst all others.
---
 src/main/java/hudson/remoting/RemoteClassLoader.java | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/main/java/hudson/remoting/RemoteClassLoader.java b/src/main/java/hudson/remoting/RemoteClassLoader.java
index 06db8e6b3..b54e4652e 100644
--- a/src/main/java/hudson/remoting/RemoteClassLoader.java
+++ b/src/main/java/hudson/remoting/RemoteClassLoader.java
@@ -44,6 +44,7 @@
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.Vector;
@@ -175,7 +176,7 @@ public static ClassLoader create(@CheckForNull ClassLoader parent, @NonNull ICla
         try {
             name = proxy.getName();
         } catch(IOException ignored) {
-            name = "unknown-due-to-io-error";
+            name = String.format(Locale.ROOT, "unknown-due-to-io-error %1$#x", System.identityHashCode(proxy));
         }
         return new RemoteClassLoader(name, parent, proxy);
     }