From c54cc68775fcc629fa33992e517b3a5b94cae22d Mon Sep 17 00:00:00 2001
From: "David M. Lloyd" <david.lloyd@redhat.com>
Date: Mon, 25 Nov 2024 11:31:22 -0600
Subject: [PATCH] Add smart service provider method

This allows a service loader to fully initialize the log manager without worrying about class init loops.
---
 src/main/java/module-info.java                |  2 +-
 .../java/org/jboss/logmanager/LogManager.java | 21 +++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/main/java/module-info.java b/src/main/java/module-info.java
index b37483c8..5cf99267 100644
--- a/src/main/java/module-info.java
+++ b/src/main/java/module-info.java
@@ -29,7 +29,7 @@
     exports org.jboss.logmanager.formatters;
     exports org.jboss.logmanager.handlers;
 
-    provides java.util.logging.LogManager with LogManager;
+    provides java.util.logging.LogManager with LogManager.Provider;
     provides System.LoggerFinder with JBossLoggerFinder;
     provides ConfiguratorFactory with DefaultConfiguratorFactory;
 
diff --git a/src/main/java/org/jboss/logmanager/LogManager.java b/src/main/java/org/jboss/logmanager/LogManager.java
index 5961095d..f50b5a01 100644
--- a/src/main/java/org/jboss/logmanager/LogManager.java
+++ b/src/main/java/org/jboss/logmanager/LogManager.java
@@ -222,4 +222,25 @@ public boolean addLogger(java.util.logging.Logger logger) {
     public Logger getLogger(String name) {
         return LogContext.getLogContext().getLogger(name);
     }
+
+    public static final class Provider {
+        /**
+         * The service provider method.
+         * This method is used when the log manager service is loaded from a modular application.
+         *
+         * @return the log manager instance (not {@code null})
+         * @throws ClassCastException if the log manager is not initialized to this class
+         */
+        public static LogManager provider() {
+            Thread ct = Thread.currentThread();
+            ClassLoader old = ct.getContextClassLoader();
+            ct.setContextClassLoader(Provider.class.getClassLoader());
+            try {
+                System.setProperty("java.util.logging.manager", LogManager.class.getName());
+                return (LogManager) getLogManager();
+            } finally {
+                ct.setContextClassLoader(old);
+            }
+        }
+    }
 }