+ better worker context switch

elf4j · Apr 25, 2024 · ec10349 · ec10349
1 parent 0cc555b
commit ec10349
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Showing 2 changed files with 22 additions and 16 deletions.
diff --git a/pom.xml b/pom.xml
@@ -31,7 +31,7 @@
 
     <groupId>io.github.elf4j</groupId>
     <artifactId>elf4j-engine</artifactId>
-    <version>15.2.1</version>
+    <version>15.2.2</version>
     <packaging>jar</packaging>
     <name>elf4j-engine</name>
     <description>A stand-alone Java log engine implementing the ELF4J (Easy Logging Facade for Java) API</description>

diff --git a/src/main/java/elf4j/engine/service/writer/GroupWriter.java b/src/main/java/elf4j/engine/service/writer/GroupWriter.java
@@ -118,6 +118,27 @@ private static List<LogWriterType> getLogWriterTypes(@NonNull LogServiceConfigur
                 .collect(Collectors.toList());
     }
 
+    private static Runnable withMdcContext(Runnable task) {
+        Map<String, String> callerContext = MDC.getCopyOfContextMap();
+        return (callerContext == null)
+                ? task
+                : () -> {
+                    Map<String, String> workerContext = replaceContextWith(callerContext);
+                    MDC.setContextMap(callerContext);
+                    try {
+                        task.run();
+                    } finally {
+                        MDC.setContextMap(workerContext);
+                    }
+                };
+    }
+
+    private static Map<String, String> replaceContextWith(Map<String, String> targetContext) {
+        Map<String, String> replaced = MDC.getCopyOfContextMap();
+        MDC.setContextMap(targetContext);
+        return replaced;
+    }
+
     @Override
     public Level getThresholdOutputLevel() {
         if (thresholdOutputLevel == null) {
@@ -137,21 +158,6 @@ public void write(@NonNull LogEvent logEvent) {
                 logEvent.getCallerThread().getId()));
     }
 
-    private static Runnable withMdcContext(Runnable task) {
-        Map<String, String> copyOfContextMap = MDC.getCopyOfContextMap();
-        return (copyOfContextMap == null)
-                ? task
-                : () -> {
-                    MDC.clear();
-                    MDC.setContextMap(copyOfContextMap);
-                    try {
-                        task.run();
-                    } finally {
-                        MDC.clear();
-                    }
-                };
-    }
-
     @Override
     public boolean includeCallerDetail() {
         if (includeCallerDetail == null) {