Fix initialization of the Metrics class

Author: eregon

src/main/java/org/truffleruby/RubyLanguage.java

@@ -67,7 +67,7 @@ public class RubyLanguage extends TruffleLanguage<RubyContext> {
     @Override
     public RubyContext createContext(Env env) {
         // We need to initialize the Metrics class of the language classloader
-        Metrics.begin();
+        Metrics.initializeOption();
 
         LOGGER.fine("createContext()");
         Metrics.printTime("before-create-context");
@@ -88,7 +88,7 @@ protected void initializeContext(RubyContext context) throws Exception {
     @Override
     protected boolean patchContext(RubyContext context, Env newEnv) {
         // We need to initialize the Metrics class of the language classloader
-        Metrics.begin();
+        Metrics.initializeOption();
 
         LOGGER.fine("patchContext()");
         Metrics.printTime("before-patch-context");

src/shared/java/org/truffleruby/shared/Metrics.java

@@ -43,19 +43,26 @@ private static void printMemory(boolean isAOT) {
         }
     }
 
-    public static void end(boolean isAOT) {
-        printTime("after-main");
-        printMemory(isAOT);
+    /**
+     * Assigned here so the property is read after processing the --native.D... options. It needs to
+     * be called in each classloader using the Metrics class.
+     */
+    public static void initializeOption() {
+        METRICS_TIME = Boolean.getBoolean("truffleruby.metrics.time");
     }
 
-    public static void begin() {
-        // Assigned here so the property is read after processing the --native.D... options
-        METRICS_TIME = Boolean.getBoolean("truffleruby.metrics.time");
+    public static boolean getMetricsTime() {
+        return METRICS_TIME;
+    }
 
+    public static void begin() {
+        initializeOption();
         printTime("before-main");
     }
 
-    public static boolean getMetricsTime() {
-        return METRICS_TIME;
+    public static void end(boolean isAOT) {
+        printTime("after-main");
+        printMemory(isAOT);
     }
+
 }