diff --git a/DiSLProject2022/src-profiler/ex11/Profiler.java b/DiSLProject2022/src-profiler/ex11/Profiler.java
index f0e0db4..d2bd75d 100644
--- a/DiSLProject2022/src-profiler/ex11/Profiler.java
+++ b/DiSLProject2022/src-profiler/ex11/Profiler.java
@@ -7,9 +7,10 @@ import java.nio.file.Path;
 import java.nio.file.StandardOpenOption;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.atomic.LongAdder;
 
 public final class Profiler {
-    private static final Map<CallInfo, long[]> count = new HashMap<>();
+    private static final Map<CallInfo, LongAdder> count = new HashMap<>();
 
     private static final Path outFile = Path.of("ex11.csv");
 
@@ -18,11 +19,11 @@ public final class Profiler {
     static {
         Runtime.getRuntime().addShutdownHook(new Thread(() -> {
             stop = true;
-            try (final OutputStream path = Files.newOutputStream(outFile, StandardOpenOption.WRITE)) {
+            try (final OutputStream path = Files.newOutputStream(outFile)) {
                 final CallInfoCSVWriter w = new CallInfoCSVWriter(path);
                 for (final var entry : count.entrySet()) {
-                    System.out.println(entry.getKey().toString() + "\n#invokes " + entry.getValue()[0] + "\n");
-                    w.write(entry.getKey(), entry.getValue()[0]);
+                    System.out.println(entry.getKey().toString() + "\n#invokes " + entry.getValue().longValue() + "\n");
+                    w.write(entry.getKey(), entry.getValue().longValue());
                 }
                 System.out.println("Invocations have been written to: " + outFile.toAbsolutePath());
             } catch (final IOException e) {
@@ -36,7 +37,7 @@ public final class Profiler {
 
     public static void registerCall(final CallInfo info) {
         if (stop) return;
-        count.computeIfAbsent(info, ignored -> new long[1])[0]++;
+        count.computeIfAbsent(info, ignored -> new LongAdder()).increment();
     }
 
 }