Fix ConcurrentModificationException while calling emitBufferedMarks in Android

Author: Vivek Varun

packages/react-native-performance/android/src/main/java/com/oblador/performance/PerformanceModule.java

@@ -14,6 +14,7 @@
 import com.facebook.react.turbomodule.core.interfaces.TurboModule;
 
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
 
 // Should extend NativeRNPerformanceManagerSpec when codegen for old architecture is solved
@@ -88,13 +89,11 @@ public static void setupListener() {
     private static void clearMarkBuffer() {
         RNPerformance.getInstance().clearEphermalEntries();
 
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
-            markBuffer.removeIf(PerformanceEntry::isEphemeral);
-        } else {
-            for (PerformanceEntry entry : markBuffer) {
-                if (entry.isEphemeral()) {
-                    markBuffer.remove(entry);
-                }
+        Iterator<PerformanceEntry> iterator = markBuffer.iterator();
+        if (iterator.hasNext()) {
+            PerformanceEntry entry = iterator.next();
+            if(entry.isEphemeral()) {
+                iterator.remove();
             }
         }
     }
@@ -156,15 +155,17 @@ private static void addMark(PerformanceEntry entry) {
 
     private void emitBufferedMarks() {
         didEmit = true;
-        for (PerformanceEntry entry : markBuffer) {
-            emitMark(entry);
+        Iterator<PerformanceEntry> iterator = markBuffer.iterator();
+        if (iterator.hasNext()) {
+            emitMark(iterator.next());
         }
         emitNativeBufferedMarks();
     }
 
     private void emitNativeBufferedMarks() {
-        for (PerformanceEntry entry : RNPerformance.getInstance().getEntries()) {
-            emitMark(entry);
+        Iterator<PerformanceEntry> iterator = RNPerformance.getInstance().getEntries().iterator();
+        if (iterator.hasNext()) {
+            emitMark(iterator.next());
         }
     }
 

packages/react-native-performance/android/src/main/java/com/oblador/performance/RNPerformance.java

@@ -1,11 +1,13 @@
 package com.oblador.performance;
 
-import android.os.Build;
 import android.os.Bundle;
 
 import androidx.annotation.NonNull;
+
 import com.facebook.proguard.annotations.DoNotStrip;
 
+import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
 
@@ -28,7 +30,7 @@ interface MarkerListener {
     }
 
     private static final List<MarkerListener> sListeners = new CopyOnWriteArrayList<>();
-    private final List<PerformanceEntry> entries = new CopyOnWriteArrayList<>();
+    private final List<PerformanceEntry> entries = new ArrayList<>();
 
     @DoNotStrip
     protected void addListener(MarkerListener listener) {
@@ -105,7 +107,8 @@ private void emitMark(@NonNull PerformanceEntry entry) {
         }
     }
 
-    protected @NonNull List<PerformanceEntry> getEntries() {
+    protected @NonNull
+    List<PerformanceEntry> getEntries() {
         return entries;
     }
 
@@ -114,13 +117,11 @@ protected void clearEntries() {
     }
 
     protected void clearEntries(String name) {
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
-            entries.removeIf((entry) -> entry.getName().equals(name));
-        } else {
-            for (PerformanceEntry entry : entries) {
-                if (entry.getName().equals(name)) {
-                    entries.remove(entry);
-                }
+        Iterator<PerformanceEntry> iterator = entries.iterator();
+        while (iterator.hasNext()) {
+            PerformanceEntry entry = iterator.next();
+            if (entry.getName().equals(name)) {
+                iterator.remove();
             }
         }
     }
@@ -130,13 +131,11 @@ protected void clearEphermalEntries() {
             return;
         }
 
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
-            entries.removeIf(PerformanceEntry::isEphemeral);
-        } else {
-            for (PerformanceEntry entry : entries) {
-                if (entry.isEphemeral()) {
-                    entries.remove(entry);
-                }
+        Iterator<PerformanceEntry> iterator = entries.iterator();
+        while (iterator.hasNext()) {
+            PerformanceEntry entry = iterator.next();
+            if (entry.isEphemeral()) {
+                iterator.remove();
             }
         }
     }