@@ -9,12 +9,18 @@ package com.facebook.react.devsupport
 
 import android.os.Handler
 import android.os.Looper
+import com.facebook.common.logging.FLog
 import com.facebook.jni.HybridData
 import com.facebook.proguard.annotations.DoNotStrip
 import com.facebook.proguard.annotations.DoNotStripAny
+import com.facebook.react.common.annotations.VisibleForTesting
 import com.facebook.react.devsupport.inspector.DevSupportHttpClient
 import com.facebook.soloader.SoLoader
 import java.io.Closeable
+import java.nio.ByteBuffer
+import java.nio.charset.StandardCharsets
+import java.util.ArrayDeque
+import java.util.Queue
 import okhttp3.Request
 import okhttp3.Response
 import okhttp3.WebSocket
@@ -66,7 +72,7 @@ internal class CxxInspectorPackagerConnection(
    */
   @DoNotStripAny
   private interface IWebSocket : Closeable {
-    fun send(message: String)
+    fun send(chunk: ByteBuffer)
 
     /**
      * Close the WebSocket connection. NOTE: There is no close() method in the C++ interface.
@@ -75,6 +81,95 @@ internal class CxxInspectorPackagerConnection(
     override fun close()
   }
 
+  /**
+   * A simple WebSocket wrapper that prevents having more than 16MiB of messages queued
+   * simultaneously. This is done to stop OkHttp from closing the WebSocket connection.
+   *
+   * https://github.com/facebook/react-native/issues/39651.
+   * https://github.com/square/okhttp/blob/4e7dbec1ea6c9cf8d80422ac9d44b9b185c749a3/okhttp/src/commonJvmAndroid/kotlin/okhttp3/internal/ws/RealWebSocket.kt#L684.
+   */
+  private class InspectorPackagerWebSocketImpl(
+      private val nativeWebSocket: WebSocket,
+      private val handler: Handler,
+  ) : IWebSocket {
+    private val messageQueue: Queue<Pair<String, Int>> = ArrayDeque()
+    private val queueLock = Any()
+    private val drainRunnable =
+        object : Runnable {
+          override fun run() {
+            FLog.d(TAG, "Attempting to drain the message queue after ${drainDelayMs}ms")
+            tryDrainQueue()
+          }
+        }
+
+    /**
+     * We are providing a String to OkHttp's WebSocket, because there is no guarantee that all CDP
+     * clients will support binary data format.
+     */
+    override fun send(chunk: ByteBuffer) {
+      synchronized(queueLock) {
+        val messageSize = chunk.capacity()
+        val message = StandardCharsets.UTF_8.decode(chunk).toString()
+        val currentQueueSize = nativeWebSocket.queueSize()
+
+        if (currentQueueSize + messageSize > MAX_QUEUE_SIZE) {
+          FLog.d(TAG, "Reached queue size limit. Queueing the message.")
+          messageQueue.offer(Pair(message, messageSize))
+          scheduleDrain()
+        } else {
+          if (messageQueue.isEmpty()) {
+            nativeWebSocket.send(message)
+          } else {
+            messageQueue.offer(Pair(message, messageSize))
+            tryDrainQueue()
+          }
+        }
+      }
+    }
+
+    override fun close() {
+      synchronized(queueLock) {
+        handler.removeCallbacks(drainRunnable)
+        messageQueue.clear()
+        nativeWebSocket.close(1000, "End of session")
+      }
+    }
+
+    private fun tryDrainQueue() {
+      synchronized(queueLock) {
+        while (messageQueue.isNotEmpty()) {
+          val (nextMessage, nextMessageSize) = messageQueue.peek() ?: break
+          val currentQueueSize = nativeWebSocket.queueSize()
+
+          if (currentQueueSize + nextMessageSize <= MAX_QUEUE_SIZE) {
+            messageQueue.poll()
+            if (!nativeWebSocket.send(nextMessage)) {
+              // The WebSocket is closing, closed, or cancelled.
+              handler.removeCallbacks(drainRunnable)
+              messageQueue.clear()
+
+              break
+            }
+          } else {
+            scheduleDrain()
+            break
+          }
+        }
+      }
+    }
+
+    private fun scheduleDrain() {
+      FLog.d(TAG, "Scheduled a task to drain messages queue.")
+      handler.removeCallbacks(drainRunnable)
+      handler.postDelayed(drainRunnable, drainDelayMs)
+    }
+
+    companion object {
+      private val TAG: String = InspectorPackagerWebSocketImpl::class.java.simpleName
+      private const val drainDelayMs: Long = 100
+    }
+  }
+
   /** Java implementation of the C++ InspectorPackagerConnectionDelegate interface. */
   private class DelegateImpl {
     private val httpClient = DevSupportHttpClient.websocketClient
@@ -124,15 +219,8 @@ internal class CxxInspectorPackagerConnection(
                 }
               },
           )
-      return object : IWebSocket {
-        override fun send(message: String) {
-          webSocket.send(message)
-        }
 
-        override fun close() {
-          webSocket.close(1000, "End of session")
-        }
-      }
+      return InspectorPackagerWebSocketImpl(webSocket, handler)
     }
 
     @DoNotStrip
@@ -146,6 +234,8 @@ internal class CxxInspectorPackagerConnection(
       SoLoader.loadLibrary("react_devsupportjni")
     }
 
+    @VisibleForTesting internal const val MAX_QUEUE_SIZE = 16L * 1024 * 1024 // 16MiB
+
     @JvmStatic
     private external fun initHybrid(
         url: String,
 
@@ -55,7 +55,7 @@ internal object InspectorNetworkHelper {
               response.body().use { responseBody ->
                 if (responseBody != null) {
                   val inputStream = responseBody.byteStream()
-                  val chunkSize = 1024
+                  val chunkSize = 8 * 1024 // 8Kb
                   val buffer = ByteArray(chunkSize)
                   var bytesRead: Int
 
 
@@ -5,17 +5,44 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+#include <fbjni/ByteBuffer.h>
+
 #include "JCxxInspectorPackagerConnectionWebSocket.h"
 
 using namespace facebook::jni;
 using namespace facebook::react::jsinspector_modern;
 
 namespace facebook::react::jsinspector_modern {
 
+namespace {
+
+local_ref<JByteBuffer::javaobject> getReadOnlyByteBufferFromStringView(
+    std::string_view sv) {
+  auto buffer = JByteBuffer::wrapBytes(
+      const_cast<uint8_t*>(reinterpret_cast<const uint8_t*>(sv.data())),
+      sv.size());
+
+  /**
+   * Return a read-only buffer that shares the underlying contents.
+   * This guards from accidential mutations on the Java side, since we did
+   * casting above.
+   *
+   * https://docs.oracle.com/javase/8/docs/api/java/nio/ByteBuffer.html#asReadOnlyBuffer--
+   */
+  static auto method =
+      buffer->javaClassStatic()->getMethod<JByteBuffer::javaobject()>(
+          "asReadOnlyBuffer");
+  return method(buffer);
+}
+
+} // namespace
+
 void JCxxInspectorPackagerConnectionWebSocket::send(std::string_view message) {
   static auto method =
-      javaClassStatic()->getMethod<void(const std::string&)>("send");
-  method(self(), std::string(message));
+      javaClassStatic()->getMethod<void(local_ref<JByteBuffer::javaobject>)>(
+          "send");
+  auto byteBuffer = getReadOnlyByteBufferFromStringView(message);
+  method(self(), byteBuffer);
 }
 
 void JCxxInspectorPackagerConnectionWebSocket::close() {
 
@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.react.devsupport
+
+import okhttp3.internal.ws.RealWebSocket
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.Test
+
+class CxxInspectorPackagerConnectionTest {
+
+  @Test
+  fun testMaxQueueSizeEquality() {
+    val okHttpRealWebSocketClass = RealWebSocket::class.java
+    val okHttpMaxQueueSizeField = okHttpRealWebSocketClass.getDeclaredField("MAX_QUEUE_SIZE")
+    okHttpMaxQueueSizeField.isAccessible = true
+
+    val okHttpMaxQueueSize = okHttpMaxQueueSizeField.getLong(null)
+    assertThat(okHttpMaxQueueSize).isNotNull
+
+    assertThat(okHttpMaxQueueSize)
+        .isEqualTo(CxxInspectorPackagerConnection.Companion.MAX_QUEUE_SIZE)
+  }
+}
@@ -26,12 +26,8 @@ const uint16_t TRACE_EVENT_CHUNK_SIZE = 1000;
 /**
  * The maximum number of ProfileChunk trace events
  * that will be sent in a single CDP Tracing.dataCollected message.
- * TODO(T219394401): Increase the size once we manage the queue on OkHTTP
- side
- * properly and avoid WebSocket disconnections when sending a message larger
- * than 16MB.
  */
-const uint16_t PROFILE_TRACE_EVENT_CHUNK_SIZE = 1;
+const uint16_t PROFILE_TRACE_EVENT_CHUNK_SIZE = 10;
 
 } // namespace