1 files changed, 12 insertions, 4 deletions
diff --git a/src/websockets/qwebsocket_wasm_p.cpp b/src/websockets/qwebsocket_wasm_p.cpp
index 199fe44..85fcab2 100644
--- a/src/websockets/qwebsocket_wasm_p.cpp
+++ b/src/websockets/qwebsocket_wasm_p.cpp
@@ -137,11 +137,19 @@ qint64 QWebSocketPrivate::sendTextMessage(const QString &message)
 
 qint64 QWebSocketPrivate::sendBinaryMessage(const QByteArray &data)
 {
-    socketContext.call<void>("send",
-                             val(typed_memory_view(data.size(),
-                                                   reinterpret_cast<const unsigned char *>
-                                                   (data.constData()))));
+    // Make a copy of the payload data; we don't know how long WebSocket.send() will
+    // retain the memory view, while the QByteArray passed to this function may be
+    // destroyed as soon as this function returns. In addition, the WebSocket.send()
+    // API does not accept data from a view backet by a SharedArrayBuffer, which will
+    // be the case for the view produced by typed_memory_view() when threads are enabled.
+    val Uint8Array = val::global("Uint8Array");
+    val dataCopy = Uint8Array.new_(data.size());
+    val dataView = val(typed_memory_view(data.size(),
+                       reinterpret_cast<const unsigned char *>
+                       (data.constData())));
+    dataCopy.call<void>("set", dataView);
 
+    socketContext.call<void>("send", dataCopy);
     return data.length();
 }