1 files changed, 46 insertions, 0 deletions
diff --git a/js/public/WasmModule.h b/js/public/WasmModule.h
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+++ b/js/public/WasmModule.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef js_WasmModule_h
+#define js_WasmModule_h
+
+#include "mozilla/RefPtr.h"  // RefPtr
+
+#include "jstypes.h"  // JS_PUBLIC_API
+
+#include "js/RefCounted.h"  // AtomicRefCounted
+#include "js/TypeDecls.h"   // HandleObject
+
+namespace JS {
+
+/**
+ * The WasmModule interface allows the embedding to hold a reference to the
+ * underying C++ implementation of a JS WebAssembly.Module object for purposes
+ * of efficient postMessage() and (de)serialization from a random thread.
+ *
+ * In particular, this allows postMessage() of a WebAssembly.Module:
+ * GetWasmModule() is called when making a structured clone of a payload
+ * containing a WebAssembly.Module object. The structured clone buffer holds a
+ * refcount of the JS::WasmModule until createObject() is called in the target
+ * agent's JSContext. The new WebAssembly.Module object continues to hold the
+ * JS::WasmModule and thus the final reference of a JS::WasmModule may be
+ * dropped from any thread and so the virtual destructor (and all internal
+ * methods of the C++ module) must be thread-safe.
+ */
+
+struct WasmModule : js::AtomicRefCounted<WasmModule> {
+  virtual ~WasmModule() = default;
+  virtual JSObject* createObject(JSContext* cx) const = 0;
+  virtual JSObject* createObjectForAsmJS(JSContext* cx) const = 0;
+};
+
+extern JS_PUBLIC_API bool IsWasmModuleObject(HandleObject obj);
+
+extern JS_PUBLIC_API RefPtr<WasmModule> GetWasmModule(HandleObject obj);
+
+}  // namespace JS
+
+#endif /* js_WasmModule_h */