js/public/WasmModule.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * vim: set ts=8 sts=2 et sw=2 tw=80:
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef js_WasmModule_h
   8 #define js_WasmModule_h
   9
  10 #include "mozilla/RefPtr.h"  // RefPtr
  11
  12 #include "jstypes.h"  // JS_PUBLIC_API
  13
  14 #include "js/RefCounted.h"  // AtomicRefCounted
  15 #include "js/TypeDecls.h"   // HandleObject
  16
  17 namespace JS {
  18
  19 /**
  20  * The WasmModule interface allows the embedding to hold a reference to the
  21  * underying C++ implementation of a JS WebAssembly.Module object for purposes
  22  * of efficient postMessage() and (de)serialization from a random thread.
  23  *
  24  * In particular, this allows postMessage() of a WebAssembly.Module:
  25  * GetWasmModule() is called when making a structured clone of a payload
  26  * containing a WebAssembly.Module object. The structured clone buffer holds a
  27  * refcount of the JS::WasmModule until createObject() is called in the target
  28  * agent's JSContext. The new WebAssembly.Module object continues to hold the
  29  * JS::WasmModule and thus the final reference of a JS::WasmModule may be
  30  * dropped from any thread and so the virtual destructor (and all internal
  31  * methods of the C++ module) must be thread-safe.
  32  */
  33
  34 struct WasmModule : js::AtomicRefCounted<WasmModule> {
  35   virtual ~WasmModule() = default;
  36   virtual JSObject* createObject(JSContext* cx) const = 0;
  37   virtual JSObject* createObjectForAsmJS(JSContext* cx) const = 0;
  38 };
  39
  40 extern JS_PUBLIC_API bool IsWasmModuleObject(HandleObject obj);
  41
  42 extern JS_PUBLIC_API RefPtr<WasmModule> GetWasmModule(HandleObject obj);
  43
  44 }  // namespace JS
  45
  46 #endif /* js_WasmModule_h */