[wasm] Transferrable modules

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 3125 matching lines @@
 
 Maybe<uint32_t> ValueSerializer::Delegate::GetSharedArrayBufferId(
     Isolate* v8_isolate, Local<SharedArrayBuffer> shared_array_buffer) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
   isolate->ScheduleThrow(*isolate->factory()->NewError(
       isolate->error_function(), i::MessageTemplate::kDataCloneError,
       Utils::OpenHandle(*shared_array_buffer)));
   return Nothing<uint32_t>();
 }
 
+Maybe<uint32_t> ValueSerializer::Delegate::GetWasmModuleTransferId(
+    Isolate* v8_isolate, Local<WasmCompiledModule> module) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
+  isolate->ScheduleThrow(*isolate->factory()->NewError(
+      isolate->error_function(), i::MessageTemplate::kDataCloneError,
+      Utils::OpenHandle(*module)));
+  return Nothing<uint32_t>();
+}
+
 void* ValueSerializer::Delegate::ReallocateBufferMemory(void* old_buffer,
                                                         size_t size,
                                                         size_t* actual_size) {
   *actual_size = size;
   return realloc(old_buffer, size);
 }
 
 void ValueSerializer::Delegate::FreeBufferMemory(void* buffer) {
   return free(buffer);
 }
@@ skipping 68 matching lines @@
 
 MaybeLocal<Object> ValueDeserializer::Delegate::ReadHostObject(
     Isolate* v8_isolate) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
   isolate->ScheduleThrow(*isolate->factory()->NewError(
       isolate->error_function(),
       i::MessageTemplate::kDataCloneDeserializationError));
   return MaybeLocal<Object>();
 }
 
+MaybeLocal<WasmCompiledModule> ValueDeserializer::Delegate::GetWasmModuleFromId(
+    Isolate* v8_isolate, uint32_t id) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
+  isolate->ScheduleThrow(*isolate->factory()->NewError(
+      isolate->error_function(),
+      i::MessageTemplate::kDataCloneDeserializationError));
+  return MaybeLocal<WasmCompiledModule>();
+}
+
 struct ValueDeserializer::PrivateData {
   PrivateData(i::Isolate* i, i::Vector<const uint8_t> data, Delegate* delegate)
       : isolate(i), deserializer(i, data, delegate) {}
   i::Isolate* isolate;
   i::ValueDeserializer deserializer;
   bool has_aborted = false;
   bool supports_legacy_wire_format = false;
 };
 
 ValueDeserializer::ValueDeserializer(Isolate* isolate, const uint8_t* data,
@@ skipping 4268 matching lines @@
 
 Local<String> WasmCompiledModule::GetWasmWireBytes() {
   i::Handle<i::JSObject> obj =
       i::Handle<i::JSObject>::cast(Utils::OpenHandle(this));
   i::Handle<i::WasmCompiledModule> compiled_part =
       i::handle(i::WasmCompiledModule::cast(obj->GetInternalField(0)));
   i::Handle<i::String> wire_bytes(compiled_part->module_bytes());
   return Local<String>::Cast(Utils::ToLocal(wire_bytes));
 }
 
+// Currently, wasm modules are bound, both to Isolate and to
+// the Context they were created in. The currently-supported means to
+// decontextualize and then re-contextualize a module is via
+// serialization/deserialization.
+WasmCompiledModule::TransferrableModule
+WasmCompiledModule::AsTransferrableModule() {
+  i::DisallowHeapAllocation no_gc;
+  WasmCompiledModule::SerializedModule compiled_part = Serialize();
+
+  Local<String> wire_bytes = GetWasmWireBytes();
+  size_t wire_size = static_cast<size_t>(wire_bytes->Length());
+  uint8_t* bytes = new uint8_t[wire_size];
+  wire_bytes->WriteOneByte(bytes, 0, wire_bytes->Length());
+
+  return TransferrableModule(
+      std::move(compiled_part),
+      std::make_pair(
+          std::unique_ptr<const uint8_t[]>(const_cast<const uint8_t*>(bytes)),
+          wire_size));
+}
+
+MaybeLocal<WasmCompiledModule> WasmCompiledModule::FromTransferrableModule(
+    Isolate* isolate,
+    WasmCompiledModule::TransferrableModule& transferrable_module) {
+  MaybeLocal<WasmCompiledModule> ret =
+      Deserialize(isolate, AsCallerOwned(transferrable_module.compiled_code),
+                  AsCallerOwned(transferrable_module.wire_bytes));
+  return ret;
+}
+
 WasmCompiledModule::SerializedModule WasmCompiledModule::Serialize() {
   i::Handle<i::JSObject> obj =
       i::Handle<i::JSObject>::cast(Utils::OpenHandle(this));
   i::Handle<i::WasmCompiledModule> compiled_part =
       i::handle(i::WasmCompiledModule::cast(obj->GetInternalField(0)));
 
   std::unique_ptr<i::ScriptData> script_data =
       i::WasmCompiledModuleSerializer::SerializeWasmModule(obj->GetIsolate(),
                                                            compiled_part);
   script_data->ReleaseDataOwnership();
@@ skipping 2711 matching lines @@
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 }  // namespace internal
 }  // namespace v8