electron/shell/browser/javascript_environment.cc

146 строки
5.0 KiB
C++

// Copyright (c) 2013 GitHub, Inc.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.
#include "shell/browser/javascript_environment.h"
#include <memory>
#include <string>
#include <unordered_set>
#include <utility>
#include "base/allocator/partition_alloc_features.h"
#include "base/allocator/partition_allocator/src/partition_alloc/partition_alloc.h"
#include "base/bits.h"
#include "base/command_line.h"
#include "base/feature_list.h"
#include "base/task/current_thread.h"
#include "base/task/single_thread_task_runner.h"
#include "base/task/thread_pool/initialization_util.h"
#include "gin/array_buffer.h"
#include "gin/v8_initializer.h"
#include "shell/browser/microtasks_runner.h"
#include "shell/common/gin_helper/cleaned_up_at_exit.h"
#include "shell/common/node_includes.h"
#include "third_party/blink/public/common/switches.h"
#include "third_party/electron_node/src/node_wasm_web_api.h"
namespace {
v8::Isolate* g_isolate;
}
namespace electron {
namespace {
gin::IsolateHolder CreateIsolateHolder(v8::Isolate* isolate) {
std::unique_ptr<v8::Isolate::CreateParams> create_params =
gin::IsolateHolder::getDefaultIsolateParams();
// Align behavior with V8 Isolate default for Node.js.
// This is necessary for important aspects of Node.js
// including heap and cpu profilers to function properly.
return gin::IsolateHolder(base::SingleThreadTaskRunner::GetCurrentDefault(),
gin::IsolateHolder::kSingleThread,
gin::IsolateHolder::IsolateType::kUtility,
std::move(create_params),
gin::IsolateHolder::IsolateCreationMode::kNormal,
nullptr, nullptr, isolate);
}
} // namespace
JavascriptEnvironment::JavascriptEnvironment(uv_loop_t* event_loop,
bool setup_wasm_streaming)
: isolate_holder_{CreateIsolateHolder(
Initialize(event_loop, setup_wasm_streaming))},
isolate_{isolate_holder_.isolate()},
locker_{isolate_} {
isolate_->Enter();
v8::HandleScope scope(isolate_);
auto context = node::NewContext(isolate_);
CHECK(!context.IsEmpty());
context->Enter();
}
JavascriptEnvironment::~JavascriptEnvironment() {
DCHECK_NE(platform_, nullptr);
{
v8::HandleScope scope(isolate_);
isolate_->GetCurrentContext()->Exit();
}
isolate_->Exit();
g_isolate = nullptr;
platform_->UnregisterIsolate(isolate_);
}
v8::Isolate* JavascriptEnvironment::Initialize(uv_loop_t* event_loop,
bool setup_wasm_streaming) {
auto* cmd = base::CommandLine::ForCurrentProcess();
// --js-flags.
std::string js_flags = "--no-freeze-flags-after-init ";
js_flags.append(cmd->GetSwitchValueASCII(blink::switches::kJavaScriptFlags));
v8::V8::SetFlagsFromString(js_flags.c_str(), js_flags.size());
// The V8Platform of gin relies on Chromium's task schedule, which has not
// been started at this point, so we have to rely on Node's V8Platform.
auto* tracing_agent = node::CreateAgent();
auto* tracing_controller = tracing_agent->GetTracingController();
node::tracing::TraceEventHelper::SetAgent(tracing_agent);
platform_ = node::MultiIsolatePlatform::Create(
base::RecommendedMaxNumberOfThreadsInThreadGroup(3, 8, 0.1, 0),
tracing_controller, gin::V8Platform::GetCurrentPageAllocator());
v8::V8::InitializePlatform(platform_.get());
gin::IsolateHolder::Initialize(gin::IsolateHolder::kNonStrictMode,
gin::ArrayBufferAllocator::SharedInstance(),
nullptr /* external_reference_table */,
js_flags, nullptr /* fatal_error_callback */,
nullptr /* oom_error_callback */,
false /* create_v8_platform */);
v8::Isolate* isolate = v8::Isolate::Allocate();
platform_->RegisterIsolate(isolate, event_loop);
// This is done here because V8 checks for the callback in NewContext.
// Our setup order doesn't allow for calling SetupIsolateForNode
// before NewContext without polluting JavaScriptEnvironment with
// Node.js logic and so we conditionally do it here to keep
// concerns separate.
if (setup_wasm_streaming) {
isolate->SetWasmStreamingCallback(
node::wasm_web_api::StartStreamingCompilation);
}
g_isolate = isolate;
return isolate;
}
// static
v8::Isolate* JavascriptEnvironment::GetIsolate() {
CHECK(g_isolate);
return g_isolate;
}
void JavascriptEnvironment::CreateMicrotasksRunner() {
DCHECK(!microtasks_runner_);
microtasks_runner_ = std::make_unique<MicrotasksRunner>(isolate());
base::CurrentThread::Get()->AddTaskObserver(microtasks_runner_.get());
}
void JavascriptEnvironment::DestroyMicrotasksRunner() {
DCHECK(microtasks_runner_);
{
v8::HandleScope scope(isolate_);
gin_helper::CleanedUpAtExit::DoCleanup();
}
base::CurrentThread::Get()->RemoveTaskObserver(microtasks_runner_.get());
}
} // namespace electron