electron/shell/renderer/web_worker_observer.cc
Charles Kerr 35969939a1
refactor: node::Environment self-cleanup (#39604)
* chore: savepoint

* chore: turn raw_ptr tests back off
2023-08-23 09:56:16 -04:00

111 lines
3.6 KiB
C++

// Copyright (c) 2017 GitHub, Inc.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.
#include "shell/renderer/web_worker_observer.h"
#include <utility>
#include "base/containers/cxx20_erase_set.h"
#include "base/no_destructor.h"
#include "base/ranges/algorithm.h"
#include "base/threading/thread_local.h"
#include "shell/common/api/electron_bindings.h"
#include "shell/common/gin_helper/event_emitter_caller.h"
#include "shell/common/node_bindings.h"
#include "shell/common/node_includes.h"
namespace electron {
namespace {
static base::NoDestructor<base::ThreadLocalOwnedPointer<WebWorkerObserver>>
lazy_tls;
} // namespace
// static
WebWorkerObserver* WebWorkerObserver::GetCurrent() {
return lazy_tls->Get();
}
// static
WebWorkerObserver* WebWorkerObserver::Create() {
auto obs = std::make_unique<WebWorkerObserver>();
auto* obs_raw = obs.get();
lazy_tls->Set(std::move(obs));
return obs_raw;
}
WebWorkerObserver::WebWorkerObserver()
: node_bindings_(
NodeBindings::Create(NodeBindings::BrowserEnvironment::kWorker)),
electron_bindings_(
std::make_unique<ElectronBindings>(node_bindings_->uv_loop())) {}
WebWorkerObserver::~WebWorkerObserver() = default;
void WebWorkerObserver::WorkerScriptReadyForEvaluation(
v8::Local<v8::Context> worker_context) {
v8::Context::Scope context_scope(worker_context);
auto* isolate = worker_context->GetIsolate();
v8::MicrotasksScope microtasks_scope(
isolate, worker_context->GetMicrotaskQueue(),
v8::MicrotasksScope::kDoNotRunMicrotasks);
// Start the embed thread.
node_bindings_->PrepareEmbedThread();
// Setup node tracing controller.
if (!node::tracing::TraceEventHelper::GetAgent())
node::tracing::TraceEventHelper::SetAgent(node::CreateAgent());
// Setup node environment for each window.
v8::Maybe<bool> initialized = node::InitializeContext(worker_context);
CHECK(!initialized.IsNothing() && initialized.FromJust());
std::shared_ptr<node::Environment> env =
node_bindings_->CreateEnvironment(worker_context, nullptr);
// Add Electron extended APIs.
electron_bindings_->BindTo(env->isolate(), env->process_object());
// Load everything.
node_bindings_->LoadEnvironment(env.get());
// Make uv loop being wrapped by window context.
node_bindings_->set_uv_env(env.get());
// Give the node loop a run to make sure everything is ready.
node_bindings_->StartPolling();
// Keep the environment alive until we free it in ContextWillDestroy()
environments_.insert(std::move(env));
}
void WebWorkerObserver::ContextWillDestroy(v8::Local<v8::Context> context) {
node::Environment* env = node::Environment::GetCurrent(context);
if (env)
gin_helper::EmitEvent(env->isolate(), env->process_object(), "exit");
// Destroying the node environment will also run the uv loop,
// Node.js expects `kExplicit` microtasks policy and will run microtasks
// checkpoints after every call into JavaScript. Since we use a different
// policy in the renderer - switch to `kExplicit`
v8::MicrotaskQueue* microtask_queue = context->GetMicrotaskQueue();
auto old_policy = microtask_queue->microtasks_policy();
DCHECK_EQ(microtask_queue->GetMicrotasksScopeDepth(), 0);
microtask_queue->set_microtasks_policy(v8::MicrotasksPolicy::kExplicit);
base::EraseIf(environments_,
[env](auto const& item) { return item.get() == env; });
microtask_queue->set_microtasks_policy(old_policy);
// ElectronBindings is tracking node environments.
electron_bindings_->EnvironmentDestroyed(env);
if (lazy_tls->Get())
lazy_tls->Set(nullptr);
}
} // namespace electron