electron/shell/renderer/web_worker_observer.cc
trop[bot] 79751340c6
fix: fetch-dependent interfaces in Web Workers (#42595)
Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Shelley Vohr <shelley.vohr@gmail.com>
2024-06-20 16:32:58 -04:00

133 lines
4.5 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 <set>
#include <utility>
#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);
// We need to use the Blink implementation of fetch in web workers
// Node.js deletes the global fetch function when their fetch implementation
// is disabled, so we need to save and re-add it after the Node.js environment
// is loaded. See corresponding change in node/init.ts.
v8::Local<v8::Object> global = worker_context->Global();
std::vector<std::string> keys = {"fetch", "Response", "FormData", "Request",
"Headers"};
for (const auto& key : keys) {
v8::MaybeLocal<v8::Value> value =
global->Get(worker_context, gin::StringToV8(isolate, key.c_str()));
if (!value.IsEmpty()) {
std::string blink_key = "blink" + key;
global
->Set(worker_context, gin::StringToV8(isolate, blink_key.c_str()),
value.ToLocalChecked())
.Check();
}
}
// 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) {
v8::Context::Scope context_scope(env->context());
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