worker: use copy of process.env

Instead of sharing the OS-backed store for all `process.env` instances,
create a copy of `process.env` for every worker that is created.

The copies do not interact. Native-addons do not see modifications to
`process.env` from Worker threads, but child processes started from
Workers do default to the Worker’s copy of `process.env`.

This makes Workers behave like child processes as far as `process.env`
is concerned, and an option corresponding to the `child_process`
module’s `env` option is added to the constructor.

Fixes: https://github.com/nodejs/node/issues/24947

PR-URL: https://github.com/nodejs/node/pull/26544
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>

1 files changed, 24 insertions, 1 deletions

diff --git a/src/node_worker.cc b/src/node_worker.cc
index d18d8023a2..8fabbffba4 100644
--- a/src/node_worker.cc
+++ b/src/node_worker.cc
@@ -68,7 +68,8 @@ Worker::Worker(Environment* env,
       exec_argv_(exec_argv),
       platform_(env->isolate_data()->platform()),
       profiler_idle_notifier_started_(env->profiler_idle_notifier_started()),
-      thread_id_(Environment::AllocateThreadId()) {
+      thread_id_(Environment::AllocateThreadId()),
+      env_vars_(env->env_vars()) {
   Debug(this, "Creating new worker instance with thread id %llu", thread_id_);
 
   // Set up everything that needs to be set up in the parent environment.
@@ -254,6 +255,7 @@ void Worker::Run() {
                                    Environment::kNoFlags,
                                    thread_id_));
         CHECK_NOT_NULL(env_);
+        env_->set_env_vars(std::move(env_vars_));
         env_->set_abort_on_uncaught_exception(false);
         env_->set_worker_context(this);
 
@@ -469,6 +471,25 @@ void Worker::New(const FunctionCallbackInfo<Value>& args) {
   new Worker(env, args.This(), url, per_isolate_opts, std::move(exec_argv_out));
 }
 
+void Worker::CloneParentEnvVars(const FunctionCallbackInfo<Value>& args) {
+  Worker* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.This());
+  CHECK(w->thread_joined_);  // The Worker has not started yet.
+
+  w->env_vars_ = w->env()->env_vars()->Clone(args.GetIsolate());
+}
+
+void Worker::SetEnvVars(const FunctionCallbackInfo<Value>& args) {
+  Worker* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.This());
+  CHECK(w->thread_joined_);  // The Worker has not started yet.
+
+  CHECK(args[0]->IsObject());
+  w->env_vars_ = KVStore::CreateMapKVStore();
+  w->env_vars_->AssignFromObject(args.GetIsolate()->GetCurrentContext(),
+                                args[0].As<Object>());
+}
+
 void Worker::StartThread(const FunctionCallbackInfo<Value>& args) {
   Worker* w;
   ASSIGN_OR_RETURN_UNWRAP(&w, args.This());
@@ -566,6 +587,8 @@ void InitWorker(Local<Object> target,
     w->InstanceTemplate()->SetInternalFieldCount(1);
     w->Inherit(AsyncWrap::GetConstructorTemplate(env));
 
+    env->SetProtoMethod(w, "setEnvVars", Worker::SetEnvVars);
+    env->SetProtoMethod(w, "cloneParentEnvVars", Worker::CloneParentEnvVars);
     env->SetProtoMethod(w, "startThread", Worker::StartThread);
     env->SetProtoMethod(w, "stopThread", Worker::StopThread);
     env->SetProtoMethod(w, "ref", Worker::Ref);