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, 4 insertions, 0 deletions

diff --git a/src/node_worker.h b/src/node_worker.h
index b23ab704b0..94af8160c6 100644
--- a/src/node_worker.h
+++ b/src/node_worker.h
@@ -43,6 +43,9 @@ class Worker : public AsyncWrap {
   bool is_stopped() const;
 
   static void New(const v8::FunctionCallbackInfo<v8::Value>& args);
+  static void CloneParentEnvVars(
+      const v8::FunctionCallbackInfo<v8::Value>& args);
+  static void SetEnvVars(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void StartThread(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void StopThread(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void Ref(const v8::FunctionCallbackInfo<v8::Value>& args);
@@ -78,6 +81,7 @@ class Worker : public AsyncWrap {
   static constexpr size_t kStackBufferSize = 192 * 1024;
 
   std::unique_ptr<MessagePortData> child_port_data_;
+  std::shared_ptr<KVStore> env_vars_;
 
   // The child port is kept alive by the child Environment's persistent
   // handle to it, as long as that child Environment exists.