src: make a Environment-independent proxy class for NativeModuleLoader

This patch splits `NativeModuleLoader` into two parts - a singleton
that only relies on v8 and `node::Mutex` and a proxy class for
the singleton (`NativeModuleEnv`) that provides limited access to
the singleton as well as C++ bindings for the Node.js binary.
`NativeModuleLoader` is then no longer aware of `Environment`.

PR-URL: https://github.com/nodejs/node/pull/27160
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>

9 files changed, 417 insertions, 322 deletions

diff --git a/src/api/environment.cc b/src/api/environment.cc
index 62eca337e1..fb7d7003bb 100644
--- a/src/api/environment.cc
+++ b/src/api/environment.cc
@@ -3,7 +3,7 @@
 #include "node_context_data.h"
 #include "node_errors.h"
 #include "node_internals.h"
-#include "node_native_module.h"
+#include "node_native_module_env.h"
 #include "node_platform.h"
 #include "node_process.h"
 #include "node_v8_platform-inl.h"
@@ -351,7 +351,7 @@ Local<Context> NewContext(Isolate* isolate,
       };
       Local<Value> arguments[] = {context->Global(), exports};
       MaybeLocal<Function> maybe_fn =
-          per_process::native_module_loader.LookupAndCompile(
+          native_module::NativeModuleEnv::LookupAndCompile(
               context, *module, &parameters, nullptr);
       if (maybe_fn.IsEmpty()) {
         return Local<Context>();
diff --git a/src/node.cc b/src/node.cc
index a5a0cf33e1..09817b8a4c 100644
--- a/src/node.cc
+++ b/src/node.cc
@@ -31,7 +31,7 @@
 #include "node_errors.h"
 #include "node_internals.h"
 #include "node_metadata.h"
-#include "node_native_module.h"
+#include "node_native_module_env.h"
 #include "node_options-inl.h"
 #include "node_perf.h"
 #include "node_platform.h"
@@ -118,8 +118,10 @@
 
 namespace node {
 
+using native_module::NativeModuleEnv;
 using options_parser::kAllowedInEnvironment;
 using options_parser::kDisallowedInEnvironment;
+
 using v8::Array;
 using v8::Boolean;
 using v8::Context;
@@ -207,8 +209,7 @@ MaybeLocal<Value> ExecuteBootstrapper(Environment* env,
                                       std::vector<Local<Value>>* arguments) {
   EscapableHandleScope scope(env->isolate());
   MaybeLocal<Function> maybe_fn =
-      per_process::native_module_loader.LookupAndCompile(
-          env->context(), id, parameters, env);
+      NativeModuleEnv::LookupAndCompile(env->context(), id, parameters, env);
 
   if (maybe_fn.IsEmpty()) {
     return MaybeLocal<Value>();
@@ -401,7 +402,7 @@ MaybeLocal<Value> StartMainThreadExecution(Environment* env) {
   // To allow people to extend Node in different ways, this hook allows
   // one to drop a file lib/_third_party_main.js into the build
   // directory which will be executed instead of Node's normal loading.
-  if (per_process::native_module_loader.Exists("_third_party_main")) {
+  if (NativeModuleEnv::Exists("_third_party_main")) {
     return StartExecution(env, "internal/main/run_third_party_main");
   }
 
@@ -724,6 +725,8 @@ int InitializeNodeWithArgs(std::vector<std::string>* argv,
   per_process::metadata.versions.InitializeIntlVersions();
 #endif
 
+  NativeModuleEnv::InitializeCodeCache();
+
   // We should set node_is_initialized here instead of in node::Start,
   // otherwise embedders using node::Init to initialize everything will not be
   // able to set it and native modules will not load for them.
diff --git a/src/node_binding.cc b/src/node_binding.cc
index ffa9ffdfdb..9a9bfa70a8 100644
--- a/src/node_binding.cc
+++ b/src/node_binding.cc
@@ -1,8 +1,8 @@
 #include "node_binding.h"
+#include <atomic>
 #include "env-inl.h"
-#include "node_native_module.h"
+#include "node_native_module_env.h"
 #include "util.h"
-#include <atomic>
 
 #if HAVE_OPENSSL
 #define NODE_BUILTIN_OPENSSL_MODULES(V) V(crypto) V(tls_wrap)
@@ -593,13 +593,13 @@ void GetInternalBinding(const FunctionCallbackInfo<Value>& args) {
         exports->SetPrototype(env->context(), Null(env->isolate())).FromJust());
     DefineConstants(env->isolate(), exports);
   } else if (!strcmp(*module_v, "natives")) {
-    exports = per_process::native_module_loader.GetSourceObject(env->context());
+    exports = native_module::NativeModuleEnv::GetSourceObject(env->context());
     // Legacy feature: process.binding('natives').config contains stringified
     // config.gypi
     CHECK(exports
               ->Set(env->context(),
                     env->config_string(),
-                    per_process::native_module_loader.GetConfigString(
+                    native_module::NativeModuleEnv::GetConfigString(
                         env->isolate()))
               .FromJust());
   } else {
diff --git a/src/node_code_cache_stub.cc b/src/node_code_cache_stub.cc
index 4fffa8e0c2..021910e829 100644
--- a/src/node_code_cache_stub.cc
+++ b/src/node_code_cache_stub.cc
@@ -1,5 +1,5 @@
 
-#include "node_native_module.h"
+#include "node_native_module_env.h"
 
 // This is supposed to be generated by tools/generate_code_cache.js
 // The stub here is used when configure is run without `--code-cache-path`
@@ -8,8 +8,8 @@ namespace node {
 namespace native_module {
 
 // The generated source code would insert <std::string, UnionString> pairs
-// into native_module_loader.code_cache_.
-void NativeModuleLoader::LoadCodeCache() {}
+// into NativeModuleLoader::instance.code_cache_.
+void NativeModuleEnv::InitializeCodeCache() {}
 
 }  // namespace native_module
 }  // namespace node
diff --git a/src/node_native_module.cc b/src/node_native_module.cc
index 6462f39ee1..814adb620d 100644
--- a/src/node_native_module.cc
+++ b/src/node_native_module.cc
@@ -1,40 +1,60 @@
 #include "node_native_module.h"
-#include "node_errors.h"
+#include "util-inl.h"
 
 namespace node {
-
-namespace per_process {
-native_module::NativeModuleLoader native_module_loader;
-}  // namespace per_process
-
 namespace native_module {
 
-using v8::Array;
-using v8::ArrayBuffer;
 using v8::Context;
-using v8::DEFAULT;
 using v8::EscapableHandleScope;
 using v8::Function;
-using v8::FunctionCallbackInfo;
 using v8::HandleScope;
 using v8::Integer;
-using v8::IntegrityLevel;
 using v8::Isolate;
 using v8::Local;
 using v8::Maybe;
 using v8::MaybeLocal;
-using v8::Name;
-using v8::None;
 using v8::Object;
-using v8::PropertyCallbackInfo;
 using v8::Script;
 using v8::ScriptCompiler;
 using v8::ScriptOrigin;
-using v8::Set;
-using v8::SideEffectType;
 using v8::String;
-using v8::Uint8Array;
-using v8::Value;
+
+NativeModuleLoader NativeModuleLoader::instance_;
+
+NativeModuleLoader::NativeModuleLoader() : config_(GetConfig()) {
+  LoadJavaScriptSource();
+}
+
+NativeModuleLoader* NativeModuleLoader::GetInstance() {
+  return &instance_;
+}
+
+bool NativeModuleLoader::Exists(const char* id) {
+  return source_.find(id) != source_.end();
+}
+
+Local<Object> NativeModuleLoader::GetSourceObject(Local<Context> context) {
+  Isolate* isolate = context->GetIsolate();
+  Local<Object> out = Object::New(isolate);
+  for (auto const& x : source_) {
+    Local<String> key = OneByteString(isolate, x.first.c_str(), x.first.size());
+    out->Set(context, key, x.second.ToStringChecked(isolate)).FromJust();
+  }
+  return out;
+}
+
+Local<String> NativeModuleLoader::GetConfigString(Isolate* isolate) {
+  return config_.ToStringChecked(isolate);
+}
+
+std::vector<std::string> NativeModuleLoader::GetModuleIds() {
+  std::vector<std::string> ids;
+  ids.reserve(source_.size());
+  for (auto const& x : source_) {
+    ids.emplace_back(x.first);
+  }
+  return ids;
+}
 
 void NativeModuleLoader::InitializeModuleCategories() {
   if (module_categories_.is_initialized) {
@@ -105,182 +125,52 @@ void NativeModuleLoader::InitializeModuleCategories() {
   module_categories_.is_initialized = true;
 }
 
-// TODO(joyeecheung): make these more general and put them into util.h
-Local<Object> MapToObject(Local<Context> context,
-                          const NativeModuleRecordMap& in) {
-  Isolate* isolate = context->GetIsolate();
-  Local<Object> out = Object::New(isolate);
-  for (auto const& x : in) {
-    Local<String> key = OneByteString(isolate, x.first.c_str(), x.first.size());
-    out->Set(context, key, x.second.ToStringChecked(isolate)).Check();
-  }
-  return out;
+const std::set<std::string>& NativeModuleLoader::GetCannotBeRequired() {
+  InitializeModuleCategories();
+  return module_categories_.cannot_be_required;
 }
 
-Local<Set> ToJsSet(Local<Context> context,
-                   const std::set<std::string>& in) {
-  Isolate* isolate = context->GetIsolate();
-  Local<Set> out = Set::New(isolate);
-  for (auto const& x : in) {
-    out->Add(context, OneByteString(isolate, x.c_str(), x.size()))
-        .ToLocalChecked();
-  }
-  return out;
+const std::set<std::string>& NativeModuleLoader::GetCanBeRequired() {
+  InitializeModuleCategories();
+  return module_categories_.can_be_required;
 }
 
-bool NativeModuleLoader::Exists(const char* id) {
-  return source_.find(id) != source_.end();
+bool NativeModuleLoader::CanBeRequired(const char* id) {
+  return GetCanBeRequired().count(id) == 1;
 }
 
-void NativeModuleLoader::GetModuleCategories(
-    Local<Name> property, const PropertyCallbackInfo<Value>& info) {
-  per_process::native_module_loader.InitializeModuleCategories();
-
-  Environment* env = Environment::GetCurrent(info);
-  Isolate* isolate = env->isolate();
-  Local<Context> context = env->context();
-  Local<Object> result = Object::New(isolate);
-
-  // Copy from the per-process categories
-  std::set<std::string> cannot_be_required =
-      per_process::native_module_loader.module_categories_.cannot_be_required;
-  std::set<std::string> can_be_required =
-      per_process::native_module_loader.module_categories_.can_be_required;
-
-  if (!env->owns_process_state()) {
-    can_be_required.erase("trace_events");
-    cannot_be_required.insert("trace_events");
-  }
-
-  result
-      ->Set(context,
-            OneByteString(isolate, "cannotBeRequired"),
-            ToJsSet(context, cannot_be_required))
-      .Check();
-  result
-      ->Set(context,
-            OneByteString(isolate, "canBeRequired"),
-            ToJsSet(context, can_be_required))
-      .Check();
-  info.GetReturnValue().Set(result);
-}
-
-void NativeModuleLoader::GetCacheUsage(
-    const FunctionCallbackInfo<Value>& args) {
-  Environment* env = Environment::GetCurrent(args);
-  Isolate* isolate = env->isolate();
-  Local<Context> context = env->context();
-  Local<Object> result = Object::New(isolate);
-  result
-      ->Set(env->context(),
-            OneByteString(isolate, "compiledWithCache"),
-            ToJsSet(context, env->native_modules_with_cache))
-      .Check();
-  result
-      ->Set(env->context(),
-            OneByteString(isolate, "compiledWithoutCache"),
-            ToJsSet(context, env->native_modules_without_cache))
-      .Check();
-  args.GetReturnValue().Set(result);
-}
-
-void NativeModuleLoader::ModuleIdsGetter(
-    Local<Name> property, const PropertyCallbackInfo<Value>& info) {
-  Isolate* isolate = info.GetIsolate();
-
-  const NativeModuleRecordMap& source_ =
-      per_process::native_module_loader.source_;
-  std::vector<Local<Value>> ids;
-  ids.reserve(source_.size());
-
-  for (auto const& x : source_) {
-    ids.emplace_back(OneByteString(isolate, x.first.c_str(), x.first.size()));
-  }
-
-  info.GetReturnValue().Set(Array::New(isolate, ids.data(), ids.size()));
-}
-
-void NativeModuleLoader::ConfigStringGetter(
-    Local<Name> property, const PropertyCallbackInfo<Value>& info) {
-  info.GetReturnValue().Set(
-      per_process::native_module_loader.GetConfigString(info.GetIsolate()));
-}
-
-Local<Object> NativeModuleLoader::GetSourceObject(
-    Local<Context> context) const {
-  return MapToObject(context, source_);
-}
-
-Local<String> NativeModuleLoader::GetConfigString(Isolate* isolate) const {
-  return config_.ToStringChecked(isolate);
-}
-
-NativeModuleLoader::NativeModuleLoader() : config_(GetConfig()) {
-  LoadJavaScriptSource();
-  LoadCodeCache();
+bool NativeModuleLoader::CannotBeRequired(const char* id) {
+  return GetCannotBeRequired().count(id) == 1;
 }
 
-// This is supposed to be run only by the main thread in
-// tools/generate_code_cache.js
-void NativeModuleLoader::GetCodeCache(const FunctionCallbackInfo<Value>& args) {
-  Environment* env = Environment::GetCurrent(args);
-  Isolate* isolate = env->isolate();
-  CHECK(env->is_main_thread());
-
-  CHECK(args[0]->IsString());
-  node::Utf8Value id_v(isolate, args[0].As<String>());
-  const char* id = *id_v;
-
-  const NativeModuleLoader& loader = per_process::native_module_loader;
-  MaybeLocal<Uint8Array> ret = loader.GetCodeCache(isolate, id);
-  if (!ret.IsEmpty()) {
-    args.GetReturnValue().Set(ret.ToLocalChecked());
-  }
+NativeModuleCacheMap* NativeModuleLoader::code_cache() {
+  return &code_cache_;
 }
 
-// This is supposed to be run only by the main thread in
-// tools/generate_code_cache.js
-MaybeLocal<Uint8Array> NativeModuleLoader::GetCodeCache(Isolate* isolate,
-                                                        const char* id) const {
-  EscapableHandleScope scope(isolate);
+ScriptCompiler::CachedData* NativeModuleLoader::GetCodeCache(
+    const char* id) const {
   Mutex::ScopedLock lock(code_cache_mutex_);
-
-  ScriptCompiler::CachedData* cached_data = nullptr;
   const auto it = code_cache_.find(id);
   if (it == code_cache_.end()) {
     // The module has not been compiled before.
-    return MaybeLocal<Uint8Array>();
-  }
-
-  cached_data = it->second.get();
-
-  Local<ArrayBuffer> buf = ArrayBuffer::New(isolate, cached_data->length);
-  memcpy(buf->GetContents().Data(), cached_data->data, cached_data->length);
-  return scope.Escape(Uint8Array::New(buf, 0, cached_data->length));
-}
-
-void NativeModuleLoader::CompileFunction(
-    const FunctionCallbackInfo<Value>& args) {
-  Environment* env = Environment::GetCurrent(args);
-  CHECK(args[0]->IsString());
-  node::Utf8Value id(env->isolate(), args[0].As<String>());
-
-  MaybeLocal<Function> result = CompileAsModule(env, *id);
-  if (!result.IsEmpty()) {
-    args.GetReturnValue().Set(result.ToLocalChecked());
+    return nullptr;
   }
+  return it->second.get();
 }
 
-MaybeLocal<Function> NativeModuleLoader::CompileAsModule(Environment* env,
-                                                         const char* id) {
-  std::vector<Local<String>> parameters = {env->exports_string(),
-                                           env->require_string(),
-                                           env->module_string(),
-                                           env->process_string(),
-                                           env->internal_binding_string(),
-                                           env->primordials_string()};
-  return per_process::native_module_loader.LookupAndCompile(
-      env->context(), id, &parameters, env);
+MaybeLocal<Function> NativeModuleLoader::CompileAsModule(
+    Local<Context> context,
+    const char* id,
+    NativeModuleLoader::Result* result) {
+  Isolate* isolate = context->GetIsolate();
+  std::vector<Local<String>> parameters = {
+      FIXED_ONE_BYTE_STRING(isolate, "exports"),
+      FIXED_ONE_BYTE_STRING(isolate, "require"),
+      FIXED_ONE_BYTE_STRING(isolate, "module"),
+      FIXED_ONE_BYTE_STRING(isolate, "process"),
+      FIXED_ONE_BYTE_STRING(isolate, "internalBinding"),
+      FIXED_ONE_BYTE_STRING(isolate, "primordials")};
+  return LookupAndCompile(context, id, &parameters, result);
 }
 
 // Returns Local<Function> of the compiled module if return_code_cache
@@ -290,7 +180,7 @@ MaybeLocal<Function> NativeModuleLoader::LookupAndCompile(
     Local<Context> context,
     const char* id,
     std::vector<Local<String>>* parameters,
-    Environment* optional_env) {
+    NativeModuleLoader::Result* result) {
   Isolate* isolate = context->GetIsolate();
   EscapableHandleScope scope(isolate);
 
@@ -317,9 +207,9 @@ MaybeLocal<Function> NativeModuleLoader::LookupAndCompile(
     }
   }
 
-  const bool use_cache = cached_data != nullptr;
+  const bool has_cache = cached_data != nullptr;
   ScriptCompiler::CompileOptions options =
-      use_cache ? ScriptCompiler::kConsumeCodeCache
+      has_cache ? ScriptCompiler::kConsumeCodeCache
                 : ScriptCompiler::kEagerCompile;
   ScriptCompiler::Source script_source(source, origin, cached_data);
 
@@ -346,22 +236,10 @@ MaybeLocal<Function> NativeModuleLoader::LookupAndCompile(
   // it only starts after the Environment is created, so the per_context.js
   // will never be in any of these two sets, but the two sets are only for
   // testing anyway.
-  if (use_cache) {
-    if (optional_env != nullptr) {
-      // This could happen when Node is run with any v8 flag, but
-      // the cache is not generated with one
-      if (script_source.GetCachedData()->rejected) {
-        optional_env->native_modules_without_cache.insert(id);
-      } else {
-        optional_env->native_modules_with_cache.insert(id);
-      }
-    }
-  } else {
-    if (optional_env != nullptr) {
-      optional_env->native_modules_without_cache.insert(id);
-    }
-  }
 
+  *result = (has_cache && !script_source.GetCachedData()->rejected)
+                ? Result::kWithCache
+                : Result::kWithoutCache;
   // Generate new cache for next compilation
   std::unique_ptr<ScriptCompiler::CachedData> new_cached_data(
       ScriptCompiler::CreateCodeCacheForFunction(fun));
@@ -373,56 +251,5 @@ MaybeLocal<Function> NativeModuleLoader::LookupAndCompile(
   return scope.Escape(fun);
 }
 
-void NativeModuleLoader::Initialize(Local<Object> target,
-                                    Local<Value> unused,
-                                    Local<Context> context,
-                                    void* priv) {
-  Environment* env = Environment::GetCurrent(context);
-
-  CHECK(target
-            ->SetAccessor(env->context(),
-                          env->config_string(),
-                          ConfigStringGetter,
-                          nullptr,
-                          MaybeLocal<Value>(),
-                          DEFAULT,
-                          None,
-                          SideEffectType::kHasNoSideEffect)
-            .FromJust());
-  CHECK(target
-            ->SetAccessor(env->context(),
-                          FIXED_ONE_BYTE_STRING(env->isolate(), "moduleIds"),
-                          ModuleIdsGetter,
-                          nullptr,
-                          MaybeLocal<Value>(),
-                          DEFAULT,
-                          None,
-                          SideEffectType::kHasNoSideEffect)
-            .FromJust());
-
-  CHECK(target
-            ->SetAccessor(
-                env->context(),
-                FIXED_ONE_BYTE_STRING(env->isolate(), "moduleCategories"),
-                GetModuleCategories,
-                nullptr,
-                env->as_callback_data(),
-                DEFAULT,
-                None,
-                SideEffectType::kHasNoSideEffect)
-            .FromJust());
-
-  env->SetMethod(
-      target, "getCacheUsage", NativeModuleLoader::GetCacheUsage);
-  env->SetMethod(
-      target, "compileFunction", NativeModuleLoader::CompileFunction);
-  env->SetMethod(target, "getCodeCache", NativeModuleLoader::GetCodeCache);
-  // internalBinding('native_module') should be frozen
-  target->SetIntegrityLevel(context, IntegrityLevel::kFrozen).Check();
-}
-
 }  // namespace native_module
 }  // namespace node
-
-NODE_MODULE_CONTEXT_AWARE_INTERNAL(
-    native_module, node::native_module::NativeModuleLoader::Initialize)
diff --git a/src/node_native_module.h b/src/node_native_module.h
index 587c59022a..bbd4d89c40 100644
--- a/src/node_native_module.h
+++ b/src/node_native_module.h
@@ -4,9 +4,9 @@
 #if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
 
 #include <map>
+#include <memory>
 #include <set>
 #include <string>
-#include "env.h"
 #include "node_mutex.h"
 #include "node_union_bytes.h"
 #include "v8.h"
@@ -23,79 +23,57 @@ using NativeModuleCacheMap =
 // handles compilation and caching of builtin modules (NativeModule)
 // and bootstrappers, whose source are bundled into the binary
 // as static data.
-// This class should not depend on a particular isolate, context, or
-// environment. Rather it should take them as arguments when necessary.
-// The instances of this class are per-process.
+// This class should not depend on any Environment, or depend on access to
+// the its own singleton - that should be encapsulated in NativeModuleEnv
+// instead.
 class NativeModuleLoader {
- public:
+ private:
+  // Only allow access from friends.
+  friend class NativeModuleEnv;
+  friend class CodeCacheBuilder;
+
   NativeModuleLoader();
-  // TODO(joyeecheung): maybe we should make this a singleton, instead of
-  // putting it in per_process.
   NativeModuleLoader(const NativeModuleLoader&) = delete;
   NativeModuleLoader& operator=(const NativeModuleLoader&) = delete;
-
-  static void Initialize(v8::Local<v8::Object> target,
-                         v8::Local<v8::Value> unused,
-                         v8::Local<v8::Context> context,
-                         void* priv);
-  v8::Local<v8::Object> GetSourceObject(v8::Local<v8::Context> context) const;
-  // Returns config.gypi as a JSON string
-  v8::Local<v8::String> GetConfigString(v8::Isolate* isolate) const;
-
-  bool Exists(const char* id);
-
-  // For bootstrappers optional_env may be a nullptr.
-  // If an exception is encountered (e.g. source code contains
-  // syntax error), the returned value is empty.
-  v8::MaybeLocal<v8::Function> LookupAndCompile(
-      v8::Local<v8::Context> context,
-      const char* id,
-      std::vector<v8::Local<v8::String>>* parameters,
-      Environment* optional_env);
-
- private:
-  static void GetModuleCategories(
-      v8::Local<v8::Name> property,
-      const v8::PropertyCallbackInfo<v8::Value>& info);
-  static void GetCacheUsage(const v8::FunctionCallbackInfo<v8::Value>& args);
-  // Passing ids of builtin module source code into JS land as
-  // internalBinding('native_module').moduleIds
-  static void ModuleIdsGetter(v8::Local<v8::Name> property,
-                              const v8::PropertyCallbackInfo<v8::Value>& info);
-  // Passing config.gypi into JS land as internalBinding('native_module').config
-  static void ConfigStringGetter(
-      v8::Local<v8::Name> property,
-      const v8::PropertyCallbackInfo<v8::Value>& info);
-  // Get code cache for a specific native module
-  static void GetCodeCache(const v8::FunctionCallbackInfo<v8::Value>& args);
-  v8::MaybeLocal<v8::Uint8Array> GetCodeCache(v8::Isolate* isolate,
-                                              const char* id) const;
-  // Compile a specific native module as a function
-  static void CompileFunction(const v8::FunctionCallbackInfo<v8::Value>& args);
+  static NativeModuleLoader* GetInstance();
 
   // Generated by tools/js2c.py as node_javascript.cc
   void LoadJavaScriptSource();  // Loads data into source_
   UnionBytes GetConfig();       // Return data for config.gypi
 
-  // Generated by tools/generate_code_cache.js as node_code_cache.cc when
-  // the build is configured with --code-cache-path=.... They are noops
-  // in node_code_cache_stub.cc
-  void LoadCodeCache();      // Loads data into code_cache_
-
-  // Compile a script as a NativeModule that can be loaded via
-  // NativeModule.p.require in JS land.
-  static v8::MaybeLocal<v8::Function> CompileAsModule(Environment* env,
-                                                      const char* id);
+  bool Exists(const char* id);
+  v8::Local<v8::Object> GetSourceObject(v8::Local<v8::Context> context);
+  v8::Local<v8::String> GetConfigString(v8::Isolate* isolate);
+  std::vector<std::string> GetModuleIds();
 
-  void InitializeModuleCategories();
   struct ModuleCategories {
     bool is_initialized = false;
     std::set<std::string> can_be_required;
     std::set<std::string> cannot_be_required;
   };
+  void InitializeModuleCategories();
+  const std::set<std::string>& GetCannotBeRequired();
+  const std::set<std::string>& GetCanBeRequired();
 
-  ModuleCategories module_categories_;
+  bool CanBeRequired(const char* id);
+  bool CannotBeRequired(const char* id);
+
+  NativeModuleCacheMap* code_cache();
+  v8::ScriptCompiler::CachedData* GetCodeCache(const char* id) const;
+  enum class Result { kWithCache, kWithoutCache };
+  // If an exception is encountered (e.g. source code contains
+  // syntax error), the returned value is empty.
+  v8::MaybeLocal<v8::Function> LookupAndCompile(
+      v8::Local<v8::Context> context,
+      const char* id,
+      std::vector<v8::Local<v8::String>>* parameters,
+      Result* result);
+  v8::MaybeLocal<v8::Function> CompileAsModule(v8::Local<v8::Context> context,
+                                               const char* id,
+                                               Result* result);
 
+  static NativeModuleLoader instance_;
+  ModuleCategories module_categories_;
   NativeModuleRecordMap source_;
   NativeModuleCacheMap code_cache_;
   UnionBytes config_;
@@ -103,13 +81,8 @@ class NativeModuleLoader {
   // Used to synchronize access to the code cache map
   Mutex code_cache_mutex_;
 };
-
 }  // namespace native_module
 
-namespace per_process {
-extern native_module::NativeModuleLoader native_module_loader;
-}  // namespace per_process
-
 }  // namespace node
 
 #endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
diff --git a/src/node_native_module_env.cc b/src/node_native_module_env.cc
new file mode 100644
index 0000000000..fc48436dc1
--- /dev/null
+++ b/src/node_native_module_env.cc
@@ -0,0 +1,229 @@
+#include "node_native_module_env.h"
+#include "env-inl.h"
+
+namespace node {
+namespace native_module {
+
+using v8::ArrayBuffer;
+using v8::Context;
+using v8::DEFAULT;
+using v8::Function;
+using v8::FunctionCallbackInfo;
+using v8::IntegrityLevel;
+using v8::Isolate;
+using v8::Local;
+using v8::Maybe;
+using v8::MaybeLocal;
+using v8::Name;
+using v8::None;
+using v8::Object;
+using v8::PropertyCallbackInfo;
+using v8::ScriptCompiler;
+using v8::Set;
+using v8::SideEffectType;
+using v8::String;
+using v8::Uint8Array;
+using v8::Value;
+
+// TODO(joyeecheung): make these more general and put them into util.h
+Local<Set> ToJsSet(Local<Context> context, const std::set<std::string>& in) {
+  Isolate* isolate = context->GetIsolate();
+  Local<Set> out = Set::New(isolate);
+  for (auto const& x : in) {
+    out->Add(context, OneByteString(isolate, x.c_str(), x.size()))
+        .ToLocalChecked();
+  }
+  return out;
+}
+
+bool NativeModuleEnv::Exists(const char* id) {
+  return NativeModuleLoader::GetInstance()->Exists(id);
+}
+
+Local<Object> NativeModuleEnv::GetSourceObject(Local<Context> context) {
+  return NativeModuleLoader::GetInstance()->GetSourceObject(context);
+}
+
+Local<String> NativeModuleEnv::GetConfigString(Isolate* isolate) {
+  return NativeModuleLoader::GetInstance()->GetConfigString(isolate);
+}
+
+void NativeModuleEnv::GetModuleCategories(
+    Local<Name> property, const PropertyCallbackInfo<Value>& info) {
+  Environment* env = Environment::GetCurrent(info);
+  Isolate* isolate = env->isolate();
+  Local<Context> context = env->context();
+  Local<Object> result = Object::New(isolate);
+
+  // Copy from the per-process categories
+  std::set<std::string> cannot_be_required =
+      NativeModuleLoader::GetInstance()->GetCannotBeRequired();
+  std::set<std::string> can_be_required =
+      NativeModuleLoader::GetInstance()->GetCanBeRequired();
+
+  if (!env->owns_process_state()) {
+    can_be_required.erase("trace_events");
+    cannot_be_required.insert("trace_events");
+  }
+
+  result
+      ->Set(context,
+            OneByteString(isolate, "cannotBeRequired"),
+            ToJsSet(context, cannot_be_required))
+      .FromJust();
+  result
+      ->Set(context,
+            OneByteString(isolate, "canBeRequired"),
+            ToJsSet(context, can_be_required))
+      .FromJust();
+  info.GetReturnValue().Set(result);
+}
+
+void NativeModuleEnv::GetCacheUsage(const FunctionCallbackInfo<Value>& args) {
+  Environment* env = Environment::GetCurrent(args);
+  Isolate* isolate = env->isolate();
+  Local<Context> context = env->context();
+  Local<Object> result = Object::New(isolate);
+  result
+      ->Set(env->context(),
+            OneByteString(isolate, "compiledWithCache"),
+            ToJsSet(context, env->native_modules_with_cache))
+      .FromJust();
+  result
+      ->Set(env->context(),
+            OneByteString(isolate, "compiledWithoutCache"),
+            ToJsSet(context, env->native_modules_without_cache))
+      .FromJust();
+  args.GetReturnValue().Set(result);
+}
+
+void NativeModuleEnv::ModuleIdsGetter(Local<Name> property,
+                                      const PropertyCallbackInfo<Value>& info) {
+  Isolate* isolate = info.GetIsolate();
+
+  std::vector<std::string> ids =
+      NativeModuleLoader::GetInstance()->GetModuleIds();
+  info.GetReturnValue().Set(
+      ToV8Value(isolate->GetCurrentContext(), ids).ToLocalChecked());
+}
+
+void NativeModuleEnv::ConfigStringGetter(
+    Local<Name> property, const PropertyCallbackInfo<Value>& info) {
+  info.GetReturnValue().Set(GetConfigString(info.GetIsolate()));
+}
+
+void NativeModuleEnv::RecordResult(const char* id,
+                                   NativeModuleLoader::Result result,
+                                   Environment* env) {
+  if (result == NativeModuleLoader::Result::kWithCache) {
+    env->native_modules_with_cache.insert(id);
+  } else {
+    env->native_modules_without_cache.insert(id);
+  }
+}
+void NativeModuleEnv::CompileFunction(const FunctionCallbackInfo<Value>& args) {
+  Environment* env = Environment::GetCurrent(args);
+  CHECK(args[0]->IsString());
+  node::Utf8Value id_v(env->isolate(), args[0].As<String>());
+  const char* id = *id_v;
+  NativeModuleLoader::Result result;
+  MaybeLocal<Function> maybe =
+      NativeModuleLoader::GetInstance()->CompileAsModule(
+          env->context(), id, &result);
+  RecordResult(id, result, env);
+  if (!maybe.IsEmpty()) {
+    args.GetReturnValue().Set(maybe.ToLocalChecked());
+  }
+}
+
+// Returns Local<Function> of the compiled module if return_code_cache
+// is false (we are only compiling the function).
+// Otherwise return a Local<Object> containing the cache.
+MaybeLocal<Function> NativeModuleEnv::LookupAndCompile(
+    Local<Context> context,
+    const char* id,
+    std::vector<Local<String>>* parameters,
+    Environment* optional_env) {
+  NativeModuleLoader::Result result;
+  MaybeLocal<Function> maybe =
+      NativeModuleLoader::GetInstance()->LookupAndCompile(
+          context, id, parameters, &result);
+  if (optional_env != nullptr) {
+    RecordResult(id, result, optional_env);
+  }
+  return maybe;
+}
+
+// This is supposed to be run only by the main thread in
+// tools/generate_code_cache.js
+void NativeModuleEnv::GetCodeCache(const FunctionCallbackInfo<Value>& args) {
+  Environment* env = Environment::GetCurrent(args);
+  Isolate* isolate = env->isolate();
+  CHECK(env->is_main_thread());
+
+  CHECK(args[0]->IsString());
+  node::Utf8Value id_v(isolate, args[0].As<String>());
+  const char* id = *id_v;
+
+  ScriptCompiler::CachedData* cached_data =
+      NativeModuleLoader::GetInstance()->GetCodeCache(id);
+  if (cached_data != nullptr) {
+    Local<ArrayBuffer> buf = ArrayBuffer::New(isolate, cached_data->length);
+    memcpy(buf->GetContents().Data(), cached_data->data, cached_data->length);
+    args.GetReturnValue().Set(Uint8Array::New(buf, 0, cached_data->length));
+  }
+}
+
+// TODO(joyeecheung): It is somewhat confusing that Class::Initialize
+// is used to initilaize to the binding, but it is the current convention.
+// Rename this across the code base to something that makes more sense.
+void NativeModuleEnv::Initialize(Local<Object> target,
+                                 Local<Value> unused,
+                                 Local<Context> context,
+                                 void* priv) {
+  Environment* env = Environment::GetCurrent(context);
+
+  target
+      ->SetAccessor(env->context(),
+                    env->config_string(),
+                    ConfigStringGetter,
+                    nullptr,
+                    MaybeLocal<Value>(),
+                    DEFAULT,
+                    None,
+                    SideEffectType::kHasNoSideEffect)
+      .Check();
+  target
+      ->SetAccessor(env->context(),
+                    FIXED_ONE_BYTE_STRING(env->isolate(), "moduleIds"),
+                    ModuleIdsGetter,
+                    nullptr,
+                    MaybeLocal<Value>(),
+                    DEFAULT,
+                    None,
+                    SideEffectType::kHasNoSideEffect)
+      .Check();
+
+  target
+      ->SetAccessor(env->context(),
+                    FIXED_ONE_BYTE_STRING(env->isolate(), "moduleCategories"),
+                    GetModuleCategories,
+                    nullptr,
+                    env->as_callback_data(),
+                    DEFAULT,
+                    None,
+                    SideEffectType::kHasNoSideEffect)
+      .Check();
+
+  env->SetMethod(target, "getCacheUsage", NativeModuleEnv::GetCacheUsage);
+  env->SetMethod(target, "getCodeCache", NativeModuleEnv::GetCodeCache);
+  env->SetMethod(target, "compileFunction", NativeModuleEnv::CompileFunction);
+  // internalBinding('native_module') should be frozen
+  target->SetIntegrityLevel(context, IntegrityLevel::kFrozen).FromJust();
+}
+
+}  // namespace native_module
+}  // namespace node
+
+NODE_MODULE_CONTEXT_AWARE_INTERNAL(
+    native_module, node::native_module::NativeModuleEnv::Initialize)
diff --git a/src/node_native_module_env.h b/src/node_native_module_env.h
new file mode 100644
index 0000000000..2b1fabf89b
--- /dev/null
+++ b/src/node_native_module_env.h
@@ -0,0 +1,64 @@
+#ifndef SRC_NODE_NATIVE_MODULE_ENV_H_
+#define SRC_NODE_NATIVE_MODULE_ENV_H_
+
+#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
+
+#include "node_native_module.h"
+
+namespace node {
+class Environment;
+
+namespace native_module {
+
+class NativeModuleEnv {
+ public:
+  static void Initialize(v8::Local<v8::Object> target,
+                         v8::Local<v8::Value> unused,
+                         v8::Local<v8::Context> context,
+                         void* priv);
+
+  static v8::MaybeLocal<v8::Function> LookupAndCompile(
+      v8::Local<v8::Context> context,
+      const char* id,
+      std::vector<v8::Local<v8::String>>* parameters,
+      Environment* optional_env);
+
+  static v8::Local<v8::Object> GetSourceObject(v8::Local<v8::Context> context);
+  // Returns config.gypi as a JSON string
+  static v8::Local<v8::String> GetConfigString(v8::Isolate* isolate);
+  static bool Exists(const char* id);
+
+  // Loads data into NativeModuleLoader::.instance.code_cache_
+  // Generated by mkcodecache as node_code_cache.cc when
+  // the build is configured with --code-cache-path=.... They are noops
+  // in node_code_cache_stub.cc
+  static void InitializeCodeCache();
+
+ private:
+  static void RecordResult(const char* id,
+                           NativeModuleLoader::Result result,
+                           Environment* env);
+  static void GetModuleCategories(
+      v8::Local<v8::Name> property,
+      const v8::PropertyCallbackInfo<v8::Value>& info);
+  static void GetCacheUsage(const v8::FunctionCallbackInfo<v8::Value>& args);
+  // Passing ids of builtin module source code into JS land as
+  // internalBinding('native_module').moduleIds
+  static void ModuleIdsGetter(v8::Local<v8::Name> property,
+                              const v8::PropertyCallbackInfo<v8::Value>& info);
+  // Passing config.gypi into JS land as internalBinding('native_module').config
+  static void ConfigStringGetter(
+      v8::Local<v8::Name> property,
+      const v8::PropertyCallbackInfo<v8::Value>& info);
+  // Compile a specific native module as a function
+  static void CompileFunction(const v8::FunctionCallbackInfo<v8::Value>& args);
+  static void GetCodeCache(const v8::FunctionCallbackInfo<v8::Value>& args);
+};
+
+}  // namespace native_module
+
+}  // namespace node
+
+#endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
+
+#endif  // SRC_NODE_NATIVE_MODULE_ENV_H_
diff --git a/src/node_union_bytes.h b/src/node_union_bytes.h
index 0034f184cc..996d9880a4 100644
--- a/src/node_union_bytes.h
+++ b/src/node_union_bytes.h
@@ -7,7 +7,6 @@
 // A union of const uint8_t* or const uint16_t* data that can be
 // turned into external v8::String when given an isolate.
 
-#include "env.h"
 #include "v8.h"
 
 namespace node {