Revert "embedding: make Stop() stop Workers"

This reverts commit 037ac99.

As flaky CI failures have revealed, this feature was implemented
incorrectly. `stop_sub_worker_contexts()` needs to be called on the
thread on which the `Environment` is currently running, it’s not
thread-safe. The current API requires `Stop()` to be thread-safe,
though.

We could add a new API for this, but unless there’s demand, that’s
probably not necessary as `FreeEnvironment()` will also stop Workers,
which is commonly the next action on an `Environment` instance after
having `Stop()` called on it.

Refs: #32531

PR-URL: #32623
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>

Author: addaleax

src/api/environment.cc

@@ -725,7 +725,8 @@ ThreadId AllocateEnvironmentThreadId() {
 }
 
 void DefaultProcessExitHandler(Environment* env, int exit_code) {
-  Stop(env);
+  env->set_can_call_into_js(false);
+  env->stop_sub_worker_contexts();
   DisposePlatform();
   exit(exit_code);
 }

src/env.cc

@@ -528,10 +528,9 @@ void Environment::InitializeLibuv(bool start_profiler_idle_notifier) {
   }
 }
 
-void Environment::Stop() {
+void Environment::ExitEnv() {
   set_can_call_into_js(false);
   set_stopping(true);
-  stop_sub_worker_contexts();
   isolate_->TerminateExecution();
   SetImmediateThreadsafe([](Environment* env) { uv_stop(env->event_loop()); });
 }

src/env.h

@@ -899,7 +899,7 @@ class Environment : public MemoryRetainer {
   void RegisterHandleCleanups();
   void CleanupHandles();
   void Exit(int code);
-  void Stop();
+  void ExitEnv();
 
   // Register clean-up cb to be called on environment destruction.
   inline void RegisterHandleCleanup(uv_handle_t* handle,

src/node.cc

@@ -1059,7 +1059,7 @@ int Start(int argc, char** argv) {
 }
 
 int Stop(Environment* env) {
-  env->Stop();
+  env->ExitEnv();
   return 0;
 }
 

src/node.h

@@ -224,8 +224,7 @@ class Environment;
 NODE_EXTERN int Start(int argc, char* argv[]);
 
 // Tear down Node.js while it is running (there are active handles
-// in the loop and / or actively executing JavaScript code). This also stops
-// all Workers that may have been started earlier.
+// in the loop and / or actively executing JavaScript code).
 NODE_EXTERN int Stop(Environment* env);
 
 // TODO(addaleax): Officially deprecate this and replace it with something
@@ -479,8 +478,8 @@ NODE_EXTERN void FreeEnvironment(Environment* env);
 // It receives the Environment* instance and the exit code as arguments.
 // This could e.g. call Stop(env); in order to terminate execution and stop
 // the event loop.
-// The default handler calls Stop(), disposes of the global V8 platform
-// instance, if one is being used, and calls exit().
+// The default handler disposes of the global V8 platform instance, if one is
+// being used, and calls exit().
 NODE_EXTERN void SetProcessExitHandler(
     Environment* env,
     std::function<void(Environment*, int)>&& handler);