Revert "src: unregister Isolate with platform before disposing"

This reverts commit 65e5a8a.

PR-URL: #31782
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>

src/node.h

@@ -280,7 +280,6 @@ class NODE_EXTERN MultiIsolatePlatform : public v8::Platform {
 
   // This function may only be called once per `Isolate`, and discard any
   // pending delayed tasks scheduled for that isolate.
-  // This needs to be called right before calling `Isolate::Dispose()`.
   virtual void UnregisterIsolate(v8::Isolate* isolate) = 0;
 
   // The platform should call the passed function once all state associated

src/node_main_instance.cc

@@ -99,8 +99,8 @@ NodeMainInstance::~NodeMainInstance() {
   if (!owns_isolate_) {
     return;
   }
-  platform_->UnregisterIsolate(isolate_);
   isolate_->Dispose();
+  platform_->UnregisterIsolate(isolate_);
 }
 
 int NodeMainInstance::Run() {

src/node_worker.cc

@@ -192,13 +192,8 @@ class WorkerThreadData {
         *static_cast<bool*>(data) = true;
       }, &platform_finished);
 
-      // The order of these calls is important; if the Isolate is first disposed
-      // and then unregistered, there is a race condition window in which no
-      // new Isolate at the same address can successfully be registered with
-      // the platform.
-      // (Refs: https://github.com/nodejs/node/issues/30846)
-      w_->platform_->UnregisterIsolate(isolate);
       isolate->Dispose();
+      w_->platform_->UnregisterIsolate(isolate);
 
       // Wait until the platform has cleaned up all relevant resources.
       while (!platform_finished)

test/cctest/node_test_fixture.h

@@ -106,9 +106,9 @@ class NodeTestFixture : public ::testing::Test {
 
   void TearDown() override {
     isolate_->Exit();
+    isolate_->Dispose();
     platform->DrainTasks(isolate_);
     platform->UnregisterIsolate(isolate_);
-    isolate_->Dispose();
     isolate_ = nullptr;
   }
 };