feat(core): prevent isolate drop for CLI main worker (#18059)

```
Benchmark 1: deno run -A ../empty.js
  Time (mean ± σ):      20.5 ms ±   0.5 ms    [User: 13.4 ms, System: 5.1 ms]
  Range (min … max):    19.8 ms …  24.0 ms    119 runs

Benchmark 2: target/release/deno run -A ../empty.js
  Time (mean ± σ):      18.8 ms ±   0.3 ms    [User: 13.0 ms, System: 4.9 ms]
  Range (min … max):    18.3 ms …  19.9 ms    129 runs
  ```

---------

Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

cli/standalone.rs

@@ -302,6 +302,7 @@ pub async fn run(
     shared_array_buffer_store: None,
     compiled_wasm_module_store: None,
     stdio: Default::default(),
+    leak_isolate: true,
   };
   let mut worker = MainWorker::bootstrap_from_options(
     main_module.clone(),

cli/worker.rs

@@ -550,6 +550,7 @@ async fn create_main_worker_internal(
     shared_array_buffer_store: Some(ps.shared_array_buffer_store.clone()),
     compiled_wasm_module_store: Some(ps.compiled_wasm_module_store.clone()),
     stdio,
+    leak_isolate: !bench_or_test && ps.options.coverage_dir().is_none(),
   };
 
   let mut worker = MainWorker::bootstrap_from_options(
@@ -780,6 +781,7 @@ mod tests {
       shared_array_buffer_store: None,
       compiled_wasm_module_store: None,
       stdio: Default::default(),
+      leak_isolate: false,
     };
 
     MainWorker::bootstrap_from_options(main_module, permissions, options)

core/gotham_state.rs

@@ -76,6 +76,10 @@ impl GothamState {
   pub fn take<T: 'static>(&mut self) -> T {
     self.try_take().unwrap_or_else(|| missing::<T>())
   }
+
+  pub fn clear(&mut self) {
+    self.data.clear();
+  }
 }
 
 fn missing<T: 'static>() -> ! {

core/ops.rs

@@ -179,6 +179,10 @@ impl OpState {
       tracker: OpsTracker::new(ops_count),
     }
   }
+
+  pub fn clear_state(&mut self) {
+    self.gotham_state.clear();
+  }
 }
 
 impl Deref for OpState {

core/runtime.rs

@@ -93,6 +93,9 @@ pub struct JsRuntime {
   event_loop_middlewares: Vec<Box<OpEventLoopFn>>,
   // Marks if this is considered the top-level runtime. Used only be inspector.
   is_main: bool,
+  // Marks if it's OK to leak the current isolate. Use only by the
+  // CLI main worker.
+  leak_isolate: bool,
 }
 
 pub(crate) struct DynImportModEvaluate {
@@ -305,6 +308,10 @@ pub struct RuntimeOptions {
   /// Describe if this is the main runtime instance, used by debuggers in some
   /// situation - like disconnecting when program finishes running.
   pub is_main: bool,
+
+  /// Whether it is OK to leak the V8 isolate. Only to be used by CLI
+  /// top-level runtime.
+  pub leak_isolate: bool,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq)]
@@ -338,6 +345,16 @@ impl Drop for JsRuntime {
     if let Some(v8_isolate) = self.v8_isolate.as_mut() {
       Self::drop_state_and_module_map(v8_isolate);
     }
+    if self.leak_isolate {
+      if let Some(v8_isolate) = self.v8_isolate.take() {
+        // Clear the GothamState. This allows final env cleanup hooks to run.
+        // Note: that OpState is cloned for every OpCtx, so we can't just drop
+        // one reference to it.
+        let rc_state = self.op_state();
+        rc_state.borrow_mut().clear_state();
+        std::mem::forget(v8_isolate);
+      }
+    }
   }
 }
 
@@ -674,6 +691,7 @@ impl JsRuntime {
       state: state_rc,
       module_map: Some(module_map_rc),
       is_main: options.is_main,
+      leak_isolate: options.leak_isolate,
     };
 
     // Init resources and ops before extensions to make sure they are

runtime/examples/hello_runtime.rs

@@ -66,6 +66,7 @@ async fn main() -> Result<(), AnyError> {
     shared_array_buffer_store: None,
     compiled_wasm_module_store: None,
     stdio: Default::default(),
+    leak_isolate: true,
   };
 
   let js_path =

runtime/worker.rs

@@ -141,6 +141,7 @@ pub struct WorkerOptions {
   /// `WebAssembly.Module` objects cannot be serialized.
   pub compiled_wasm_module_store: Option<CompiledWasmModuleStore>,
   pub stdio: Stdio,
+  pub leak_isolate: bool,
 }
 
 impl Default for WorkerOptions {
@@ -177,6 +178,7 @@ impl Default for WorkerOptions {
       startup_snapshot: Default::default(),
       bootstrap: Default::default(),
       stdio: Default::default(),
+      leak_isolate: false,
     }
   }
 }
@@ -304,6 +306,7 @@ impl MainWorker {
       extensions_with_js: options.extensions_with_js,
       inspector: options.maybe_inspector_server.is_some(),
       is_main: true,
+      leak_isolate: options.leak_isolate,
       ..Default::default()
     });