protect opt

Author: fraidev

src/binding.cc

@@ -3101,8 +3101,9 @@ class CustomPlatform : public v8::platform::DefaultPlatform {
 
  public:
   CustomPlatform(int thread_pool_size, IdleTaskSupport idle_task_support,
-                 void* context)
+                 bool unprotected, void* context)
       : DefaultPlatform(thread_pool_size, idle_task_support),
+        unprotected_(unprotected),
         context_(context) {}
 
   // SAFETY: The platform is single-owner (via unique_ptr). The destructor
@@ -3128,14 +3129,17 @@ class CustomPlatform : public v8::platform::DefaultPlatform {
     return custom;
   }
 
-  // Disable thread-isolated allocations (same as UnprotectedDefaultPlatform).
-  // Required when isolates may be created on threads other than the one that
-  // called v8::V8::Initialize (e.g. worker threads in Deno).
+  // When unprotected, disable thread-isolated allocations (same as
+  // UnprotectedDefaultPlatform). Required when isolates may be created on
+  // threads other than the one that called v8::V8::Initialize (e.g. worker
+  // threads in Deno).
   v8::ThreadIsolatedAllocator* GetThreadIsolatedAllocator() override {
-    return nullptr;
+    if (unprotected_) return nullptr;
+    return DefaultPlatform::GetThreadIsolatedAllocator();
   }
 
  private:
+  bool unprotected_;
   void* context_;
   std::mutex mutex_;
   // weak_ptr so runners are kept alive only while V8 holds a reference.
@@ -3202,7 +3206,7 @@ v8::Platform* v8__Platform__NewSingleThreadedDefaultPlatform(
 
 v8::Platform* v8__Platform__NewCustomPlatform(int thread_pool_size,
                                               bool idle_task_support,
-                                              void* context) {
+                                              bool unprotected, void* context) {
   if (thread_pool_size < 1) {
     thread_pool_size = std::thread::hardware_concurrency();
   }
@@ -3211,7 +3215,7 @@ v8::Platform* v8__Platform__NewCustomPlatform(int thread_pool_size,
              thread_pool_size,
              idle_task_support ? v8::platform::IdleTaskSupport::kEnabled
                                : v8::platform::IdleTaskSupport::kDisabled,
-             context)
+             unprotected, context)
       .release();
 }
 

src/platform.rs

@@ -25,6 +25,7 @@ unsafe extern "C" {
   fn v8__Platform__NewCustomPlatform(
     thread_pool_size: int,
     idle_task_support: bool,
+    unprotected: bool,
     context: *mut std::ffi::c_void,
   ) -> *mut Platform;
   fn v8__Platform__DELETE(this: *mut Platform);
@@ -245,15 +246,18 @@ pub fn new_single_threaded_default_platform(
 /// This follows the same pattern as
 /// [`V8InspectorClient::new`](crate::inspector::V8InspectorClient::new).
 ///
-/// Thread-isolated allocations are disabled (same as
-/// `new_unprotected_default_platform`).
+/// When `unprotected` is true, thread-isolated allocations are disabled
+/// (same as `new_unprotected_default_platform`). This is required when
+/// isolates may be created on threads other than the one that called
+/// `V8::initialize`.
 #[inline(always)]
 pub fn new_custom_platform(
   thread_pool_size: u32,
   idle_task_support: bool,
+  unprotected: bool,
   platform_impl: impl PlatformImpl + 'static,
 ) -> UniqueRef<Platform> {
-  Platform::new_custom(thread_pool_size, idle_task_support, platform_impl)
+  Platform::new_custom(thread_pool_size, idle_task_support, unprotected, platform_impl)
 }
 
 impl Platform {
@@ -330,6 +334,7 @@ impl Platform {
   pub fn new_custom(
     thread_pool_size: u32,
     idle_task_support: bool,
+    unprotected: bool,
     platform_impl: impl PlatformImpl + 'static,
   ) -> UniqueRef<Self> {
     // Double-box: inner Box<dyn> is a fat pointer, outer Box gives us a
@@ -342,6 +347,7 @@ impl Platform {
       UniqueRef::from_raw(v8__Platform__NewCustomPlatform(
         thread_pool_size as i32,
         idle_task_support,
+        unprotected,
         context,
       ))
     }