core: let embedders plug in their own V8 platform

Fixes denoland#9912.

core/runtime.rs

@@ -142,11 +142,19 @@ impl Drop for JsRuntime {
  }
 }
 
-#[allow(clippy::missing_safety_doc)]
-pub unsafe fn v8_init() {
- let platform = v8::new_default_platform().unwrap();
- v8::V8::initialize_platform(platform);
+fn v8_init(v8_platform: Option<v8::UniquePtr<v8::Platform>>) {
+ // Include 10MB ICU data file.
+ #[repr(C, align(16))]
+ struct IcuData([u8; 10413584]);
+ static ICU_DATA: IcuData = IcuData(*include_bytes!("icudtl.dat"));
+ v8::icu::set_common_data(&ICU_DATA.0).unwrap();
+
+ let v8_platform = v8_platform
+ .unwrap_or_else(v8::new_default_platform)
+ .unwrap();
+ v8::V8::initialize_platform(v8_platform);
  v8::V8::initialize();
+
  let argv = vec![
  "".to_string(),
  "--wasm-test-streaming".to_string(),
@@ -192,20 +200,19 @@ pub struct RuntimeOptions {
 
  /// Isolate creation parameters.
  pub create_params: Option<v8::CreateParams>,
+
+ /// V8 platform instance to use. Used when Deno initializes V8
+ /// (which it only does once), otherwise it's silenty dropped.
+ pub v8_platform: Option<v8::UniquePtr<v8::Platform>>,
 }
 
 impl JsRuntime {
  /// Only constructor, configuration is done through `options`.
  pub fn new(mut options: RuntimeOptions) -> Self {
+ let v8_platform = options.v8_platform.take();
+
  static DENO_INIT: Once = Once::new();
- DENO_INIT.call_once(|| {
- // Include 10MB ICU data file.
- #[repr(C, align(16))]
- struct IcuData([u8; 10413584]);
- static ICU_DATA: IcuData = IcuData(*include_bytes!("icudtl.dat"));
- v8::icu::set_common_data(&ICU_DATA.0).unwrap();
- unsafe { v8_init() };
- });
+ DENO_INIT.call_once(move || v8_init(v8_platform));
 
  let has_startup_snapshot = options.startup_snapshot.is_some();
 
@@ -2381,4 +2388,14 @@ main();
  // Test that the script specifier is a URL: `deno:<repo-relative path>`.
  assert!(error_string.contains("deno:core/core.js"));
  }
+
+ #[test]
+ fn test_v8_platform() {
+ let options = RuntimeOptions {
+ v8_platform: Some(v8::new_default_platform()),
+ ..Default::default()
+ };
+ let mut runtime = JsRuntime::new(options);
+ runtime.execute("<none>", "").unwrap();
+ }
 }