core: let embedders plug in their own V8 platform

Fixes #9912.

1 files changed, 29 insertions, 12 deletions

diff --git a/core/runtime.rs b/core/runtime.rs
index 3583ad89e..4174e0598 100644
--- a/core/runtime.rs
+++ b/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();
+  }
 }