Wire up configuration to use modern version of RuntimeScheduler (#40945)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/40945

This adds some temporary logic to configure the use of the modern version of RuntimeScheduler based on values coming from the app configuration.

This logic is centralized in `ReactInstance` so from that point the code is completely cross-platform.

This doesn't use `ReactNativeConfig`/`CoreFeatures` because they're initialized after the point where we need to access them for this use case. This way is a bit uglier but this isn't intended to live for long (only until we verify this doesn't have regressions in a complex app).

Changelog: [internal]

 ---

Reviewed By: sammy-SC

Differential Revision: D50171297

fbshipit-source-id: 8d96e228550cc6112ffe2abec4d531514b052f82

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/config/ReactFeatureFlags.java

@@ -165,4 +165,10 @@ public class ReactFeatureFlags {
 
   /** Enables Stable API for TurboModule (removal of ReactModule, ReactModuleInfoProvider). */
   public static boolean enableTurboModuleStableAPI = false;
+
+  /**
+   * When enabled, it uses the modern fork of RuntimeScheduler that allows scheduling tasks with
+   * priorities from any thread.
+   */
+  public static boolean useModernRuntimeScheduler = false;
 }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/runtime/ReactInstance.java

@@ -170,6 +170,9 @@ final class ReactInstance {
     // Notify JS if profiling is enabled
     boolean isProfiling =
         Systrace.isTracing(Systrace.TRACE_TAG_REACT_APPS | Systrace.TRACE_TAG_REACT_JS_VM_CALLS);
+    // TODO(T166383606): Remove this parameter when we remove the legacy runtime scheduler or we
+    // have access to ReactNativeConfig before we initialize it.
+    boolean useModernRuntimeScheduler = ReactFeatureFlags.useModernRuntimeScheduler;
     mHybridData =
         initHybrid(
             jsEngineInstance,
@@ -179,7 +182,8 @@ final class ReactInstance {
             jsTimerExecutor,
             reactExceptionManager,
             bindingsInstaller,
-            isProfiling);
+            isProfiling,
+            useModernRuntimeScheduler);
 
     RuntimeExecutor unbufferedRuntimeExecutor = getUnbufferedRuntimeExecutor();
 
@@ -435,7 +439,8 @@ final class ReactInstance {
       JSTimerExecutor jsTimerExecutor,
       ReactJsExceptionHandler jReactExceptionsManager,
       @Nullable BindingsInstaller jBindingsInstaller,
-      boolean isProfiling);
+      boolean isProfiling,
+      boolean useModernRuntimeScheduler);
 
   @DoNotStrip
   private static native JSTimerExecutor createJSTimerExecutor();

packages/react-native/ReactAndroid/src/main/jni/react/runtime/jni/JReactInstance.cpp

@@ -36,7 +36,8 @@ JReactInstance::JReactInstance(
     jni::alias_ref<JJSTimerExecutor::javaobject> jsTimerExecutor,
     jni::alias_ref<JReactExceptionManager::javaobject> jReactExceptionManager,
     jni::alias_ref<JBindingsInstaller::javaobject> jBindingsInstaller,
-    bool isProfiling) noexcept {
+    bool isProfiling,
+    bool useModernRuntimeScheduler) noexcept {
   // TODO(janzer): Lazily create runtime
   auto sharedJSMessageQueueThread =
       std::make_shared<JMessageQueueThread>(jsMessageQueueThread);
@@ -64,7 +65,8 @@ JReactInstance::JReactInstance(
       jsEngineInstance->cthis()->createJSRuntime(sharedJSMessageQueueThread),
       sharedJSMessageQueueThread,
       timerManager,
-      std::move(jsErrorHandlingFunc));
+      std::move(jsErrorHandlingFunc),
+      useModernRuntimeScheduler);
 
   auto bufferedRuntimeExecutor = instance_->getBufferedRuntimeExecutor();
   timerManager->setRuntimeExecutor(bufferedRuntimeExecutor);
@@ -115,7 +117,8 @@ jni::local_ref<JReactInstance::jhybriddata> JReactInstance::initHybrid(
     jni::alias_ref<JJSTimerExecutor::javaobject> jsTimerExecutor,
     jni::alias_ref<JReactExceptionManager::javaobject> jReactExceptionManager,
     jni::alias_ref<JBindingsInstaller::javaobject> jBindingsInstaller,
-    bool isProfiling) {
+    bool isProfiling,
+    bool useModernRuntimeScheduler) {
   return makeCxxInstance(
       jsEngineInstance,
       jsMessageQueueThread,
@@ -124,7 +127,8 @@ jni::local_ref<JReactInstance::jhybriddata> JReactInstance::initHybrid(
       jsTimerExecutor,
       jReactExceptionManager,
       jBindingsInstaller,
-      isProfiling);
+      isProfiling,
+      useModernRuntimeScheduler);
 }
 
 void JReactInstance::loadJSBundleFromAssets(

packages/react-native/ReactAndroid/src/main/jni/react/runtime/jni/JReactInstance.h

@@ -45,7 +45,8 @@ class JReactInstance : public jni::HybridClass<JReactInstance> {
       jni::alias_ref<JJSTimerExecutor::javaobject> jsTimerExecutor,
       jni::alias_ref<JReactExceptionManager::javaobject> jReactExceptionManager,
       jni::alias_ref<JBindingsInstaller::javaobject> jBindingsInstaller,
-      bool isProfiling);
+      bool isProfiling,
+      bool useModernRuntimeScheduler);
 
   /*
    * Instantiates and returns an instance of `JSTimerExecutor`.
@@ -90,7 +91,8 @@ class JReactInstance : public jni::HybridClass<JReactInstance> {
       jni::alias_ref<JJSTimerExecutor::javaobject> jsTimerExecutor,
       jni::alias_ref<JReactExceptionManager::javaobject> jReactExceptionManager,
       jni::alias_ref<JBindingsInstaller::javaobject> jBindingsInstaller,
-      bool isProfiling) noexcept;
+      bool isProfiling,
+      bool useModernRuntimeScheduler) noexcept;
 
   jni::alias_ref<CallInvokerHolder::javaobject> getJSCallInvokerHolder();
   jni::alias_ref<NativeMethodCallInvokerHolder::javaobject>

packages/react-native/ReactCommon/react/runtime/ReactInstance.cpp

@@ -28,7 +28,8 @@ ReactInstance::ReactInstance(
     std::unique_ptr<jsi::Runtime> runtime,
     std::shared_ptr<MessageQueueThread> jsMessageQueueThread,
     std::shared_ptr<TimerManager> timerManager,
-    JsErrorHandler::JsErrorHandlingFunc jsErrorHandlingFunc)
+    JsErrorHandler::JsErrorHandlingFunc jsErrorHandlingFunc,
+    bool useModernRuntimeScheduler)
     : runtime_(std::move(runtime)),
       jsMessageQueueThread_(jsMessageQueueThread),
       timerManager_(std::move(timerManager)),
@@ -75,8 +76,8 @@ ReactInstance::ReactInstance(
     }
   };
 
-  runtimeScheduler_ =
-      std::make_shared<RuntimeScheduler>(std::move(runtimeExecutor));
+  runtimeScheduler_ = std::make_shared<RuntimeScheduler>(
+      std::move(runtimeExecutor), useModernRuntimeScheduler);
 
   auto pipedRuntimeExecutor =
       [runtimeScheduler = runtimeScheduler_.get()](

packages/react-native/ReactCommon/react/runtime/ReactInstance.h

@@ -32,7 +32,8 @@ class ReactInstance final {
       std::unique_ptr<jsi::Runtime> runtime,
       std::shared_ptr<MessageQueueThread> jsMessageQueueThread,
       std::shared_ptr<TimerManager> timerManager,
-      JsErrorHandler::JsErrorHandlingFunc JsErrorHandlingFunc);
+      JsErrorHandler::JsErrorHandlingFunc JsErrorHandlingFunc,
+      bool useModernRuntimeScheduler = false);
 
   RuntimeExecutor getUnbufferedRuntimeExecutor() noexcept;
 

packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTHost.h

@@ -35,6 +35,18 @@ NS_ASSUME_NONNULL_BEGIN
 
 @end
 
+/**
+ * This is a private protocol used to configure internal behavior of the runtime.
+ * DO NOT USE THIS OUTSIDE OF THE REACT NATIVE CODEBASE.
+ */
+@protocol RCTHostDelegateInternal <NSObject>
+
+// TODO(T166383606): Remove this method when we remove the legacy runtime scheduler or we have access to
+// ReactNativeConfig before we initialize it.
+- (BOOL)useModernRuntimeScheduler:(RCTHost *)host;
+
+@end
+
 @protocol RCTHostRuntimeDelegate <NSObject>
 
 - (void)host:(RCTHost *)host didInitializeRuntime:(facebook::jsi::Runtime &)runtime;

packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTHost.mm

@@ -23,7 +23,7 @@ RCT_MOCK_DEF(RCTHost, _RCTLogNativeInternal);
 
 using namespace facebook::react;
 
-@interface RCTHost () <RCTReloadListener, RCTInstanceDelegate>
+@interface RCTHost () <RCTReloadListener, RCTInstanceDelegate, RCTInstanceDelegateInternal>
 @end
 
 @implementation RCTHost {
@@ -247,6 +247,17 @@ using namespace facebook::react;
   [self.runtimeDelegate host:self didInitializeRuntime:runtime];
 }
 
+#pragma mark - RCTInstanceDelegateInternal
+
+- (BOOL)useModernRuntimeScheduler:(RCTHost *)host
+{
+  if ([_hostDelegate respondsToSelector:@selector(useModernRuntimeScheduler:)]) {
+    return [(id)_hostDelegate useModernRuntimeScheduler:self];
+  }
+
+  return NO;
+}
+
 #pragma mark - RCTContextContainerHandling
 
 - (void)didCreateContextContainer:(std::shared_ptr<facebook::react::ContextContainer>)contextContainer

packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTInstance.h

@@ -46,6 +46,18 @@ RCT_EXTERN void RCTInstanceSetRuntimeDiagnosticFlags(NSString *_Nullable flags);
 
 @end
 
+/**
+ * This is a private protocol used to configure internal behavior of the runtime.
+ * DO NOT USE THIS OUTSIDE OF THE REACT NATIVE CODEBASE.
+ */
+@protocol RCTInstanceDelegateInternal <NSObject>
+
+// TODO(T166383606): Remove this method when we remove the legacy runtime scheduler or we have access to
+// ReactNativeConfig before we initialize it.
+- (BOOL)useModernRuntimeScheduler:(RCTInstance *)instance;
+
+@end
+
 typedef void (^_Null_unspecified RCTInstanceInitialBundleLoadCompletionBlock)();
 
 /**

packages/react-native/ReactCommon/react/runtime/platform/ios/ReactCommon/RCTInstance.mm

@@ -216,12 +216,18 @@ void RCTInstanceSetRuntimeDiagnosticFlags(NSString *flags)
   __weak __typeof(self) weakSelf = self;
   auto jsErrorHandlingFunc = [=](MapBuffer errorMap) { [weakSelf _handleJSErrorMap:std::move(errorMap)]; };
 
+  auto useModernRuntimeScheduler = false;
+  if ([_delegate respondsToSelector:@selector(useModernRuntimeScheduler:)]) {
+    useModernRuntimeScheduler = [(id)_delegate useModernRuntimeScheduler:self];
+  }
+
   // Create the React Instance
   _reactInstance = std::make_unique<ReactInstance>(
       _jsEngineInstance->createJSRuntime(_jsThreadManager.jsMessageThread),
       _jsThreadManager.jsMessageThread,
       timerManager,
-      jsErrorHandlingFunc);
+      jsErrorHandlingFunc,
+      useModernRuntimeScheduler);
   _valid = true;
 
   RuntimeExecutor bufferedRuntimeExecutor = _reactInstance->getBufferedRuntimeExecutor();