feat: Expose WorkletRuntime using a global object

packages/react-native-worklets/Common/cpp/worklets/WorkletRuntime/WorkletRuntime.cpp

@@ -23,6 +23,15 @@
 
 namespace worklets {
 
+WorkletRuntimeHolderNativeState::WorkletRuntimeHolderNativeState(
+    const std::weak_ptr<WorkletRuntime> &workletRuntime)
+    : weakWorkletRuntime_(workletRuntime) {}
+
+std::weak_ptr<WorkletRuntime>
+WorkletRuntimeHolderNativeState::getWorkletRuntime() const {
+  return weakWorkletRuntime_;
+}
+
 class AroundLock {
   const std::shared_ptr<std::recursive_mutex> mutex_;
 
@@ -100,6 +109,13 @@ void WorkletRuntime::init(
   auto optimizedJsiWorkletsModuleProxy =
       jsi_utils::optimizedFromHostObject(rt, std::move(jsiWorkletsModuleProxy));
 
+  auto workletRuntimeHolder = jsi::Object(rt);
+  workletRuntimeHolder.setNativeState(
+      rt, std::make_shared<WorkletRuntimeHolderNativeState>(weak_from_this()));
+
+  rt.global().setProperty(
+      rt, "_WORKLET_RUNTIME_HOLDER", std::move(workletRuntimeHolder));
+
   WorkletRuntimeDecorator::decorate(
       rt,
       name_,

packages/react-native-worklets/Common/cpp/worklets/WorkletRuntime/WorkletRuntime.h

@@ -26,6 +26,18 @@ namespace worklets {
  * Forward declaration to avoid circular dependencies.
  */
 class JSIWorkletsModuleProxy;
+class WorkletRuntime;
+
+class WorkletRuntimeHolderNativeState : public jsi::NativeState {
+ public:
+  explicit WorkletRuntimeHolderNativeState(
+      const std::weak_ptr<WorkletRuntime> &workletRuntime);
+
+  std::weak_ptr<WorkletRuntime> getWorkletRuntime() const;
+
+ private:
+  std::weak_ptr<WorkletRuntime> weakWorkletRuntime_;
+};
 
 class WorkletRuntime : public jsi::HostObject,
                        public std::enable_shared_from_this<WorkletRuntime> {

packages/react-native-worklets/src/publicGlobals.ts

@@ -36,4 +36,10 @@ declare global {
    * - Value _3_: Worker Worklet Runtime
    */
   var __RUNTIME_KIND: RuntimeKind | 1 | 2 | 3;
+
+  /**
+   * Holds a reference to the WorkletRuntimeHolderNativeState instance used to
+   * obtain a weak reference to the WorkletRuntime.
+   */
+  var _WORKLET_RUNTIME_HOLDER: object | undefined;
 }