Implement RuntimeScheduler::getShouldYield

Summary: Changelog: [internal] Implement RuntimeScheduler::getShouldYield and expose it through JSI. For now we are only returning `false`. The value is backed by atomic_bool and in the future we will be able to indicate that React should yield to native. JavaScript implementation: https://github.com/facebook/react/blob/master/packages/scheduler/src/forks/SchedulerNoDOM.js#L439-L441 Reviewed By: JoshuaGross Differential Revision: D27648579 fbshipit-source-id: b9313e2efbd9daae8975357df9de803f24a35e89
sasmit · Apr 14, 2021 · cc3e87c · cc3e87c
1 parent aee07e1
commit cc3e87c
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Showing 4 changed files with 31 additions and 7 deletions.
diff --git a/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler.cpp b/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler.cpp
@@ -26,4 +26,8 @@ void RuntimeScheduler::cancelTask(const std::shared_ptr<Task> &task) {
   task->cancel();
 }
 
+bool RuntimeScheduler::getShouldYield() const {
+  return shouldYield_;
+}
+
 } // namespace facebook::react
diff --git a/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler.h b/ReactCommon/react/renderer/runtimescheduler/RuntimeScheduler.h
@@ -9,6 +9,7 @@
 
 #include <ReactCommon/RuntimeExecutor.h>
 #include <react/renderer/runtimescheduler/Task.h>
+#include <atomic>
 #include <memory>
 #include <queue>
 
@@ -22,13 +23,16 @@ class RuntimeScheduler final {
 
   void cancelTask(std::shared_ptr<Task> const &task);
 
+  bool getShouldYield() const;
+
  private:
   mutable std::priority_queue<
       std::shared_ptr<Task>,
       std::vector<std::shared_ptr<Task>>,
       TaskPriorityComparer>
       taskQueue_;
   RuntimeExecutor const runtimeExecutor_;
+  std::atomic_bool shouldYield_{false};
 };
 
 } // namespace facebook::react
diff --git a/ReactCommon/react/renderer/runtimescheduler/RuntimeSchedulerBinding.cpp b/ReactCommon/react/renderer/runtimescheduler/RuntimeSchedulerBinding.cpp
@@ -25,8 +25,9 @@ RuntimeSchedulerBinding::createAndInstallIfNeeded(
   if (runtimeSchedulerValue.isUndefined()) {
     // The global namespace does not have an instance of the binding;
     // we need to create, install and return it.
-    auto runtimeSchedulerBinding = std::make_shared<RuntimeSchedulerBinding>(
-        RuntimeScheduler(runtimeExecutor));
+    auto runtimeScheduler = std::make_unique<RuntimeScheduler>(runtimeExecutor);
+    auto runtimeSchedulerBinding =
+        std::make_shared<RuntimeSchedulerBinding>(std::move(runtimeScheduler));
     auto object =
         jsi::Object::createFromHostObject(runtime, runtimeSchedulerBinding);
     runtime.global().setProperty(
@@ -41,7 +42,7 @@ RuntimeSchedulerBinding::createAndInstallIfNeeded(
 }
 
 RuntimeSchedulerBinding::RuntimeSchedulerBinding(
-    RuntimeScheduler runtimeScheduler)
+    std::unique_ptr<RuntimeScheduler> runtimeScheduler)
     : runtimeScheduler_(std::move(runtimeScheduler)) {}
 
 jsi::Value RuntimeSchedulerBinding::get(
@@ -64,7 +65,7 @@ jsi::Value RuntimeSchedulerBinding::get(
           react_native_assert(arguments[2].isUndefined());
 
           auto task = std::make_shared<Task>(priority, std::move(callback));
-          runtimeScheduler_.scheduleTask(task);
+          runtimeScheduler_->scheduleTask(task);
 
           return valueFromTask(runtime, task);
         });
@@ -80,10 +81,25 @@ jsi::Value RuntimeSchedulerBinding::get(
             jsi::Value const &,
             jsi::Value const *arguments,
             size_t) noexcept -> jsi::Value {
-          runtimeScheduler_.cancelTask(taskFromValue(runtime, arguments[0]));
+          runtimeScheduler_->cancelTask(taskFromValue(runtime, arguments[0]));
           return jsi::Value::undefined();
         });
   }
+
+  if (propertyName == "unstable_shouldYield") {
+    return jsi::Function::createFromHostFunction(
+        runtime,
+        name,
+        0,
+        [this](
+            jsi::Runtime &,
+            jsi::Value const &,
+            jsi::Value const *,
+            size_t) noexcept -> jsi::Value {
+          auto shouldYield = runtimeScheduler_->getShouldYield();
+          return jsi::Value(shouldYield);
+        });
+  }
   if (propertyName == "unstable_ImmediatePriority") {
     return jsi::Value(runtime, serialize(SchedulerPriority::ImmediatePriority));
   }

diff --git a/ReactCommon/react/renderer/runtimescheduler/RuntimeSchedulerBinding.h b/ReactCommon/react/renderer/runtimescheduler/RuntimeSchedulerBinding.h
@@ -17,7 +17,7 @@ namespace facebook::react {
  */
 class RuntimeSchedulerBinding : public jsi::HostObject {
  public:
-  RuntimeSchedulerBinding(RuntimeScheduler runtimeScheduler);
+  RuntimeSchedulerBinding(std::unique_ptr<RuntimeScheduler> runtimeScheduler);
 
   /*
    * Installs RuntimeSchedulerBinding into JavaScript runtime if needed.
@@ -35,7 +35,7 @@ class RuntimeSchedulerBinding : public jsi::HostObject {
   jsi::Value get(jsi::Runtime &runtime, jsi::PropNameID const &name) override;
 
  private:
-  RuntimeScheduler runtimeScheduler_;
+  std::unique_ptr<RuntimeScheduler> runtimeScheduler_;
 };
 
 } // namespace facebook::react