+ class KeepAlive {
+ public:
+ KeepAlive() {}
+
+ void reset() {
+ executor_.reset();
+ }
+
+ explicit operator bool() const {
+ return executor_ != nullptr;
+ }
+
+ Executor* get() const {
+ return executor_.get();
+ }
+
+ private:
+ friend class Executor;
+ explicit KeepAlive(folly::Executor* executor) : executor_(executor) {}
+
+ struct Deleter {
+ void operator()(folly::Executor* executor) {
+ executor->keepAliveRelease();
+ }
+ };
+ std::unique_ptr<folly::Executor, Deleter> executor_;
+ };
+
+ /// Returns a keep-alive token which guarantees that Executor will keep
+ /// processing tasks until the token is released.