/*
- * Copyright 2016 Facebook, Inc.
+ * Copyright 2017 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#pragma once
-#include <atomic>
#include <climits>
-#include <functional>
-#include <stdexcept>
#include <folly/Function.h>
/// Enqueue a function with a given priority, where 0 is the medium priority
/// This is up to the implementation to enforce
- virtual void addWithPriority(Func, int8_t /*priority*/) {
- throw std::runtime_error(
- "addWithPriority() is not implemented for this Executor");
- }
+ virtual void addWithPriority(Func, int8_t priority);
virtual uint8_t getNumPriorities() const {
return 1;
void addPtr(P fn) {
this->add([fn]() mutable { (*fn)(); });
}
+
+ class KeepAlive {
+ public:
+ KeepAlive() {}
+
+ void reset() {
+ executor_.reset();
+ }
+
+ explicit operator bool() const {
+ return executor_ != nullptr;
+ }
+
+ 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. keep-alive token can only
+ /// be destroyed from within the task, scheduled to be run on an executor.
+ ///
+ /// If executor does not support keep-alive functionality - dummy token will
+ /// be returned.
+ virtual KeepAlive getKeepAliveToken() {
+ return {};
+ }
+
+ protected:
+ virtual void keepAliveRelease();
+
+ KeepAlive makeKeepAlive() {
+ return KeepAlive{this};
+ }
};
} // folly