blob: ca7f60fdbbd32a7f52da678c0cb39d76d7e7fb5d [file] [log] [blame]
// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <functional>
#include "flutter/fml/macros.h"
namespace fml {
using closure = std::function<void()>;
/// @brief Wraps a closure that is invoked in the destructor unless
/// released by the caller.
/// This is especially useful in dealing with APIs that return a
/// resource by accepting ownership of a sub-resource and a closure
/// that releases that resource. When such APIs are chained, each
/// link in the chain must check that the next member in the chain
/// has accepted the resource. If not, it must invoke the closure
/// eagerly. Not doing this results in a resource leak in the
/// erroneous case. Using this wrapper, the closure can be released
/// once the next call in the chain has successfully accepted
/// ownership of the resource. If not, the closure gets invoked
/// automatically at the end of the scope. This covers the cases
/// where there are early returns as well.
class ScopedCleanupClosure {
ScopedCleanupClosure() = default;
ScopedCleanupClosure(const fml::closure& closure) : closure_(closure) {}
~ScopedCleanupClosure() {
if (closure_) {
fml::closure SetClosure(const fml::closure& closure) {
auto old_closure = closure_;
closure_ = closure;
return old_closure;
fml::closure Release() {
fml::closure closure = closure_;
closure_ = nullptr;
return closure;
fml::closure closure_;
} // namespace fml