naiveproxy/base/ios/callback_counter.h
2018-01-28 13:32:06 -05:00

47 lines
1.5 KiB
C++

// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef IOS_CHROME_BROWSER_CALLBACK_COUNTER_H_
#define IOS_CHROME_BROWSER_CALLBACK_COUNTER_H_
#include "base/callback.h"
#include "base/logging.h"
#include "base/memory/ref_counted.h"
#include "base/threading/thread.h"
// A helper class that keeps count of the number of pending callbacks that need
// to be received. Calls |final_callback| when all callbacks have been received.
// All methods (except the destructor) must be called on the same thread.
class CallbackCounter : public base::RefCounted<CallbackCounter> {
public:
typedef base::Callback<void()> FinalCallback;
explicit CallbackCounter(const FinalCallback& final_callback);
// Increments the count of pending callbacks by |count| .
void IncrementCount(int count);
// Increments the count of pending callbacks by 1.
void IncrementCount();
// Decrements the count of pending callbacks.
void DecrementCount();
private:
friend class base::RefCounted<CallbackCounter>;
~CallbackCounter();
// The number of callbacks that still need to be received.
unsigned callback_count_;
// The callback that is finally called when all callbacks have been received
// (when the |callback_count_| goes down to 0).
FinalCallback final_callback_;
base::ThreadChecker thread_checker_;
DISALLOW_COPY_AND_ASSIGN(CallbackCounter);
};
#endif // IOS_CHROME_BROWSER_CALLBACK_COUNTER_H_