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tdlib-fork/tdutils/td/utils/CancellationToken.h
levlam 80c35676a2 Update copyright year.
GitOrigin-RevId: 09afb551b6e637dc69739fa735b0051a38b9e14c
2020-01-01 04:23:48 +03:00

67 lines
1.7 KiB
C++

//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2020
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#pragma once
#include <atomic>
#include <memory>
namespace td {
namespace detail {
struct RawCancellationToken {
std::atomic<bool> is_cancelled_{false};
};
} // namespace detail
class CancellationToken {
public:
explicit operator bool() const {
return token_->is_cancelled_.load(std::memory_order_acquire);
}
explicit CancellationToken(std::shared_ptr<detail::RawCancellationToken> token) : token_(std::move(token)) {
}
private:
std::shared_ptr<detail::RawCancellationToken> token_;
};
class CancellationTokenSource {
public:
CancellationTokenSource() = default;
CancellationTokenSource(CancellationTokenSource &&other) : token_(std::move(other.token_)) {
}
CancellationTokenSource &operator=(CancellationTokenSource &&other) {
cancel();
token_ = std::move(other.token_);
return *this;
}
CancellationTokenSource(const CancellationTokenSource &other) = delete;
CancellationTokenSource &operator=(const CancellationTokenSource &other) = delete;
~CancellationTokenSource() {
cancel();
}
CancellationToken get_cancellation_token() {
if (!token_) {
token_ = std::make_shared<detail::RawCancellationToken>();
}
return CancellationToken(token_);
}
void cancel() {
if (!token_) {
return;
}
token_->is_cancelled_.store(true, std::memory_order_release);
token_.reset();
}
private:
std::shared_ptr<detail::RawCancellationToken> token_;
};
} // namespace td