62 lines
1.9 KiB
C
62 lines
1.9 KiB
C
|
#pragma once
|
||
|
|
|
||
|
|
#include <mutex>
|
||
|
|
|
||
|
|
namespace c10 {
|
||
|
|
|
||
|
|
/**
|
||
|
|
* A very simple Synchronization class for error-free use of data
|
||
|
|
* in a multi-threaded context. See folly/docs/Synchronized.md for
|
||
|
|
* the inspiration of this class.
|
||
|
|
*
|
||
|
|
* Full URL:
|
||
|
|
* https://github.com/facebook/folly/blob/main/folly/docs/Synchronized.md
|
||
|
|
*
|
||
|
|
* This class implements a small subset of the generic functionality
|
||
|
|
* implemented by folly:Synchronized<T>. Specifically, only withLock<T>
|
||
|
|
* is implemented here since it's the smallest possible API that is
|
||
|
|
* able to cover a large surface area of functionality offered by
|
||
|
|
* folly::Synchronized<T>.
|
||
|
|
*/
|
||
|
|
template <typename T>
|
||
|
|
class Synchronized final {
|
||
|
|
mutable std::mutex mutex_;
|
||
|
|
T data_;
|
||
|
|
|
||
|
|
public:
|
||
|
|
Synchronized() = default;
|
||
|
|
Synchronized(T const& data) : data_(data) {}
|
||
|
|
Synchronized(T&& data) : data_(std::move(data)) {}
|
||
|
|
|
||
|
|
// Don't permit copy construction, move, assignment, or
|
||
|
|
// move assignment, since the underlying std::mutex
|
||
|
|
// isn't necessarily copyable/moveable.
|
||
|
|
Synchronized(Synchronized const&) = delete;
|
||
|
|
Synchronized(Synchronized&&) = delete;
|
||
|
|
Synchronized operator=(Synchronized const&) = delete;
|
||
|
|
Synchronized operator=(Synchronized&&) = delete;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* To use, call withLock<T> with a callback that accepts T either
|
||
|
|
* by copy or by reference. Use the protected variable in the
|
||
|
|
* provided callback safely.
|
||
|
|
*/
|
||
|
|
template <typename CB>
|
||
|
|
auto withLock(CB&& cb) {
|
||
|
|
std::lock_guard<std::mutex> guard(this->mutex_);
|
||
|
|
return std::forward<CB>(cb)(this->data_);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* To use, call withLock<T> with a callback that accepts T either
|
||
|
|
* by copy or by const reference. Use the protected variable in
|
||
|
|
* the provided callback safely.
|
||
|
|
*/
|
||
|
|
template <typename CB>
|
||
|
|
auto withLock(CB&& cb) const {
|
||
|
|
std::lock_guard<std::mutex> guard(this->mutex_);
|
||
|
|
return std::forward<CB>(cb)(this->data_);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
} // end namespace c10
|