CancellationContext.h

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/*
 * SPDX-License-Identifier: GPL-2.0-or-later
 * SPDX-FileName: CancellationContext.h
 * SPDX-FileContributor: Dmitry Vedenko
 */
 
#pragma once
 
#include <atomic>
#include <memory>
#include <mutex>
#include <vector>
 
namespace audacity::concurrency
{
class ICancellable;
 
class CancellationContext;
using CancellationContextPtr = std::shared_ptr<CancellationContext>;
 
class CONCURRENCY_API CancellationContext final
{
   struct Tag final
   {
   };
 
public:
   explicit CancellationContext(Tag);
 
   CancellationContext(const CancellationContext&)            = delete;
   CancellationContext(CancellationContext&&)                 = delete;
   CancellationContext& operator=(const CancellationContext&) = delete;
   CancellationContext& operator=(CancellationContext&&)      = delete;
 
   [[nodiscard]] static CancellationContextPtr Create();
 
   void Cancel();
 
   using CancellableWPtr = std::weak_ptr<ICancellable>;
   void OnCancelled(CancellableWPtr cancellable);
 
private:
   std::atomic<bool> mCancelled { false };
 
   std::mutex mCancellableObjectsMutex;
   std::vector<CancellableWPtr> mCancellableObjects;
}; // struct CancellationContext
} // namespace audacity::concurrency