87 lines
2.5 KiB
C++
87 lines
2.5 KiB
C++
/*
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* Copyright 2020-2022 CM4all GmbH
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* All rights reserved.
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*
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* author: Max Kellermann <mk@cm4all.com>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* - Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#pragma once
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namespace Uring {
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class CancellableOperation;
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/**
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* An asynchronous I/O operation to be queued in a #Queue instance.
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*/
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class Operation {
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friend class CancellableOperation;
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CancellableOperation *cancellable = nullptr;
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public:
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Operation() noexcept = default;
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~Operation() noexcept {
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CancelUring();
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}
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Operation(const Operation &) = delete;
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Operation &operator=(const Operation &) = delete;
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/**
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* Are we waiting for the operation to complete?
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*/
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bool IsUringPending() const noexcept {
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return cancellable != nullptr;
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}
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/**
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* Cancel the operation. OnUringCompletion() will not be
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* invoked. This is a no-op if none is pending.
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*/
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void CancelUring() noexcept;
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/**
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* Replace this pending operation with a new one. This method
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* is only legal if IsUringPending().
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*/
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void ReplaceUring(Operation &new_operation) noexcept;
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/**
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* This method is called when the operation completes.
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*
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* @param res the result code; the meaning is specific to the
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* operation, but negative values usually mean an error has
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* occurred
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*/
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virtual void OnUringCompletion(int res) noexcept = 0;
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};
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} // namespace Uring
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