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/*
* Copyright 2020 CM4all GmbH
* All rights reserved.
*
* author: Max Kellermann <mk@cm4all.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include "Ring.hxx"
#include <liburing.h>
#include <boost/intrusive/list.hpp>
namespace Uring {
class Operation;
class CancellableOperation;
/**
* High-level C++ wrapper for a `struct io_uring`. It supports a
* handler class, cancellation, ...
*/
class Queue {
Ring ring;
boost::intrusive::list<CancellableOperation,
boost::intrusive::base_hook<boost::intrusive::list_base_hook<boost::intrusive::link_mode<boost::intrusive::normal_link>>>,
boost::intrusive::constant_time_size<false>> operations;
public:
Queue(unsigned entries, unsigned flags);
~Queue() noexcept;
FileDescriptor GetFileDescriptor() const noexcept {
return ring.GetFileDescriptor();
}
struct io_uring_sqe *GetSubmitEntry() noexcept {
return ring.GetSubmitEntry();
}
bool HasPending() const noexcept {
return !operations.empty();
}
protected:
void AddPending(struct io_uring_sqe &sqe,
Operation &operation) noexcept;
public:
virtual void Push(struct io_uring_sqe &sqe,
Operation &operation) noexcept {
AddPending(sqe, operation);
Submit();
}
void Submit() {
ring.Submit();
}
bool DispatchOneCompletion();
void DispatchCompletions() {
while (DispatchOneCompletion()) {}
}
bool WaitDispatchOneCompletion();
void WaitDispatchCompletions() {
while (WaitDispatchOneCompletion()) {}
}
private:
void DispatchOneCompletion(struct io_uring_cqe &cqe) noexcept;
};
} // namespace Uring