58 lines
2.0 KiB
C++
58 lines
2.0 KiB
C++
/***
|
|
Copyright (C) 2021 J Reece Wilson (a/k/a "Reece"). All rights reserved.
|
|
|
|
File: RWLock.hpp
|
|
Date: 2021-6-9
|
|
Author: Reece
|
|
***/
|
|
#pragma once
|
|
|
|
namespace Aurora::Threading::Primitives
|
|
{
|
|
struct IRWLock
|
|
{
|
|
/**
|
|
* @brief Returns a complete IWaitable interface for reantrant access to the protected resources.
|
|
* Once a thread takes exclusive access of the resource, only it shall pass read. Noting this
|
|
* is critical section behaviour, not mutex behaviour.
|
|
* @return
|
|
*/
|
|
virtual IWaitable *AsReadable() = 0;
|
|
|
|
/**
|
|
* @brief Returns a complete IWaitable interface for exclusive thread access to the protected resources
|
|
*
|
|
* @return
|
|
*/
|
|
virtual IWaitable *AsWritable() = 0;
|
|
|
|
/**
|
|
* @brief Allows for read-to-write upgrades when the decision to esclate is made based upon a shared resource
|
|
* which would be lost by unlocking and relocking in exclusive mode.
|
|
* You must be careful to consider how this is used to prevent dead-locks
|
|
* @param timeout in relative nanoseconds
|
|
* @return
|
|
*/
|
|
virtual bool UpgradeReadToWrite(AuUInt64 timeout) = 0;
|
|
|
|
/**
|
|
* @brief Reverses UpgradeReadToWrite.
|
|
* @return
|
|
*/
|
|
virtual bool DowngradeWriteToRead() = 0;
|
|
|
|
/**
|
|
* @brief Checks if the current thread has acquired a critical-section lock on the mutually exclusive resource
|
|
* @return
|
|
*/
|
|
virtual bool CheckSelfThreadIsWriter() = 0;
|
|
};
|
|
|
|
/// Allows AsReadable() holder entrancy as AsWritable() lock
|
|
/// Check CheckSelfThreadIsWriter() before any lock guards, if non-reentrant mutual exclusion is desired.
|
|
AUKN_SHARED_SOO_NCM(RWLock, IRWLock, kPrimitiveSizeRWLock);
|
|
|
|
/// Allows AsWritable() holder reentrancy, and allows AsReadable() holder entrancy as AsWritable() lock
|
|
AUKN_SHARED_SOO_NCM(RWRenterableLock, IRWLock, kPrimitiveSizeRWLock);
|
|
|
|
} |