contur::Mmu Class Reference

Concrete Memory Management Unit implementation. More...

#include <mmu.h>

Inheritance diagram for contur::Mmu:

Public Member Functions
	Mmu (IMemory &memory, std::unique_ptr< IPageReplacementPolicy > replacementPolicy, ITracer &tracer)
	Constructs an MMU backed by the given physical memory.
	~Mmu () override
	Destroys MMU and associated paging state.
	Mmu (const Mmu &)=delete
Mmu &	operator= (const Mmu &)=delete
	Mmu (Mmu &&) noexcept
	Move-constructs MMU state.
Mmu &	operator= (Mmu &&) noexcept
	Move-assigns MMU state.
Result< Block >	read (ProcessId processId, MemoryAddress virtualAddress) const override
	Reads a Block from a virtual address in a given process's address space.
Result< void >	write (ProcessId processId, MemoryAddress virtualAddress, const Block &block) override
	Writes a Block to a virtual address in a given process's address space.
Result< MemoryAddress >	allocate (ProcessId processId, std::size_t pageCount) override
	Allocates a range of frames for a process.
Result< void >	deallocate (ProcessId processId) override
	Deallocates all frames owned by a process.
Result< void >	swapIn (ProcessId processId, MemoryAddress virtualAddress) override
	Swaps a page into physical memory.
Result< void >	swapOut (ProcessId processId, MemoryAddress virtualAddress) override
	Swaps a page out of physical memory (to simulated disk).
std::size_t	totalFrames () const noexcept override
	Returns the total number of physical frames managed.
std::size_t	freeFrames () const noexcept override
	Returns the number of free (unallocated) physical frames.
Public Member Functions inherited from contur::IMMU
virtual	~IMMU ()=default

Private Attributes
std::unique_ptr< Impl >	impl_

Detailed Description

Concrete Memory Management Unit implementation.

Manages per-process page tables, translates virtual addresses to physical frame addresses, handles frame allocation/deallocation, and delegates page replacement decisions to an IPageReplacementPolicy.

The MMU operates on top of an IMemory instance (physical memory) and maintains a simulated swap space for pages evicted from RAM.

Definition at line 25 of file mmu.h.

Constructor & Destructor Documentation

Mmu() [1/3]

contur::Mmu::Mmu ( IMemory & memory, std::unique_ptr< IPageReplacementPolicy > replacementPolicy, ITracer & tracer )

explicit

Constructs an MMU backed by the given physical memory.

Parameters

memory	The physical memory to manage (non-owning reference).
replacementPolicy	The page replacement policy to use.

Referenced by Mmu(), Mmu(), operator=(), and operator=().

~Mmu()

contur::Mmu::~Mmu ( )

override

Destroys MMU and associated paging state.

Mmu() [2/3]

contur::Mmu::Mmu ( const Mmu & )

delete

References Mmu().

Mmu() [3/3]

contur::Mmu::Mmu ( Mmu && )

noexcept

Move-constructs MMU state.

References Mmu().

Member Function Documentation

allocate()

Result< MemoryAddress > contur::Mmu::allocate ( ProcessId processId, std::size_t pageCount )

nodiscardoverridevirtual

Allocates a range of frames for a process.

Parameters

processId	The owning process.
pageCount	Number of pages (frames) to allocate.

Returns

The starting virtual address, or an error if out of memory.

Implements contur::IMMU.

References allocate().

Referenced by allocate().

deallocate()

Result< void > contur::Mmu::deallocate ( ProcessId processId )

nodiscardoverridevirtual

Deallocates all frames owned by a process.

Parameters

processId

The process whose frames should be freed.

Returns

Success, or an error if the process has no allocations.

Implements contur::IMMU.

References deallocate().

Referenced by deallocate().

freeFrames()

std::size_t contur::Mmu::freeFrames ( ) const

nodiscardoverridevirtualnoexcept

Returns the number of free (unallocated) physical frames.

Implements contur::IMMU.

References freeFrames().

Referenced by freeFrames().

operator=() [1/2]

Mmu & contur::Mmu::operator= ( const Mmu & )

delete

References Mmu().

operator=() [2/2]

Mmu & contur::Mmu::operator= ( Mmu && )

noexcept

Move-assigns MMU state.

References Mmu().

read()

Result< Block > contur::Mmu::read ( ProcessId processId, MemoryAddress virtualAddress ) const

nodiscardoverridevirtual

Reads a Block from a virtual address in a given process's address space.

Parameters

processId	The owning process.
virtualAddress	The virtual address to read from.

Returns

The Block at the translated physical address, or an error.

Implements contur::IMMU.

References read().

Referenced by read().

swapIn()

Result< void > contur::Mmu::swapIn ( ProcessId processId, MemoryAddress virtualAddress )

nodiscardoverridevirtual

Swaps a page into physical memory.

Parameters

processId	The owning process.
virtualAddress	A virtual address within the target page.

Returns

Success, or an error if swap fails.

Implements contur::IMMU.

References swapIn().

Referenced by swapIn().

swapOut()

Result< void > contur::Mmu::swapOut ( ProcessId processId, MemoryAddress virtualAddress )

nodiscardoverridevirtual

Swaps a page out of physical memory (to simulated disk).

Parameters

processId	The owning process.
virtualAddress	A virtual address within the target page.

Returns

Success, or an error if swap fails.

Implements contur::IMMU.

References swapOut().

Referenced by swapOut().

totalFrames()

std::size_t contur::Mmu::totalFrames ( ) const

nodiscardoverridevirtualnoexcept

Returns the total number of physical frames managed.

Implements contur::IMMU.

References totalFrames().

Referenced by totalFrames().

write()

Result< void > contur::Mmu::write ( ProcessId processId, MemoryAddress virtualAddress, const Block & block )

nodiscardoverridevirtual

Writes a Block to a virtual address in a given process's address space.

Parameters

processId	The owning process.
virtualAddress	The virtual address to write to.
block	The Block to store.

Returns

Success, or an error if translation fails.

Implements contur::IMMU.

References write().

Referenced by write().

Member Data Documentation

impl_

std::unique_ptr<Impl> contur::Mmu::impl_

private

Definition at line 73 of file mmu.h.

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The documentation for this class was generated from the following file:

• include/contur/memory/mmu.h