mixal::IODevice Class Reference

#include <io.h>

Inheritance diagram for mixal::IODevice:

Public Member Functions
	IODevice (int32_t blockSize, bool allowRead, bool allowWrite)
IODeviceType	type () const
int	blockSize () const
bool	allowRead () const
bool	allowWrite () const
virtual bool	ready (int32_t elapsed)
virtual void	control (int32_t)
virtual void	read (ComputerWord *memory, int32_t address)=0
virtual void	write (const ComputerWord *memory, int32_t address)=0
virtual ComputerWord &	wordAt (int32_t index)=0

Protected Member Functions
virtual void	doRead ()=0
virtual void	doWrite ()=0

Protected Attributes
IODeviceType	_type
int32_t	_blockSize
bool	_allowRead
bool	_allowWrite
int32_t	_timestamp
double	_readyRate

Detailed Description

The IO device.

Once read or write, the device will not be ready immediately. The reading or writing operation is saved, the actual reading or writing is performed only when the device is explicitly being queried.

Definition at line 40 of file io.h.

Constructor & Destructor Documentation

IODevice()

mixal::IODevice::IODevice	(	int32_t	blockSize,
		bool	allowRead,
		bool	allowWrite
	)

Initialize an IO device.

Parameters

blockSize	The number of bytes in one reading or writing.
allowRead	Whether the device can be read.
allowWrite	Whether the device can be wrote.

Definition at line 10 of file io.cpp.

                                                                     : _type(IODeviceType::TAPE),
        _blockSize(blockSize), _allowRead(allowRead), _allowWrite(allowWrite),
        _timestamp(), _readyRate(1.0) {}

Member Function Documentation

allowRead()

bool mixal::IODevice::allowRead ( ) const

inline

Whether the device can be read.

Definition at line 56 of file io.h.

{ return _allowRead; }

References _allowRead.

allowWrite()

bool mixal::IODevice::allowWrite ( ) const

inline

Whether the device can be wrote.

Definition at line 58 of file io.h.

{ return _allowWrite; }

References _allowWrite.

blockSize()

int mixal::IODevice::blockSize ( ) const

inline

The number of bytes in one reading or writing.

Definition at line 54 of file io.h.

{ return _blockSize; }

References _blockSize.

control()

virtual void mixal::IODevice::control ( int32_t  )

inlinevirtual

Special control of the device.

Reimplemented in mixal::IODevicePaperTape, mixal::IODeviceLinePrinter, mixal::IODeviceDisk, and mixal::IODeviceTape.

Definition at line 63 of file io.h.

{}

doRead()

virtual void mixal::IODevice::doRead ( )

protectedpure virtual

Perform the actual reading.

Implemented in mixal::IODeviceStorage.

doWrite()

virtual void mixal::IODevice::doWrite ( )

protectedpure virtual

Perform the actual writing.

Implemented in mixal::IODeviceStorage.

read()

virtual void mixal::IODevice::read ( ComputerWord *  memory, int32_t  address  )

pure virtual

Read one block from the device.

Implemented in mixal::IODeviceStorage.

ready()

bool mixal::IODevice::ready ( int32_t  elapsed )

virtual

Whether the device is ready for reading or writing.

Reimplemented in mixal::IODeviceStorage.

Definition at line 14 of file io.cpp.

                                      {
    int32_t elapsed = std::max(0, timestamp - _timestamp);
    _timestamp = timestamp;
    double r = static_cast<double>(rand()) / RAND_MAX;
    double successRate = 1.0 - pow(1.0 - _readyRate, elapsed);
    return r <= successRate;
}

References _readyRate, and _timestamp.

Referenced by mixal::IODeviceStorage::ready(), and mixal::Computer::waitDevice().

type()

IODeviceType mixal::IODevice::type ( ) const

inline

Get the type of the IO device.

Definition at line 52 of file io.h.

{ return _type; }

References _type.

wordAt()

virtual ComputerWord& mixal::IODevice::wordAt ( int32_t  index )

pure virtual

Get a word from the storage of the device.

Implemented in mixal::IODeviceStorage.

Referenced by mixal::Computer::getDeviceWordAt().

write()

virtual void mixal::IODevice::write ( const ComputerWord *  memory, int32_t  address  )

pure virtual

Write one block to the device.

Implemented in mixal::IODeviceStorage.

Member Data Documentation

_allowRead

bool mixal::IODevice::_allowRead

protected

Whether the device can be read.

Definition at line 75 of file io.h.

Referenced by allowRead().

_allowWrite

bool mixal::IODevice::_allowWrite

protected

Whether the device can be wrote.

Definition at line 76 of file io.h.

Referenced by allowWrite().

_blockSize

int32_t mixal::IODevice::_blockSize

protected

The number of bytes in one reading or writing.

Definition at line 74 of file io.h.

Referenced by blockSize(), mixal::IODeviceTape::control(), mixal::IODeviceLinePrinter::control(), mixal::IODeviceStorage::doRead(), mixal::IODeviceStorage::doWrite(), mixal::IODeviceLinePrinter::line(), mixal::IODeviceLinePrinter::pageOffsetAt(), and mixal::IODeviceStorage::read().

_readyRate

double mixal::IODevice::_readyRate

protected

The rate that the device could be ready in one unit time.

Definition at line 78 of file io.h.

Referenced by ready().

_timestamp

int32_t mixal::IODevice::_timestamp

protected

The latest time that the device being triggered.

Definition at line 77 of file io.h.

Referenced by mixal::IODeviceStorage::read(), and ready().

_type

IODeviceType mixal::IODevice::_type

protected

The type of the IO device.

Definition at line 73 of file io.h.

Referenced by type().

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

• include/io.h
• src/io.cpp