Console Class Reference

The following class defines a hardware console device. Input and output to the device is simulated by reading and writing to UNIX files ("readFile" and "writeFile"). More...

#include <console.h>

Public Member Functions
	Console (char *readFile, char *writeFile, VoidFunctionPtr readAvail, VoidFunctionPtr writeDone, int callArg)
	Console::Console Initialize the simulation of a hardware console device. More...
	~Console ()
	Console::~Console Clean up console emulation.
void	PutChar (char ch)
	Console::PutChar() Write a character to the simulated display, schedule an interrupt to occur in the future, and return. More...
char	GetChar ()
	Console::GetChar() Read a character from the input buffer, if there is any there. Either return the character, or EOF if none buffered. More...
void	WriteDone ()
	Console::WriteDone() Internal routine called when it is time to invoke the interrupt handler to tell the Nachos kernel that the output character has completed.
void	CheckCharAvail ()
	Console::CheckCharAvail() Periodically called to check if a character is available for input from the simulated keyboard (eg, has it been typed?). More...
bool	Feof ()
	Console::Feof Initialize the simulation of a hardware console device. More...

Detailed Description

The following class defines a hardware console device. Input and output to the device is simulated by reading and writing to UNIX files ("readFile" and "writeFile").

Since the device is asynchronous, the interrupt handler "readAvail" is called when a character has arrived, ready to be read in. The interrupt handler "writeDone" is called when an output character has been "put", so that the next character can be written.

Constructor & Destructor Documentation

Console::Console	(	char *	readFile,
		char *	writeFile,
		VoidFunctionPtr	readAvail,
		VoidFunctionPtr	writeDone,
		int	callArg
	)

Console::Console Initialize the simulation of a hardware console device.

Parameters

readFile	– UNIX file simulating the keyboard (NULL -> use stdin)
writeFile	– UNIX file simulating the display (NULL -> use stdout)
readAvail	is the interrupt handler called when a character arrives from the keyboard
writeDone	is the interrupt handler called when a character has been output, so that it is ok to request the next char be output

Member Function Documentation

void Console::CheckCharAvail

(

)

Console::CheckCharAvail() Periodically called to check if a character is available for input from the simulated keyboard (eg, has it been typed?).

Only read it in if there is buffer space for it (if the previous character has been grabbed out of the buffer by the Nachos kernel). Invoke the "read" interrupt handler, once the character has been put into the buffer.

bool Console::Feof

(

)

Console::Feof Initialize the simulation of a hardware console device.

Returns

bool : Return a bololean that indicate wether there is something more to read or not

char Console::GetChar

(

)

Console::GetChar() Read a character from the input buffer, if there is any there. Either return the character, or EOF if none buffered.

Returns

char The caracter available in the current FD

void Console::PutChar

(

char

ch

)

Console::PutChar() Write a character to the simulated display, schedule an interrupt to occur in the future, and return.

Parameters

ch	: The caracter you wanted to be Put

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

• code/machine/console.h
• code/machine/console.cc