Null Class Reference

Null device instance. More...

Inheritance diagram for Null:

Public Member Functions
	Null (const char *path)
	Constructor.
int	open (File *, const char *, int, int) OVERRIDE
	Open method.
int	close (File *) OVERRIDE
	Close method.
ssize_t	read (File *, void *, size_t) OVERRIDE
	Read method.
ssize_t	write (File *, const void *, size_t) OVERRIDE
	Write method.
int	fstat (File *file, struct stat *stat) OVERRIDE
	Get the status information of a file or device.
Public Member Functions inherited from Device
	Device (const char *name)
	Constructor.
virtual	~Device ()
	Destructor.

Additional Inherited Members
Static Public Member Functions inherited from Device
static int	open (struct _reent *reent, const char *path, int flags, int mode)
	Open a file or device.
static int	close (struct _reent *reent, int fd)
	Close a file or device.
static int	stat (struct _reent *reent, const char *path, struct stat *stat)
	Get the status information of a file or device.
static int	select (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, long long timeout)
	POSIX select().
static void	select_clear ()
	Clears the current thread's select bits.
Static Public Member Functions inherited from FileIO
static ssize_t	read (struct _reent *reent, int fd, void *buf, size_t count)
	Read from a file or device.
static ssize_t	write (struct _reent *reent, int fd, const void *buf, size_t count)
	Write to a file or device.
static _off_t	lseek (struct _reent *reent, int fd, _off_t offset, int whence)
	Change the offset index of a file or device.
static int	fstat (struct _reent *reent, int fd, struct stat *stat)
	Get the status information of a file or device.
static int	ioctl (int fd, unsigned long int key, unsigned long data)
	Request and ioctl transaction.
static int	fcntl (int fd, int cmd, unsigned long data)
	Manipulate a file descriptor.
static bool	is_device (int fd)
	Test if the file descriptor belongs to a device.
Protected Member Functions inherited from Device
virtual mode_t	get_mode ()
	Get the mode of the device.
Protected Member Functions inherited from FileIO
	FileIO (const char *name)
	Constructor.
virtual	~FileIO ()
	Destructor.
virtual off_t	lseek (File *f, off_t offset, int whence)
	Seek method.
virtual int	ioctl (File *file, unsigned long int key, unsigned long data)
	Request an ioctl transaction.
virtual int	fcntl (File *file, int cmd, unsigned long data)
	Manipulate a file descriptor.
virtual bool	select (File *file, int mode)
	Device select method.
Static Protected Member Functions inherited from Device
static void	select_insert (SelectInfo *info)
	Add client to list of clients needing woken.
static void	select_wakeup (SelectInfo *info)
	Wakeup the list of clients needing woken.
static void	select_wakeup_from_isr (SelectInfo *info, int *woken)
	Wakeup the list of clients needing woken.
Static Protected Member Functions inherited from FileIO
static int	fd_alloc (void)
	Allocate a free file descriptor.
static void	fd_free (int fd)
	Free up a file descriptor.
static File *	file_lookup (int fd)
	Looks up a reference to a File corresponding to a given file descriptor.
static int	fd_lookup (File *file)
	Looks up a file descriptor corresponding to a given File reference.
Protected Attributes inherited from FileIO
const char *	name
	device name
Static Protected Attributes inherited from FileIO
static const unsigned int	numOpenFiles = 20
static File	files []
	File descriptor pool.
static OSMutex	mutex
	mutual exclusion for fileio

Detailed Description

Null device instance.

Definition at line 48 of file Null.cxx.

Constructor & Destructor Documentation

Null()

Null::Null ( const char *  path )

inline

Constructor.

Definition at line 52 of file Null.cxx.

~Null()

Null::~Null ( )

inline

Definition at line 56 of file Null.cxx.

Member Function Documentation

close()

int Null::close ( File *  file )

virtual

Close method.

Close a device.

Parameters

file	file reference for this device

Returns

0 upon success, negative errno upon failure

Implements FileIO.

Definition at line 97 of file Null.cxx.

fstat()

int Null::fstat ( File *  file, struct stat *  stat  )

virtual

Get the status information of a file or device.

Parameters

file	file reference for this device
stat	structure to fill status info into

Returns

0 upon successor or negative error number upon error.

Implements FileIO.

Definition at line 130 of file Null.cxx.

open()

int Null::open ( File *  file, const char *  path, int  flags, int  mode  )

virtual

Open method.

Open a device.

Parameters

file	new file reference to this device
path	file or device name
flags	open flags
mode	open mode

Returns

0 upon success, negative errno upon failure

Implements FileIO.

Definition at line 88 of file Null.cxx.

read()

ssize_t Null::read ( File *  file, void *  buf, size_t  count  )

virtual

Read method.

Read from a file or device.

Parameters

file	file reference for this device
buf	location to place read data
count	number of bytes to read

Returns

number of bytes read upon success, -1 upon failure with errno containing the cause

Implements FileIO.

Definition at line 108 of file Null.cxx.

write()

ssize_t Null::write ( File *  file, const void *  buf, size_t  count  )

virtual

Write method.

Write to a file or device.

Parameters

file	file reference for this device
buf	location to find write data
count	number of bytes to write

Returns

number of bytes written upon success, -1 upon failure with errno containing the cause

Implements FileIO.

Definition at line 120 of file Null.cxx.

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

• Null.cxx