A buffer class that holds a known capacity of fixed sized objects defined during creation. More...

#include <buffer.h>

Inheritance diagram for FixedBuffer:

Collaboration diagram for FixedBuffer:

Public Member Functions
	FixedBuffer (size_t capacity, size_t objsize)
	Create a buffer of known capacity for objects of a specified size. More...

	FixedBuffer (const FixedBuffer &fb)
	Create a copy of an existing fixed size buffer and duplicate it's contents. More...

virtual	~FixedBuffer ()
	Destroy the fixed buffer and free the memory used to store objects. More...

FixedBuffer &	operator= (const FixedBuffer &fb)

bool	isValid (void)
	New virtual to test if buffer is a valid object. More...

size_t	getSize (void)
	Return the capacity of the buffer as specified at creation. More...

size_t	getUsed (void)
	Return the current capacity in use for the buffer. More...

size_t	wait (void *buf, timeout_t timeout=0)
	Let one or more threads wait for an object to become available in the buffer. More...

bool	wait (timeout_t timer=0, bool locked=false)
	Wait to be signaled from another thread. More...

size_t	post (void *buf, timeout_t timeout=0)
	Post an object into the buffer and enable a waiting thread to receive it. More...

size_t	peek (void *buf)
	Peek at the current content (first object) in the buffer. More...

void	signal (bool broadcast)
	Signal a conditional object and a waiting threads. More...

void	enterMutex (void)
	Locks the conditional's mutex for this thread. More...

void	lock (void)
	In the future we will use lock in place of enterMutex since the conditional composite is not a recursive mutex, and hence using enterMutex may cause confusion in expectation with the behavior of the Mutex class. More...

bool	tryEnterMutex (void)
	Tries to lock the conditional for the current thread. More...

bool	test (void)

void	leaveMutex (void)
	Leaving a mutex frees that mutex for use by another thread. More...

void	unlock (void)

Static Public Attributes
static const size_t	timeout
	value to return when a timed operation returned with a timeout. More...

Protected Member Functions
size_t	onPeek (void *buf)
	Return the first object in the buffer. More...

size_t	onWait (void *buf)
	Wait for and return a fixed object in the buffer. More...

size_t	onPost (void *buf)
	Post an object of the appropriate size into the buffer. More...

Private Attributes
char *	buf

char *	head

char *	tail

size_t	objsize

Related Functions
(Note that these are not member functions.)
size_t	peek (Buffer &b, void *o)

size_t	get (Buffer &b, void *o, timeout_t t=0)

size_t	put (Buffer &b, void *o, timeout_t t=0)

Detailed Description

A buffer class that holds a known capacity of fixed sized objects defined during creation.

Author: David Sugar dyfet.nosp@m.@ost.nosp@m.el.co.nosp@m.m producer/consumer buffer for fixed size objects.

Definition at line 190 of file buffer.h.

Constructor & Destructor Documentation

FixedBuffer::FixedBuffer	(	size_t	capacity,
		size_t	objsize
	)

Create a buffer of known capacity for objects of a specified size.

Parameters

capacity	of the buffer.
objsize	for each object held in the buffer.

FixedBuffer::FixedBuffer ( const FixedBuffer & fb )

Create a copy of an existing fixed size buffer and duplicate it's contents.

Parameters

fb	existing FixedBuffer object.

virtual FixedBuffer::~FixedBuffer ( )

virtual

Destroy the fixed buffer and free the memory used to store objects.

Member Function Documentation

void Conditional::enterMutex ( void )

inherited

Locks the conditional's mutex for this thread.

Remember that Conditional's mutex is NOT a recursive mutex!

See Also: leaveMutex

size_t Buffer::getSize ( void )

inlineinherited

Return the capacity of the buffer as specified at creation.

Returns: size of buffer.

Definition at line 135 of file buffer.h.

size_t Buffer::getUsed ( void )

inlineinherited

Return the current capacity in use for the buffer.

Free space is technically getSize() - getUsed().

Returns: integer used capacity of the buffer.

See Also: getSize

Definition at line 144 of file buffer.h.

bool FixedBuffer::isValid ( void )

virtual

New virtual to test if buffer is a valid object.

Returns: true if object is valid.

Reimplemented from Buffer.

void Conditional::leaveMutex ( void )

inherited

Leaving a mutex frees that mutex for use by another thread.

See Also: enterMutex

void Conditional::lock ( void )

inlineinherited

In the future we will use lock in place of enterMutex since the conditional composite is not a recursive mutex, and hence using enterMutex may cause confusion in expectation with the behavior of the Mutex class.

See Also: enterMutex

Definition at line 686 of file thread.h.

size_t FixedBuffer::onPeek ( void * buf )

protectedvirtual

Return the first object in the buffer.

Returns: predefined size of this buffers objects.

Parameters

buf	pointer to copy contents of head of buffer to.

Implements Buffer.

size_t FixedBuffer::onPost ( void * buf )

protectedvirtual

Post an object of the appropriate size into the buffer.

Returns: predefined size of this buffers objects.

Parameters

buf	pointer to data to copy into the buffer.

Implements Buffer.

size_t FixedBuffer::onWait ( void * buf )

protectedvirtual

Wait for and return a fixed object in the buffer.

Returns: predefined size of this buffers objects.

Parameters

buf	pointer to hold object returned from the buffer.

Implements Buffer.

FixedBuffer& FixedBuffer::operator= ( const FixedBuffer & fb )

size_t Buffer::peek ( void * buf )

inherited

Peek at the current content (first object) in the buffer.

Returns: size of object in the buffer.

Parameters

buf	pointer to store object found in the buffer.

size_t Buffer::post	(	void *	buf,
		timeout_t	timeout = `0`
	)

inherited

Post an object into the buffer and enable a waiting thread to receive it.

Returns: size of object posted in bytes.

Parameters

buf	pointer to object to store in the buffer.
timeout	time to wait.

void Conditional::signal ( bool broadcast )

inherited

Signal a conditional object and a waiting threads.

Parameters

broadcast this signal to all waiting threads if true.

bool Conditional::test ( void )

inlineinherited

Definition at line 701 of file thread.h.

bool Conditional::tryEnterMutex ( void )

inherited

Tries to lock the conditional for the current thread.

Behaves like enterMutex , except that it doesn't block the calling thread.

Returns: true if locking the mutex was succesful otherwise false

See Also: enterMutex; leaveMutex

void Conditional::unlock ( void )

inlineinherited

Definition at line 711 of file thread.h.

size_t Buffer::wait	(	void *	buf,
		timeout_t	timeout = `0`
	)

inherited

Let one or more threads wait for an object to become available in the buffer.

The waiting thread(s) will wait forever if no object is ever placed into the buffer.

Returns: size of object passed by buffer in bytes.

Parameters

buf	pointer to store object retrieved from the buffer.
timeout	time to wait.

bool Conditional::wait	(	timeout_t	timer = `0`,
		bool	locked = `false`
	)

inherited

Wait to be signaled from another thread.

Parameters

timer	time period to wait.
locked	flag if already locked the mutex.

Friends And Related Function Documentation

size_t get	(	Buffer &	b,
		void *	o,
		timeout_t	t = `0`
	)

size_t peek	(	Buffer &	b,
		void *	o
	)

size_t put	(	Buffer &	b,
		void *	o,
		timeout_t	t = `0`
	)

Field Documentation

char* FixedBuffer::buf

private

Definition at line 193 of file buffer.h.

char * FixedBuffer::head

private

Definition at line 193 of file buffer.h.

size_t FixedBuffer::objsize

private

Definition at line 194 of file buffer.h.

char * FixedBuffer::tail

private

Definition at line 193 of file buffer.h.

const size_t Buffer::timeout

staticinherited

value to return when a timed operation returned with a timeout.

Definition at line 118 of file buffer.h.

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

buffer.h

Public Member Functions

Static Public Attributes

Protected Member Functions

Private Attributes

Related Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Field Documentation