Go4Queue
Class TGo4BufferQueue

class TGo4BufferQueue

derived from TGo4Queue

Class containing a pointer queue for TBuffers. Is able to stream
any external TObject into a TBuffer which then is added to the queue.

Constructor Summary

TGo4BufferQueue()

TGo4BufferQueue(const char * name)

Destructor Summary
virtual synchronized	~TGo4BufferQueue()

Method Summary
void	AddBuffer(TBuffer* buffer, Bool_t clone)           Add buffer pointer to queue.
void	AddBufferFromObject(TObject* object)           Reconstruct a TObject queue entry from a given TBuffer pointer.
virtual void	Clear(Option_t* opt)           Empty the queue and give free buffers back
static TBuffer*	CreateValueBuffer(UInt_t val)           Create a root buffer that contains a single value val.
static Int_t	DecodeValueBuffer(TBuffer* buf)           Extract value from buffer that was created by CreateValueBuffer method.
void	FreeBuffer(TBuffer* buffer)           Free internal buffer to be re-used by the AddBuffer as clone method.
private void	InitBuffers()           Initialization of internal queue buffer.
private TBuffer*	NewEntry()           Create dummy buffer for queue.
private void	Realloc(TBuffer* buffer, Int_t oldsize, Int_t newsize)           Reallocate buffer of TBuffer to newsize.
TBuffer*	WaitBuffer()           Wait for buffer object from queue.
TObject*	WaitObjectFromBuffer()           Wait for buffer object from queue.

Methods inherited from class Go4Queue.TGo4Queue

Add, GetEntries, IsEmpty, Next, SetMaxEntries, Wait, Wake

Methods inherited from class TNamed

operator=, Clone, Compare, Copy, FillBuffer, GetName, GetTitle, Hash, IsSortable, SetName, SetNameTitle, SetTitle, ls, Print, Sizeof, Class, Class_Name, Class_Version, Dictionary, IsA, ShowMembers, Streamer, StreamerNVirtual, DeclFileName, ImplFileLine, ImplFileName, DeclFileLine

Field Detail

fgiISOWNER

public const static const Int_t fgiISOWNER

.we emulate the protected owner flag of the TBuffer class, needed for reallocation!

private Int_t fiMaxBuffers

Number of preallocated buffer TBuffers
(maximum entries in fxBufferList).

private Int_t fiOverflowcount

private TIterator* fxBufferIterator

Iterator for fxBufferList.

private TList* fxBufferList

List of preallocated buffer TBuffers which
are used when TBuffer added to queue should
be "cloned". Each AddBuffer with option clone
will memcopy the input buffer char field to
the next TBuffer field in this list. Output buffer
after WaitBuffer is then this internal TBuffer,
not the input TBuffer. If all buffer buffers are in
use, no further buffer is allowed to be added as
clone.

private TMutex* fxBufferMutex

private TList* fxFreeList

List of buffers which are free for the next add.

public TGo4BufferQueue()

public TGo4BufferQueue(const char * name)

public virtual synchronized ~TGo4BufferQueue()

public void AddBuffer(TBuffer* buffer, Bool_t clone)

Add buffer pointer to queue. We Renamed the protected baseclass method
to avoid user confusion. If clone is true, a clone (deep streamer copy)
of the given buffer will be done and this clone is added to the queue.

public void AddBufferFromObject(TObject* object)

Reconstruct a TObject queue entry from a given TBuffer pointer.
To be used for streaming the receiving socket contents into the queue.
Operation should be thread locked by the calling user.

public virtual void Clear(Option_t* opt)

Empty the queue and give free buffers back

public static TBuffer* CreateValueBuffer(UInt_t val)

Create a root buffer that contains a single value val.
This feature is used to wrap direct (emergency) commands
into a TBuffer to send it via the taskhandler queues and
sockets. Also used to indicate disconnect mode for
the taskhandler threads.

public static Int_t DecodeValueBuffer(TBuffer* buf)

Extract value from buffer that was created by
CreateValueBuffer method. Used to decode a
direct command or disconnect value that is
received from queue or socket connection.
Negative value means no valid value buffer.

public void FreeBuffer(TBuffer* buffer)

Free internal buffer to be re-used by the AddBuffer as clone
method. To be used by the thread that got the
buffer from WaitBuffer after working on it. If buffer does not
belong to the internal buffers list of this queue, it is _not_
added to the free buffer list.

private void InitBuffers()

Initialization of internal queue buffer.

private TBuffer* NewEntry()

Create dummy buffer for queue.

private void Realloc(TBuffer* buffer, Int_t oldsize, Int_t newsize)

Reallocate buffer of TBuffer to newsize.

public TBuffer* WaitBuffer()

Wait for buffer object from queue. We Renamed the protected baseclass method
to avoid user confusion.

public TObject* WaitObjectFromBuffer()

Wait for buffer object from queue. When buffer is received, object is
reconstructed out of it (thread mainlock aqcuired!). NULL in case of
unknown class.

Association Links

to Class TList

List of preallocated buffer TBuffers which
are used when TBuffer added to queue should
be "cloned". Each AddBuffer with option clone
will memcopy the input buffer char field to
the next TBuffer field in this list. Output buffer
after WaitBuffer is then this internal TBuffer,
not the input TBuffer. If all buffer buffers are in
use, no further buffer is allowed to be added as
clone.

to Class TList

List of buffers which are free for the next add.

to Class TMutex

to Class TIterator

Iterator for fxBufferList.