ucommon
Public Member Functions | Protected Member Functions | Protected Attributes | Friends
ucommon::Queue Class Reference

Manage a thread-safe queue of objects through reference pointers. More...

#include <containers.h>

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Public Member Functions

size_t count (void)
 Get number of object points currently in the queue.
 
ObjectProtocolfifo (timeout_t timeout=0)
 Get and remove last object posted to the queue.
 
ObjectProtocolget (unsigned offset=0)
 Examine pending existing object in queue.
 
ObjectProtocollifo (timeout_t timeout=0)
 Get and remove first object posted to the queue.
 
bool post (ObjectProtocol *object, timeout_t timeout=0)
 Post an object into the queue by it's pointer.
 
 Queue (mempager *pager=((void *) 0), size_t number=0)
 Create a queue that uses a memory pager for internally managed member objects for a specified maximum number of object pointers.
 
bool remove (ObjectProtocol *object)
 Remove a specific object pointer for the queue.
 
 ~Queue ()
 Destroy queue.
 

Protected Member Functions

virtual ObjectProtocolinvalid (void) const
 
- Protected Member Functions inherited from ucommon::OrderedIndex
void add (OrderedObject *ordered)
 Add an object into the ordered index.
 
LinkedObjectbegin (void) const
 Return first object in list for iterators.
 
unsigned count (void) const
 Count of objects this list manages.
 
LinkedObjectend (void) const
 Return last object in list for iterators.
 
LinkedObjectfind (unsigned offset) const
 Find a specific member in the ordered list.
 
LinkedObjectget (void)
 Get (pull) object off the list.
 
LinkedObjectgetIndexed (unsigned index) const
 Get an indexed member from the ordered index.
 
LinkedObject ** index (void) const
 Return a pointer to the head of the list.
 
virtual void lock_index (void)
 Used to synchronize lists managed by multiple threads.
 
LinkedObjectoperator* () const
 Return head object pointer.
 
void operator*= (OrderedObject *object)
 Add object to our list.
 
OrderedIndexoperator= (const OrderedIndex &object)
 Assign ordered index.
 
 OrderedIndex ()
 Create and initialize an empty index.
 
 OrderedIndex (const OrderedIndex &source)
 
void purge (void)
 Purge the linked list and then set the index to empty.
 
void reset (void)
 Reset linked list to empty without purging.
 
virtual void unlock_index (void)
 Used to synchronize lists managed by multiple threads.
 
virtual ~OrderedIndex ()
 Destroy index.
 
void copy (const OrderedIndex &source)
 

Protected Attributes

size_t limit
 

Friends

class member
 

Additional Inherited Members

- Static Protected Member Functions inherited from ucommon::Conditional
static pthread_condattr_t * initializer (void)
 Support function for getting conditional attributes for realtime scheduling.
 
static void set (struct timespec *hires, timeout_t timeout)
 Convert a millisecond timeout into use for high resolution conditional timers.
 

Detailed Description

Manage a thread-safe queue of objects through reference pointers.

This can be particularly interesting when used to enqueue/dequeue reference counted managed objects. Thread-safe access is managed through a conditional. Both lifo and fifo forms of queue access may be used. A pool of self-managed member objects are used to operate the queue. This queue is optimized for fifo access; while lifo is supported, it will be slow. If you need primarily lifo, you should use stack instead.

Author
David Sugar dyfet.nosp@m.@gnu.nosp@m.telep.nosp@m.hony.nosp@m..org

Definition at line 215 of file containers.h.

Constructor & Destructor Documentation

ucommon::Queue::Queue ( mempager pager = ((void *) 0),
size_t  number = 0 
)

Create a queue that uses a memory pager for internally managed member objects for a specified maximum number of object pointers.

Parameters
pagerto use for internal member object or NULL to use heap.
numberof pointers that can be in the queue or 0 for unlimited. size limit.
ucommon::Queue::~Queue ( )

Destroy queue.

If no mempager is used, then frees heap.

Member Function Documentation

size_t ucommon::Queue::count ( void  )

Get number of object points currently in the queue.

Returns
number of objects in queue.
ObjectProtocol* ucommon::Queue::fifo ( timeout_t  timeout = 0)

Get and remove last object posted to the queue.

This can wait for a specified timeout of the queue is empty. The object is still retained and must be released or deleted by the receiving function.

Parameters
timeoutto wait if empty in milliseconds.
Returns
object from queue or NULL if empty and timed out.
ObjectProtocol* ucommon::Queue::get ( unsigned  offset = 0)

Examine pending existing object in queue.

Does not remove it.

Parameters
numberof elements back.
Returns
object in queue or NULL if invalid value.
ObjectProtocol* ucommon::Queue::lifo ( timeout_t  timeout = 0)

Get and remove first object posted to the queue.

This can wait for a specified timeout of the queue is empty. The object is still retained and must be released or deleted by the receiving function.

Parameters
timeoutto wait if empty in milliseconds.
Returns
object from queue or NULL if empty and timed out.
bool ucommon::Queue::post ( ObjectProtocol object,
timeout_t  timeout = 0 
)

Post an object into the queue by it's pointer.

This can wait for a specified timeout if the queue is full, for example, for another thread to remove an object pointer. This also retains the object.

Parameters
objectto post.
timeoutto wait if queue is full in milliseconds.
Returns
true if object posted, false if queue full and timeout expired.
bool ucommon::Queue::remove ( ObjectProtocol object)

Remove a specific object pointer for the queue.

This can remove a member from any location in the queue, whether beginning, end, or somewhere in the middle. This also releases the object.

Parameters
objectto remove.
Returns
true if object was removed, false if not found.

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