Orocos Real-Time Toolkit
2.8.3
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Create an atomic, non-blocking single ended queue (FIFO) for storing a pointer to T. More...
#include <rtt/internal/AtomicQueue.hpp>
Public Types | |
typedef unsigned int | size_type |
Public Member Functions | |
AtomicQueue (unsigned int size) | |
Create an AtomicQueue with queue size size. More... | |
~AtomicQueue () | |
bool | isFull () const |
Inspect if the Queue is full. More... | |
bool | isEmpty () const |
Inspect if the Queue is empty. More... | |
size_type | capacity () const |
Return the maximum number of items this queue can contain. More... | |
size_type | size () const |
Return the exact number of elements in the queue. More... | |
bool | enqueue (const T &value) |
Enqueue an item. More... | |
bool | dequeue (T &result) |
Dequeue an item. More... | |
const T | front () const |
Return the next to be read value. More... | |
void | clear () |
Clear all contents of the Queue and thus make it empty. More... | |
Create an atomic, non-blocking single ended queue (FIFO) for storing a pointer to T.
It is a Many Readers, Many Writers implementation based on the atomic Compare And Swap instruction. Any number of threads may access the queue concurrently.
This queue tries to obey strict ordering, but under high contention of reads interfering writes, one or more elements may be dequeued out of order. For this reason, size() is expensive to accurately calculate the size.
Due to the same limitations, it is possible that the full capacity of the queue is not used (simulations show seldomly an off by one element if capacity==10) and that isFull() returns true, while size() < capacity().
T | The pointer type to be stored in the Queue. Example : AtomicQueue< A* > is a queue of pointers to A. |
Definition at line 70 of file AtomicQueue.hpp.
typedef unsigned int RTT::internal::AtomicQueue< T >::size_type |
Definition at line 184 of file AtomicQueue.hpp.
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Create an AtomicQueue with queue size size.
size | The size of the queue, should be 1 or greater. |
Definition at line 190 of file AtomicQueue.hpp.
References RTT::internal::AtomicQueue< T >::clear().
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Definition at line 197 of file AtomicQueue.hpp.
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Return the maximum number of items this queue can contain.
Definition at line 231 of file AtomicQueue.hpp.
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Clear all contents of the Queue and thus make it empty.
Definition at line 304 of file AtomicQueue.hpp.
Referenced by RTT::internal::AtomicQueue< T >::AtomicQueue().
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Dequeue an item.
value | The value dequeued. |
Definition at line 278 of file AtomicQueue.hpp.
References RTT::os::CAS().
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Enqueue an item.
value | The value to enqueue, not zero. |
Definition at line 258 of file AtomicQueue.hpp.
References RTT::os::CAS().
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Return the next to be read value.
Definition at line 296 of file AtomicQueue.hpp.
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Inspect if the Queue is empty.
Definition at line 220 of file AtomicQueue.hpp.
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Inspect if the Queue is full.
Definition at line 206 of file AtomicQueue.hpp.
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Return the exact number of elements in the queue.
This is slow because it scans the whole queue.
Definition at line 241 of file AtomicQueue.hpp.