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RWTPCValQueueGuardedPrioritized< Type > Class Template Reference
SourcePro Core » Threads Module » Interthread Communication

First-in-first-out (FIFO) queue that provides producer-consumer synchronization semantics for exchanging guarded and prioritized values between cooperating threads. More...

#include <rw/itc/RWTPCValQueueGuardedPrioritized.h>

Inheritance diagram for RWTPCValQueueGuardedPrioritized< Type >:
RWTPCValBufferBaseGuardedPrioritized< Type, RWTGuardAndPriorityDecorator< Type > > RWTPCValBufferBaseGuarded< Type, RWTGuardAndPriorityDecorator< Type > > RWTPCValBufferBasePrioritized< Type, RWTGuardAndPriorityDecorator< Type > > RWTPCValBufferBaseDecorated< Type, RWTGuardAndPriorityDecorator< Type > > RWTPCValBufferBaseDecorated< Type, RWTGuardAndPriorityDecorator< Type > > RWTPCValBufferBase< RWTGuardAndPriorityDecorator< Type > > RWTPCValBufferBase< RWTGuardAndPriorityDecorator< Type > > RWPCBufferBase RWPCBufferBase RWTMonitor< RWMutexLock > RWTMonitor< RWMutexLock >

Public Member Functions

 RWTPCValQueueGuardedPrioritized (void)
 
 RWTPCValQueueGuardedPrioritized (size_t maxCapacity)
 
 RWTPCValQueueGuardedPrioritized (size_t maxCapacity, bool isOpen)
 
 ~RWTPCValQueueGuardedPrioritized (void)
 
- Public Member Functions inherited from RWTPCValBufferBaseGuardedPrioritized< Type, RWTGuardAndPriorityDecorator< Type > >
virtual ~RWTPCValBufferBaseGuardedPrioritized (void)
 
bool tryWrite (const Type &value)
 
bool tryWrite (const Type &value, const RWTFunctor< bool()> &guard)
 
bool tryWrite (long priority, const Type &value)
 
bool tryWrite (long priority, const Type &value, const RWTFunctor< bool()> &guard)
 
void write (const Type &value)
 
RWWaitStatus write (const Type &value, unsigned long milliseconds)
 
void write (const Type &value, const RWTFunctor< bool()> &guard)
 
RWWaitStatus write (const Type &value, const RWTFunctor< bool()> &guard, unsigned long milliseconds)
 
void write (long priority, const Type &value)
 
RWWaitStatus write (long priority, const Type &value, unsigned long milliseconds)
 
void write (long priority, const Type &value, const RWTFunctor< bool()> &guard)
 
RWWaitStatus write (long priority, const Type &value, const RWTFunctor< bool()> &guard, unsigned long milliseconds)
 
- Public Member Functions inherited from RWTPCValBufferBaseGuarded< Type, RWTGuardAndPriorityDecorator< Type > >
virtual ~RWTPCValBufferBaseGuarded (void)
 
Type peek (void)
 
RWWaitStatus peek (Type &result, unsigned long milliseconds)
 
Type read (void)
 
RWWaitStatus read (Type &result, unsigned long milliseconds)
 
bool tryPeek (Type &value)
 
bool tryRead (Type &value)
 
bool tryWrite (const Type &value, const RWTFunctor< bool()> &guard)
 
void write (const Type &value, const RWTFunctor< bool()> &guard)
 
RWWaitStatus write (const Type &value, const RWTFunctor< bool()> &guard, unsigned long milliseconds)
 
- Public Member Functions inherited from RWTPCValBufferBaseDecorated< Type, RWTGuardAndPriorityDecorator< Type > >
virtual ~RWTPCValBufferBaseDecorated (void)
 
Type peek (void)
 
RWWaitStatus peek (Type &result, unsigned long milliseconds)
 
Type read (void)
 
RWWaitStatus read (Type &result, unsigned long milliseconds)
 
bool tryPeek (Type &result)
 
bool tryRead (Type &result)
 
bool tryWrite (const Type &value)
 
void write (const Type &value)
 
RWWaitStatus write (const Type &value, unsigned long milliseconds)
 
- Public Member Functions inherited from RWTPCValBufferBasePrioritized< Type, RWTGuardAndPriorityDecorator< Type > >
virtual ~RWTPCValBufferBasePrioritized (void)
 
bool tryWrite (long priority, const Type &value)
 
void write (long priority, const Type &value)
 
RWWaitStatus write (long priority, const Type &value, unsigned long milliseconds)
 

Additional Inherited Members

- Protected Types inherited from RWTMonitor< RWMutexLock >
typedef RWTLockGuard< RWTMonitor< RWMutexLock > > LockGuard
 
typedef RWTTryLockGuard< RWTMonitor< RWMutexLock > > TryLockGuard
 
typedef RWTUnlockGuard< RWTMonitor< RWMutexLock > > UnlockGuard
 
- Protected Member Functions inherited from RWTPCValBufferBase< RWTGuardAndPriorityDecorator< Type > >
virtual ~RWTPCValBufferBase (void)
 
RWTGuardAndPriorityDecorator< Type > peek (void)
 
RWWaitStatus peek (RWTGuardAndPriorityDecorator< Type > &result, unsigned long milliseconds)
 
RWTGuardAndPriorityDecorator< Type > read (void)
 
RWWaitStatus read (RWTGuardAndPriorityDecorator< Type > &result, unsigned long milliseconds)
 
bool tryPeek (RWTGuardAndPriorityDecorator< Type > &result)
 
bool tryRead (RWTGuardAndPriorityDecorator< Type > &result)
 
bool tryWrite (const RWTGuardAndPriorityDecorator< Type > &value)
 
void write (const RWTGuardAndPriorityDecorator< Type > &value)
 
RWWaitStatus write (const RWTGuardAndPriorityDecorator< Type > &value, unsigned long milliseconds)
 
virtual ~RWPCBufferBase (void)
 
bool canRead (void) const
 
bool canWrite (void) const
 
void close (void)
 
size_t entries (void) const
 
void flush (void)
 
size_t getCapacity (void) const
 
RWTFunctor< void()> getCloseCallback (void) const
 
RWTFunctor< void()> getEmptyCallback (void) const
 
RWTFunctor< void()> getFullCallback (void) const
 
RWTFunctor< void()> getOpenCallback (void) const
 
bool isOpen (void) const
 
void open (void)
 
size_t setCapacity (size_t maxCapacity)
 
void setCloseCallback (const RWTFunctor< void()> &onCloseCallback)
 
void setEmptyCallback (const RWTFunctor< void()> &onEmptyCallback)
 
void setFullCallback (const RWTFunctor< void()> &onFullCallback)
 
void setOpenCallback (const RWTFunctor< void()> &onOpenCallback)
 
- Protected Member Functions inherited from RWTMonitor< RWMutexLock >
 RWTMonitor ()
 
 RWTMonitor (RWStaticCtor)
 
 RWTMonitor (const RWTMonitor< RWMutexLock > &second)
 
 ~RWTMonitor ()
 
void acquire ()
 
bool isAcquired () const
 
RWTMonitor< RWMutexLock > & monitor () const
 
RWMutexLock & mutex ()
 
RWTMonitor< RWMutexLock > & operator= (const RWTMonitor< RWMutexLock > &)
 
void release ()
 
bool tryAcquire ()
 

Detailed Description

template<class Type>
class RWTPCValQueueGuardedPrioritized< Type >

RWTPCValQueueGuardedPrioritized is a first-in-first-out (FIFO) queue that provides producer-consumer synchronization semantics for exchanging guarded and prioritized values between cooperating threads.

In the producer-consumer synchronization model, reader threads (consumers) are blocked while the queue is empty, and writer threads (producers) are blocked while the queue is full. The queue is considered full when the number of unread entries equals or exceeds some user-specified maximum capacity.

The write operations inherited by this class bind a guard functor and priority value to each data value prior to storing that value in an internal buffer. The guard functor is used during read operations to determine whether the associated value is currently eligible for retrieval from the buffer. The priority value is used during write operations to determine a value's insertion point within the queue, such that the set of unread values will be retrieved in priority order when they are eventually read from the queue. A new value is retrieved after any previously inserted values of the same priority, except when the retrieval of the older values is prohibited by their guard functors.

Example
#include <rw/functor/RWTFunctor.h>
#include <rw/itc/RWTPCValQueueGuardedPrioritized.h>
#include <rw/thread/RWThreadFunction.h>
#include <iostream>
enum Command {
RUN, STOP, PROCESS_HIGH, PROCESS_MED, PROCESS_LOW, EXIT
};
RWTPCValQueueGuardedPrioritized<Command> pcQueue;
bool isRunning = false;
// The guard function
bool canProcess()
{
return isRunning;
}
void reader(void)
{
// Get commands from queue, update state,
// and write to stdout.
Command command;
while (EXIT != (command = pcQueue.read())) {
switch (command) {
case RUN:
std::cout << "RUN" << std::endl;
isRunning = true;
break;
case STOP:
std::cout << "STOP" << std::endl;
isRunning = false;
break;
case PROCESS_HIGH:
std::cout << "PROCESS_HIGH" << std::endl;
break;
case PROCESS_MED:
std::cout << "PROCESS_MED" << std::endl;
break;
case PROCESS_LOW:
std::cout << "PROCESS_LOW" << std::endl;
break;
}
}
std::cout << "EXIT" << std::endl;
}
int main()
{
RWThread thread = RWThreadFunction::make(reader);
RWTFunctor<bool()> guard = canProcess;
thread.start();
pcQueue.write(1, PROCESS_LOW, guard);
pcQueue.write(2, PROCESS_MED, guard);
pcQueue.write(1, PROCESS_LOW, guard);
pcQueue.write(1, PROCESS_LOW, guard);
pcQueue.write(3, PROCESS_HIGH, guard);
pcQueue.write(4, RUN);
pcQueue.write(2, PROCESS_MED, guard);
pcQueue.write(1, PROCESS_LOW, guard);
pcQueue.write(1, PROCESS_LOW, guard);
pcQueue.write(1, PROCESS_LOW, guard);
pcQueue.write(3, PROCESS_HIGH, guard);
pcQueue.write(4, STOP);
pcQueue.write(3, PROCESS_HIGH, guard);
pcQueue.write(1, PROCESS_LOW, guard);
pcQueue.write(4, RUN);
pcQueue.write(0, EXIT);
thread.join();
return 0;
}

OUTPUT:

RUN
PROCESS_HIGH
PROCESS_MED
PROCESS_MED
PROCESS_LOW
PROCESS_LOW
PROCESS_LOW
PROCESS_LOW
PROCESS_LOW
PROCESS_LOW
STOP
RUN
PROCESS_HIGH
PROCESS_HIGH
PROCESS_LOW
EXIT

Constructor & Destructor Documentation

template<class Type >
RWTPCValQueueGuardedPrioritized< Type >::RWTPCValQueueGuardedPrioritized ( void  )
inline

Constructs a value-based, guarded, prioritized, producer-consumer queue instance.

The queue is open on construction and enforces no limit on the number of items in the queue.

template<class Type >
RWTPCValQueueGuardedPrioritized< Type >::RWTPCValQueueGuardedPrioritized ( size_t  maxCapacity)
inline

Constructs a value-based, guarded, prioritized, producer-consumer queue instance.

The parameter maxCapacity specifies the maximum number of unread entries to allow to accumulate within the queue. Once the number of entries in the queue equals this number, any thread attempting to write an additional entry is blocked until an entry is removed by a read() operation, or until the capacity is increased. A capacity of zero is used to indicate that the queue has no size limit other than that imposed by memory limitations, and that all write() operations should complete without blocking.

The queue is open on construction.

template<class Type >
RWTPCValQueueGuardedPrioritized< Type >::RWTPCValQueueGuardedPrioritized ( size_t  maxCapacity,
bool  isOpen 
)
inline

Constructs a value-based, guarded, prioritized, producer-consumer queue instance.

The parameter maxCapacity specifies the maximum number of unread entries to allow to accumulate within the queue. Once the number of entries in the queue equals this number, any thread attempting to write an additional entry is blocked until an entry is removed by a read() operation, or until the capacity is increased. A capacity of zero is used to indicate that the queue has no size limit other than that imposed by memory limitations, and that all write() operations should complete without blocking.

The parameter isOpen is a bool value that specifies whether the queue should be initialized in the open state, true, or the closed state, false.

template<class Type >
RWTPCValQueueGuardedPrioritized< Type >::~RWTPCValQueueGuardedPrioritized ( void  )
inline

Destructor.

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