bmptk::rtos::pool< T > Class Template Reference

rtos private implementation class More...

#include <rtos.h>

Inheritance diagram for bmptk::rtos::pool< T >:

Public Member Functions
	pool (const char *name="")
	construct a pool, specify its name (for debgging only)
void	write (T item)
	atomic write operation on a pool
T	read (void)
	atomic read operation on a pool

Detailed Description

template<class T>
class bmptk::rtos::pool< T >

rtos private implementation class

place to store and retrieve data, no built-in synchronisation A (communication) pool is a template class that stores a single value. It supports the read and write operations, which are guaranteed to be atomic. (On a non-preemptive rtos every assignment is atomic, but the pool template is still usefull to make it explicit that data is transferred between tasks.)

The example below demonstrates the use of a pool to maintain a seconds-since-startup counter. Note that the call RTOS::runtime() returns the time elapsed since startup, so there is no need to maintain a seconds-since-startup this way yourself.

<< code >> make it an example

pool< unsigned int > seconds;

void show_time(){ 
   unsigned int n = seconds.read();
   std::cout << ( seconds / 60 ) % 60 << ":" << seconds % 60;
}

class seconds_counter_class : public periodic_task {
   seconds_counter(){
      periodic_task::periodic_task( "sec-counter", 10, 1000 MS );
      seconds.write( 0 );
   }
   void main(){
      for(;;){
         (void)wait(); // only one thing to wait for
         seconds.write( seconds.read() + 1 );
      }
   }
}
   
seconds_counter_class seconds_counter;

Definition at line 895 of file rtos.h.

Constructor & Destructor Documentation

template<class T >

bmptk::rtos::pool< T >::pool ( const char *  name = "" )

inline

construct a pool, specify its name (for debgging only)

Use it to make (global) variables use for communication between tasks explicit.

The template argument T must be a class that has a non-arguments constructor and supports assignment.

Definition at line 905 of file rtos.h.

Member Function Documentation

template<class T >

T bmptk::rtos::pool< T >::read ( void  )

inline

atomic read operation on a pool

A read operation returns the most recently written data.In the context of co-operative multitasking a read of write operation on anything is always atomic, unless the implementation of that operating somehow invokes the rtos. But for clearness it is a good idea to implement such task-global data as pools.

Definition at line 924 of file rtos.h.

template<class T >

void bmptk::rtos::pool< T >::write ( T  item )

inline

atomic write operation on a pool

A read operation returns the most recently written data.

In the context of co-operative multitasking a read of write operation on anything is always atomic, unless the implementation of that operating somehow invokes the rtos. But for clearness it is a good idea to implement such task-global data as pools.

Definition at line 916 of file rtos.h.

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

• core/rtos.h