TNL::Pointers::SharedPointer< Object, Device > Class Template Reference

Cross-device shared smart pointer. More...

#include <TNL/Pointers/SharedPointer.h>

Detailed Description

template<typename Object, typename Device = typename Object::DeviceType>
class TNL::Pointers::SharedPointer< Object, Device >

Cross-device shared smart pointer.

This smart pointer is inspired by std::shared_ptr from STL library. It means that the object owned by the smart pointer can be shared with other smart pointers. One can make a copy of this smart pointer. In addition, the smart pointer is able to work across different devices which means that the object owned by the smart pointer is mirrored on both host and device.

**NOTE: When using smart pointers to pass objects on GPU, one must call Pointers::synchronizeSmartPointersOnDevice< Devices::Cuda >() before calling a CUDA kernel working with smart pointers.**

Template Parameters

Object	is a type of object to be owned by the pointer.
Device	is device where the object is to be allocated. The object is always allocated on the host system as well for easier object manipulation.

See also UniquePointer and DevicePointer.

See also SharedPointer< Object, Devices::Host > and SharedPointer< Object, Devices::Cuda >.

Example

#include <iostream>
#include <cstdlib>
#include <TNL/Containers/Array.h>
#include <TNL/Pointers/SharedPointer.h>
 
using namespace TNL;
 
using ArrayCuda = Containers::Array< int, Devices::Cuda >;
 
struct Tuple
{
   Tuple( const int size ) : a1( size ), a2( size ) {}
 
   void
   setSize( const int size )
   {
      a1->setSize( size );
      a2->setSize( size );
   }
 
   Pointers::SharedPointer< ArrayCuda > a1, a2;
};
 
#ifdef __CUDACC__
__global__
void
printTuple( const Tuple t )
{
   printf( "Tuple size is: %d\n", t.a1->getSize() );
   for( int i = 0; i < t.a1->getSize(); i++ ) {
      printf( "a1[ %d ] = %d \n", i, ( *t.a1 )[ i ] );
      printf( "a2[ %d ] = %d \n", i, ( *t.a2 )[ i ] );
   }
}
#endif
 
int
main( int argc, char* argv[] )
{
   /***
    * Create a tuple of arrays and print them in CUDA kernel
    */
#ifdef __CUDACC__
   Tuple t( 3 );
   *t.a1 = 1;
   *t.a2 = 2;
   Pointers::synchronizeSmartPointersOnDevice< Devices::Cuda >();
   printTuple<<< 1, 1 >>>( t );
 
   /***
    * Resize the arrays
    */
   t.setSize( 5 );
   *t.a1 = 3;
   *t.a2 = 4;
   Pointers::synchronizeSmartPointersOnDevice< Devices::Cuda >();
   printTuple<<< 1, 1 >>>( t );
#endif
   return EXIT_SUCCESS;
}

Output

Tuple size is: 3
a1[ 0 ] = 1 
a2[ 0 ] = 2 
a1[ 1 ] = 1 
a2[ 1 ] = 2 
a1[ 2 ] = 1 
a2[ 2 ] = 2 
Tuple size is: 5
a1[ 0 ] = 3 
a2[ 0 ] = 4 
a1[ 1 ] = 3 
a2[ 1 ] = 4 
a1[ 2 ] = 3 
a2[ 2 ] = 4 
a1[ 3 ] = 3 
a2[ 3 ] = 4 
a1[ 4 ] = 3 
a2[ 4 ] = 4 

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

• src/TNL/Pointers/SharedPointer.h