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Full Discussion: Shared memory and C++ Objects (cont)
Top Forums Programming Shared memory and C++ Objects (cont) Post 14418 by thalex on Thursday 31st of January 2002 12:22:49 PM
Old 01-31-2002
As far as I can understand the objects that contain pointers to "virtual" functions suit exactly the definition of a shared library (maybe u have seen these libraries with the .so.0 extension in other OSes). This is the AIX way. Else u have to reinvent all the appropriate mechanism to do the job. Look at this :

Shared libraries and shared objects (normally called Dynamically Loaded Libraries, or DLLs in Windows terminology) are terms used to refer to object code components that are handled in a special way.
Shared libraries are used in two stages when creating an executable. At link time, the link editor (the ld command) searches the specified library to resolve all undefined symbols that are referenced in the main application code. If a shared library contains the referenced symbols, the loader section
of the header of the created executable contains a reference to the shared library . Unlike using the static library, the object files containing the referenced symbols are not incorporated into the executable. At run time, the system loader (the kernel
component that starts new processes) reads the header information of the executable and attempts to locate and load any referenced shared libraries.
Assuming all the referenced shared libraries are found, the executable can be started. This process is known as dynamic linking.

The header of a shared library is composed only of
Header information
Program code
Program data
Shared object information

And an example

For example, to make the shared object libone.so from the source files
source1.c and source2.c, use:
cc -g -c source1.c
cc -g -c source2.c
ld -G -o libone.so source1.o source2.o

U can seek some redbook from IBM for more info
 

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LEARN ABOUT DEBIAN

qwtcpointerdata

QwtCPointerData(3)						 Qwt User's Guide						QwtCPointerData(3)

NAME

       QwtCPointerData -

       Data class containing two pointers to memory blocks of doubles.

SYNOPSIS

       #include <qwt_data.h>

       Inherits QwtData.

   Public Member Functions
       virtual QwtDoubleRect boundingRect () const
       virtual QwtData * copy () const
       QwtCPointerData & operator= (const QwtCPointerData &)
       QwtCPointerData (const double *x, const double *y, size_t size)
       virtual size_t size () const
       virtual double x (size_t i) const
       const double * xData () const
       virtual double y (size_t i) const
       const double * yData () const

Detailed Description
       Data class containing two pointers to memory blocks of doubles.

Constructor &; Destructor Documentation
   QwtCPointerData::QwtCPointerData (const double *x, const double *y, size_tsize) Constructor
       Parameters:
	   x Array of x values
	   y Array of y values
	   size Size of the x and y arrays

       Warning:
	   The programmer must assure that the memory blocks referenced by the pointers remain valid during the lifetime of the QwtPlotCPointer
	   object.

       See also:
	   QwtPlotCurve::setData(), QwtPlotCurve::setRawData()

Member Function Documentation
   QwtDoubleRect QwtCPointerData::boundingRect () const [virtual] Returns the bounding rectangle of the data. If there is no bounding rect, like
       for empty data the rectangle is invalid: QwtDoubleRect::isValid() == false
       Reimplemented from QwtData.

   QwtData * QwtCPointerData::copy () const [virtual] Returns:
	   Pointer to a copy (virtual copy constructor)

       Implements QwtData.

   QwtCPointerData & QwtCPointerData::operator= (const QwtCPointerData &data)
       Assignment.

   size_t QwtCPointerData::size () const [virtual] Returns:
	   Size of the data set

       Implements QwtData.

   double QwtCPointerData::x (size_ti) const [virtual] Return the x value of data point i
       Parameters:
	   i Index

       Returns:
	   x X value of data point i

       Implements QwtData.

   const double * QwtCPointerData::xData () const Returns:
	   Array of the x-values

   double QwtCPointerData::y (size_ti) const [virtual] Return the y value of data point i
       Parameters:
	   i Index

       Returns:
	   y Y value of data point i

       Implements QwtData.

   const double * QwtCPointerData::yData () const Returns:
	   Array of the y-values

Author
       Generated automatically by Doxygen for Qwt User's Guide from the source code.

Version 5.2.2							  Mon Aug 1 2011						QwtCPointerData(3)
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