smartptrdemo.cpp

C++垃圾回收框架

/*************************************************************************
 FILE       : SmartPtrDemo.cpp

 Description: This project is intended to test the capabilities
			  of SmartPtr classes. Use this project under the 
			  same copyright as SmartPtr.h

 Created By : Stefan Tchekanov

*************************************************************************/
/* #    Revisions    # */


//////////////////////////////////////////////////////////////////////

#include <windows.h>
#include <stdio.h>

//////////////////////////////////////////////////////////////////////

//	ASSERT needs to be defined before inclusion of SmartPtr.h
//	Because it is used inside it.
#define	ASSERT(p)
#include "SmartPtr.h"

//////////////////////////////////////////////////////////////////////

//	A base class
class B
{
public:
	B( char* data ) { m_data = data; };
	virtual ~B() {
		int i = 0;
	}

	virtual	void	print() {
		printf( "B : %s\n", m_data );
	};
	char*	m_data;
};
//////////////////////////////////////////////////////////////////////

//	A sub class (inherited from class B)
class A : public B
{
public:
	A( char* data ) : B(data) {};
	virtual ~A() {
		int i = 0;
	}

	virtual	void	print() {
		printf( "A : %s\n", m_data );
	};
};
//////////////////////////////////////////////////////////////////////

//	An independent class
class C
{
public:
	C( char* data ) : m_data( data ) {};
	virtual ~C() {
		int i = 0;
	}

	virtual	void	println() {
		printf( "C : %s\n", m_data );
	};
	char*	m_data;
};
//////////////////////////////////////////////////////////////////////

//	Thread data
class	T {
public:
	RefCountPtr<A>	m_pa;
};

//	It is more readable to read LPT than SyncRefCountPtr<T>
typedef		SyncRefCountPtr<T>	LPT;

//	structure used to gracefully pass parameters to the thread
struct	ThreadArgs {
public:
	LPT		m_ptr;
};
//////////////////////////////////////////////////////////////////////

DWORD WINAPI ThreadProc( LPVOID lpParam )
{
	ThreadArgs*	pargs = (ThreadArgs*)lpParam;
	LPT			pData = pargs->m_ptr;

	pData->m_pa->print();
	for( int i = 0; i < 200000; i++ )
	{
		pData->m_pa->m_data = "new text";
	}
	pData->m_pa->print();

	return	0;
}
//////////////////////////////////////////////////////////////////////

void	TestSynchroniztion()
{
	HANDLE	ahThread[2];
	DWORD	aThreadID[2];

	LPT	pData = new T;
	pData->m_pa = new A( "thread object" );

	ThreadArgs*	pargs = new ThreadArgs;
	pargs->m_ptr = pData;

	ahThread[0] = ::CreateThread( NULL, 0, ThreadProc, &pData, CREATE_SUSPENDED, &aThreadID[0] );
	ahThread[1] = ::CreateThread( NULL, 0, ThreadProc, &pData, CREATE_SUSPENDED, &aThreadID[1] );

	::ResumeThread( ahThread[0] );
	::ResumeThread( ahThread[1] );

	::WaitForMultipleObjects( 2, (HANDLE*)ahThread, TRUE, INFINITE );
	pData->m_pa->print();

	delete	pargs;
}
//////////////////////////////////////////////////////////////////////

void	TestRefCounting()
{
	int	i = 0;

	//	Test construction/destruction
	{
		A*	pa = new A( "A object" );
		A*	pa1 = new A( "A1 object" );
		B*	pb = new B( "Base object" );
		C*	pc = new C( "C object" );

		//	Regular construction
		RefCountPtr<A> a = pa;
		RefCountPtr<B> b = pb;
		RefCountPtr<B> b1 = b;
		
		//	pointer to Super (base) class receives
		//	an object of sub class                
		RefCountPtr<B> b2 = a;
		RefCountPtr<B> b3 = pa1;
		
		RefCountPtr<C> c = pc;
		//	the pointer receives
		//	an object of independent class                
		RefCountPtr<B> b4 = c;
//		RefCountPtr<B> b5 = pc;	//	illegal

		//	Comparison operator
		if( b2 == a ) {
			i = 1;
		}
	}

	//	Test assignment operatos
	{
		A*	pa = new A( "A object" );
		A*	pa1 = new A( "A1 object" );
		B*	pb = new B( "Base object" );
		C*	pc = new C( "C object" );

		RefCountPtr<A> a;
		RefCountPtr<B> b;
		RefCountPtr<B> b1;
		RefCountPtr<B> b2;
		RefCountPtr<B> b3;
		RefCountPtr<C> c;

		a = pa;
		b = pb;
		b1 = b;

		//	pointer to Super (base) class receives
		//	an object of sub class                
		b2 = a;
		b3 = pa1;

		c = pc;
		//	the pointer receives
		//	an object of independent class                
		b = c;
//		b1 = pc;	//	illegal

		b->m_data = "pppppp";
		a->print();
		b->print();

		pb = a;
		A	aa = *a;

		if( b == b2 ) {
			i = 2;
		}
		if( b != b2 ) {
			i = 3;
		}
		i = sizeof(b);
	}
}
//////////////////////////////////////////////////////////////////////

int main( int argc, char* argv[] )
{
	TestRefCounting();
	TestSynchroniztion();

	return 0;
}
//////////////////////////////////////////////////////////////////////