yield汇编实现

yield汇编实现.

　

#include <stdio.h
#include <conio.h
#include <iostream.h


//
// marks a location in the program for resume
// does not return control, exits function from inside macro
//
// yield( x, ret )
//      x : the 'name' of the yield, cannot be ambiguous in the
//          function namespace
//    ret : the return value for when yield() exits the function;

//          must match function return type (leave blank for no return type)

#define yield(x,ret)                            
    {                                           
        /* store the resume location */         
        __asm {                                 
            mov _myStaticMkr,offset label_##x   
        }                                       
                                                
        /* return the supplied value */         
        return ret;                             
    }                                           
    /* our offset in the function */            
    label_##x:



//
// resumes function from the stored offset, or
// continues without notice if there's not one
// stored
//
// resume()
//   <void

#define resume()                        
    /* our stored offset */             
    static _myStaticMkr=0;              
                                        
    /* test for no offset */            
    if( _myStaticMkr )                  
    {                                   
        /* resume from offset */        
        __asm                           
        {                               
            jmp _myStaticMkr            
        }                               
    }


// example demonstrating a function with an int return type
// using the yield() and resume() macros
//
// myFunc()
//   <void

int myFunc()
{
    resume();

    cout << "1
";

    yield(1,1);

    cout << "2
";

    yield(2,1);

    cout << "3
";

    yield(3,1);

    cout << "4
";

    return 0;
}



// main function
//
// main()
//   <void

void main( void )
{
    cout << "Yield in C++
";
    cout << "Chris Pergrossi

";

    myFunc();

    do

    {
        cout << "main()
";
        cout.flush();
    } while( myFunc() );

    cout.flush();

    getch();
}


/*

// example demonstrating a function with no return type
// using the yield() and resume() macros
//
// myFunc()
//   <void

void myFunc()
{
    resume();

    cout << "1
";

    yield(1);

    cout << "2
";

    yield(2);

    cout << "3
";

    yield(3);

    cout << "4
";

    return;
}



// main function
//
// main()
//   <void

void main( void )
{
    cout << "Yield in C++
";
    cout << "Chris Pergrossi

";

    myFunc();

    for( int k = 0; k < 4; k ++ )
    {
        cout << "main()
";
        cout.flush();

        myFunc();
    }

    cout.flush();

    getch();
}

*/