C 多线程

C 多线程

// sample_multithread_c_program.c// compile with: /c////  Bounce - Creates a new thread each time the letter 'a' is typed.//  Each thread bounces a happy face of a different color around//  the screen. All threads are terminated when the letter 'Q' is//  entered.//#include <windows.h>#include <stdlib.h>#include <string.h>#include <stdio.h>#include <conio.h>#include <process.h>#define MAX_THREADS  32// The function getrandom returns a random number between // min and max, which must be in integer range.#define getrandom( min, max ) (SHORT)((rand() % (int)(((max) + 1) - \                               (min))) + (min))int main( void );                    // Thread 1: main void KbdFunc( void  );               // Keyboard input, thread dispatchvoid BounceProc( void * MyID );      // Threads 2 to n: display void ClearScreen( void );            // Screen clear void ShutDown( void );               // Program shutdown void WriteTitle( int ThreadNum );    // Display title bar information HANDLE  hConsoleOut;                 // Handle to the console HANDLE  hRunMutex;                   // "Keep Running" mutex HANDLE  hScreenMutex;                // "Screen update" mutexint     ThreadNr;                    // Number of threads started CONSOLE_SCREEN_BUFFER_INFO csbiInfo; // Console information int main() // Thread One {    // Get display screen information & clear the screen.    hConsoleOut = GetStdHandle( STD_OUTPUT_HANDLE );    GetConsoleScreenBufferInfo( hConsoleOut, &csbiInfo );    ClearScreen();    WriteTitle( 0 );    // Create the mutexes and reset thread count.    hScreenMutex = CreateMutex( NULL, FALSE, NULL );  // Cleared     hRunMutex = CreateMutex( NULL, TRUE, NULL );      // Set     ThreadNr = 0;    // Start waiting for keyboard input to dispatch threads or exit.    KbdFunc();    // All threads done. Clean up handles.    CloseHandle( hScreenMutex );    CloseHandle( hRunMutex );    CloseHandle( hConsoleOut );}void ShutDown( void ) // Shut down threads {    while ( ThreadNr > 0 )    {        // Tell thread to die and record its death.        ReleaseMutex( hRunMutex );        printf("thread %d is shutdown\n",ThreadNr);ThreadNr--;     }        // Clean up display when done    WaitForSingleObject( hScreenMutex, INFINITE );    //ClearScreen();}void KbdFunc( void ) // Dispatch and count threads.{    int         KeyInfo;    do    {        KeyInfo = _getch();        if ( tolower( KeyInfo ) == 'a' &&              ThreadNr < MAX_THREADS )        {            ThreadNr++;            _beginthread( BounceProc, 0, &ThreadNr );            WriteTitle( ThreadNr );        }    } while( tolower( KeyInfo ) != 'q' );    ShutDown();}void BounceProc( void *pMyID ){    char    MyCell, OldCell;    WORD    MyAttrib, OldAttrib;    char    BlankCell = 0x20;    COORD   Coords, Delta;    COORD   Old = {0,0};    DWORD   Dummy;    char    *MyID = (char*)pMyID;    // Generate update increments and initial     // display coordinates.    srand( (unsigned int) *MyID * 3 );    Coords.X = getrandom( 0, csbiInfo.dwSize.X - 1 );    Coords.Y = getrandom( 0, csbiInfo.dwSize.Y - 1 );    Delta.X = getrandom( -3, 3 );    Delta.Y = getrandom( -3, 3 );    // Set up "happy face" & generate color     // attribute from thread number.    if( *MyID > 16)        MyCell = 0x01;          // outline face     else        MyCell = 0x02;          // solid face     MyAttrib =  *MyID & 0x0F;   // force black background     do    {        // Wait for display to be available, then lock it.        WaitForSingleObject( hScreenMutex, INFINITE );        // If we still occupy the old screen position, blank it out.         ReadConsoleOutputCharacter( hConsoleOut, &OldCell, 1,                                     Old, &Dummy );        ReadConsoleOutputAttribute( hConsoleOut, &OldAttrib, 1,                                     Old, &Dummy );        if (( OldCell == MyCell ) && (OldAttrib == MyAttrib))            WriteConsoleOutputCharacter( hConsoleOut, &BlankCell, 1,                                         Old, &Dummy );        // Draw new face, then clear screen lock         WriteConsoleOutputCharacter( hConsoleOut, &MyCell, 1,                                      Coords, &Dummy );        WriteConsoleOutputAttribute( hConsoleOut, &MyAttrib, 1,                                      Coords, &Dummy );        ReleaseMutex( hScreenMutex );        // Increment the coordinates for next placement of the block.         Old.X = Coords.X;        Old.Y = Coords.Y;        Coords.X += Delta.X;        Coords.Y += Delta.Y;        // If we are about to go off the screen, reverse direction         if( Coords.X < 0 || Coords.X >= csbiInfo.dwSize.X )        {            Delta.X = -Delta.X;            printf("%d\n",Delta.X);//Beep( 400, 50 );        }        if( Coords.Y < 0 || Coords.Y > csbiInfo.dwSize.Y )        {            Delta.Y = -Delta.Y;printf("%d\n",Delta.Y);            //Beep( 600, 50 );        }    }    // Repeat while RunMutex is still taken.     while ( WaitForSingleObject( hRunMutex, 75L ) == WAIT_TIMEOUT );}void WriteTitle( int ThreadNum ){    enum {         sizeOfNThreadMsg = 80     };    char    NThreadMsg[sizeOfNThreadMsg];    sprintf( NThreadMsg, "Threads running: %02d.  Press 'A' "               "to start a thread,'Q' to quit.", ThreadNum );    SetConsoleTitle( NThreadMsg );}void ClearScreen( void ){    DWORD    dummy;    COORD    Home = { 0, 0 };    FillConsoleOutputCharacter( hConsoleOut, ' ',                                 csbiInfo.dwSize.X * csbiInfo.dwSize.Y,                                 Home, &dummy );}