/////////////////////////////////////////////////////////////////////////////
// Creation 18/12/2003                                               
// 
// 
//                           SEMAPHORE.C
//                           -----------
// 
// 
// Sylvain MARECHAL - sylvain.marechal1@libertysurf.fr
/////////////////////////////////////////////////////////////////////////////
// 
// Show how to use semaphore under WIN32
// 
/////////////////////////////////////////////////////////////////////////////
#include <windows.h>
#include <stdio.h>


DWORD WINAPI ThreadProc(  LPVOID lpParameter );


static CRITICAL_SECTION s_cs;

void main()
{
    HANDLE hSem;
    DWORD dwThreadID; LONG PreviousCount;

    InitializeCriticalSection(&s_cs); 

    hSem = CreateSemaphore( NULL, 0, 2, NULL );

    CreateThread( NULL, 0, ThreadProc, (LPVOID)hSem, 0, &dwThreadID );
    CreateThread( NULL, 0, ThreadProc, (LPVOID)hSem, 0, &dwThreadID );
    Sleep( 1000 );
    
    printf( "ReleaseSemaphore()\n" );
    ReleaseSemaphore( hSem, 2, &PreviousCount );
    
    Sleep( INFINITE );
}


static void PrintThread( char * sz )
{
    EnterCriticalSection( &s_cs );
    printf( "%s  - thread (%d)\n", sz, GetCurrentThreadId() );
    LeaveCriticalSection( &s_cs );
}


DWORD WINAPI ThreadProc(  LPVOID lpParameter )
{
    HANDLE hSem = (HANDLE)lpParameter;

    PrintThread( "Waiting for the semaphore" );
    if( WaitForSingleObject( hSem, INFINITE ) == WAIT_OBJECT_0 )
	PrintThread( "Semaphore OK" );
    else
	printf( "WaitForSingleObject() error (%d)\n", GetLastError() );
    return 0;
}