Waiting for Multiple Objects, C++ (vc++)

Waiting for Multiple Objects

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

HANDLE ghEvents[2];

DWORD WINAPI ThreadProc( LPVOID );

int main( void )
{
    HANDLE hThread; 
    DWORD i, dwEvent, dwThreadID;

// Create two event objects

for (i = 0; i < 2; i++) 
    { 
        ghEvents[i] = CreateEvent( 
            NULL,   // default security attributes
            FALSE,  // auto-reset event object
            FALSE,  // initial state is nonsignaled
            NULL);  // unnamed object

if (ghEvents[i] == NULL) 
        { 
            printf("CreateEvent error: %d\n", GetLastError() ); 
            ExitProcess(0); 
        } 
    }

// Create a thread

hThread = CreateThread( 
                 NULL,         // default security attributes
                 0,            // default stack size
                 (LPTHREAD_START_ROUTINE) ThreadProc, 
                 NULL,         // no thread function arguments
                 0,            // default creation flags
                 &dwThreadID); // receive thread identifier

if( hThread == NULL )
    {
        printf("CreateThread error: %d\n", GetLastError());
        return 1;
    }

// Wait for the thread to signal one of the event objects

dwEvent = WaitForMultipleObjects( 
        2,           // number of objects in array
        ghEvents,     // array of objects
        FALSE,       // wait for any object
        5000);       // five-second wait

// The return value indicates which event is signaled

switch (dwEvent) 
    { 
        // ghEvents[0] was signaled
        case WAIT_OBJECT_0 + 0: 
            // TODO: Perform tasks required by this event
            printf("First event was signaled.\n");
            break;

// ghEvents[1] was signaled
        case WAIT_OBJECT_0 + 1: 
            // TODO: Perform tasks required by this event
            printf("Second event was signaled.\n");
            break;

case WAIT_TIMEOUT:
            printf("Wait timed out.\n");
            break;

// Return value is invalid.
        default: 
            printf("Wait error: %d\n", GetLastError()); 
            ExitProcess(0); 
    }

// Close event handles

for (i = 0; i < 2; i++) 
        CloseHandle(ghEvents[i]); 
    
    return 0;   
}

DWORD WINAPI ThreadProc( LPVOID lpParam )
{

// lpParam not used in this example
    UNREFERENCED_PARAMETER( lpParam);

// Set one event to the signaled state

if ( !SetEvent(ghEvents[0]) ) 
    {
        printf("SetEvent failed (%d)\n", GetLastError());
        return 1;
    }
    return 0;
}


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