WaitForEvent.cpp

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

int main(int argc, char** argv)
{
    if (argc < 2)
    {
        fprintf(stderr, "Incorrect process start\n");
        return 1;
    }

    HANDLE hEvent = OpenEvent(EVENT_ALL_ACCESS, FALSE, argv[1]);
    if (hEvent == NULL)
    {
        fprintf(stderr, "Can't open event, error: %d\n", GetLastError());
        system("pause");
        return 1;
    }

    HANDLE hSemaphore = OpenSemaphore(SEMAPHORE_ALL_ACCESS, FALSE, "Semaphore");
    if (!hSemaphore)
    {
        fprintf(stderr, "Can't open a semaphore, error: %d", GetLastError());
        CloseHandle(hEvent);
        return 1;
    }

    HANDLE hHandles[2] = { hEvent, hSemaphore };
    int running = 1;

    while (running)
    {
        DWORD dWaitResult = WaitForMultipleObjects(2, hHandles, FALSE, INFINITE);
        switch (dWaitResult)
        {
        case WAIT_OBJECT_0:
            ResetEvent(hEvent);
            running = 0;
            break;
        case WAIT_OBJECT_0 + 1:
            fprintf(stdout, "%s\n", argv[1]);
            ReleaseSemaphore(hSemaphore, 1, NULL);
            break;
        default:
            fprintf(stderr, "Waiting error: %d\n", GetLastError());
            running = 0;
            break;
        }
    }

    CloseHandle(hEvent);
    CloseHandle(hSemaphore);

    return 0;
}