Semafori windows (prod_cons)

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

#define DIM 1024
char buffer[DIM];
LPCTSTR nome = "EsempioSemaforo";
HANDLE sem_t;

DWORD WINAPI thread_function(PVOID arg) {
   LONG dwSemCount;
   HANDLE hSemaphore = OpenSemaphore( SYNCHRONIZE |
SEMAPHORE_MODIFY_STATE, FALSE, nome );

   WaitForSingleObject( hSemaphore, INFINITE );
   while(strncmp("stop", buffer, 4) != 0) {
       printf("Ha inserito %d caratteri\n", strlen(buffer) -1);
       ReleaseSemaphore(hSemaphore, 1, &dwSemCount);
       WaitForSingleObject( hSemaphore, INFINITE );
   }
   ReleaseSemaphore(hSemaphore, 1, &dwSemCount);
   CloseHandle( hSemaphore );
   return 0;
}

int main() {
    HANDLE a_thread;
    DWORD a_threadId;
    DWORD thread_result;
    LONG dwSemCount;

// Inizializza un semaforo.
  sem_t = CreateSemaphore( NULL, 0, 1, nome );

  if (sem_t == NULL) {
        perror("Inizializzazione del semaforo fallita");
        exit(EXIT_FAILURE);
    }

// Crea un secondo thread.
    a_thread = CreateThread(NULL, 0, thread_function, (PVOID)NULL, 0,
&a_threadId);

    if (a_thread == NULL) {
        perror("Creazione del thread fallita");
        exit(EXIT_FAILURE);
    }

    printf("Scrivi qualcosa ('stop' per uscire)\n");
    while(strncmp("stop", buffer, 4) != 0) {
        fgets(buffer, DIM, stdin);
        ReleaseSemaphore(sem_t, 1, &dwSemCount);
    WaitForSingleObject(sem_t, INFINITE);
    }

    printf("\nAttenti la fine del thread...\n");
    if (WaitForSingleObject(a_thread, INFINITE) != WAIT_OBJECT_0) {
        perror("Riunione thread fallita");
        exit(EXIT_FAILURE);
    }

    GetExitCodeThread(a_thread, &thread_result);
    printf("\nThread riuniti\n");
    exit(EXIT_SUCCESS);
}