static int readQueueLengthFromFifo(void)
{
int queue_length = 0;
int fifo_fd = open(FIFO_NAME, O_RDWR);
if(fifo_fd < 0)
{
deleteFifo();
// No checking needed, exits with error code.
write(STDERR_FILENO, OPEN_ERROR, sizeof(OPEN_ERROR));
exit(EXIT_ERROR_CODE);
}
// Read the queue length.
if(read(fifo_fd, (void*)&queue_length, sizeof(queue_length)) != sizeof(queue_length))
{
deleteFifo();
// No checking needed, exits with error code.
write(STDERR_FILENO, READ_ERROR, sizeof(READ_ERROR));
exit(EXIT_ERROR_CODE);
}
// Close FIFO.
if(close(fifo_fd) < 0)
{
deleteFifo();
// No checking needed, exits with error code.
write(STDERR_FILENO, CLOSE_ERROR, sizeof(CLOSE_ERROR));
exit(EXIT_ERROR_CODE);
}
return queue_length;
}
static int createBinarySemaphore(key_t sem_key, int shm_id)
{
union semun sem_conf;
int sem_id = semget(sem_key, NUM_OF_SEMAPHORES, IPC_CREAT|ALLOW_READ_WRITE_TO_ALL);
if(sem_id < 0)
{
deleteFifo();
deleteSharedMemory(shm_id);
// No checking needed, exits with error code.
write(STDERR_FILENO, SEMGET_ERROR, sizeof(SEMGET_ERROR));
exit(EXIT_ERROR_CODE);
}
sem_conf.val = SEM_INIT;
if(semctl(sem_id, 0, SETVAL, sem_conf) < 0)
{
deleteFifo();
deleteResources(shm_id, sem_id);
// No checking needed, exits with error code.
write(STDERR_FILENO, SEMCTL_ERROR, sizeof(SEMCTL_ERROR));
exit(EXIT_ERROR_CODE);
}
return sem_id;
}
char *createSharedMemory(key_t key, int *shm_id)
{
char *p_shm_data = NULL;
// Create shared memory
*shm_id = shmget(key, SHM_SIZE_IN_BYTES, IPC_CREAT|ALLOW_READ_WRITE_TO_ALL);
if(*shm_id < 0)
{
deleteFifo();
// No checking needed, exits with error code.
write(STDERR_FILENO, SHMGET_ERROR, sizeof(SHMGET_ERROR));
exit(EXIT_ERROR_CODE);
}
// Connect to the shared memory.
p_shm_data = (char *)shmat(*shm_id, 0, 0);
if(SHMAT_FAILED == p_shm_data)
{
deleteFifo();
deleteSharedMemory(*shm_id);
// No checking needed, exits with error code.
write(STDERR_FILENO, SHMAT_ERROR, sizeof(SHMAT_ERROR));
exit(EXIT_ERROR_CODE);
}
return p_shm_data;
}
int devClose(myDev * dev)
{
fifo * i = NULL;
fifo * temp = NULL;
if(dev==NULL)
{
errnoSet(NOT_OPEN);
return -1;
}
//Prevent anyone from accessing this device while we're modifying it :
if(semTake(dev->semMData,WAIT_FOREVER)==-1)
{
errnoSet(SEM_ERR);
return -1;
}
if (dev->openned == 0)
{
errnoSet(NOT_OPEN);
return -1;
} else {
//Find fifo corresponding to this task in drv->listFifo and deallocate it
if (dev->firstFifo->taskId==taskIdSelf())
{
temp=dev->firstFifo;
dev->firstFifo=temp->nextFifo;
deleteFifo(temp);
free(temp);
} else {
for (i=dev->firstFifo;i->nextFifo->taskId==taskIdSelf();i=i->nextFifo);
temp=i->nextFifo;
i->nextFifo=temp->nextFifo;
deleteFifo(temp);
free(temp);
}
dev->openned--;
}
semGive(dev->semMData);
return 0;
}
static void writePidToFifo(void)
{
pid_t my_pid = 0;
int fifo_fd = 0;
// Get self PID.
my_pid = getpid();
// Open FIFO.
fifo_fd = open(FIFO_NAME, O_WRONLY);
if(fifo_fd < 0)
{
deleteFifo();
// No checking needed, exits with error code.
write(STDERR_FILENO, OPEN_ERROR, sizeof(OPEN_ERROR));
exit(EXIT_ERROR_CODE);
}
// Write process PID to FIFO.
if(write(fifo_fd, (void*)&my_pid, sizeof(my_pid)) != sizeof(my_pid))
{
deleteFifo();
// No checking needed, exits with error code.
write(STDERR_FILENO, WRITE_ERROR, sizeof(WRITE_ERROR));
exit(EXIT_ERROR_CODE);
}
// Close FIFO.
if(close(fifo_fd) < 0)
{
deleteFifo();
// No checking needed, exits with error code.
write(STDERR_FILENO, CLOSE_ERROR, sizeof(CLOSE_ERROR));
exit(EXIT_ERROR_CODE);
}
}
int main(int argc, char *argv[])
{
const unsigned int EXPECTED_ARGC = 2;
const unsigned int KEY_FILE_ARG_INDEX = 1;
const unsigned char KEY_CHAR = 'H';
const char ENDLINE[] = "\n";
const char SEPERATOR[] = ",";
key_t key = 0;
char *shm_addr = NULL;
int csv_fd = 0, queue_length = 0, shm_id = 0, sem_id = 0;
int job_number = 0, rel_prio = 0, real_prio = 0;
initSigactions();
// Initialize the rand() seed.
srand(time(NULL));
if(argc != EXPECTED_ARGC)
{
// No checking needed, exits with error code.
write(STDERR_FILENO, NOF_INPUTS_ERROR, sizeof(NOF_INPUTS_ERROR));
exit(EXIT_ERROR_CODE);
}
// Create fifo.
if(mkfifo(FIFO_NAME, ALLOW_READ_WRITE_TO_ALL) < 0)
{
// No checking needed, exits with error code.
write(STDERR_FILENO, MKFIFO_ERROR, sizeof(MKFIFO_ERROR));
exit(EXIT_ERROR_CODE);
}
writePidToFifo();
// Wait for the queue process' singal.
waitForSignal();
printf("got signal from %d!\n", Queue_Pid);
// Generate key from the given file
key = ftok(argv[KEY_FILE_ARG_INDEX], KEY_CHAR);
if(key < 0)
{
deleteFifo();
// No checking needed, exits with error code.
write(STDERR_FILENO, FTOK_ERROR, sizeof(FTOK_ERROR));
exit(EXIT_ERROR_CODE);
}
// Create shared memory.
shm_addr = createSharedMemory(key, &shm_id);
// Create semaphore.
sem_id = createBinarySemaphore(key, shm_id);
// Notify the queue.out process.
if(kill(Queue_Pid, SIGUSR1) < 0)
{
deleteFifo();
// No checking needed, exits with error code.
write(STDERR_FILENO, KILL_ERROR, sizeof(KILL_ERROR) - 1);
exit(EXIT_ERROR_CODE);
}
queue_length = readQueueLengthFromFifo();
printf("Got N: %d\n", queue_length);
// Done using the fifo - delete it.
deleteFifo();
// Game Started!
handleGame(shm_id, shm_addr, sem_id, queue_length, &job_number, \
&rel_prio, &real_prio);
deleteResources(shm_id, sem_id);
// Write results
csv_fd = open(CSV_FILE_PATH, O_CREAT | O_APPEND | O_RDWR, ALLOW_READ_WRITE_TO_ALL);
if(csv_fd < 0)
{
// No checking needed, exits with error code.
write(STDERR_FILENO, OPEN_ERROR, sizeof(OPEN_ERROR) - 1);
exit(EXIT_ERROR_CODE);
}
writeIntWithEnding(csv_fd, queue_length, SEPERATOR);
writeIntWithEnding(csv_fd, job_number, SEPERATOR);
writeIntWithEnding(csv_fd, rel_prio, SEPERATOR);
writeIntWithEnding(csv_fd, real_prio, ENDLINE);
return EXIT_OK_CODE;
}