| | |
| | | static Logger logger = LoggerFactory::getLogger(); |
| | | |
| | | int SemUtil::get(key_t key, unsigned int value) { |
| | | // printf("==================SemUtil::get===============================\n"); |
| | | int semid, perms; |
| | | |
| | | perms = S_IRUSR | S_IWUSR; |
| | |
| | | union semun arg; |
| | | struct sembuf sop; |
| | | |
| | | logger.info("%ld: created semaphore\n", (long)getpid()); |
| | | //logger.info("%ld: created semaphore\n", (long)getpid()); |
| | | |
| | | arg.val = 0; /* So initialize it to 0 */ |
| | | if (semctl(semid, 0, SETVAL, arg) == -1) |
| | | err_exit(errno, "semctl 1"); |
| | | logger.info("%ld: initialized semaphore\n", (long)getpid()); |
| | | //logger.info("%ld: initialized semaphore\n", (long)getpid()); |
| | | |
| | | /* Perform a "no-op" semaphore operation - changes sem_otime |
| | | so other processes can see we've initialized the set. */ |
| | |
| | | sop.sem_flg = 0; |
| | | if (semop(semid, &sop, 1) == -1) |
| | | err_exit(errno, "semop"); |
| | | logger.info("%ld: completed dummy semop()\n", (long)getpid()); |
| | | //logger.info("%ld: completed dummy semop()\n", (long)getpid()); |
| | | |
| | | } else { /* We didn't create the semaphore set */ |
| | | |
| | |
| | | if (semid == -1) |
| | | err_exit(errno, "semget 2"); |
| | | |
| | | logger.info("%ld: got semaphore key\n", (long)getpid()); |
| | | // logger.info("%ld: got semaphore key\n", (long)getpid()); |
| | | /* Wait until another process has called semop() */ |
| | | |
| | | arg.buf = &ds; |
| | | for (j = 0; j < MAX_TRIES; j++) { |
| | | logger.info("Try %d\n", j); |
| | | //logger.info("Try %d\n", j); |
| | | if (semctl(semid, 0, IPC_STAT, arg) == -1) |
| | | err_exit(errno, "semctl 2"); |
| | | |
| | |
| | | |
| | | /* Reserve semaphore - decrement it by 1 */ |
| | | int SemUtil::dec(int semId) { |
| | | // logger.debug("%d: SemUtil::dec\n", semId); |
| | | struct sembuf sops; |
| | | |
| | | sops.sem_num = 0; |
| | |
| | | return 0; |
| | | } |
| | | |
| | | int SemUtil::dec_timeout(int semId, struct timespec *timeout) { |
| | | int SemUtil::dec_timeout(const int semId, const struct timespec *timeout) { |
| | | struct sembuf sops; |
| | | |
| | | sops.sem_num = 0; |
| | |
| | | |
| | | while (semtimedop(semId, &sops, 1, timeout) == -1) |
| | | if (errno != EINTR) { |
| | | err_msg(errno, "SemUtil::dec_timeout"); |
| | | // err_msg(errno, "SemUtil::dec_timeout"); |
| | | return -1; |
| | | } |
| | | |