diff options
Diffstat (limited to '')
| -rw-r--r-- | src/semaphore.c | 223 |
1 files changed, 0 insertions, 223 deletions
diff --git a/src/semaphore.c b/src/semaphore.c deleted file mode 100644 index 8c9f099..0000000 --- a/src/semaphore.c +++ /dev/null @@ -1,223 +0,0 @@ -#include <stdlib.h> -#include <stdio.h> -#include <time.h> -#include <errno.h> -#include <string.h> - -#include <sys/ipc.h> -#include <sys/sem.h> - - -#ifdef _SEM_SEMUN_UNDEFINED -union semun { - int val; - struct semid_ds *buf; - unsigned short *array; -}; -#endif - - -#define P 0 -#define Q 1 -#define N 2 - -#define SEMAPHORES 3 - - -char *argv0; - - -static int -create_semaphores(void) -{ - key_t key; - int id = -1, saved_errno; - union semun values; - - values.array = NULL; - - /* Create semaphore array. */ - srand(time(NULL)); - for (;;) { - double r = (double)rand(); - r /= (double)RAND_MAX + 1; - r *= (1 << (8 * sizeof(key_t) - 2)) - 1; - key = (key_t)r + 1; - if (key == IPC_PRIVATE) - continue; - id = semget(key, SEMAPHORES, IPC_CREAT | IPC_EXCL | 0600); - if (id != -1) - break; - if ((errno != EEXIST) && (errno != EINTR)) - goto fail; - } - - /* Initialise the array. */ - values.array = calloc(SEMAPHORES, sizeof(unsigned short)); - if (values.array == NULL) - goto fail; - if (semctl(id, 0, SETALL, values.array) == -1) - goto fail; - free(values.array); - values.array = NULL; - - printf("key:%zi(x%zx), id:%i\n", (ssize_t)key, (size_t)key, id); - return 0; - -fail: - saved_errno = errno; - if ((id != -1) && (semctl(id, 0, IPC_RMID) == -1)) - perror(argv0); - free(values.array); - errno = saved_errno; - return -1; -} - - -static int -remove_semaphores(key_t key) -{ - int id = semget(key, SEMAPHORES, 0600); - - if (id == -1) - return -1; - - if (semctl(id, 0, IPC_RMID) == -1) - return -1; - - return 0; -} - - -static int -acquire_semaphore(key_t key, int semaphore, int delta) -{ - struct sembuf op; - int id; - - id = semget(key, SEMAPHORES, 0600); - if (id == -1) - return -1; - - op.sem_op = -delta; - op.sem_num = semaphore; - op.sem_flg = 0; - - return semop(id, &op, 1); -} - - -static int -release_semaphore(key_t key, int semaphore, int delta) -{ - struct sembuf op; - int id; - - id = semget(key, SEMAPHORES, 0600); - if (id == -1) - return -1; - - op.sem_op = delta; - op.sem_num = semaphore; - op.sem_flg = 0; - - return semop(id, &op, 1); -} - - -static int -zero_semaphore(key_t key, int semaphore) -{ - struct sembuf op; - int id; - - id = semget(key, SEMAPHORES, 0600); - if (id == -1) - return -1; - - op.sem_op = 0; - op.sem_num = semaphore; - op.sem_flg = 0; - - return semop(id, &op, 1); -} - - -static int -read_semaphore(key_t key, int semaphore, int *z, int *n, int *v) -{ - struct sembuf op; - int id, r; - - id = semget(key, SEMAPHORES, 0600); - if (id == -1) - return -1; - - if (r = semctl(id, semaphore, GETZCNT), r == -1) - return -1; - if (z) - *z = r; - - if (r = semctl(id, semaphore, GETNCNT), r == -1) - return -1; - if (n) - *n = r; - - if (r = semctl(id, semaphore, GETVAL), r == -1) - return -1; - if (v) - *v = r; - - return 0; -} - - -int -main(int argc, char *argv[]) -{ - int r = -1, saved_errno, value; - key_t key = argc > 2 ? (key_t)atoll(argv[2]) : 0; - - argv0 = *argv; - - if (!strcmp(argv[1], "create")) { - r = create_semaphores(); - } else if (!strcmp(argv[1], "remove")) { - r = remove_semaphores(key); - } else if (!strcmp(argv[1], "pick-up")) { - r = release_semaphore(key, N, 1); - } else if (!strcmp(argv[1], "hang-up")) { - r = acquire_semaphore(key, N, 1); - } else if (!strcmp(argv[1], "listen")) { - r = acquire_semaphore(key, Q, 1); - if (r) { - saved_errno = errno; - r = release_semaphore(key, P, 1); - if (r) - perror(argv0); - errno = saved_errno; - goto fail; - } - printf("read here\n"); - r = release_semaphore(key, P, 1); - } else if (!strcmp(argv[1], "speak")) { - printf("write here\n"); - r = read_semaphore(key, N, NULL, NULL, &value); - if (r) - goto fail; - r = release_semaphore(key, Q, value); - if (r) - goto fail; - r = acquire_semaphore(key, P, value); - } else - return 2; - - if (r) - goto fail; - return 0; - -fail: - perror(argv0); - return 1; -} - |