diff options
| -rw-r--r-- | src/cmdline.c | 67 |
1 files changed, 50 insertions, 17 deletions
diff --git a/src/cmdline.c b/src/cmdline.c index 7ee8c0c..6c70f33 100644 --- a/src/cmdline.c +++ b/src/cmdline.c @@ -4,6 +4,7 @@ #include <time.h> #include <errno.h> #include <string.h> +#include <unistd.h> #include <sys/ipc.h> #include <sys/sem.h> @@ -61,7 +62,7 @@ get_keys(void) line = NULL, len = 0; t(getline(&line, &len, stdin)); - t(key_sem = (key_t)atoll(line)); + t(key_shm = (key_t)atoll(line)); free(line); return 0; @@ -77,14 +78,16 @@ fail: static int create_semaphores(void) { - int id = -1, saved_errno; + int id = -1, rint, saved_errno; + double r; union semun values; values.array = NULL; /* Create semaphore array. */ for (;;) { - double r = (double)rand(); + rint = rand(); + r = (double)rint; r /= (double)RAND_MAX + 1; r *= (1 << (8 * sizeof(key_t) - 2)) - 1; key_sem = (key_t)r + 1; @@ -123,12 +126,14 @@ fail: static int create_shared_memory(void) { - int id = -1, saved_errno; + int id = -1, rint, saved_errno; + double r; struct shmid_ds _info; /* Create shared memory. */ for (;;) { - double r = (double)rand(); + rint = rand(); + r = (double)rint; r /= (double)RAND_MAX + 1; r *= (1 << (8 * sizeof(key_t) - 2)) - 1; key_shm = (key_t)r + 1; @@ -171,18 +176,18 @@ remove_shared_memory(void) static int -semaphore_op(int semaphore, int delta, int undo) +semaphore_op(unsigned short semaphore, short delta, int undo) { struct sembuf op; op.sem_op = delta; op.sem_num = semaphore; - op.sem_flg = undo * SEM_UNDO; + op.sem_flg = undo ? SEM_UNDO : 0; return semop(sem_id, &op, 1); } static int -write_semaphore(int semaphore, int value) +write_semaphore(unsigned short semaphore, int value) { union semun semval; semval.val = value; @@ -197,7 +202,7 @@ read_shared_memory(char *message) int id, saved_errno; void *address = NULL; - t(shmget(key_shm, MEMORY_SIZE, 0600)); + t(id = shmget(key_shm, MEMORY_SIZE, 0600)); address = shmat(id, NULL, SHM_RDONLY); if ((address == (void *)-1) || !address) goto fail; @@ -237,25 +242,39 @@ fail: } +static int +spawn(const char *command, const char *message) +{ + pid_t pid = fork(); + + if (pid) + return pid == -1 ? -1 : 0; + + setenv("arg", message, 1); + execlp("sh", "sh", "-c", command, NULL); + perror(argv0); + exit(1); +} + + int main(int argc, char *argv[]) { - const char *message = argc > 2 ? argv[2] : "default message"; char read_message[MEMORY_SIZE]; argv0 = *argv; - if (!strcmp(argv[1], "create")) { - srand(time(NULL)); + if ((argc == 2) && !strcmp(argv[1], "create")) { + srand((unsigned int)time(NULL)); t(create_semaphores()); t(create_shared_memory()); - } else if (!strcmp(argv[1], "remove")) { + } else if ((argc == 2) && !strcmp(argv[1], "remove")) { t(get_keys()); t(remove_semaphores()); t(remove_shared_memory()); - } else if (!strcmp(argv[1], "listen")) { + } else if ((argc == 3) && !strcmp(argv[1], "listen")) { t(get_keys()); t(open_semaphore()); t(release_semaphore(S, 1, 1)); @@ -263,7 +282,7 @@ main(int argc, char *argv[]) t(release_semaphore(Q, 1, 0)); t(zero_semaphore(Q)); t(read_shared_memory(read_message)); - printf("%s\n", read_message); + t(spawn(argv[2], read_message)); t(release_semaphore(W, 1, 1)); t(acquire_semaphore(S, 1, 1)); t(zero_semaphore(S)); @@ -271,12 +290,26 @@ main(int argc, char *argv[]) t(acquire_semaphore(W, 1, 1)); } - } else if (!strcmp(argv[1], "broadcast")) { + } else if ((argc == 3) && !strcmp(argv[1], "wait")) { + t(get_keys()); + t(open_semaphore()); + t(release_semaphore(S, 1, 1)); + t(release_semaphore(Q, 1, 0)); + t(zero_semaphore(Q)); + t(read_shared_memory(read_message)); + spawn(argv[2], read_message); + t(release_semaphore(W, 1, 1)); + t(acquire_semaphore(S, 1, 1)); + t(zero_semaphore(S)); + t(release_semaphore(S, 1, 1)); + t(acquire_semaphore(W, 1, 1)); + + } else if ((argc == 3) && !strcmp(argv[1], "broadcast")) { t(get_keys()); t(open_semaphore()); t(acquire_semaphore(X, 1, 1)); t(zero_semaphore(W)); - t(write_shared_memory(message)); + t(write_shared_memory(argv[2])); t(write_semaphore(Q, 0)); t(zero_semaphore(S)); t(release_semaphore(X, 1, 1)); |