diff options
Diffstat (limited to '')
| -rw-r--r-- | src/cmdline.c | 342 | ||||
| -rw-r--r-- | src/semaphore.c | 223 |
2 files changed, 342 insertions, 223 deletions
diff --git a/src/cmdline.c b/src/cmdline.c new file mode 100644 index 0000000..8974d5b --- /dev/null +++ b/src/cmdline.c @@ -0,0 +1,342 @@ +#include <stdlib.h> +#include <stdio.h> +#include <time.h> +#include <errno.h> +#include <string.h> + +#include <sys/ipc.h> +#include <sys/sem.h> +#include <sys/shm.h> + + + +#ifdef _SEM_SEMUN_UNDEFINED +union semun { + int val; + struct semid_ds *buf; + unsigned short *array; +}; +#endif + + +#define S 0 +#define P 0 +#define Q 1 + +#define SEMAPHORES 2 +#define MEMORY_SIZE (2 * 1024) + + +char *argv0; + + +static int +create_semaphores(void) +{ + key_t key; + int id = -1, saved_errno; + union semun values; + + values.array = NULL; + + /* Create semaphore array. */ + 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) + 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 +create_shared_memory(void) +{ + key_t key; + int id = -1, saved_errno; + struct shmid_ds _info; + + 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 = shmget(key, MEMORY_SIZE, IPC_CREAT | IPC_EXCL | 0600); + if (id != -1) + break; + if ((errno != EEXIST) && (errno != EINTR)) + goto fail; + } + + printf("key:%zi(x%zx), id:%i\n", (ssize_t)key, (size_t)key, id); + return 0; + +fail: + saved_errno = errno; + if ((id != -1) && (shmctl(id, IPC_RMID, &_info) == -1)) + perror(argv0); + 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 +remove_shared_memory(key_t key) +{ + int id = shmget(key, MEMORY_SIZE, 0600); + struct shmid_ds _info; + + if (id == -1) + return -1; + + if (shmctl(id, IPC_RMID, &_info) == -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; +} + + +static int +write_shared_memory(key_t key, const char *message) +{ + int id, saved_errno; + void *address = NULL; + + id = shmget(key, MEMORY_SIZE, 0600); + if (id == -1) + goto fail; + + address = shmat(id, NULL, 0); + if ((address == (void *)-1) || !address) + goto fail; + + memcpy(address, message, (strlen(message) + 1) * sizeof(char)); + + if (shmdt(address) == -1) + goto fail; + + return 0; + +fail: + saved_errno = errno; + if (address && (shmdt(address) == -1)) + perror(argv0); + errno = saved_errno; + return -1; +} + + +static int +read_shared_memory(key_t key, char *message) +{ + int id, saved_errno; + void *address = NULL; + + id = shmget(key, MEMORY_SIZE, 0600); + if (id == -1) + goto fail; + + address = shmat(id, NULL, SHM_RDONLY); + if ((address == (void *)-1) || !address) + goto fail; + + strncpy(message, address, MEMORY_SIZE); + + if (shmdt(address) == -1) + goto fail; + + return 0; + +fail: + saved_errno = errno; + if (address && (shmdt(address) == -1)) + perror(argv0); + errno = saved_errno; + return -1; +} + + +#define t(inst) if (r = inst, r) goto fail + + +int +main(int argc, char *argv[]) +{ + int r = -1, saved_errno, value; + key_t key_sem = argc > 2 ? (key_t)atoll(argv[2]) : 0; + key_t key_shm = argc > 3 ? (key_t)atoll(argv[3]) : 0; + const char *message = argc > 4 ? argv[4] : "default message"; + char read_message[MEMORY_SIZE]; + + argv0 = *argv; + + if (!strcmp(argv[1], "create")) { + srand(time(NULL)); + t(create_semaphores()); + t(create_shared_memory()); + + } else if (!strcmp(argv[1], "remove")) { + t(remove_semaphores(key_sem)); + t(remove_shared_memory(key_sem)); + + } else if (!strcmp(argv[1], "listen")) { /* TODO must support cancellation */ + t(release_semaphore(key_sem, S, 1)); + for (;;) { + t(zero_semaphore(key_sem, S)); + t(read_shared_memory(key_shm, read_message)); + printf("%s\n", read_message); + t(release_semaphore(key_sem, Q, 1)); + t(zero_semaphore(key_sem, Q)); + t(release_semaphore(key_sem, S, 1)); + t(release_semaphore(key_sem, P, 1)); + } + + } else if (!strcmp(argv[1], "broadcast")) { + t(read_semaphore(key_sem, S, &value, NULL, NULL)); + if (value) { + t(write_shared_memory(key_shm, message)); + t(acquire_semaphore(key_sem, S, value)); + t(acquire_semaphore(key_sem, Q, value)); + t(acquire_semaphore(key_sem, P, value)); + } + + } else + return 2; + + return 0; + +fail: + perror(argv0); + return 1; +} + + +#undef t + 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; -} - |