7 #define MAX_SEMOP_RETRIES 500
11 int ret = semget(IPC_PRIVATE, 1, IPC_CREAT | 0666);
12 return ret < 0? -E_SEM_GET : ret;
15 int mutex_destroy(int id)
17 int ret = semctl(id, 0, IPC_RMID);
18 return ret < 0? -E_SEM_REMOVE : 1;
21 static void para_semop(int id, struct sembuf *sops, int num)
25 for (i = 0; i < MAX_SEMOP_RETRIES; i++)
26 if (semop(id, sops, num) >= 0)
28 PARA_EMERG_LOG("semop failed %d times, aborting\n", MAX_SEMOP_RETRIES);
33 * lock the given mutex
35 * \sa semop(2), struct misc_meta_data
37 void mutex_lock(int id)
39 struct sembuf sops[2] = {
51 para_semop(id, sops, 2);
57 * \sa semop(2), struct misc_meta_data
59 void mutex_unlock(int id)
61 struct sembuf sops[1] = {
68 para_semop(id, sops, 1);
72 * create a new shared memory area of given size
76 int shm_new(size_t size)
78 int ret = shmget(IPC_PRIVATE, size, IPC_CREAT | IPC_EXCL | 0600);
79 return ret < 0 ? -E_SHM_GET : ret;
83 * destroy the given shared memory area
86 int shm_destroy(int id)
88 struct shmid_ds shm_desc;
89 int ret = shmctl(id, IPC_RMID, &shm_desc);
90 return ret < 0? -E_SHM_DESTROY : ret;
94 * attach a shared memory area
98 int shm_attach(int id, enum shm_attach_mode mode, void **result)
100 if (mode == ATTACH_RW) {
101 *result = shmat(id, NULL, 0);
102 return *result? 1 : -E_SHM_ATTACH;
104 *result = shmat(id, NULL, SHM_RDONLY);
105 return *result? 1 : -E_SHM_ATTACH;
108 int shm_detach(void *addr)
110 int ret = shmdt(addr);
111 return ret < 0? -E_SHM_DETACH : 1;