973a9eaf4ffee1e69eb5a5e5460f7060f654b433
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;