008c5c415f3d8d9c383fdcaa3620cb36a06bc46d
1 #ifndef _LIBRINGBUFFER_SHM_H
2 #define _LIBRINGBUFFER_SHM_H
7 * Copyright 2011 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
9 * Dual LGPL v2.1/GPL v2 license.
13 #include <ust/usterr-signal-safe.h>
15 #include "shm_types.h"
17 #define SHM_MAGIC 0x54335433
22 * Pointer dereferencing. We don't trust the shm_ref, so we validate
23 * both the index and offset with known boundaries.
26 char *_shmp(struct shm_object_table
*table
, struct shm_ref
*ref
)
28 struct shm_object
*obj
;
31 index
= (size_t) ref
->index
;
32 if (unlikely(index
>= table
->allocated_len
))
34 obj
= &table
->objects
[index
];
35 offset
= (size_t) ref
->offset
;
36 if (unlikely(offset
>= obj
->memory_map_size
))
38 return &obj
->memory_map
[offset
];
41 #define shmp(handle, ref) \
43 __typeof__((ref)._type) ____ptr_ret; \
44 ____ptr_ret = (__typeof__(____ptr_ret)) _shmp((handle)->table, &(ref)._ref); \
49 void _set_shmp(struct shm_ref
*ref
, struct shm_ref src
)
54 #define set_shmp(ref, src) _set_shmp(&(ref)._ref, src)
56 struct shm_object_table
*shm_object_table_create(size_t max_nb_obj
);
57 void shm_object_table_destroy(struct shm_object_table
*table
);
58 struct shm_object
*shm_object_table_append(struct shm_object_table
*table
,
59 size_t memory_map_size
);
62 * zalloc_shm - allocate memory within a shm object.
64 * Shared memory is already zeroed by shmget.
65 * *NOT* multithread-safe (should be protected by mutex).
66 * Returns a -1, -1 tuple on error.
68 struct shm_ref
zalloc_shm(struct shm_object
*obj
, size_t len
);
69 void align_shm(struct shm_object
*obj
, size_t align
);
72 int shm_get_wakeup_fd(struct shm_handle
*handle
, struct shm_ref
*ref
)
74 struct shm_object_table
*table
= handle
->table
;
75 struct shm_object
*obj
;
78 index
= (size_t) ref
->index
;
79 if (unlikely(index
>= table
->allocated_len
))
81 obj
= &table
->objects
[index
];
82 return obj
->wait_fd
[1];
87 int shm_get_wait_fd(struct shm_handle
*handle
, struct shm_ref
*ref
)
89 struct shm_object_table
*table
= handle
->table
;
90 struct shm_object
*obj
;
93 index
= (size_t) ref
->index
;
94 if (unlikely(index
>= table
->allocated_len
))
96 obj
= &table
->objects
[index
];
97 return obj
->wait_fd
[0];
100 #endif /* _LIBRINGBUFFER_SHM_H */
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