4 * Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; only
9 * version 2.1 of the License.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
27 #include <sys/types.h>
28 #include <sys/stat.h> /* For mode constants */
29 #include <fcntl.h> /* For O_* constants */
34 #include <lttng/align.h>
46 * Ensure we have the required amount of space available by writing 0
47 * into the entire buffer. Not doing so can trigger SIGBUS when going
48 * beyond the available shm space.
51 int zero_file(int fd
, size_t len
)
59 pagelen
= sysconf(_SC_PAGESIZE
);
62 zeropage
= calloc(pagelen
, 1);
66 while (len
> written
) {
68 retlen
= write(fd
, zeropage
,
69 min_t(size_t, pagelen
, len
- written
));
70 } while (retlen
== -1UL && errno
== EINTR
);
83 struct shm_object_table
*shm_object_table_create(size_t max_nb_obj
)
85 struct shm_object_table
*table
;
87 table
= zmalloc(sizeof(struct shm_object_table
) +
88 max_nb_obj
* sizeof(table
->objects
[0]));
91 table
->size
= max_nb_obj
;
96 struct shm_object
*_shm_object_table_alloc_shm(struct shm_object_table
*table
,
97 size_t memory_map_size
,
100 int shmfd
, waitfd
[2], ret
, i
;
101 struct shm_object
*obj
;
106 if (table
->allocated_len
>= table
->size
)
108 obj
= &table
->objects
[table
->allocated_len
];
110 /* wait_fd: create pipe */
111 ret
= pipe2(waitfd
, O_CLOEXEC
);
116 /* The write end of the pipe needs to be non-blocking */
117 ret
= fcntl(waitfd
[1], F_SETFL
, O_NONBLOCK
);
122 memcpy(obj
->wait_fd
, waitfd
, sizeof(waitfd
));
127 ret
= zero_file(shmfd
, memory_map_size
);
130 goto error_zero_file
;
132 ret
= ftruncate(shmfd
, memory_map_size
);
135 goto error_ftruncate
;
138 * Also ensure the file metadata is synced with the storage by using
146 obj
->shm_fd_ownership
= 0;
149 /* memory_map: mmap */
150 memory_map
= mmap(NULL
, memory_map_size
, PROT_READ
| PROT_WRITE
,
151 MAP_SHARED
| LTTNG_MAP_POPULATE
, shmfd
, 0);
152 if (memory_map
== MAP_FAILED
) {
156 obj
->type
= SHM_OBJECT_SHM
;
157 obj
->memory_map
= memory_map
;
158 obj
->memory_map_size
= memory_map_size
;
159 obj
->allocated_len
= 0;
160 obj
->index
= table
->allocated_len
++;
169 for (i
= 0; i
< 2; i
++) {
170 ret
= close(waitfd
[i
]);
181 struct shm_object
*_shm_object_table_alloc_mem(struct shm_object_table
*table
,
182 size_t memory_map_size
)
184 struct shm_object
*obj
;
186 int waitfd
[2], i
, ret
;
188 if (table
->allocated_len
>= table
->size
)
190 obj
= &table
->objects
[table
->allocated_len
];
192 memory_map
= zmalloc(memory_map_size
);
196 /* wait_fd: create pipe */
197 ret
= pipe2(waitfd
, O_CLOEXEC
);
202 /* The write end of the pipe needs to be non-blocking */
203 ret
= fcntl(waitfd
[1], F_SETFL
, O_NONBLOCK
);
208 memcpy(obj
->wait_fd
, waitfd
, sizeof(waitfd
));
212 obj
->shm_fd_ownership
= 0;
214 obj
->type
= SHM_OBJECT_MEM
;
215 obj
->memory_map
= memory_map
;
216 obj
->memory_map_size
= memory_map_size
;
217 obj
->allocated_len
= 0;
218 obj
->index
= table
->allocated_len
++;
223 for (i
= 0; i
< 2; i
++) {
224 ret
= close(waitfd
[i
]);
237 * libnuma prints errors on the console even for numa_available().
238 * Work-around this limitation by using get_mempolicy() directly to
239 * check whether the kernel supports mempolicy.
242 static bool lttng_is_numa_available(void)
246 ret
= get_mempolicy(NULL
, NULL
, 0, NULL
, 0);
247 if (ret
&& errno
== ENOSYS
) {
250 return numa_available() > 0;
254 struct shm_object
*shm_object_table_alloc(struct shm_object_table
*table
,
255 size_t memory_map_size
,
256 enum shm_object_type type
,
260 struct shm_object
*shm_object
;
262 int oldnode
= 0, node
;
265 numa_avail
= lttng_is_numa_available();
267 oldnode
= numa_preferred();
269 node
= numa_node_of_cpu(cpu
);
271 numa_set_preferred(node
);
273 if (cpu
< 0 || node
< 0)
274 numa_set_localalloc();
276 #endif /* HAVE_LIBNUMA */
279 shm_object
= _shm_object_table_alloc_shm(table
, memory_map_size
,
283 shm_object
= _shm_object_table_alloc_mem(table
, memory_map_size
);
290 numa_set_preferred(oldnode
);
291 #endif /* HAVE_LIBNUMA */
295 struct shm_object
*shm_object_table_append_shm(struct shm_object_table
*table
,
296 int shm_fd
, int wakeup_fd
, uint32_t stream_nr
,
297 size_t memory_map_size
)
299 struct shm_object
*obj
;
303 if (table
->allocated_len
>= table
->size
)
305 /* streams _must_ be received in sequential order, else fail. */
306 if (stream_nr
+ 1 != table
->allocated_len
)
309 obj
= &table
->objects
[table
->allocated_len
];
311 /* wait_fd: set write end of the pipe. */
312 obj
->wait_fd
[0] = -1; /* read end is unset */
313 obj
->wait_fd
[1] = wakeup_fd
;
314 obj
->shm_fd
= shm_fd
;
315 obj
->shm_fd_ownership
= 1;
317 /* The write end of the pipe needs to be non-blocking */
318 ret
= fcntl(obj
->wait_fd
[1], F_SETFL
, O_NONBLOCK
);
324 /* memory_map: mmap */
325 memory_map
= mmap(NULL
, memory_map_size
, PROT_READ
| PROT_WRITE
,
326 MAP_SHARED
| LTTNG_MAP_POPULATE
, shm_fd
, 0);
327 if (memory_map
== MAP_FAILED
) {
331 obj
->type
= SHM_OBJECT_SHM
;
332 obj
->memory_map
= memory_map
;
333 obj
->memory_map_size
= memory_map_size
;
334 obj
->allocated_len
= memory_map_size
;
335 obj
->index
= table
->allocated_len
++;
345 * Passing ownership of mem to object.
347 struct shm_object
*shm_object_table_append_mem(struct shm_object_table
*table
,
348 void *mem
, size_t memory_map_size
, int wakeup_fd
)
350 struct shm_object
*obj
;
353 if (table
->allocated_len
>= table
->size
)
355 obj
= &table
->objects
[table
->allocated_len
];
357 obj
->wait_fd
[0] = -1; /* read end is unset */
358 obj
->wait_fd
[1] = wakeup_fd
;
360 obj
->shm_fd_ownership
= 0;
362 /* The write end of the pipe needs to be non-blocking */
363 ret
= fcntl(obj
->wait_fd
[1], F_SETFL
, O_NONBLOCK
);
369 obj
->type
= SHM_OBJECT_MEM
;
370 obj
->memory_map
= mem
;
371 obj
->memory_map_size
= memory_map_size
;
372 obj
->allocated_len
= memory_map_size
;
373 obj
->index
= table
->allocated_len
++;
382 void shmp_object_destroy(struct shm_object
*obj
, int consumer
)
389 ret
= munmap(obj
->memory_map
, obj
->memory_map_size
);
395 if (obj
->shm_fd_ownership
) {
396 /* Delete FDs only if called from app (not consumer). */
398 lttng_ust_lock_fd_tracker();
399 ret
= close(obj
->shm_fd
);
401 lttng_ust_delete_fd_from_tracker(obj
->shm_fd
);
406 lttng_ust_unlock_fd_tracker();
408 ret
= close(obj
->shm_fd
);
415 for (i
= 0; i
< 2; i
++) {
416 if (obj
->wait_fd
[i
] < 0)
419 lttng_ust_lock_fd_tracker();
420 ret
= close(obj
->wait_fd
[i
]);
422 lttng_ust_delete_fd_from_tracker(obj
->wait_fd
[i
]);
427 lttng_ust_unlock_fd_tracker();
429 ret
= close(obj
->wait_fd
[i
]);
442 for (i
= 0; i
< 2; i
++) {
443 if (obj
->wait_fd
[i
] < 0)
446 lttng_ust_lock_fd_tracker();
447 ret
= close(obj
->wait_fd
[i
]);
449 lttng_ust_delete_fd_from_tracker(obj
->wait_fd
[i
]);
454 lttng_ust_unlock_fd_tracker();
456 ret
= close(obj
->wait_fd
[i
]);
463 free(obj
->memory_map
);
471 void shm_object_table_destroy(struct shm_object_table
*table
, int consumer
)
475 for (i
= 0; i
< table
->allocated_len
; i
++)
476 shmp_object_destroy(&table
->objects
[i
], consumer
);
481 * zalloc_shm - allocate memory within a shm object.
483 * Shared memory is already zeroed by shmget.
484 * *NOT* multithread-safe (should be protected by mutex).
485 * Returns a -1, -1 tuple on error.
487 struct shm_ref
zalloc_shm(struct shm_object
*obj
, size_t len
)
490 struct shm_ref shm_ref_error
= { -1, -1 };
492 if (obj
->memory_map_size
- obj
->allocated_len
< len
)
493 return shm_ref_error
;
494 ref
.index
= obj
->index
;
495 ref
.offset
= obj
->allocated_len
;
496 obj
->allocated_len
+= len
;
500 void align_shm(struct shm_object
*obj
, size_t align
)
502 size_t offset_len
= offset_align(obj
->allocated_len
, align
);
503 obj
->allocated_len
+= offset_len
;
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