mmap_offset += subbuf_size;
}
}
-
return 0;
free_array:
* @subbuf_size: size of sub-buffers (> PAGE_SIZE, power of 2)
* @num_subbuf: number of sub-buffers (power of 2)
* @lttng_ust_shm_handle: shared memory handle
+ * @stream_fds: stream file descriptors.
*
* Returns channel pointer if successful, %NULL otherwise.
*
const char *name,
const struct lttng_ust_lib_ring_buffer_config *config,
size_t subbuf_size, size_t num_subbuf,
- struct lttng_ust_shm_handle *handle)
+ struct lttng_ust_shm_handle *handle,
+ const int *stream_fds)
{
struct channel *chan = caa_container_of(chanb, struct channel, backend);
unsigned int i;
return -EINVAL;
if (!num_subbuf || (num_subbuf & (num_subbuf - 1)))
return -EINVAL;
+ /*
+ * Overwrite mode buffers require at least 2 subbuffers per
+ * buffer.
+ */
+ if (config->mode == RING_BUFFER_OVERWRITE && num_subbuf < 2)
+ return -EINVAL;
ret = subbuffer_id_check_index(config, num_subbuf);
if (ret)
struct shm_object *shmobj;
shmobj = shm_object_table_alloc(handle->table, shmsize,
- SHM_OBJECT_SHM);
+ SHM_OBJECT_SHM, stream_fds[i]);
if (!shmobj)
goto end;
align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer));
struct lttng_ust_lib_ring_buffer *buf;
shmobj = shm_object_table_alloc(handle->table, shmsize,
- SHM_OBJECT_SHM);
+ SHM_OBJECT_SHM, stream_fds[0]);
if (!shmobj)
goto end;
align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer));
*
* Return the address where a given offset is located (for read).
* Should be used to get the current subbuffer header pointer. Given we know
- * it's never on a page boundary, it's safe to write directly to this address,
- * as long as the write is never bigger than a page size.
+ * it's never on a page boundary, it's safe to read/write directly
+ * from/to this address, as long as the read/write is never bigger than
+ * a page size.
*/
void *lib_ring_buffer_read_offset_address(struct lttng_ust_lib_ring_buffer_backend *bufb,
size_t offset,