/*
* ring_buffer_backend.c
*
- * Copyright (C) 2005-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
- * Dual LGPL v2.1/GPL v2 license.
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; only
+ * version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#define _GNU_SOURCE
#include <urcu/arch.h>
-
-#include "lttng/core.h"
+#include <limits.h>
#include <lttng/ringbuffer-config.h>
+#include "vatomic.h"
#include "backend.h"
#include "frontend.h"
#include "smp.h"
handle, shmobj);
}
-void lib_ring_buffer_backend_free(struct lttng_ust_lib_ring_buffer_backend *bufb)
-{
- /* bufb->buf_wsb will be freed by shm teardown */
- /* bufb->array[i] will be freed by shm teardown */
- /* bufb->array will be freed by shm teardown */
- bufb->allocated = 0;
-}
-
void lib_ring_buffer_backend_reset(struct lttng_ust_lib_ring_buffer_backend *bufb,
struct lttng_ust_shm_handle *handle)
{
if (!name)
return -EPERM;
- if (!(subbuf_size && num_subbuf))
- return -EPERM;
-
/* Check that the subbuffer size is larger than a page. */
if (subbuf_size < PAGE_SIZE)
return -EINVAL;
/*
- * Make sure the number of subbuffers and subbuffer size are power of 2.
+ * Make sure the number of subbuffers and subbuffer size are
+ * power of 2, and nonzero.
*/
- CHAN_WARN_ON(chanb, hweight32(subbuf_size) != 1);
- CHAN_WARN_ON(chanb, hweight32(num_subbuf) != 1);
+ if (!subbuf_size || (subbuf_size & (subbuf_size - 1)))
+ return -EINVAL;
+ if (!num_subbuf || (num_subbuf & (num_subbuf - 1)))
+ return -EINVAL;
ret = subbuffer_id_check_index(config, num_subbuf);
if (ret)
for_each_possible_cpu(i) {
struct shm_object *shmobj;
- shmobj = shm_object_table_append(handle->table, shmsize);
+ shmobj = shm_object_table_alloc(handle->table, shmsize,
+ SHM_OBJECT_SHM);
if (!shmobj)
goto end;
align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer));
struct shm_object *shmobj;
struct lttng_ust_lib_ring_buffer *buf;
- shmobj = shm_object_table_append(handle->table, shmsize);
+ shmobj = shm_object_table_alloc(handle->table, shmsize,
+ SHM_OBJECT_SHM);
if (!shmobj)
goto end;
align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer));
buf = shmp(handle, chanb->buf[0].shmp);
if (!buf)
goto end;
+ set_shmp(buf->self, chanb->buf[0].shmp._ref);
ret = lib_ring_buffer_create(buf, chanb, -1,
handle, shmobj);
if (ret)
return 0;
free_bufs:
- if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
- for_each_possible_cpu(i) {
- struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chanb->buf[i].shmp);
-
- if (!buf->backend.allocated)
- continue;
- lib_ring_buffer_free(buf, handle);
- }
- }
/* We only free the buffer data upon shm teardown */
end:
return -ENOMEM;
void channel_backend_free(struct channel_backend *chanb,
struct lttng_ust_shm_handle *handle)
{
- const struct lttng_ust_lib_ring_buffer_config *config = &chanb->config;
- unsigned int i;
-
- if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
- for_each_possible_cpu(i) {
- struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chanb->buf[i].shmp);
-
- if (!buf->backend.allocated)
- continue;
- lib_ring_buffer_free(buf, handle);
- }
- } else {
- struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chanb->buf[0].shmp);
-
- CHAN_WARN_ON(chanb, !buf->backend.allocated);
- lib_ring_buffer_free(buf, handle);
- }
- /* We only free the buffer data upon shm teardown */
+ /* SHM teardown takes care of everything */
}
/**
* @dest : destination address
* @len : destination's length
*
- * return string's length
+ * Return string's length, or -EINVAL on error.
* Should be protected by get_subbuf/put_subbuf.
+ * Destination length should be at least 1 to hold '\0'.
*/
int lib_ring_buffer_read_cstr(struct lttng_ust_lib_ring_buffer_backend *bufb, size_t offset,
void *dest, size_t len, struct lttng_ust_shm_handle *handle)
struct lttng_ust_lib_ring_buffer_backend_pages_shmp *rpages;
unsigned long sb_bindex, id;
+ if (caa_unlikely(!len))
+ return -EINVAL;
offset &= chanb->buf_size - 1;
orig_offset = offset;
id = bufb->buf_rsb.id;
*
* 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,
projects / lttng-ust.git / blobdiff