void lib_ring_buffer_backend_reset(struct lttng_ust_lib_ring_buffer_backend *bufb,
struct lttng_ust_shm_handle *handle)
{
struct channel_backend *chanb;
const struct lttng_ust_lib_ring_buffer_config *config;
unsigned long num_subbuf_alloc;
unsigned int i;
chanb = &shmp(handle, bufb->chan)->backend;
if (!chanb)
abort();
config = &chanb->config;
num_subbuf_alloc = chanb->num_subbuf;
if (chanb->extra_reader_sb)
num_subbuf_alloc++;
for (i = 0; i < chanb->num_subbuf; i++) {
struct lttng_ust_lib_ring_buffer_backend_subbuffer *sb;
sb = shmp_index(handle, bufb->buf_wsb, i);
if (!sb)
abort();
sb->id = subbuffer_id(config, 0, 1, i);
}
if (chanb->extra_reader_sb)
bufb->buf_rsb.id = subbuffer_id(config, 0, 1,
num_subbuf_alloc - 1);
else
bufb->buf_rsb.id = subbuffer_id(config, 0, 1, 0);
for (i = 0; i < num_subbuf_alloc; i++) {
struct lttng_ust_lib_ring_buffer_backend_pages_shmp *sbp;
struct lttng_ust_lib_ring_buffer_backend_pages *pages;
sbp = shmp_index(handle, bufb->array, i);
if (!sbp)
abort();
pages = shmp(handle, sbp->shmp);
if (!pages)
abort();
/* Don't reset mmap_offset */
v_set(config, &pages->records_commit, 0);
v_set(config, &pages->records_unread, 0);
pages->data_size = 0;
/* Don't reset backend page and virt addresses */
}
/* Don't reset num_pages_per_subbuf, cpu, allocated */
v_set(config, &bufb->records_read, 0);
}
void *ustctl_get_mmap_base(struct lttng_ust_shm_handle *handle,
struct lttng_ust_lib_ring_buffer *buf)
{
if (!handle || !buf)
return NULL;
return shmp(handle, buf->backend.memory_map);
}
void ustctl_unmap_channel(struct lttng_ust_shm_handle *handle)
{
struct channel *chan;
assert(handle);
chan = shmp(handle, handle->chan);
channel_destroy(chan, handle, 1);
}
static
void unmap_channel(struct lttng_ust_shm_handle *handle)
{
struct channel *chan;
chan = shmp(handle, handle->chan);
/* unmap channel */
channel_destroy(chan, handle, 1);
}
void *ustctl_get_mmap_base(struct ustctl_consumer_stream *stream)
{
struct lttng_ust_lib_ring_buffer *buf;
struct ustctl_consumer_channel *consumer_chan;
if (!stream)
return NULL;
buf = stream->buf;
consumer_chan = stream->chan;
return shmp(consumer_chan->chan->handle, buf->backend.memory_map);
}
/* returns the offset of the subbuffer belonging to the mmap reader. */
int ustctl_get_mmap_read_offset(struct lttng_ust_shm_handle *handle,
struct lttng_ust_lib_ring_buffer *buf, unsigned long *off)
{
struct channel *chan = handle->shadow_chan;
unsigned long sb_bindex;
if (!handle || !buf || !off)
return -EINVAL;
if (chan->backend.config.output != RING_BUFFER_MMAP)
return -EINVAL;
sb_bindex = subbuffer_id_get_index(&chan->backend.config,
buf->backend.buf_rsb.id);
*off = shmp(handle, shmp_index(handle, buf->backend.array, sb_bindex)->shmp)->mmap_offset;
return 0;
}
static
struct lttng_ust_client_lib_ring_buffer_client_cb *get_client_cb(
struct lttng_ust_lib_ring_buffer *buf,
struct lttng_ust_shm_handle *handle)
{
struct channel *chan;
const struct lttng_ust_lib_ring_buffer_config *config;
struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
chan = shmp(handle, buf->backend.chan);
config = &chan->backend.config;
if (!config->cb_ptr)
return NULL;
client_cb = caa_container_of(config->cb_ptr,
struct lttng_ust_client_lib_ring_buffer_client_cb,
parent);
return client_cb;
}
static
struct lttng_ust_shm_handle *map_channel(struct lttng_ust_object_data *chan_data,
struct lttng_ust_object_data *stream_datas, int nr_check)
{
struct lttng_ust_shm_handle *handle;
struct channel *chan;
int k, ret;
/* map metadata channel */
handle = channel_handle_create(chan_data->shm_fd,
chan_data->wait_fd,
chan_data->memory_map_size);
if (!handle) {
printf("create handle error\n");
return NULL;
}
chan_data->shm_fd = -1;
chan_data->wait_fd = -1;
chan = shmp(handle, handle->chan);
for (k = 0; k < nr_check; k++) {
struct lttng_ust_object_data *stream_data = &stream_datas[k];
if (!stream_data->handle)
break;
/* map stream */
ret = channel_handle_add_stream(handle,
stream_data->shm_fd,
stream_data->wait_fd,
stream_data->memory_map_size);
if (ret) {
printf("add stream error\n");
goto error_destroy;
}
stream_data->shm_fd = -1;
stream_data->wait_fd = -1;
}
return handle;
error_destroy:
channel_destroy(chan, handle, 1);
return NULL;
}
/* returns the offset of the subbuffer belonging to the mmap reader. */
int ustctl_get_mmap_read_offset(struct ustctl_consumer_stream *stream,
unsigned long *off)
{
struct channel *chan;
unsigned long sb_bindex;
struct lttng_ust_lib_ring_buffer *buf;
struct ustctl_consumer_channel *consumer_chan;
if (!stream)
return -EINVAL;
buf = stream->buf;
consumer_chan = stream->chan;
chan = consumer_chan->chan->chan;
if (chan->backend.config.output != RING_BUFFER_MMAP)
return -EINVAL;
sb_bindex = subbuffer_id_get_index(&chan->backend.config,
buf->backend.buf_rsb.id);
*off = shmp(consumer_chan->chan->handle,
shmp_index(consumer_chan->chan->handle, buf->backend.array, sb_bindex)->shmp)->mmap_offset;
return 0;
}
static
int consume_stream(struct lttng_ust_shm_handle *handle, int cpu, char *outfile)
{
struct channel *chan;
struct lttng_ust_lib_ring_buffer *buf;
int outfd, ret;
int *shm_fd, *wait_fd;
uint64_t *memory_map_size;
chan = shmp(handle, handle->chan);
/* open stream */
buf = channel_get_ring_buffer(&chan->backend.config,
chan, cpu, handle, &shm_fd, &wait_fd, &memory_map_size);
if (!buf)
return -ENOENT;
ret = lib_ring_buffer_open_read(buf, handle, 1);
if (ret) {
return -1;
}
/* copy */
outfd = open(outfile, O_WRONLY | O_CREAT | O_TRUNC,
S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
if (outfd < 0) {
perror("open output");
return -1;
}
printf("Waiting for buffer data for %s\n", outfile);
for (;;) {
unsigned long read_size;
unsigned long copy_size;
char *ptr;
ret = lib_ring_buffer_get_next_subbuf(buf, handle);
printf("get next ret %d\n", ret);
if (ret == -ENODATA)
break;
if (ret == -EAGAIN) {
sleep(1);
continue;
}
if (ret) {
printf("Error %d in lib_ring_buffer_get_next_subbuf\n", ret);
return -1;
}
read_size = lib_ring_buffer_get_read_data_size(
&chan->backend.config, buf, handle);
read_size = PAGE_ALIGN(read_size);
ptr = lib_ring_buffer_read_offset_address(
&buf->backend, 0, handle);
printf("WRITE: copy %lu bytes\n", read_size);
copy_size = write(outfd, ptr, read_size);
if (copy_size < read_size) {
printf("write issue: copied %lu, expected %lu\n", copy_size, read_size);
}
lib_ring_buffer_put_next_subbuf(buf, handle);
}
ret = close(outfd);
if (ret) {
perror("close");
return -1;
}
/* close stream */
lib_ring_buffer_release_read(buf, handle, 1);
return 0;
}
/**
* lib_ring_buffer_backend_allocate - allocate a channel buffer
* @config: ring buffer instance configuration
* @buf: the buffer struct
* @size: total size of the buffer
* @num_subbuf: number of subbuffers
* @extra_reader_sb: need extra subbuffer for reader
*/
static
int lib_ring_buffer_backend_allocate(const struct lttng_ust_lib_ring_buffer_config *config,
struct lttng_ust_lib_ring_buffer_backend *bufb,
size_t size, size_t num_subbuf,
int extra_reader_sb,
struct lttng_ust_shm_handle *handle,
struct shm_object *shmobj)
{
struct channel_backend *chanb;
unsigned long subbuf_size, mmap_offset = 0;
unsigned long num_subbuf_alloc;
unsigned long i;
long page_size;
chanb = &shmp(handle, bufb->chan)->backend;
if (!chanb)
return -EINVAL;
subbuf_size = chanb->subbuf_size;
num_subbuf_alloc = num_subbuf;
if (extra_reader_sb)
num_subbuf_alloc++;
page_size = sysconf(_SC_PAGE_SIZE);
if (page_size <= 0) {
goto page_size_error;
}
align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer_backend_pages_shmp));
set_shmp(bufb->array, zalloc_shm(shmobj,
sizeof(struct lttng_ust_lib_ring_buffer_backend_pages_shmp) * num_subbuf_alloc));
if (caa_unlikely(!shmp(handle, bufb->array)))
goto array_error;
/*
* This is the largest element (the buffer pages) which needs to
* be aligned on page size.
*/
align_shm(shmobj, page_size);
set_shmp(bufb->memory_map, zalloc_shm(shmobj,
subbuf_size * num_subbuf_alloc));
if (caa_unlikely(!shmp(handle, bufb->memory_map)))
goto memory_map_error;
/* Allocate backend pages array elements */
for (i = 0; i < num_subbuf_alloc; i++) {
align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer_backend_pages));
set_shmp(shmp_index(handle, bufb->array, i)->shmp,
zalloc_shm(shmobj,
sizeof(struct lttng_ust_lib_ring_buffer_backend_pages)));
if (!shmp(handle, shmp_index(handle, bufb->array, i)->shmp))
goto free_array;
}
/* Allocate write-side subbuffer table */
align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer_backend_subbuffer));
set_shmp(bufb->buf_wsb, zalloc_shm(shmobj,
sizeof(struct lttng_ust_lib_ring_buffer_backend_subbuffer)
* num_subbuf));
if (caa_unlikely(!shmp(handle, bufb->buf_wsb)))
goto free_array;
for (i = 0; i < num_subbuf; i++) {
struct lttng_ust_lib_ring_buffer_backend_subbuffer *sb;
sb = shmp_index(handle, bufb->buf_wsb, i);
if (!sb)
goto free_array;
sb->id = subbuffer_id(config, 0, 1, i);
}
/* Assign read-side subbuffer table */
if (extra_reader_sb)
bufb->buf_rsb.id = subbuffer_id(config, 0, 1,
num_subbuf_alloc - 1);
else
bufb->buf_rsb.id = subbuffer_id(config, 0, 1, 0);
/* Allocate subbuffer packet counter table */
align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer_backend_subbuffer));
set_shmp(bufb->buf_cnt, zalloc_shm(shmobj,
sizeof(struct lttng_ust_lib_ring_buffer_backend_counts)
* num_subbuf));
if (caa_unlikely(!shmp(handle, bufb->buf_cnt)))
goto free_wsb;
/* Assign pages to page index */
for (i = 0; i < num_subbuf_alloc; i++) {
struct lttng_ust_lib_ring_buffer_backend_pages_shmp *sbp;
struct lttng_ust_lib_ring_buffer_backend_pages *pages;
struct shm_ref ref;
ref.index = bufb->memory_map._ref.index;
ref.offset = bufb->memory_map._ref.offset;
ref.offset += i * subbuf_size;
sbp = shmp_index(handle, bufb->array, i);
if (!sbp)
goto free_array;
pages = shmp(handle, sbp->shmp);
if (!pages)
goto free_array;
set_shmp(pages->p, ref);
if (config->output == RING_BUFFER_MMAP) {
pages->mmap_offset = mmap_offset;
mmap_offset += subbuf_size;
}
}
return 0;
free_wsb:
/* bufb->buf_wsb will be freed by shm teardown */
free_array:
/* bufb->array[i] will be freed by shm teardown */
memory_map_error:
/* bufb->array will be freed by shm teardown */
array_error:
page_size_error:
return -ENOMEM;
}
/**
* channel_backend_init - initialize a channel backend
* @chanb: channel backend
* @name: channel name
* @config: client ring buffer configuration
* @parent: dentry of parent directory, %NULL for root directory
* @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.
*
* Creates per-cpu channel buffers using the sizes and attributes
* specified. The created channel buffer files will be named
* name_0...name_N-1. File permissions will be %S_IRUSR.
*
* Called with CPU hotplug disabled.
*/
int channel_backend_init(struct channel_backend *chanb,
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,
const int *stream_fds)
{
struct channel *chan = caa_container_of(chanb, struct channel, backend);
unsigned int i;
int ret;
size_t shmsize = 0, num_subbuf_alloc;
long page_size;
if (!name)
return -EPERM;
page_size = sysconf(_SC_PAGE_SIZE);
if (page_size <= 0) {
return -ENOMEM;
}
/* 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, and nonzero.
*/
if (!subbuf_size || (subbuf_size & (subbuf_size - 1)))
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)
return ret;
chanb->buf_size = num_subbuf * subbuf_size;
chanb->subbuf_size = subbuf_size;
chanb->buf_size_order = get_count_order(chanb->buf_size);
chanb->subbuf_size_order = get_count_order(subbuf_size);
chanb->num_subbuf_order = get_count_order(num_subbuf);
chanb->extra_reader_sb =
(config->mode == RING_BUFFER_OVERWRITE) ? 1 : 0;
chanb->num_subbuf = num_subbuf;
strncpy(chanb->name, name, NAME_MAX);
chanb->name[NAME_MAX - 1] = '\0';
memcpy(&chanb->config, config, sizeof(*config));
/* Per-cpu buffer size: control (prior to backend) */
shmsize = offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer));
shmsize += sizeof(struct lttng_ust_lib_ring_buffer);
/* Per-cpu buffer size: backend */
/* num_subbuf + 1 is the worse case */
num_subbuf_alloc = num_subbuf + 1;
shmsize += offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer_backend_pages_shmp));
shmsize += sizeof(struct lttng_ust_lib_ring_buffer_backend_pages_shmp) * num_subbuf_alloc;
shmsize += offset_align(shmsize, page_size);
shmsize += subbuf_size * num_subbuf_alloc;
shmsize += offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer_backend_pages));
shmsize += sizeof(struct lttng_ust_lib_ring_buffer_backend_pages) * num_subbuf_alloc;
shmsize += offset_align(shmsize, __alignof__(struct lttng_ust_lib_ring_buffer_backend_subbuffer));
shmsize += sizeof(struct lttng_ust_lib_ring_buffer_backend_subbuffer) * num_subbuf;
/* Per-cpu buffer size: control (after backend) */
shmsize += offset_align(shmsize, __alignof__(struct commit_counters_hot));
shmsize += sizeof(struct commit_counters_hot) * num_subbuf;
shmsize += offset_align(shmsize, __alignof__(struct commit_counters_cold));
shmsize += sizeof(struct commit_counters_cold) * num_subbuf;
if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
struct lttng_ust_lib_ring_buffer *buf;
/*
* We need to allocate for all possible cpus.
*/
for_each_possible_cpu(i) {
struct shm_object *shmobj;
shmobj = shm_object_table_alloc(handle->table, shmsize,
SHM_OBJECT_SHM, stream_fds[i]);
if (!shmobj)
goto end;
align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer));
set_shmp(chanb->buf[i].shmp, zalloc_shm(shmobj, sizeof(struct lttng_ust_lib_ring_buffer)));
buf = shmp(handle, chanb->buf[i].shmp);
if (!buf)
goto end;
set_shmp(buf->self, chanb->buf[i].shmp._ref);
ret = lib_ring_buffer_create(buf, chanb, i,
handle, shmobj);
if (ret)
goto free_bufs; /* cpu hotplug locked */
}
} else {
/* Map channel shm into process memory */
struct lttng_ust_shm_handle *ustctl_map_channel(struct lttng_ust_object_data *chan_data)
{
struct lttng_ust_shm_handle *handle;
struct channel *chan;
size_t chan_size;
struct lttng_ust_lib_ring_buffer_config *config;
int ret;
if (!chan_data)
return NULL;
handle = channel_handle_create(chan_data->shm_fd,
chan_data->wait_fd,
chan_data->memory_map_size);
if (!handle) {
ERR("create handle error");
return NULL;
}
/*
* Set to -1, and then close the shm fd, and set the handle shm
* fd to -1 too. We don't need the shm fds after they have been
* mapped.
* The wait_fd is set to -1 in chan_data because it is now owned
* by the handle.
*/
chan_data->shm_fd = -1;
chan_data->wait_fd = -1;
/* chan is object 0. This is hardcoded. */
if (handle->table->objects[0].shm_fd >= 0) {
ret = close(handle->table->objects[0].shm_fd);
if (ret) {
perror("Error closing shm_fd");
}
handle->table->objects[0].shm_fd = -1;
}
/*
* TODO: add consistency checks to be resilient if the
* application try to feed us with incoherent channel structure
* values.
*/
chan = shmp(handle, handle->chan);
/* chan is object 0. This is hardcoded. */
chan_size = handle->table->objects[0].allocated_len;
handle->shadow_chan = malloc(chan_size);
if (!handle->shadow_chan) {
channel_destroy(chan, handle, 1);
return NULL;
}
memcpy(handle->shadow_chan, chan, chan_size);
/*
* The callback pointers in the producer are invalid in the
* consumer. We need to look them up here.
*/
config = &handle->shadow_chan->backend.config;
switch (config->client_type) {
case LTTNG_CLIENT_METADATA:
memcpy(&config->cb, lttng_client_callbacks_metadata,
sizeof(config->cb));
break;
case LTTNG_CLIENT_DISCARD:
memcpy(&config->cb, lttng_client_callbacks_discard,
sizeof(config->cb));
break;
case LTTNG_CLIENT_OVERWRITE:
memcpy(&config->cb, lttng_client_callbacks_overwrite,
sizeof(config->cb));
break;
default:
ERR("Unknown client type %d", config->client_type);
channel_destroy(chan, handle, 1);
return NULL;
}
/* Replace the object table pointer. */
ret = munmap(handle->table->objects[0].memory_map,
handle->table->objects[0].memory_map_size);
if (ret) {
perror("munmap");
assert(0);
}
handle->table->objects[0].memory_map = (char *) handle->shadow_chan;
handle->table->objects[0].is_shadow = 1;
return handle;
}
