*/
while ((ustream = ustctl_create_stream(channel->uchan, cpu))) {
int wait_fd;
+ int ust_metadata_pipe[2];
- wait_fd = ustctl_stream_get_wait_fd(ustream);
+ if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && channel->monitor) {
+ ret = utils_create_pipe_cloexec_nonblock(ust_metadata_pipe);
+ if (ret < 0) {
+ ERR("Create ust metadata poll pipe");
+ goto error;
+ }
+ wait_fd = ust_metadata_pipe[0];
+ } else {
+ wait_fd = ustctl_stream_get_wait_fd(ustream);
+ }
/* Allocate consumer stream object. */
stream = allocate_stream(cpu, wait_fd, channel, ctx, &ret);
/* Keep stream reference when creating metadata. */
if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) {
channel->metadata_stream = stream;
+ stream->ust_metadata_poll_pipe[0] = ust_metadata_pipe[0];
+ stream->ust_metadata_poll_pipe[1] = ust_metadata_pipe[1];
}
}
return ret;
}
-/*
- * Write metadata to the given channel using ustctl to convert the string to
- * the ringbuffer.
- * Called only from consumer_metadata_cache_write.
- * The metadata cache lock MUST be acquired to write in the cache.
- *
- * Return 0 on success else a negative value.
- */
-int lttng_ustconsumer_push_metadata(struct lttng_consumer_channel *metadata,
- const char *metadata_str, uint64_t target_offset, uint64_t len)
-{
- int ret;
-
- assert(metadata);
- assert(metadata_str);
-
- DBG("UST consumer writing metadata to channel %s", metadata->name);
-
- if (!metadata->metadata_stream) {
- ret = 0;
- goto error;
- }
-
- assert(target_offset <= metadata->metadata_cache->max_offset);
- ret = ustctl_write_metadata_to_channel(metadata->uchan,
- metadata_str + target_offset, len);
- if (ret < 0) {
- ERR("ustctl write metadata fail with ret %d, len %" PRIu64, ret, len);
- goto error;
- }
-
- ustctl_flush_buffer(metadata->metadata_stream->ustream, 1);
-
-error:
- return ret;
-}
-
/*
* Flush channel's streams using the given key to retrieve the channel.
*
cds_lfht_for_each_entry_duplicate(ht->ht,
ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
&channel->key, &iter.iter, stream, node_channel_id.node) {
- ustctl_flush_buffer(stream->ustream, 1);
+ ustctl_flush_buffer(stream->ustream, 1);
}
error:
rcu_read_unlock();
ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
goto error_unlock;
}
+ if (channel->monitor) {
+ /* close the read-side in consumer_del_metadata_stream */
+ ret = close(channel->metadata_stream->ust_metadata_poll_pipe[1]);
+ if (ret < 0) {
+ PERROR("Close UST metadata write-side poll pipe");
+ }
+ }
}
error_unlock:
struct lttng_consumer_local_data *ctx)
{
int ret = 0;
- ssize_t write_len;
- uint64_t total_len = 0;
struct lttng_consumer_channel *metadata_channel;
struct lttng_consumer_stream *metadata_stream;
* Ask the sessiond if we have new metadata waiting and update the
* consumer metadata cache.
*/
- ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel);
+ ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel, 0);
if (ret < 0) {
goto error;
}
}
pthread_mutex_lock(&metadata_channel->metadata_cache->lock);
- while (total_len < metadata_channel->metadata_cache->total_bytes_written) {
- /*
- * Write at most one packet of metadata into the channel
- * to avoid blocking here.
- */
- write_len = ustctl_write_one_packet_to_channel(metadata_channel->uchan,
- metadata_channel->metadata_cache->data,
- metadata_channel->metadata_cache->total_bytes_written);
- if (write_len < 0) {
- ERR("UST consumer snapshot writing metadata packet");
- ret = -1;
- goto error_unlock;
- }
- total_len += write_len;
- DBG("Written %" PRIu64 " bytes to metadata (left: %" PRIu64 ")",
- write_len,
- metadata_channel->metadata_cache->total_bytes_written - write_len);
- ustctl_flush_buffer(metadata_stream->ustream, 1);
+ do {
ret = lttng_consumer_read_subbuffer(metadata_stream, ctx);
if (ret < 0) {
goto error_unlock;
}
- }
+ } while (ret > 0);
error_unlock:
pthread_mutex_unlock(&metadata_channel->metadata_cache->lock);
* Receive the metadata updates from the sessiond.
*/
int lttng_ustconsumer_recv_metadata(int sock, uint64_t key, uint64_t offset,
- uint64_t len, struct lttng_consumer_channel *channel)
+ uint64_t len, struct lttng_consumer_channel *channel,
+ int timer)
{
int ret, ret_code = LTTNG_OK;
char *metadata_str;
goto end_free;
}
- /*
- * XXX: The consumer data lock is acquired before calling metadata cache
- * write which calls push metadata that MUST be protected by the consumer
- * lock in order to be able to check the validity of the metadata stream of
- * the channel.
- *
- * Note that this will be subject to change to better fine grained locking
- * and ultimately try to get rid of this global consumer data lock.
- */
- pthread_mutex_lock(&consumer_data.lock);
- pthread_mutex_lock(&channel->lock);
pthread_mutex_lock(&channel->metadata_cache->lock);
ret = consumer_metadata_cache_write(channel, offset, len, metadata_str);
if (ret < 0) {
* waiting for the metadata cache to be flushed.
*/
pthread_mutex_unlock(&channel->metadata_cache->lock);
- pthread_mutex_unlock(&channel->lock);
- pthread_mutex_unlock(&consumer_data.lock);
goto end_free;
}
pthread_mutex_unlock(&channel->metadata_cache->lock);
- pthread_mutex_unlock(&channel->lock);
- pthread_mutex_unlock(&consumer_data.lock);
- while (consumer_metadata_cache_flushed(channel, offset + len)) {
+ while (consumer_metadata_cache_flushed(channel, offset + len, timer)) {
DBG("Waiting for metadata to be flushed");
usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME);
}
}
ret = lttng_ustconsumer_recv_metadata(sock, key, offset,
- len, channel);
+ len, channel, 0);
if (ret < 0) {
/* error receiving from sessiond */
goto error_fatal;
ustream = stream->ustream;
/* We can consume the 1 byte written into the wait_fd by UST */
- if (!stream->hangup_flush_done) {
+ if (stream->monitor && !stream->hangup_flush_done) {
ssize_t readlen;
do {
readlen = read(stream->wait_fd, &dummy, 1);
} while (readlen == -1 && errno == EINTR);
- if (readlen == -1) {
+ if (readlen == -1 && errno != EAGAIN && errno != EWOULDBLOCK) {
ret = readlen;
goto end;
}
}
+retry:
/* Get the next subbuffer */
err = ustctl_get_next_subbuf(ustream);
if (err != 0) {
+ /*
+ * Populate metadata info if the existing info has
+ * already been read.
+ */
+ if (stream->metadata_flag) {
+ ssize_t write_len;
+
+ if (stream->chan->metadata_cache->contiguous
+ == stream->ust_metadata_pushed) {
+ ret = 0;
+ goto end;
+ }
+
+ write_len = ustctl_write_one_packet_to_channel(stream->chan->uchan,
+ &stream->chan->metadata_cache->data[stream->ust_metadata_pushed],
+ stream->chan->metadata_cache->contiguous
+ - stream->ust_metadata_pushed);
+ assert(write_len != 0);
+ if (write_len < 0) {
+ ERR("Writing one metadata packet");
+ ret = -1;
+ goto end;
+ }
+ stream->ust_metadata_pushed += write_len;
+ ustctl_flush_buffer(stream->ustream, 1);
+ goto retry;
+ }
+
ret = err; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
/*
* This is a debug message even for single-threaded consumer,
goto end;
}
- ret = ustctl_get_next_subbuf(stream->ustream);
- if (ret == 0) {
- /* There is still data so let's put back this subbuffer. */
- ret = ustctl_put_subbuf(stream->ustream);
- assert(ret == 0);
- ret = 1; /* Data is pending */
- goto end;
+ if (stream->chan->type == CONSUMER_CHANNEL_TYPE_METADATA) {
+ /*
+ * We can simply check whether all contiguously available data
+ * has been pushed to the ring buffer, since the push operation
+ * is performed within get_next_subbuf(), and because both
+ * get_next_subbuf() and put_next_subbuf() are issued atomically
+ * thanks to the stream lock within
+ * lttng_ustconsumer_read_subbuffer(). This basically means that
+ * whetnever ust_metadata_pushed is incremented, the associated
+ * metadata has been consumed from the metadata stream.
+ */
+ DBG("UST consumer metadata pending check: contiguous %" PRIu64 " vs pushed %" PRIu64,
+ stream->chan->metadata_cache->contiguous,
+ stream->ust_metadata_pushed);
+ if (stream->chan->metadata_cache->contiguous
+ != stream->ust_metadata_pushed) {
+ ret = 1; /* Data is pending */
+ goto end;
+ }
+ } else {
+ ret = ustctl_get_next_subbuf(stream->ustream);
+ if (ret == 0) {
+ /*
+ * There is still data so let's put back this
+ * subbuffer.
+ */
+ ret = ustctl_put_subbuf(stream->ustream);
+ assert(ret == 0);
+ ret = 1; /* Data is pending */
+ goto end;
+ }
}
/* Data is NOT pending so ready to be read. */
}
}
+/*
+ * Please refer to consumer-timer.c before adding any lock within this
+ * function or any of its callees. Timers have a very strict locking
+ * semantic with respect to teardown. Failure to respect this semantic
+ * introduces deadlocks.
+ */
int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
- struct lttng_consumer_channel *channel)
+ struct lttng_consumer_channel *channel, int timer)
{
struct lttcomm_metadata_request_msg request;
struct lttcomm_consumer_msg msg;
channel->session_id,
channel->session_id_per_pid);
+ pthread_mutex_lock(&ctx->metadata_socket_lock);
ret = lttcomm_send_unix_sock(ctx->consumer_metadata_socket, &request,
sizeof(request));
if (ret < 0) {
}
ret_code = lttng_ustconsumer_recv_metadata(ctx->consumer_metadata_socket,
- key, offset, len, channel);
+ key, offset, len, channel, timer);
if (ret_code >= 0) {
/*
* Only send the status msg if the sessiond is alive meaning a positive
ret = 0;
end:
+ pthread_mutex_unlock(&ctx->metadata_socket_lock);
return ret;
}
projects / lttng-tools.git / blobdiff