int sock, struct pollfd *consumer_sockpoll)
{
ssize_t ret;
+ enum lttng_error_code ret_code = LTTNG_OK;
struct lttcomm_consumer_msg msg;
ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
return ret;
}
if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
+ /*
+ * Notify the session daemon that the command is completed.
+ *
+ * On transport layer error, the function call will print an error
+ * message so handling the returned code is a bit useless since we
+ * return an error code anyway.
+ */
+ (void) consumer_send_status_msg(sock, ret_code);
return -ENOENT;
}
switch (msg.cmd_type) {
case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
{
+ /* Session daemon status message are handled in the following call. */
ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
- &msg.u.relayd_sock.sock);
+ &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id);
goto end_nosignal;
}
case LTTNG_CONSUMER_ADD_CHANNEL:
{
struct lttng_consumer_channel *new_channel;
+ /* First send a status message before receiving the fds. */
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+
DBG("consumer_add_channel %d", msg.u.channel.channel_key);
new_channel = consumer_allocate_channel(msg.u.channel.channel_key,
-1, -1,
}
case LTTNG_CONSUMER_ADD_STREAM:
{
- int fd;
+ int fd, stream_pipe;
struct consumer_relayd_sock_pair *relayd = NULL;
struct lttng_consumer_stream *new_stream;
int alloc_ret = 0;
+ /* First send a status message before receiving the fds. */
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+
/* block */
if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
rcu_read_unlock();
return ret;
}
+ /*
+ * Send status code to session daemon only if the recv works. If the
+ * above recv() failed, the session daemon is notified through the
+ * error socket and the teardown is eventually done.
+ */
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+
new_stream = consumer_allocate_stream(msg.u.stream.channel_key,
msg.u.stream.stream_key,
fd, fd,
msg.u.stream.gid,
msg.u.stream.net_index,
msg.u.stream.metadata_flag,
+ msg.u.stream.session_id,
&alloc_ret);
if (new_stream == NULL) {
switch (alloc_ret) {
}
}
- /* Send stream to the metadata thread */
+ /* Get the right pipe where the stream will be sent. */
if (new_stream->metadata_flag) {
- do {
- ret = write(ctx->consumer_metadata_pipe[1], &new_stream,
- sizeof(new_stream));
- } while (ret < 0 && errno == EINTR);
- if (ret < 0) {
- PERROR("write metadata pipe");
- consumer_del_stream(new_stream, NULL);
- }
+ stream_pipe = ctx->consumer_metadata_pipe[1];
} else {
- ret = consumer_add_stream(new_stream);
- if (ret) {
- ERR("Consumer add stream %d failed. Continuing",
- new_stream->key);
- consumer_del_stream(new_stream, NULL);
- goto end_nosignal;
- }
+ stream_pipe = ctx->consumer_data_pipe[1];
}
- DBG("Kernel consumer_add_stream (%d)", fd);
+ do {
+ ret = write(stream_pipe, &new_stream, sizeof(new_stream));
+ } while (ret < 0 && errno == EINTR);
+ if (ret < 0) {
+ PERROR("Consumer write %s stream to pipe %d",
+ new_stream->metadata_flag ? "metadata" : "data",
+ stream_pipe);
+ consumer_del_stream(new_stream, NULL);
+ goto end_nosignal;
+ }
+
+ DBG("Kernel consumer ADD_STREAM %s (fd: %d) with relayd id %" PRIu64,
+ msg.u.stream.path_name, fd, new_stream->relayd_stream_id);
break;
}
case LTTNG_CONSUMER_UPDATE_STREAM:
/* Get relayd reference if exists. */
relayd = consumer_find_relayd(index);
if (relayd == NULL) {
- ERR("Unable to find relayd %" PRIu64, index);
- goto end_nosignal;
+ DBG("Unable to find relayd %" PRIu64, index);
+ ret_code = LTTNG_ERR_NO_CONSUMER;
}
/*
*
* The destroy can happen either here or when a stream fd hangs up.
*/
- consumer_flag_relayd_for_destroy(relayd);
+ if (relayd) {
+ consumer_flag_relayd_for_destroy(relayd);
+ }
+
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
goto end_nosignal;
}
+ case LTTNG_CONSUMER_DATA_PENDING:
+ {
+ int32_t ret;
+ uint64_t id = msg.u.data_pending.session_id;
+
+ DBG("Kernel consumer data pending command for id %" PRIu64, id);
+
+ ret = consumer_data_pending(id);
+
+ /* Send back returned value to session daemon */
+ ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret));
+ if (ret < 0) {
+ PERROR("send data pending ret code");
+ }
+
+ /*
+ * No need to send back a status message since the data pending
+ * returned value is the response.
+ */
+ break;
+ }
default:
goto end_nosignal;
}
- /*
- * Wake-up the other end by writing a null byte in the pipe (non-blocking).
- * Important note: Because writing into the pipe is non-blocking (and
- * therefore we allow dropping wakeup data, as long as there is wakeup data
- * present in the pipe buffer to wake up the other end), the other end
- * should perform the following sequence for waiting:
- *
- * 1) empty the pipe (reads).
- * 2) perform update operation.
- * 3) wait on the pipe (poll).
- */
- do {
- ret = write(ctx->consumer_poll_pipe[1], "", 1);
- } while (ret < 0 && errno == EINTR);
end_nosignal:
rcu_read_unlock();
return ret;
}
+/*
+ * Check if data is still being extracted from the buffers for a specific
+ * stream. Consumer data lock MUST be acquired before calling this function
+ * and the stream lock.
+ *
+ * Return 1 if the traced data are still getting read else 0 meaning that the
+ * data is available for trace viewer reading.
+ */
+int lttng_kconsumer_data_pending(struct lttng_consumer_stream *stream)
+{
+ int ret;
+
+ assert(stream);
+
+ ret = kernctl_get_next_subbuf(stream->wait_fd);
+ if (ret == 0) {
+ /* There is still data so let's put back this subbuffer. */
+ ret = kernctl_put_subbuf(stream->wait_fd);
+ assert(ret == 0);
+ ret = 1; /* Data is pending */
+ goto end;
+ }
+
+ /* Data is NOT pending and ready to be read. */
+ ret = 0;
+
+end:
+ return ret;
+}