{
struct lttng_viewer_cmd cmd;
struct lttng_viewer_connect connect;
+ const size_t cmd_buf_len = sizeof(cmd) + sizeof(connect);
+ char cmd_buf[cmd_buf_len];
int ret;
ssize_t ret_len;
connect.minor = htobe32(LTTNG_LIVE_MINOR);
connect.type = htobe32(LTTNG_VIEWER_CLIENT_COMMAND);
- ret_len = lttng_live_send(viewer_connection, &cmd, sizeof(cmd));
- if (ret_len == BT_SOCKET_ERROR) {
- BT_LOGE("Error sending cmd: %s", bt_socket_errormsg());
- goto error;
- }
- assert(ret_len == sizeof(cmd));
+ /*
+ * Merge the cmd and connection request to prevent a write-write
+ * sequence on the TCP socket. Otherwise, a delayed ACK will prevent the
+ * second write to be performed quickly in presence of Nagle's algorithm
+ */
+ memcpy(cmd_buf, &cmd, sizeof(cmd));
+ memcpy(cmd_buf + sizeof(cmd), &connect, sizeof(connect));
- ret_len = lttng_live_send(viewer_connection, &connect, sizeof(connect));
+ ret_len = lttng_live_send(viewer_connection, &cmd_buf, cmd_buf_len);
if (ret_len == BT_SOCKET_ERROR) {
BT_LOGE("Error sending version: %s", bt_socket_errormsg());
goto error;
}
- assert(ret_len == sizeof(connect));
+ assert(ret_len == cmd_buf_len);
ret_len = lttng_live_recv(viewer_connection, &connect, sizeof(connect));
if (ret_len == 0) {
lttng_live->viewer_connection;
uint64_t session_id = session->id;
uint32_t streams_count;
+ const size_t cmd_buf_len = sizeof(cmd) + sizeof(rq);
+ char cmd_buf[cmd_buf_len];
if (session->attached) {
return 0;
// rq.seek = htobe32(LTTNG_VIEWER_SEEK_BEGINNING);
rq.seek = htobe32(LTTNG_VIEWER_SEEK_LAST);
- ret_len = lttng_live_send(viewer_connection, &cmd, sizeof(cmd));
- if (ret_len == BT_SOCKET_ERROR) {
- BT_LOGE("Error sending cmd: %s", bt_socket_errormsg());
- goto error;
- }
- assert(ret_len == sizeof(cmd));
+ /*
+ * Merge the cmd and connection request to prevent a write-write
+ * sequence on the TCP socket. Otherwise, a delayed ACK will prevent the
+ * second write to be performed quickly in presence of Nagle's algorithm.
+ */
+ memcpy(cmd_buf, &cmd, sizeof(cmd));
+ memcpy(cmd_buf + sizeof(cmd), &rq, sizeof(rq));
- ret_len = lttng_live_send(viewer_connection, &rq, sizeof(rq));
+ ret_len = lttng_live_send(viewer_connection, &cmd_buf, cmd_buf_len);
if (ret_len == BT_SOCKET_ERROR) {
BT_LOGE("Error sending attach request: %s", bt_socket_errormsg());
goto error;
}
- assert(ret_len == sizeof(rq));
+ assert(ret_len == cmd_buf_len);
ret_len = lttng_live_recv(viewer_connection, &rp, sizeof(rp));
if (ret_len == 0) {
struct bt_live_viewer_connection *viewer_connection =
lttng_live->viewer_connection;
uint64_t session_id = session->id;
+ const size_t cmd_buf_len = sizeof(cmd) + sizeof(rq);
+ char cmd_buf[cmd_buf_len];
if (!session->attached) {
return 0;
memset(&rq, 0, sizeof(rq));
rq.session_id = htobe64(session_id);
- ret_len = lttng_live_send(viewer_connection, &cmd, sizeof(cmd));
- if (ret_len == BT_SOCKET_ERROR) {
- BT_LOGE("Error sending cmd: %s", bt_socket_errormsg());
- goto error;
- }
- assert(ret_len == sizeof(cmd));
+ /*
+ * Merge the cmd and connection request to prevent a write-write
+ * sequence on the TCP socket. Otherwise, a delayed ACK will prevent the
+ * second write to be performed quickly in presence of Nagle's algorithm.
+ */
+ memcpy(cmd_buf, &cmd, sizeof(cmd));
+ memcpy(cmd_buf + sizeof(cmd), &rq, sizeof(rq));
- ret_len = lttng_live_send(viewer_connection, &rq, sizeof(rq));
+ ret_len = lttng_live_send(viewer_connection, &cmd_buf, cmd_buf_len);
if (ret_len == BT_SOCKET_ERROR) {
BT_LOGE("Error sending detach request: %s", bt_socket_errormsg());
goto error;
}
- assert(ret_len == sizeof(rq));
+ assert(ret_len == cmd_buf_len);
ret_len = lttng_live_recv(viewer_connection, &rp, sizeof(rp));
if (ret_len == 0) {
struct lttng_live_metadata *metadata = trace->metadata;
struct bt_live_viewer_connection *viewer_connection =
lttng_live->viewer_connection;
+ const size_t cmd_buf_len = sizeof(cmd) + sizeof(rq);
+ char cmd_buf[cmd_buf_len];
rq.stream_id = htobe64(metadata->stream_id);
cmd.cmd = htobe32(LTTNG_VIEWER_GET_METADATA);
cmd.data_size = htobe64((uint64_t) sizeof(rq));
cmd.cmd_version = htobe32(0);
- ret_len = lttng_live_send(viewer_connection, &cmd, sizeof(cmd));
- if (ret_len == BT_SOCKET_ERROR) {
- BT_LOGE("Error sending cmd: %s", bt_socket_errormsg());
- goto error;
- }
- assert(ret_len == sizeof(cmd));
+ /*
+ * Merge the cmd and connection request to prevent a write-write
+ * sequence on the TCP socket. Otherwise, a delayed ACK will prevent the
+ * second write to be performed quickly in presence of Nagle's algorithm.
+ */
+ memcpy(cmd_buf, &cmd, sizeof(cmd));
+ memcpy(cmd_buf + sizeof(cmd), &rq, sizeof(rq));
- ret_len = lttng_live_send(viewer_connection, &rq, sizeof(rq));
+ ret_len = lttng_live_send(viewer_connection, &cmd_buf, cmd_buf_len);
if (ret_len == BT_SOCKET_ERROR) {
BT_LOGE("Error sending get_metadata request: %s", bt_socket_errormsg());
goto error;
}
- assert(ret_len == sizeof(rq));
+ assert(ret_len == cmd_buf_len);
ret_len = lttng_live_recv(viewer_connection, &rp, sizeof(rp));
if (ret_len == 0) {
struct bt_live_viewer_connection *viewer_connection =
lttng_live->viewer_connection;
struct lttng_live_trace *trace = stream->trace;
+ const size_t cmd_buf_len = sizeof(cmd) + sizeof(rq);
+ char cmd_buf[cmd_buf_len];
cmd.cmd = htobe32(LTTNG_VIEWER_GET_NEXT_INDEX);
cmd.data_size = htobe64((uint64_t) sizeof(rq));
cmd.cmd_version = htobe32(0);
+
memset(&rq, 0, sizeof(rq));
rq.stream_id = htobe64(stream->viewer_stream_id);
- ret_len = lttng_live_send(viewer_connection, &cmd, sizeof(cmd));
- if (ret_len == BT_SOCKET_ERROR) {
- BT_LOGE("Error sending cmd: %s", bt_socket_errormsg());
- goto error;
- }
- assert(ret_len == sizeof(cmd));
+ /*
+ * Merge the cmd and connection request to prevent a write-write
+ * sequence on the TCP socket. Otherwise, a delayed ACK will prevent the
+ * second write to be performed quickly in presence of Nagle's algorithm.
+ */
+ memcpy(cmd_buf, &cmd, sizeof(cmd));
+ memcpy(cmd_buf + sizeof(cmd), &rq, sizeof(rq));
- ret_len = lttng_live_send(viewer_connection, &rq, sizeof(rq));
+ ret_len = lttng_live_send(viewer_connection, &cmd_buf, cmd_buf_len);
if (ret_len == BT_SOCKET_ERROR) {
BT_LOGE("Error sending get_next_index request: %s", bt_socket_errormsg());
goto error;
}
- assert(ret_len == sizeof(rq));
+ assert(ret_len == cmd_buf_len);
ret_len = lttng_live_recv(viewer_connection, &rp, sizeof(rp));
if (ret_len == 0) {
struct bt_live_viewer_connection *viewer_connection =
lttng_live->viewer_connection;
struct lttng_live_trace *trace = stream->trace;
+ const size_t cmd_buf_len = sizeof(cmd) + sizeof(rq);
+ char cmd_buf[cmd_buf_len];
BT_LOGD("lttng_live_get_stream_bytes: offset=%" PRIu64 ", req_len=%" PRIu64,
offset, req_len);
rq.offset = htobe64(offset);
rq.len = htobe32(req_len);
- ret_len = lttng_live_send(viewer_connection, &cmd, sizeof(cmd));
- if (ret_len == BT_SOCKET_ERROR) {
- BT_LOGE("Error sending cmd: %s", bt_socket_errormsg());
- goto error;
- }
- assert(ret_len == sizeof(cmd));
+ /*
+ * Merge the cmd and connection request to prevent a write-write
+ * sequence on the TCP socket. Otherwise, a delayed ACK will prevent the
+ * second write to be performed quickly in presence of Nagle's algorithm.
+ */
+ memcpy(cmd_buf, &cmd, sizeof(cmd));
+ memcpy(cmd_buf + sizeof(cmd), &rq, sizeof(rq));
- ret_len = lttng_live_send(viewer_connection, &rq, sizeof(rq));
+ ret_len = lttng_live_send(viewer_connection, &cmd_buf, cmd_buf_len);
if (ret_len == BT_SOCKET_ERROR) {
BT_LOGE("Error sending get_data request: %s", bt_socket_errormsg());
goto error;
}
- assert(ret_len == sizeof(rq));
+ assert(ret_len == cmd_buf_len);
ret_len = lttng_live_recv(viewer_connection, &rp, sizeof(rp));
if (ret_len == 0) {
struct bt_live_viewer_connection *viewer_connection =
lttng_live->viewer_connection;
uint32_t streams_count;
+ const size_t cmd_buf_len = sizeof(cmd) + sizeof(rq);
+ char cmd_buf[cmd_buf_len];
if (!session->new_streams_needed) {
return BT_LTTNG_LIVE_ITERATOR_STATUS_OK;
memset(&rq, 0, sizeof(rq));
rq.session_id = htobe64(session->id);
- ret_len = lttng_live_send(viewer_connection, &cmd, sizeof(cmd));
- if (ret_len == BT_SOCKET_ERROR) {
- BT_LOGE("Error sending cmd: %s", bt_socket_errormsg());
- goto error;
- }
- assert(ret_len == sizeof(cmd));
+ /*
+ * Merge the cmd and connection request to prevent a write-write
+ * sequence on the TCP socket. Otherwise, a delayed ACK will prevent the
+ * second write to be performed quickly in presence of Nagle's algorithm.
+ */
+ memcpy(cmd_buf, &cmd, sizeof(cmd));
+ memcpy(cmd_buf + sizeof(cmd), &rq, sizeof(rq));
- ret_len = lttng_live_send(viewer_connection, &rq, sizeof(rq));
+ ret_len = lttng_live_send(viewer_connection, &cmd_buf, cmd_buf_len);
if (ret_len == BT_SOCKET_ERROR) {
BT_LOGE("Error sending get_new_streams request: %s", bt_socket_errormsg());
goto error;
}
- assert(ret_len == sizeof(rq));
+ assert(ret_len == cmd_buf_len);
ret_len = lttng_live_recv(viewer_connection, &rp, sizeof(rp));
if (ret_len == 0) {