{
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(ctx->control_sock, &cmd, sizeof(cmd));
- if (ret_len < 0) {
- perror("[error] Error sending cmd");
- 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(ctx->control_sock, &connect, sizeof(connect));
+ ret_len = lttng_live_send(ctx->control_sock, cmd_buf, cmd_buf_len);
if (ret_len < 0) {
- perror("[error] Error sending version");
+ perror("[error] Error sending cmd for establishing session");
goto error;
}
- assert(ret_len == sizeof(connect));
+ assert(ret_len == cmd_buf_len);
ret_len = lttng_live_recv(ctx->control_sock, &connect, sizeof(connect));
if (ret_len == 0) {
struct lttng_viewer_attach_session_request rq;
struct lttng_viewer_attach_session_response rp;
struct lttng_viewer_stream stream;
+ const size_t cmd_buf_len = sizeof(cmd) + sizeof(rq);
+ char cmd_buf[cmd_buf_len];
int ret, i;
ssize_t ret_len;
// rq.seek = htobe32(LTTNG_VIEWER_SEEK_BEGINNING);
rq.seek = htobe32(LTTNG_VIEWER_SEEK_LAST);
- ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
- if (ret_len < 0) {
- perror("[error] Error sending cmd");
- 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(ctx->control_sock, &rq, sizeof(rq));
+ ret_len = lttng_live_send(ctx->control_sock, cmd_buf, cmd_buf_len);
if (ret_len < 0) {
- perror("[error] Error sending attach request");
+ perror("[error] Error sending attach command and request");
goto error;
}
- assert(ret_len == sizeof(rq));
+ assert(ret_len == cmd_buf_len);
ret_len = lttng_live_recv(ctx->control_sock, &rp, sizeof(rp));
if (ret_len == 0) {
struct lttng_viewer_cmd cmd;
struct lttng_viewer_get_packet rq;
struct lttng_viewer_trace_packet rp;
+ const size_t cmd_buf_len = sizeof(cmd) + sizeof(rq);
+ char cmd_buf[cmd_buf_len];
ssize_t ret_len;
int ret;
rq.offset = htobe64(offset);
rq.len = htobe32(len);
- ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
- if (ret_len < 0) {
- perror("[error] Error sending cmd");
- 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(ctx->control_sock, &rq, sizeof(rq));
+ ret_len = lttng_live_send(ctx->control_sock, cmd_buf, cmd_buf_len);
if (ret_len < 0) {
- perror("[error] Error sending get_data_packet request");
+ perror("[error] Error sending get_data_packet cmd and request");
goto error;
}
- assert(ret_len == sizeof(rq));
+ assert(ret_len == cmd_buf_len);
ret_len = lttng_live_recv(ctx->control_sock, &rp, sizeof(rp));
if (ret_len == 0) {
struct lttng_viewer_metadata_packet rp;
char *data = NULL;
ssize_t ret_len;
+ const size_t cmd_buf_len = sizeof(cmd) + sizeof(rq);
+ char cmd_buf[cmd_buf_len];
if (lttng_live_should_quit()) {
ret = -1;
cmd.data_size = htobe64((uint64_t) sizeof(rq));
cmd.cmd_version = htobe32(0);
- ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
- if (ret_len < 0) {
- perror("[error] Error sending cmd");
- 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(ctx->control_sock, &rq, sizeof(rq));
+ ret_len = lttng_live_send(ctx->control_sock, cmd_buf, cmd_buf_len);
if (ret_len < 0) {
- perror("[error] Error sending get_metadata request");
+ perror("[error] Error sending get_metadata cmd and request");
goto error;
}
- assert(ret_len == sizeof(rq));
+ assert(ret_len == cmd_buf_len);
ret_len = lttng_live_recv(ctx->control_sock, &rp, sizeof(rp));
if (ret_len == 0) {
int ret;
ssize_t ret_len;
struct lttng_viewer_index *rp = &viewer_stream->current_index;
+ 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));
memset(&rq, 0, sizeof(rq));
rq.stream_id = htobe64(viewer_stream->id);
+ /*
+ * 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));
retry:
if (lttng_live_should_quit()) {
ret = -1;
goto end;
}
- ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
+ ret_len = lttng_live_send(ctx->control_sock, &cmd_buf, cmd_buf_len);
if (ret_len < 0) {
- perror("[error] Error sending cmd");
+ perror("[error] Error sending get_next_index cmd and request");
goto error;
}
- assert(ret_len == sizeof(cmd));
-
- ret_len = lttng_live_send(ctx->control_sock, &rq, sizeof(rq));
- if (ret_len < 0) {
- perror("[error] Error sending get_next_index request");
- goto error;
- }
- assert(ret_len == sizeof(rq));
+ assert(ret_len == cmd_buf_len);
ret_len = lttng_live_recv(ctx->control_sock, rp, sizeof(*rp));
if (ret_len == 0) {
int ret, i, nb_streams = 0;
ssize_t ret_len;
uint32_t stream_count;
+ const size_t cmd_buf_len = sizeof(cmd) + sizeof(rq);
+ char cmd_buf[cmd_buf_len];
if (lttng_live_should_quit()) {
ret = -1;
memset(&rq, 0, sizeof(rq));
rq.session_id = htobe64(id);
- ret_len = lttng_live_send(ctx->control_sock, &cmd, sizeof(cmd));
- if (ret_len < 0) {
- perror("[error] Error sending cmd");
- 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(ctx->control_sock, &rq, sizeof(rq));
+ ret_len = lttng_live_send(ctx->control_sock, cmd_buf, cmd_buf_len);
if (ret_len < 0) {
- perror("[error] Error sending get_new_streams request");
+ perror("[error] Error sending get_new_streams cmd and request");
goto error;
}
- assert(ret_len == sizeof(rq));
+ assert(ret_len == cmd_buf_len);
ret_len = lttng_live_recv(ctx->control_sock, &rp, sizeof(rp));
if (ret_len == 0) {