X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng%2Fcommands%2Fstart.c;h=b353eb6e3888174483ac52932145f575a1089f92;hp=0f44f4cdac511a750d884546cc65d6a96001d52f;hb=890d8fe47755c3bad936389cf48ffa141cff41c9;hpb=d14d33bf091e72b23b1f90ea18a0a01bed098b76

diff --git a/src/bin/lttng/commands/start.c b/src/bin/lttng/commands/start.c
index 0f44f4cda..b353eb6e3 100644
--- a/src/bin/lttng/commands/start.c
+++ b/src/bin/lttng/commands/start.c
@@ -15,7 +15,7 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <popt.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -24,9 +24,14 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include <common/sessiond-comm/sessiond-comm.h>
+#include <common/mi-lttng.h>
+
 #include "../command.h"
 
+
 static char *opt_session_name;
+static struct mi_writer *writer;
 
 enum {
 	OPT_HELP = 1,
@@ -45,16 +50,47 @@ static struct poptOption long_options[] = {
  */
 static void usage(FILE *ofp)
 {
-	fprintf(ofp, "usage: lttng start [options] [NAME]\n");
+	fprintf(ofp, "usage: lttng start [NAME] [OPTIONS]\n");
 	fprintf(ofp, "\n");
 	fprintf(ofp, "Where NAME is an optional session name. If not specified, lttng will\n");
 	fprintf(ofp, "get it from the configuration directory (.lttng).\n");
 	fprintf(ofp, "\n");
+	fprintf(ofp, "Options:\n");
 	fprintf(ofp, "  -h, --help               Show this help\n");
 	fprintf(ofp, "      --list-options       Simple listing of options\n");
 	fprintf(ofp, "\n");
 }
 
+static int mi_print_session(char *session_name, int enabled)
+{
+	int ret;
+
+	/* Open session element */
+	ret = mi_lttng_writer_open_element(writer, config_element_session);
+	if (ret) {
+		goto end;
+	}
+
+	/* Print session name element */
+	ret = mi_lttng_writer_write_element_string(writer, config_element_name,
+			session_name);
+	if (ret) {
+		goto end;
+	}
+
+	ret = mi_lttng_writer_write_element_bool(writer, config_element_enabled,
+			enabled);
+	if (ret) {
+		goto end;
+	}
+
+	/* Close session element */
+	ret = mi_lttng_writer_close_element(writer);
+
+end:
+	return ret;
+}
+
 /*
  *  start_tracing
  *
@@ -79,13 +115,27 @@ static int start_tracing(void)
 
 	ret = lttng_start_tracing(session_name);
 	if (ret < 0) {
-		/* Don't set ret so lttng can interpret the sessiond error. */
+		switch (-ret) {
+		case LTTNG_ERR_TRACE_ALREADY_STARTED:
+			WARN("Tracing already started for session %s", session_name);
+			break;
+		default:
+			ERR("%s", lttng_strerror(ret));
+			break;
+		}
 		goto free_name;
 	}
 
 	ret = CMD_SUCCESS;
 
 	MSG("Tracing started for session %s", session_name);
+	if (lttng_opt_mi) {
+		ret = mi_print_session(session_name, 1);
+		if (ret) {
+			ret = CMD_ERROR;
+			goto free_name;
+		}
+	}
 
 free_name:
 	if (opt_session_name == NULL) {
@@ -102,7 +152,7 @@ error:
  */
 int cmd_start(int argc, const char **argv)
 {
-	int opt, ret = CMD_SUCCESS;
+	int opt, ret = CMD_SUCCESS, command_ret = CMD_SUCCESS, success = 1;
 	static poptContext pc;
 
 	pc = poptGetContext(NULL, argc, argv, long_options, 0);
@@ -125,9 +175,81 @@ int cmd_start(int argc, const char **argv)
 
 	opt_session_name = (char*) poptGetArg(pc);
 
-	ret = start_tracing();
+	/* Mi check */
+	if (lttng_opt_mi) {
+		writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
+		if (!writer) {
+			ret = -LTTNG_ERR_NOMEM;
+			goto end;
+		}
+
+		/* Open command element */
+		ret = mi_lttng_writer_command_open(writer,
+				mi_lttng_element_command_start);
+		if (ret) {
+			ret = CMD_ERROR;
+			goto end;
+		}
+
+		/* Open output element */
+		ret = mi_lttng_writer_open_element(writer,
+				mi_lttng_element_command_output);
+		if (ret) {
+			ret = CMD_ERROR;
+			goto end;
+		}
+
+		/*
+		 * Open sessions element
+		 * For validation purpose
+		 */
+		ret = mi_lttng_writer_open_element(writer,
+			config_element_sessions);
+		if (ret) {
+			ret = CMD_ERROR;
+			goto end;
+		}
+	}
+
+	command_ret = start_tracing();
+	if (command_ret) {
+		success = 0;
+	}
+
+	/* Mi closing */
+	if (lttng_opt_mi) {
+		/* Close  sessions and output element */
+		ret = mi_lttng_close_multi_element(writer, 2);
+		if (ret) {
+			ret = CMD_ERROR;
+			goto end;
+		}
+
+		/* Success ? */
+		ret = mi_lttng_writer_write_element_bool(writer,
+				mi_lttng_element_command_success, success);
+		if (ret) {
+			ret = CMD_ERROR;
+			goto end;
+		}
+
+		/* Command element close */
+		ret = mi_lttng_writer_command_close(writer);
+		if (ret) {
+			ret = CMD_ERROR;
+			goto end;
+		}
+	}
 
 end:
+	/* Mi clean-up */
+	if (writer && mi_lttng_writer_destroy(writer)) {
+		/* Preserve original error code */
+		ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
+	}
+
+	/* Overwrite ret if an error occurred with start_tracing */
+	ret = command_ret ? command_ret : ret;
 	poptFreeContext(pc);
 	return ret;
 }