[lttng-dev] [PATCH lttng-tools] Snapshot: fix: mi code path

Mathieu Desnoyers mathieu.desnoyers at efficios.com
Mon Mar 21 21:49:48 UTC 2016


----- On Mar 21, 2016, at 4:47 PM, Jonathan Rajotte jonathan.rajotte-julien at efficios.com wrote:

> Reduce possible code paths by embedding mi into existing code paths.

I don't understand the changelog :-/

Mathieu

> 
> fixes #1002
> 
> Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien at efficios.com>
> ---
> src/bin/lttng/commands/snapshot.c | 258 ++++++++++----------------------------
> 1 file changed, 63 insertions(+), 195 deletions(-)
> 
> diff --git a/src/bin/lttng/commands/snapshot.c
> b/src/bin/lttng/commands/snapshot.c
> index abdf189..c8a7ba0 100644
> --- a/src/bin/lttng/commands/snapshot.c
> +++ b/src/bin/lttng/commands/snapshot.c
> @@ -150,65 +150,28 @@ error_create:
> 	return NULL;
> }
> 
> -static int mi_list_output(void)
> +static int list_output(void)
> {
> -	int ret;
> +	int ret, output_seen = 0;
> 	struct lttng_snapshot_output *s_iter;
> 	struct lttng_snapshot_output_list *list;
> 
> -	assert(writer);
> -
> 	ret = lttng_snapshot_list_output(current_session_name, &list);
> 	if (ret < 0) {
> 		goto error;
> 	}
> 
> -	ret = mi_lttng_snapshot_output_session_name(writer, current_session_name);
> -	if (ret) {
> -		ret = CMD_ERROR;
> -		goto end;
> -	}
> +	MSG("Snapshot output list for session %s", current_session_name);
> 
> -	while ((s_iter = lttng_snapshot_output_list_get_next(list)) != NULL) {
> -		ret = mi_lttng_snapshot_list_output(writer, s_iter);
> +	if (lttng_opt_mi) {
> +		ret = mi_lttng_snapshot_output_session_name(writer,
> +				current_session_name);
> 		if (ret) {
> 			ret = CMD_ERROR;
> 			goto end;
> 		}
> 	}
> 
> -
> -	/* Close snapshot snapshots element */
> -	ret = mi_lttng_writer_close_element(writer);
> -	if (ret) {
> -		ret = CMD_ERROR;
> -		goto end;
> -	}
> -
> -	/* Close snapshot session element */
> -	ret = mi_lttng_writer_close_element(writer);
> -	if (ret) {
> -		ret = CMD_ERROR;
> -	}
> -end:
> -	lttng_snapshot_output_list_destroy(list);
> -error:
> -	return ret;
> -}
> -
> -static int list_output(void)
> -{
> -	int ret, output_seen = 0;
> -	struct lttng_snapshot_output *s_iter;
> -	struct lttng_snapshot_output_list *list;
> -
> -	ret = lttng_snapshot_list_output(current_session_name, &list);
> -	if (ret < 0) {
> -		goto error;
> -	}
> -
> -	MSG("Snapshot output list for session %s", current_session_name);
> -
> 	while ((s_iter = lttng_snapshot_output_list_get_next(list)) != NULL) {
> 		MSG("%s[%" PRIu32 "] %s: %s (max-size: %" PRId64 ")", indent4,
> 				lttng_snapshot_output_get_id(s_iter),
> @@ -216,8 +179,30 @@ static int list_output(void)
> 				lttng_snapshot_output_get_ctrl_url(s_iter),
> 				lttng_snapshot_output_get_maxsize(s_iter));
> 		output_seen = 1;
> +		if (lttng_opt_mi) {
> +			ret = mi_lttng_snapshot_list_output(writer, s_iter);
> +			if (ret) {
> +				ret = CMD_ERROR;
> +				goto end;
> +			}
> +		}
> 	}
> 
> +	if (lttng_opt_mi) {
> +		/* Close snapshot snapshots element */
> +		ret = mi_lttng_writer_close_element(writer);
> +		if (ret) {
> +			ret = CMD_ERROR;
> +			goto end;
> +		}
> +
> +		/* Close snapshot session element */
> +		ret = mi_lttng_writer_close_element(writer);
> +		if (ret) {
> +			ret = CMD_ERROR;
> +		}
> +	}
> +end:
> 	lttng_snapshot_output_list_destroy(list);
> 
> 	if (!output_seen) {
> @@ -229,50 +214,6 @@ error:
> }
> 
> /*
> - * Delete output by ID (machine interface version).
> - */
> -static int mi_del_output(uint32_t id, const char *name)
> -{
> -	int ret;
> -	struct lttng_snapshot_output *output = NULL;
> -
> -	assert(writer);
> -
> -	output = lttng_snapshot_output_create();
> -	if (!output) {
> -		ret = CMD_FATAL;
> -		goto error;
> -	}
> -
> -	if (name) {
> -		ret = lttng_snapshot_output_set_name(name, output);
> -	} else if (id != UINT32_MAX) {
> -		ret = lttng_snapshot_output_set_id(id, output);
> -	} else {
> -		ret = CMD_ERROR;
> -		goto error;
> -	}
> -	if (ret < 0) {
> -		ret = CMD_FATAL;
> -		goto error;
> -	}
> -
> -	ret = lttng_snapshot_del_output(current_session_name, output);
> -	if (ret < 0) {
> -		goto error;
> -	}
> -
> -	ret = mi_lttng_snapshot_del_output(writer, id, name, current_session_name);
> -	if (ret) {
> -		ret = CMD_ERROR;
> -	}
> -
> -error:
> -	lttng_snapshot_output_destroy(output);
> -	return ret;
> -}
> -
> -/*
>  * Delete output by ID.
>  */
> static int del_output(uint32_t id, const char *name)
> @@ -312,53 +253,12 @@ static int del_output(uint32_t id, const char *name)
> 				name, current_session_name);
> 	}
> 
> -error:
> -	lttng_snapshot_output_destroy(output);
> -	return ret;
> -}
> -
> -/*
> - * Add output from the user URL (machine interface).
> - */
> -static int mi_add_output(const char *url)
> -{
> -	int ret;
> -	struct lttng_snapshot_output *output = NULL;
> -	char name[NAME_MAX];
> -	const char *n_ptr;
> -
> -	if (!url && (!opt_data_url || !opt_ctrl_url)) {
> -		ret = CMD_ERROR;
> -		goto error;
> -	}
> -
> -	output = create_output_from_args(url);
> -	if (!output) {
> -		ret = CMD_FATAL;
> -		goto error;
> -	}
> -
> -	/* This call, if successful, populates the id of the output object. */
> -	ret = lttng_snapshot_add_output(current_session_name, output);
> -	if (ret < 0) {
> -		goto error;
> -	}
> -
> -	n_ptr = lttng_snapshot_output_get_name(output);
> -	if (*n_ptr == '\0') {
> -		int pret;
> -		pret = snprintf(name, sizeof(name), DEFAULT_SNAPSHOT_NAME "-%" PRIu32,
> -				lttng_snapshot_output_get_id(output));
> -		if (pret < 0) {
> -			PERROR("snprintf add output name");
> +	if (lttng_opt_mi) {
> +		ret = mi_lttng_snapshot_del_output(writer, id, name,
> +				current_session_name);
> +		if (ret) {
> +			ret = CMD_ERROR;
> 		}
> -		n_ptr = name;
> -	}
> -
> -	ret = mi_lttng_snapshot_add_output(writer, current_session_name, n_ptr,
> -			output);
> -	if (ret) {
> -		ret = CMD_ERROR;
> 	}
> 
> error:
> @@ -410,6 +310,13 @@ static int add_output(const char *url)
> 			lttng_snapshot_output_get_id(output), n_ptr,
> 			lttng_snapshot_output_get_ctrl_url(output),
> 			lttng_snapshot_output_get_maxsize(output));
> +	if (lttng_opt_mi) {
> +		ret = mi_lttng_snapshot_add_output(writer, current_session_name,
> +				n_ptr, output);
> +		if (ret) {
> +			ret = CMD_ERROR;
> +		}
> +	}
> error:
> 	lttng_snapshot_output_destroy(output);
> 	return ret;
> @@ -424,11 +331,7 @@ static int cmd_add_output(int argc, const char **argv)
> 		goto end;
> 	}
> 
> -	if (lttng_opt_mi) {
> -		ret = mi_add_output(argv[1]);
> -	} else {
> -		ret = add_output(argv[1]);
> -	}
> +	ret = add_output(argv[1]);
> 
> end:
> 	return ret;
> @@ -448,17 +351,9 @@ static int cmd_del_output(int argc, const char **argv)
> 	errno = 0;
> 	id = strtol(argv[1], &name, 10);
> 	if (id == 0 && errno == 0) {
> -		if (lttng_opt_mi) {
> -			ret = mi_del_output(UINT32_MAX, name);
> -		} else {
> -			ret = del_output(UINT32_MAX, name);
> -		}
> +		ret = del_output(UINT32_MAX, name);
> 	} else if (errno == 0 && *name == '\0') {
> -		if (lttng_opt_mi) {
> -			ret = mi_del_output(id, NULL);
> -		} else {
> -			ret = del_output(id, NULL);
> -		}
> +		ret = del_output(id, NULL);
> 	} else {
> 		ERR("Argument %s not recognized", argv[1]);
> 		ret = -1;
> @@ -473,47 +368,12 @@ static int cmd_list_output(int argc, const char **argv)
> {
> 	int ret;
> 
> -	if (lttng_opt_mi) {
> -		ret = mi_list_output();
> -	} else {
> -		ret = list_output();
> -	}
> +	ret = list_output();
> 
> 	return ret;
> }
> 
> /*
> - * Do a snapshot record with the URL if one is given (machine interface).
> - */
> -static int mi_record(const char *url)
> -{
> -	int ret;
> -	struct lttng_snapshot_output *output = NULL;
> -
> -	output = create_output_from_args(url);
> -	if (!output) {
> -		ret = CMD_FATAL;
> -		goto error;
> -	}
> -
> -	ret = lttng_snapshot_record(current_session_name, output, 0);
> -	if (ret < 0) {
> -		ret = CMD_ERROR;
> -		goto error;
> -	}
> -
> -	ret = mi_lttng_snapshot_record(writer, current_session_name, url,
> -			opt_ctrl_url, opt_data_url);
> -	if (ret) {
> -		ret = CMD_ERROR;
> -	}
> -
> -error:
> -	lttng_snapshot_output_destroy(output);
> -	return ret;
> -}
> -
> -/*
>  * Do a snapshot record with the URL if one is given.
>  */
> static int record(const char *url)
> @@ -544,6 +404,14 @@ static int record(const char *url)
> 				opt_data_url);
> 	}
> 
> +	if (lttng_opt_mi) {
> +		ret = mi_lttng_snapshot_record(writer, current_session_name, url,
> +				opt_ctrl_url, opt_data_url);
> +		if (ret) {
> +			ret = CMD_ERROR;
> +		}
> +	}
> +
> error:
> 	lttng_snapshot_output_destroy(output);
> 	return ret;
> @@ -554,18 +422,9 @@ static int cmd_record(int argc, const char **argv)
> 	int ret;
> 
> 	if (argc == 2) {
> -		/* With a given URL */
> -		if (lttng_opt_mi) {
> -			ret = mi_record(argv[1]);
> -		} else {
> -			ret = record(argv[1]);
> -		}
> +		ret = record(argv[1]);
> 	} else {
> -		if (lttng_opt_mi) {
> -			ret = mi_record(NULL);
> -		} else {
> -			ret = record(NULL);
> -		}
> +		ret = record(NULL);
> 	}
> 
> 	return ret;
> @@ -725,6 +584,15 @@ int cmd_snapshot(int argc, const char **argv)
> 			break;
> 		case LTTNG_ERR_SNAPSHOT_NODATA:
> 			WARN("%s", lttng_strerror(command_ret));
> +
> +			/*  A warning is fine since the user has no control on
> +			 *  whether or not applications (or the kernel) have
> +			 *  produced any event between the start of the tracing
> +			 *  session and the recording of the snapshot. MI wise
> +			 *  the command is not a success since nothing was
> +			 *  recorded.
> +			 */
> +			command_ret = 0;
> 			break;
> 		default:
> 			ERR("%s", lttng_strerror(command_ret));
> --
> 2.7.0
> 
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> lttng-dev at lists.lttng.org
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-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com


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