From e20ee7c273030ac52eea4778f03dc3a9d65857b3 Mon Sep 17 00:00:00 2001 From: Julien Desfossez Date: Fri, 3 Jul 2015 17:08:27 -0400 Subject: [PATCH] Explicitly stop the session on lttng destroy MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This changes the default behavior of the "destroy" command and API: now it implicitely stops the tracing and waits for the data to be available on disk or the network. Like the "stop" command and API, a no_wait option is available to skip the waiting and destroy directly the session. Signed-off-by: Julien Desfossez Signed-off-by: Jérémie Galarneau --- include/lttng/session.h | 13 ++++++++++ src/bin/lttng/commands/destroy.c | 40 ++++++++++++++++++++++------- src/lib/lttng-ctl/lttng-ctl.c | 44 +++++++++++++++++++++++++++++++- 3 files changed, 87 insertions(+), 10 deletions(-) diff --git a/include/lttng/session.h b/include/lttng/session.h index 4e515ad77..599892d13 100644 --- a/include/lttng/session.h +++ b/include/lttng/session.h @@ -90,12 +90,25 @@ extern int lttng_create_session_live(const char *name, const char *url, * The session will not be usable, tracing will be stopped thus buffers will be * flushed. * + * This call will wait for data availability for each domain of the session, + * which can take an arbitrary amount of time. However, when returning the + * tracing data is guaranteed to be ready to be read and analyzed. + * + * lttng_destroy_session_no_wait() may be used if such a guarantee is not + * needed. + * * The name can't be NULL here. * * Return 0 on success else a negative LTTng error code. */ extern int lttng_destroy_session(const char *name); +/* + * Behaves exactly like lttng_destroy_session but does not wait for data + * availability. + */ +extern int lttng_destroy_session_no_wait(const char *name); + /* * List all the tracing sessions. * diff --git a/src/bin/lttng/commands/destroy.c b/src/bin/lttng/commands/destroy.c index f74bf515c..87231858f 100644 --- a/src/bin/lttng/commands/destroy.c +++ b/src/bin/lttng/commands/destroy.c @@ -32,6 +32,7 @@ static char *opt_session_name; static int opt_destroy_all; +static int opt_no_wait; /* Mi writer */ static struct mi_writer *writer; @@ -46,6 +47,7 @@ static struct poptOption long_options[] = { {"help", 'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0}, {"all", 'a', POPT_ARG_VAL, &opt_destroy_all, 1, 0, 0}, {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL}, + {"no-wait", 'n', POPT_ARG_VAL, &opt_no_wait, 1, 0, 0}, {0, 0, 0, 0, 0, 0, 0} }; @@ -63,6 +65,7 @@ static void usage(FILE *ofp) fprintf(ofp, " -h, --help Show this help\n"); fprintf(ofp, " -a, --all Destroy all sessions\n"); fprintf(ofp, " --list-options Simple listing of options\n"); + fprintf(ofp, " -n, --no-wait Don't wait for data availability\n"); fprintf(ofp, "\n"); } @@ -77,16 +80,35 @@ static int destroy_session(struct lttng_session *session) int ret; char *session_name = NULL; - ret = lttng_destroy_session(session->name); + ret = lttng_stop_tracing_no_wait(session->name); + if (ret < 0 && ret != -LTTNG_ERR_TRACE_ALREADY_STOPPED) { + ERR("%s", lttng_strerror(ret)); + } + if (!opt_no_wait) { + _MSG("Waiting for data availability"); + fflush(stdout); + do { + ret = lttng_data_pending(session->name); + if (ret < 0) { + /* Return the data available call error. */ + goto error; + } + + /* + * Data sleep time before retrying (in usec). Don't sleep if the call + * returned value indicates availability. + */ + if (ret) { + usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME); + _MSG("."); + fflush(stdout); + } + } while (ret != 0); + MSG(""); + } + + ret = lttng_destroy_session_no_wait(session->name); if (ret < 0) { - switch (-ret) { - case LTTNG_ERR_SESS_NOT_FOUND: - WARN("Session name %s not found", session->name); - break; - default: - ERR("%s", lttng_strerror(ret)); - break; - } goto error; } diff --git a/src/lib/lttng-ctl/lttng-ctl.c b/src/lib/lttng-ctl/lttng-ctl.c index 14bb7b32d..afa741c05 100644 --- a/src/lib/lttng-ctl/lttng-ctl.c +++ b/src/lib/lttng-ctl/lttng-ctl.c @@ -1525,7 +1525,7 @@ int lttng_create_session(const char *name, const char *url) * Destroy session using name. * Returns size of returned session payload data or a negative error code. */ -int lttng_destroy_session(const char *session_name) +int _lttng_destroy_session(const char *session_name) { struct lttcomm_session_msg lsm; @@ -1542,6 +1542,48 @@ int lttng_destroy_session(const char *session_name) return lttng_ctl_ask_sessiond(&lsm, NULL); } +/* + * Stop the session and wait for the data before destroying it + */ +int lttng_destroy_session(const char *session_name) +{ + int ret; + + /* + * Stop the tracing and wait for the data. + */ + ret = _lttng_stop_tracing(session_name, 1); + if (ret && ret != -LTTNG_ERR_TRACE_ALREADY_STOPPED) { + goto end; + } + + ret = _lttng_destroy_session(session_name); +end: + return ret; +} + +/* + * Destroy the session without waiting for the data. + */ +int lttng_destroy_session_no_wait(const char *session_name) +{ + int ret; + + /* + * Stop the tracing without waiting for the data. + * The session might already have been stopped, so just + * skip this error. + */ + ret = _lttng_stop_tracing(session_name, 0); + if (ret && ret != -LTTNG_ERR_TRACE_ALREADY_STOPPED) { + goto end; + } + + ret = _lttng_destroy_session(session_name); +end: + return ret; +} + /* * Ask the session daemon for all available sessions. * Sets the contents of the sessions array. -- 2.34.1