[ltt-dev] [UST PATCH 3/3] Add functions and command line for listing trace_events
David Goulet
david.goulet at polymtl.ca
Wed Sep 8 14:23:30 EDT 2010
Comment below.
On 10-09-08 01:52 PM, Nils Carlson wrote:
>
> Signed-off-by: Nils Carlson<nils.carlson at ericsson.com>
> ---
> include/ust/ustcmd.h | 6 ++++
> libust/tracectl.c | 34 ++++++++++++++++++++-
> libustcmd/ustcmd.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++
> ustctl/ustctl.c | 23 ++++++++++++++-
> 4 files changed, 138 insertions(+), 3 deletions(-)
>
> diff --git a/include/ust/ustcmd.h b/include/ust/ustcmd.h
> index 60f5018..986ae61 100644
> --- a/include/ust/ustcmd.h
> +++ b/include/ust/ustcmd.h
> @@ -43,6 +43,10 @@ struct marker_status {
> char *fs; /* Format string (end of marker_status array if NULL) */
> };
>
> +struct trace_event_status {
> + char *name;
> +};
> +
> extern pid_t *ustcmd_get_online_pids(void);
> extern int ustcmd_set_marker_state(const char *, int, pid_t);
> extern int ustcmd_set_subbuf_size(const char *, pid_t);
> @@ -59,6 +63,8 @@ extern int ustcmd_free_cmsf(struct marker_status *);
> extern unsigned int ustcmd_count_nl(const char *);
> extern int ustcmd_send_cmd(const char *, pid_t, char **);
> extern int ustcmd_get_cmsf(struct marker_status **, pid_t);
> +extern int ustcmd_free_tes(struct trace_event_status *);
> +extern int ustcmd_get_tes(struct trace_event_status **, pid_t);
> extern int ustcmd_set_sock_path(const char *, pid_t);
> extern int ustcmd_get_sock_path(char **, pid_t);
> extern int ustcmd_force_switch(pid_t);
> diff --git a/libust/tracectl.c b/libust/tracectl.c
> index e64b26f..7dbc572 100644
> --- a/libust/tracectl.c
> +++ b/libust/tracectl.c
> @@ -35,6 +35,7 @@
> #include<urcu/uatomic_arch.h>
>
> #include<ust/marker.h>
> +#include<ust/tracepoint.h>
> #include<ust/tracectl.h>
> #include "tracer.h"
> #include "usterr.h"
> @@ -127,6 +128,21 @@ static void print_markers(FILE *fp)
> unlock_markers();
> }
>
> +static void print_trace_events(FILE *fp)
> +{
> + struct trace_event_iter iter;
> +
> + lock_trace_events();
> + trace_event_iter_reset(&iter);
> + trace_event_iter_start(&iter);
> +
> + while(iter.trace_event) {
> + fprintf(fp, "trace_event: %s\n", iter.trace_event->name);
> + trace_event_iter_next(&iter);
> + }
> + unlock_trace_events();
> +}
> +
> static int init_socket(void);
>
> /* Ask the daemon to collect a trace called trace_name and being
> @@ -867,8 +883,22 @@ int process_client_cmd(char *recvbuf, struct ustcomm_source *src)
> result = ustcomm_send_reply(&ustcomm_app.server, ptr, src);
>
> free(ptr);
> - }
> - else if(!strcmp(recvbuf, "start")) {
> + } else if (!strcmp(recvbuf, "print_trace_events")) {
> + print_trace_events(stderr);
> +
> + } else if(!strcmp(recvbuf, "list_trace_events")) {
> + char *ptr;
> + size_t size;
> + FILE *fp;
> +
> + fp = open_memstream(&ptr,&size);
Might want to check if fp is not NULL since print_trace_events don't
check it either.
> + print_trace_events(fp);
> + fclose(fp);
> +
> + result = ustcomm_send_reply(&ustcomm_app.server, ptr, src);
> +
Following the discussion on ltt-dev about error handling and trying to
have consistency through the code, it might be good to handle the return
code here and print the appropriate error. (ERR macro)
> + free(ptr);
> + } else if(!strcmp(recvbuf, "start")) {
> /* start is an operation that setups the trace, allocates it and starts it */
> result = ltt_trace_setup(trace_name);
> if(result< 0) {
> diff --git a/libustcmd/ustcmd.c b/libustcmd/ustcmd.c
> index 5b4fd02..21e4846 100644
> --- a/libustcmd/ustcmd.c
> +++ b/libustcmd/ustcmd.c
> @@ -440,6 +440,84 @@ int ustcmd_get_cmsf(struct marker_status **cmsf, const pid_t pid)
> return 0;
> }
>
> +
> +/**
> + * Frees a TES array.
> + *
> + * @param tes TES array to free
> + * @return 0 if successful, or error USTCMD_ERR_ARG
> + */
> +int ustcmd_free_tes(struct trace_event_status *tes)
> +{
> + if (tes == NULL) {
> + return USTCMD_ERR_ARG;
> + }
> +
> + unsigned int i = 0;
> + while (tes[i].name != NULL) {
> + free(tes[i].name);
> + ++i;
> + }
> + free(tes);
> +
> + return 0;
> +}
> +
> +/**
> + * Gets trace_events string for a given PID.
> + *
> + * @param tes Pointer to TES array to be filled (callee allocates, caller
> + * frees with `ustcmd_free_tes')
> + * @param pid Targeted PID
> + * @return 0 if successful, or -1 on error
> + */
> +int ustcmd_get_tes(struct trace_event_status **tes,
> + const pid_t pid)
> +{
> + char *big_str = NULL;
> + int result;
> + struct trace_event_status *tmp_tes = NULL;
> + unsigned int i = 0, tes_ind = 0;
> +
> + if (tes == NULL) {
> + return -1;
> + }
> + result = ustcmd_send_cmd("list_trace_events", pid,&big_str);
For a matter of code beauty :), there is a space missing after "pid, "
> + if (result != 1) {
> + return -1;
> + }
> +
> + if (result != 1) {
> + ERR("error while getting trace_event list");
> + return -1;
> + }
This last if, isn't a bit useless ;)
> +
> + tmp_tes = (struct trace_event_status *) malloc(sizeof(struct trace_event_status) *
> + (ustcmd_count_nl(big_str) + 1));
malloc -> zmalloc
> + if (tmp_tes == NULL) {
> + return -1;
> + }
> +
> + /* Parse received reply string (format: "[chan]/[mark] [st] [fs]"): */
> + while (big_str[i] != '\0') {
> + char state;
> +
> + sscanf(big_str + i, "trace_event: %a[^\n]",
> + &tmp_tes[tes_ind].name);
> + while (big_str[i] != '\n') {
> + ++i; /* Go to next '\n' */
> + }
> + ++i; /* Skip current pointed '\n' */
> + ++tes_ind;
> + }
> + tmp_tes[tes_ind].name = NULL;
> +
> + *tes = tmp_tes;
> +
> + free(big_str);
> + return 0;
> +}
> +
> /**
> * Set socket path
> *
> diff --git a/ustctl/ustctl.c b/ustctl/ustctl.c
> index d290975..9daa043 100644
> --- a/ustctl/ustctl.c
> +++ b/ustctl/ustctl.c
> @@ -32,6 +32,7 @@ enum command {
> STOP_TRACE,
> DESTROY_TRACE,
> LIST_MARKERS,
> + LIST_TRACE_EVENTS,
> ENABLE_MARKER,
> DISABLE_MARKER,
> GET_ONLINE_PIDS,
> @@ -73,6 +74,7 @@ Commands:\n\
> --enable-marker \"CHANNEL/MARKER\"\tEnable a marker\n\
> --disable-marker \"CHANNEL/MARKER\"\tDisable a marker\n\
> --list-markers\t\t\tList the markers of the process, their\n\t\t\t\t\t state and format string\n\
> + --list-trace-events\t\t\tList the trace-events of the process\n\
> --force-switch\t\t\tForce a subbuffer switch\n\
> \
> ");
> @@ -94,6 +96,7 @@ int parse_opts_long(int argc, char **argv, struct ust_opts *opts)
> { "stop-trace", 0, 0, STOP_TRACE },
> { "destroy-trace", 0, 0, DESTROY_TRACE },
> { "list-markers", 0, 0, LIST_MARKERS },
> + { "list-trace-events", 0, 0, LIST_TRACE_EVENTS},
> { "enable-marker", 1, 0, ENABLE_MARKER },
> { "disable-marker", 1, 0, DISABLE_MARKER },
> { "help", 0, 0, 'h' },
> @@ -215,6 +218,8 @@ int main(int argc, char *argv[])
>
> pidit = opts.pids;
> struct marker_status *cmsf = NULL;
> + struct trace_event_status *tes = NULL;
> + unsigned int i = 0;
>
> while(*pidit != -1) {
> switch (opts.cmd) {
> @@ -258,7 +263,6 @@ int main(int argc, char *argv[])
> " PID %u\n", (unsigned int) *pidit);
> break;
> }
> - unsigned int i = 0;
> while (cmsf[i].channel != NULL) {
> printf("{PID: %u, channel/marker: %s/%s, "
> "state: %u, fmt: %s}\n",
> @@ -272,6 +276,23 @@ int main(int argc, char *argv[])
> ustcmd_free_cmsf(cmsf);
> break;
>
> + case LIST_TRACE_EVENTS:
> + tes = NULL;
Isn't set to NULL before. Why again?
> + if (ustcmd_get_tes(&tes, *pidit)) {
> + fprintf(stderr,
> + "error while trying to list trace_events for"
> + " PID %u\n", (unsigned int) *pidit);
ERR macro do just that. We might want to use it everywhere instead of
partial fprintf and ERR usage.
Thanks
David
> + break;
> + }
> + while (tes[i].name != NULL) {
> + printf("{PID: %u, trace_event: %s}\n",
> + (unsigned int) *pidit,
> + tes[i].name);
> + ++i;
> + }
> + ustcmd_free_tes(tes);
> +
> + break;
> case ENABLE_MARKER:
> if(opts.regex)
> ustcmd_set_marker_state(opts.regex, 1, *pidit);
--
David Goulet
LTTng project, DORSAL Lab.
PGP/GPG : 1024D/16BD8563
BE3C 672B 9331 9796 291A 14C6 4AF7 C14B 16BD 8563
More information about the lttng-dev
mailing list