[ltt-dev] [UST PATCH 3/3] Add functions and command line for listing trace_events v2

Nils Carlson nils.carlson at ericsson.com
Thu Sep 9 09:06:21 EDT 2010


Changes from version 1: Fix silly things per Davids comments,
realise that we are looping over pids and therefore need to set
all pointers to NULL and all counters to zero each time.

Signed-off-by: Nils Carlson <nils.carlson at ericsson.com>
---
 include/ust/ustcmd.h |    6 ++++
 libust/tracectl.c    |   41 +++++++++++++++++++++++++-
 libustcmd/ustcmd.c   |   77 ++++++++++++++++++++++++++++++++++++++++++++++++++
 ustctl/ustctl.c      |   25 +++++++++++++++-
 4 files changed, 146 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..f1b644c 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 +883,29 @@ 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);
+		if (fp == NULL) {
+			ERR("opening memstream failed");
+			return -1;
+		}
+		print_trace_events(fp);
+		fclose(fp);
+
+		result = ustcomm_send_reply(&ustcomm_app.server, ptr, src);
+		if (result < 0) {
+			ERR("list_trace_events failed");
+			return -1;
+		}
+		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..e47d5f7 100644
--- a/libustcmd/ustcmd.c
+++ b/libustcmd/ustcmd.c
@@ -440,6 +440,83 @@ 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);
+	if (result != 1) {
+		ERR("error while getting trace_event list");
+		return -1;
+	}
+
+	tmp_tes = (struct trace_event_status *)
+		zmalloc(sizeof(struct trace_event_status) *
+			(ustcmd_count_nl(big_str) + 1));
+	if (tmp_tes == NULL) {
+		ERR("Failed to allocate TES array");
+		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..7340a47 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 +263,7 @@ int main(int argc, char *argv[])
 						" PID %u\n", (unsigned int) *pidit);
 					break;
 				}
-				unsigned int i = 0;
+				i = 0;
 				while (cmsf[i].channel != NULL) {
 					printf("{PID: %u, channel/marker: %s/%s, "
 						"state: %u, fmt: %s}\n",
@@ -272,6 +277,24 @@ int main(int argc, char *argv[])
 				ustcmd_free_cmsf(cmsf);
 				break;
 
+			case LIST_TRACE_EVENTS:
+				tes = NULL;
+				if (ustcmd_get_tes(&tes, *pidit)) {
+					ERR("error while trying to list "
+					    "trace_events for PID %u\n",
+					    (unsigned int) *pidit);
+					break;
+				}
+				i = 0;
+				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);
-- 
1.7.1





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