Add ust stop trace feature

[lttng-tools.git] / lttng / lttng.c

diff --git a/lttng/lttng.c b/lttng/lttng.c
index e538df2fd403f0eefaf2be2c58b3c8a04973067d..8a0d58faeaa8ac7ec7299a7a633d9ada73e8e513 100644 (file)
--- a/lttng/lttng.c
+++ b/lttng/lttng.c
@@ -42,11 +42,12 @@ static char *progname;
 static int process_client_opt(void);
 static int process_opt_list_apps(void);
 static int process_opt_list_sessions(void);
+static int process_opt_list_traces(void);
 static int process_opt_create_session(void);
 static void sighandler(int sig);
 static int set_signal_handler(void);
-static int get_cmdline_by_pid(pid_t pid, char **cmdline);
 static int validate_options(void);
+static char *get_cmdline_by_pid(pid_t pid);
 
 /*
  *  start_client
@@ -80,6 +81,13 @@ static int process_client_opt(void)
                }
        }
 
+       if (opt_list_traces) {
+               ret = process_opt_list_traces();
+               if (ret < 0) {
+                       goto end;
+               }
+       }
+
        if (opt_create_session != NULL) {
                ret = process_opt_create_session();
                if (ret < 0) {
@@ -118,6 +126,15 @@ static int process_client_opt(void)
                MSG("Trace started successfully!");
        }
 
+       if (opt_stop_trace) {
+               DBG("Stop trace for pid %d", opt_stop_trace);
+               ret = lttng_ust_stop_trace(opt_stop_trace);
+               if (ret < 0) {
+                       goto end;
+               }
+               MSG("Trace stopped successfully!");
+       }
+
        return 0;
 
 end:
@@ -125,6 +142,47 @@ end:
        return ret;
 }
 
+/*
+ *  process_opt_list_traces
+ *
+ *  Get list of all traces for a specific session uuid.
+ */
+static int process_opt_list_traces(void)
+{
+       int ret, i;
+       uuid_t uuid;
+       struct lttng_trace *traces;
+
+       uuid_parse(opt_session_uuid, uuid);
+       ret = lttng_list_traces(&uuid, &traces);
+       if (ret < 0) {
+               goto error;
+       }
+
+       MSG("Userspace traces:");
+       for (i = 0; i < ret; i++) {
+               if (traces[i].type == USERSPACE) {
+                       MSG("\t%d) %s (pid: %d): %s",
+                                       i, traces[i].name, traces[i].pid,
+                                       get_cmdline_by_pid(traces[i].pid));
+               } else {
+                       break;
+               }
+       }
+
+       MSG("Kernel traces:");
+       for (;i < ret; i++) {
+               if (traces[i].type == KERNEL) {
+                       MSG("\t%d) %s", i, traces[i].name);
+               }
+       }
+
+       free(traces);
+
+error:
+       return ret;
+}
+
 /*
  *  process_opt_create_session
  *
@@ -202,8 +260,8 @@ static int process_opt_list_apps(void)
 
        MSG("LTTng UST traceable application [name (pid)]:");
        for (i=0; i < count; i++) {
-               ret = get_cmdline_by_pid(pids[i], &cmdline);
-               if (!ret) {
+               cmdline = get_cmdline_by_pid(pids[i]);
+               if (cmdline == NULL) {
                        MSG("\t(not running) (%d)", pids[i]);
                        continue;
                }
@@ -223,34 +281,32 @@ error:
 /*
  *  get_cmdline_by_pid
  *
- *  Get command line from /proc for a
- *  specific pid. Allocate cmdline so the
- *  user must free() that pointer.
+ *  Get command line from /proc for a specific pid.
  *
- *  On success, return 1
- *  On error (not found), return 0
+ *  On success, return an allocated string pointer pointing to
+ *  the proc cmdline.
+ *  On error, return NULL.
  */
-static int get_cmdline_by_pid(pid_t pid, char **cmdline)
+static char *get_cmdline_by_pid(pid_t pid)
 {
        int ret;
        FILE *fp;
+       char *cmdline = NULL;
        char path[24];  /* Can't go bigger than /proc/65535/cmdline */
 
        snprintf(path, sizeof(path), "/proc/%d/cmdline", pid);
        fp = fopen(path, "r");
        if (fp == NULL) {
-               goto not_running;
+               goto end;
        }
 
        /* Caller must free() *cmdline */
-       *cmdline = malloc(PATH_MAX);
-       ret = fread(*cmdline, 1, PATH_MAX, fp);
+       cmdline = malloc(PATH_MAX);
+       ret = fread(cmdline, 1, PATH_MAX, fp);
        fclose(fp);
 
-       return 1;
-
-not_running:
-       return 0;
+end:
+       return cmdline;
 }
 
 /*
@@ -265,8 +321,8 @@ not_running:
 static int validate_options(void)
 {
        if ((opt_session_uuid == NULL) &&
-                       (opt_create_trace || opt_start_trace)) {
-               ERR("Can't act on trace without a session ID.\nPlease specify using --session UUID");
+                       (opt_create_trace || opt_start_trace || opt_list_traces)) {
+               ERR("You need to specify a session UUID.\nPlease use --session UUID to do so.");
                goto error;
        }