Fix lttctl flight recorder wait for daemon (temp fix)

[ltt-control.git] / lttctl / lttctl.c

diff --git a/lttctl/lttctl.c b/lttctl/lttctl.c
index e08280aab2e066cd19f3b8479df1e6ae8ad9397a..e77b7f38d6833f8abc2cc8dd0fba8b19b9a9c146 100644 (file)
--- a/lttctl/lttctl.c
+++ b/lttctl/lttctl.c
@@ -2,14 +2,26 @@
  *
  * Linux Trace Toolkit Control
  *
- * Small program that controls LTT through libltt.
- *
- * Copyright 2005 -
- *     Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ * Small program that controls LTTng through liblttctl.
  *
  * Copyright 2008 FUJITSU
  *     Zhao Lei <zhaolei@cn.fujitsu.com>
  *     Gui Jianfeng <guijianfeng@cn.fujitsu.com>
+ * Copyright 2009-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
 #ifdef HAVE_CONFIG_H
@@ -41,6 +53,7 @@ struct channel_option {
        int overwrite;
        int bufnum;
        int bufsize;
+       int switch_timer;
 };
 
 struct lttctl_option {
@@ -124,6 +137,8 @@ static void show_arguments(void)
        printf("        channel.<channelname>.bufsize= (in bytes, rounded to "
               "next power of 2)\n");
        printf("        <channelname> can be set to all for all channels\n");
+       printf("        channel.<channelname>.switch_timer= (timer interval in "
+              "ms)\n");
        printf("\n");
        printf(" Integration options:\n");
        printf("  -C, --create_start\n");
@@ -141,6 +156,11 @@ static void show_arguments(void)
        printf("        Set channels root path, For -w option."
                " (ex. /mnt/debugfs/ltt)\n");
        printf("\n");
+       printf(" Environment variables:\n");
+       printf("  LTT_DAEMON\n");
+       printf("       Complete path to the lttd binary (needs to be\n");
+       printf("       specified if different than package build prefix).\n");
+       printf("\n");
 }
 
 /*
@@ -205,6 +225,7 @@ static void init_channel_opt(struct channel_option *opt, char *opt_name)
                opt->overwrite = -1;
                opt->bufnum = -1;
                opt->bufsize = -1;
+               opt->switch_timer = -1;
                strcpy(opt->chan_name, opt_name);
        }
 }
@@ -291,6 +312,14 @@ int set_channel_opt(struct channel_option *opt, char *opt_name, char *opt_valstr
                
                opt->bufsize = opt_val;
                return 0;
+       } else if (!strcmp("switch_timer", opt_name)) {
+               ret = sscanf(opt_valstr, "%d", &opt_val);
+               if (ret != 1 || opt_val < 0) {
+                       return -EINVAL;
+               }
+               
+               opt->switch_timer = opt_val;
+               return 0;
        } else {
                return -EINVAL;
        }
@@ -622,6 +651,11 @@ static int lttctl_channel_setup(struct channel_option *opt)
                                                          opt->bufsize)) != 0)
                        return ret;
        }
+       if (opt->switch_timer != -1) {
+               if ((ret = lttctl_set_channel_switch_timer(opt_tracename,
+                               opt->chan_name, opt->switch_timer)) != 0)
+                       return ret;
+       }
 
        return 0;
 }
@@ -662,10 +696,13 @@ setup_trace_fail:
 }
 
 /*
- * Start a lttd daemon to write trace datas
+ * Start a lttd daemon to write trace data
  * Dump overwrite channels on overwrite!=0
  * Dump normal(non-overwrite) channels on overwrite=0
  *
+ * When called for overwrite mode, wait for lttd to return, so we are sure that
+ * trace session teardown is not executed before lttd can grab the buffer data.
+ *
  * ret: 0 on success
  *      !0 on fail
  */
@@ -760,6 +797,16 @@ static int lttctl_daemon(int overwrite)
        if (WEXITSTATUS(status))
                fprintf(stderr, "lttd process running failed\n");
 
+       /*
+        * FIXME
+        * This is a temporary hack to ensure that the lttd daemon grabs
+        * handles on the debugfs buffer files before we destroy the trace
+        * session. Properly handling this will imply separating the "flush"
+        * from the "destroy" operation at kernel-level in LTTng.
+        */
+       if (overwrite)
+               sleep(2);
+
        return WEXITSTATUS(status);
 }